Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Los Nuevos Sujetos del Agua: Organización social y la democratización del agua en los Andes ecuatorianos
    Hoogesteger van Dijk, J.D. - \ 2014
    Quito : Instituto de Estudios Peruanos (IEP) (Agua y sociedad 20) - ISBN 9789942091857 - 251
    waterrechten - waterverdeling - waterbeleid - watervoorraden - waterbeheer - sociale verandering - democratisering - boerenorganisaties - ecuador - water rights - water distribution - water policy - water resources - water management - social change - democratization - farmers' associations - ecuador
    Vermindering wortelproblemen Miltonia (Miltoniopsis)
    Kromwijk, J.A.M. ; Noort, F.R. van; Ludeking, D.J.W. ; IJdo, M.L. ; Blok, C. - \ 2012
    Bleiswijk : Wageningen UR Glastuinbouw (Rapporten GTB 1202) - 74
    miltoniopsis - wortelbehandeling - aantasting - waterverdeling - frequentie - teelt onder bescherming - orchideeën als sierplanten - miltoniopsis - root treatment - infestation - water distribution - frequency - protected cultivation - ornamental orchids
    Bij de teelt van Miltonia (Miltoniopsis) komen veel wortelproblemen voor. Planten komen los op de pot te staan en vallen weg. Onderzoek gefinancierd door het Productschap Tuinbouw heeft laten zien dat de sterke zuigkracht van sphagnum er voor zorgt dat de sphagnumplug opgepot in bark of Allure na een watergift veel water aan zuigt en daarna te lang nat blijft. Daardoor ontstaat zuurstofgebrek bij de wortels en sterven wortels af. In een proef met de huidige opkweek- en teeltsubstraten was de kwaliteit van de wortels bij een partij planten op bark beter dan bij een partij planten op Allure en een watergift van 1 x 5 liter was beter dan een watergift van 2 x 3 liter per m2. Tijdens de koeling droogden de potten minder snel af dan tijdens de opkweek. Als de watergeeffrequentie dan onvoldoende aangepast wordt, kunnen de wortelproblemen in de koeling verergeren. Het meten van het gewicht van de potten kan een goed hulpmiddel zijn om de watergeeffrequentie op de juiste manier aan te passen en wortelproblemen te verminderen. De beste manier om wortelproblemen te voorkomen is een nieuwe combinatie van opkweek- en teeltsubstraat waarvan de eigenschappen meer in elkaars verlengde liggen. Abstract Many Miltonia (Miltoniopsis) growers suffer plant losses, as a result of root problems. Research financed by the Dutch Product Board of Horticulture has shown that when the sphagnum plug containing the young plant is potted in bark or ‘Allure’ (a new orchid substrate) the plug remains wet for too long after irrigation. This causes a lack of oxygen to the roots and roots die. In a trial with the current substrates, the quality of the roots on bark was better than on ‘allure’ and an irrigation with 1 x 5 litres was better than an irrigation with 2 x 3 litres per m2. During the generative phase, pots dried less rapidly than during the vegetative phase. If the irrigation is not adjusted, the substrate becomes wetter and root problems can increase in the generative phase. Measuring the weight of the pots can be a good tool to adjust the irrigation frequency and decrease root problems. The best solution to solve these root problems would be a new combination of propagation and growing substrate with similar properties for both media.
    Knoppenkast voor verdeling zoet water
    Stuyt, L.C.P.M. - \ 2012
    Kennis Online 9 (2012)juni. - p. 7 - 7.
    waterverdeling - watervoorziening - zoet water - water distribution - water supply - fresh water
    Onderzoekers van Alterra hebben een eerste rekeninstrument ontwikkeld waarmee waterbeheerders gevoel kunnen krijgen voor de verdeling van zoet water over Laag-Nederland. ‘Het is de vraag of we alles uit de bestaande infrastructuur hebben gehaald om in tijden van schaarste overal voldoende zoet water te krijgen.’
    Concurrerende claims op schaars water : eerlijk delen
    Bosch, Rik van den; Froebrich, Jochen ; Hellegers, Petra - \ 2011
    water management - water distribution - water supply - water resources - economic analysis
    Handing over the sunset. External factors influencing the establishment of water user associations in Uzbekistan: Evidence from Khorezm Province
    Wegerich, K. - \ 2010
    Göttingen : Cuvillier Verlag - ISBN 9783869552194 - 169
    watergebruik - waterbeleid - watergebruiksrendement - belangengroepen - overheidsbeleid - waterbeheer - watertoewijzing - waterbeschikbaarheid - waterverdeling - oezbekistan - associaties - water use - water policy - water use efficiency - interest groups - government policy - water management - water allocation - water availability - water distribution - uzbekistan - associations
    Recently, large-scale surface-water or canal irrigation systems have been termed ‘a sunset industry’ (Rijsberman 2003). Handing over this sunset industry by means of irrigation management transfer (IMT) policies and the creation of water user associations (WUAs) has three main objectives: to increase efficiency, equity, and empowerment. The Uzbek government, together with the international organizations, the United States Agency for International Development (USAID), and the International Water Management Institute (IWMI), is currently promoting IMT and the creation of WUAs nationwide. The onset of the policy seemed to be a rational development since the former state and collective farms, which were also responsible for water management on their territories, were disintegrating, and new private farms were emerging rapidly. This study seeks to assess the potential of IMT policies by examining the broader physical, organizational, socio-economic, and political factors that might facilitate or hinder the main objectives of IMT and the creation of WUAs. These factors are addressed and analyzed separately through eight case study chapters that address questions on basin water management, the organizational capacities, and the socio-political dependencies of the district water management departments, the potential for multi-stakeholder platforms (MSPs), the politics of social network structures, and the process of land reforms. The study concludes that none of the external factors is conducive to the introduction of IMT policies and for creating WUAs. The implication is that IMT policies will not increase efficiency, equity, and empowerment, but could even worsen the water management situation. Furthermore, these policies will not increase the empowerment of either the WUAs or their members. Hence, under the current conditions, handing over the ‘sunset industry’ will not lead to a new sunrise for irrigation in Uzbekistan.
    Application of (economic) water valuation for devising a multiple uses operational strategy for Hoa Binh Dam. Hoa Binh hydropower dam and command area (Hoa Binh Province).
    Wageningen International, - \ 2008
    Hanoi, Vietnam : Hanoi Water resources university (HWRU) (Main case study 3) - 129
    waterbeheer - waterverdeling - watervoorziening - waterbeschikbaarheid - dammen - hydraulische systemen - reservoirs - vietnam - integraal waterbeheer - water management - water distribution - water supply - water availability - dams - hydraulic structures - reservoirs - vietnam - integrated water management
    Vietnam is located in typical monsoon climate region and therefore river are very abundant water. However, about 2/3 of water resources is originated from neighboring countries. Moreover, uneven spatial distribution and huge seasonal change are additional reasons that make Vietnam ranked low compared to other South East Asian countries in term of water resource availability (the index of water availability per capital in Vietnam is 4,170m3/s compared to 4,900 m3/s in South East Asian region). In Vietnam, there is dense network of river systems, out of which about 2,360 river have length of 10km or more with total volume of 835 billion m3. However, the flow during 6 or 7 months of dry season is counted for only 15-30% of total annual flow. As a result, every yeas, drought and water shortage have always occurred in many areas of different basins. To cope with this situation and also to meet increasing water demand, number of reservoirs has been built for water resource regulation. After many years of development, many large exploitation work systems have been constructed and operated in all the basins thought the country, such as dams, reservoirs, weirs, embankments and so on. Those systems are to supply water for all kinds of use, including: irrigation, drainage, and hydropower generation, households, industry and flood control. Those works have been played an important role in water supply for major social-economic development sectors of the country, such as irrigation, hydropower generation, domestic and industrial used.
    The rules of the game and the game of the rules : normalization and resistance in Andean water control
    Boelens, R.A. - \ 2008
    Wageningen University. Promotor(en): Jandouwe van der Ploeg; H. Achterhuis. - [S.l.] : s.n. - ISBN 9789085048961 - 573
    irrigatiewater - irrigatiesystemen - waterbeheer - gemeenschappen - watergebruik - waterverdeling - waterbeleid - gebergten - Peru - Ecuador - Chili - Zuid-Amerika - waterrechten - andes - staat - irrigation water - irrigation systems - water management - communities - water use - water distribution - water policy - mountains - Peru - Ecuador - Chile - South America - water rights - andes - state - cum laude
    cum laude graduation (with distinction)
    Pirámides de agua. Constucción e impacto de imperios de riego en la costa norte de Perú
    Vos, J.M.C. - \ 2006
    Lima : Instituto de Estudios Peruanos (Agua y sociedad : Walir ) - ISBN 9789972511530 - 363
    waterbeheer - irrigatie - waterverdeling - peru - water management - irrigation - water distribution - peru
    Water voor voedsel of natuur, of voor beide? Mondiaal vraagstuk vergt fundamenteel technologische oplossingen
    Bindraban, P.S. - \ 2004
    Spil 207-208 (2004)5. - ISSN 0165-6252 - p. 5 - 8.
    landbouwproductie - waterbeheer - probleemoplossing - watergebruik - waterverdeling - internationale orde - agricultural production - water management - water use - water distribution - problem solving - international order
    De auteur stelt dat de huidige pogingen tot een beter gebruik en verdeling van het water nog te veel berusten op korte-termijnoplossingen. Hij geeft voorbeelden van fundamenteel technologische oplossingen
    Indexing constitutional accountability in local governance: the search for the water-power interface
    Regmi, A. - \ 2004
    Resources, Energy, and Development 1 (2004)1 en 2. - ISSN 0973-0516 - p. 91 - 94.
    irrigatiewater - waterverdeling - kracht - internationale samenwerking - nepal - irrigation water - water distribution - power - international cooperation - nepal
    This paper cites an example from a case study of the first small 2.4 MW anauti hydropower system in Nepal. Designed and implemented by Russian technical assistence in 1965, this power plant has impacted on several local irrigation systems and has become a site of contestation for local people, both for water and power
    Hydraulisch ontwerp dubbelwerkende meetschuif bij de Gietwaterplas
    Boiten, W. - \ 2004
    Wageningen : Sectie Waterhuishouding (Rapport / Wageningen Universiteit, Sectie Waterhuishouding 118) - 12
    stuwen - overlaten - ontwerp - wateropslag - reservoirs - waterverdeling - drenthe - weirs - spillways - water storage - reservoirs - water distribution - design - drenthe
    Via de geplande meetschuif wordt water vanuit de Runde (met 7,5 ha retentie) naar de Gietwaterplas (12,5 ha oppervlakte) geleid. Van hieruit kan de glastuinbouw water ontvangen voor beregening van gewassen. Bij de plas is een zgn. waterfabriek aanwezig, die het water reinigt en distribueert. Tussen het waterschap Hunze en Aa's en de Waterfabriek (WMD) zullen de hoeveelheden worden verrekend. Een V-vormige lange overlaat is ontworpen
    Leveraging water delivery. Irrigation technology choices and operations and maintenance in smallholder systems in Zimbabwe
    Chidenga, E.E. - \ 2003
    Wageningen University. Promotor(en): Linden Vincent, co-promotor(en): A. Senzanje. - Wageningen : Wageningen Universiteit - ISBN 9789058088918 - 297
    irrigatie - landbouw met irrigatie - irrigatiesystemen - kleine landbouwbedrijven - bedrijfsvoering - waterverdeling - technologie - zimbabwe - irrigation - irrigated farming - irrigation systems - small farms - management - water distribution - technology - zimbabwe
    Irrigation development and management in Zimbabwe like many other sub-Saharan countries has problems related to sustainability. These problems are of a socio-technical nature related to both physical artefacts and configuration of the water delivery continuum as well as the social, economic, regulatory, financial and other institutional factors that shape the management subsystem. Six schemes in the SavecatchmentofManicalandprovince in Zimbabwe with different attributes related to water sources, mobilisation, conveyance, distribution, application and management were investigated for two cropping seasons in the period 1999 to 2000 to find out major elements that affected their sustainability. The focused on the concept ofteretechnology, thatis the ability to care for artefacts. It looked at whether this concept was present in Zimbabwe. Two old gravity surface irrigation schemes ofChakowaandDeurewere found to differ significantly due to system design and level of cooperation.Chakowascheme had no source regulation, was vulnerable to summer floods and was structured in a way that allowed head-end farmers unlimited access to water at any time leading to serious head -end tail end problems that resulted in significant differences in cropping programs and patterns. In contrastDeurehad a stabilised water source and cooperation that allowed farmers to practice across block water rotation through the distribution canal, cropping programs and patterns were similar and all farmers had access to a local niche market. This also translated to cooperation in operation and maintenance activities. AtMutema, a second-generation groundwater pumped conventional sprinkler scheme, poor water delivery due to power cuts and lack of repair resulted in salinity that lead to changes in cropping especially from vulnerable beans to mainly tomatoes and cotton. The need to save on electricity costs saw farmers at the newMusikavanhupumped surface scheme with proportional water division structures and a more reliable water delivery system deliberately enforcing reduced water supplies to winter crops. The new pumpeddraghosesprinkler system atBondeexperienced unreliable water delivery right from commissioning. This led farmers to emulate the simple gravity surface practices at theDeurewith which they share both a water source and abstraction. This is in contrast with the gravitydraghosesystem atMpudziwhere farmers on the heavier soils are engaged in full time market gardeningwiththeir main problem centring on strategies to replace worn out sprinklers or reduce the rate sprinkler wear. In conclusion it is thus observed that farmers are primarily concerned with water delivery security, and can operate systems effectively that are simple. They maintain components that are within their capacity only to avoid disruption of delivery and that the institutions need support to enhance capacity to deal with complex systems. It is therefore recommended that future planning and design of water delivery subsystems consider the engineering precepts that take into account theseteretechnologyrequirements to ensure that sustainable systems are developed such that the users can operate and maintain and using local resources and available managerial support structures from government and the private sector and other production related structures like markets to leverage the water delivery.

    The role of seguias in soil and water conservation within the Talkjounte watershed
    Schiettecatte, W. ; Fleskens, L. ; Kabbachi, B. ; Voort, D. van de - \ 2002
    In: Water harvesting in Mediterranean zones : an impact assessment and economic evaluation : proceedings from EU Wahia project final seminar in Lanzarote / de Graaff, J., Ouessar, M., - p. 61 - 70.
    stroomgebieden - oppervlakte-irrigatie - waterverdeling - erosie - marokko - bodembescherming - watersheds - surface irrigation - water distribution - soil conservation - erosion - morocco
    Metric matters : the performance and organisation of volumetric water control in large-scale irrigation in the North Coast of Peru
    Vos, J.M.C. - \ 2002
    Wageningen University. Promotor(en): F. von Benda-Beckmann; L.F. Vincent. - S.l. : S.n. - ISBN 9789058086600 - 237
    irrigatie - bedrijfsvoering - waterbehoefte - irrigatiewater - irrigatiewater-toedieningsschema - watertoewijzing - waterverdeling - peru - irrigation - management - water requirements - irrigation water - irrigation scheduling - water allocation - water distribution - peru

    This thesis describes the organisation and performance of two large-scale irrigation systems in the North Coast of Peru. Good water management is important in this area because water is scarce and irrigated agriculture provides a livelihood to many small and middle-sized farmers. Water in the coast of Peru is considered to be badly managed, however this study shows that performance is more optimal than critics assume. Apart from the relevance in the local water management discussion, the study also addresses two internationally much debated topics in irrigation water management: irrigation management transfer (from government to water users' associations) and modernisation of infrastructure.

    Large-scale irrigation is often associated with low water use efficiencies, low control over the deliveries and low fee-recovery. Volumetric water control is one of the solutions proposed to solve these problems. The idea behind volumetric water control is to allocate and schedule precise volumes of water to meet crop water requirements, if possible on request of the water users. The user is charged per volume of water used to prevent over-use, and to raise sufficient funds to operate and maintain the irrigation system. Many authors stress the difficulties of volumetric water control. For example: on-request scheduling is too costly in large systems with many smallholders. High-tech automatic water control systems are too expensive and difficult to operate and maintain. Setting of the Irrigation Service Fee (ISF) might be too low to provide an incentive for water saving, or might be too high for poor farmers to pay.

    The study aims to achieve a better understanding of the practices in organisation and performance of volumetric water control in two large-scale irrigation systems in the North Coast. The coastal zone of Peru is extremely arid. Precipitation is near zero, except once in about 15 years when the El Niño phenomenon brings heavy rains and floods. The irrigation systems depend on the highly irregular rivers, which flow from the Andean Mountains. Main crops in the coastal areas are: sugarcane, rice and maize. Two systems were selected for a comparative study: Chancay-Lambayeque (100,000 ha) and Jequetepeque (40,000 ha). In the Chancay-Lambayeque system the users pay US$ 2 per 576 m 3scheduled to be delivered at field level. In the Jequetepeque system the farmers pay a fixed fee according to the crop allowed to grow. For example they pay US$ 60 per hectare of rice.

    The analytical framework highlights two main points: First, the irrigation infrastructure has certain properties, because different stakeholders designed and constructed parts of it in the past. These properties set certain requirements for use. For example the manually operated, undershot gates need skilled and experienced personnel to operate them well. The properties of the infrastructure also affect the water distribution in particular ways. For example a system with undershot offtakes and no check structures in the ongoing canal transports all fluctuations in the inflow to the tail-end of the canals. This affects the farmers in these areas. Second, the organisations can be regarded as 'semi-autonomous fields' where rules and regulations are transformed and local regulations are applied. Social power relations, technical properties, environmental conditions and the interests of actors influence the rules that are used, how and when. The different organisations that manage the irrigation system form a complex entity. At different levels in the system; water users' organisations, private companies and government agencies play a role in water management. This complex entity can be studied by looking at the domains of authority the organisations have, the rules they use, and the structure of decision-making and accountability between the organisations. Conflicts can reveal the rules used and the power plays involved. During one and a half year field research many key informants and water users were interviewed and a water flow measurement programme was executed.

    Chapter 2 describes the setting of the two irrigation systems: the natural resources, the long history of irrigation in the area and the present production systems. As the coast is arid and plain, waterlogging and salinity are dangers of irrigation. Irrigation began already 3000 years ago. The present main canal of the Chancay-Lambayeque system was built around AD 1000 and the irrigated area then was larger than today. After the conquest the Spaniards largely continued the management of the Incas. Only when the new settlers claimed increasingly more land for their haciendas, conflicts about water grew. State interventions in the management of the systems started early 20 thcentury. At that time the idea of volumetric water control was proposed. However, it was not until the Agrarian Reform of 1969, when the management became completely in the hands of the State, that volumetric allocation and delivery was introduced. And only with the Irrigation Management Transfer (IMT) to the Comisiones de Regantes and Juntas de Usuarios in 1992 volumetric charging was enforced. Today sugarcane and rice are cultivated in high input - high output production systems. Main problem for the small and middle-sized landowners is to obtain credit. The local rice purchasers ( molinos ) provide credit, which leads often to ever greater indebtedness of the smallholders. Execpt for the three sugarcane co-operatives the average landholding is 5 ha.

    Chapter 3 introduces the complex structure of the entities that manage the irrigation systems. Since the Irrigation Management Transfer in 1992 the Comisiones de Regantes (CRs) at the level of the secondary canals operate and maintain the secondary canals. The board of the Comisiones is elected by all water users. For the operation the board hires staff. At the level of the tertiary canals the Comités de Canal maintain (and sometimes operate) the tertiary canals. In 1994 (for Chancay-Lambayeque) and 1998 (for Jequetepeque) the Juntas de Usuarios formed private companies to take over the operation and maintenance of the main canal and reservoirs. The local irrigation offices of the Ministry of Agriculture (ATDR) retained the authority to allocate water (up to the individual plot level) and supervise the management by the water users' organisation. Besides the ATDR also the Autonomous Watershed Authorities (AACH) and the Special Project Bureaus are government organisations that have certain domains of authority in water management.

    The main difference in water use between the systems is that the water users in Jequetepeque apply on average twice as much water per hectare of the same crop compared to the users in Chancay-Lambayeque. This is not caused by the volumetric payment in Chancay, but by the difference in water availability per hectare. After the Land Reform the Chancay system was expanded to win political support with the new water users, whereas in Jequetepeque the luxurious water right position acquired by the haciendas was not changed.

    Chapter 4 describes the practices of volumetric water allocation and scheduling. The National Water Law of 1969 establishes that all water is property of the State and that the ATDR is the organisation that gives concessions for use to individual water users. The ATDR also establishes how much water each user can request maximum depending on the defined cropping zones. However, for the scheduling of water turns according to the cropping plan the ATDR depends on the Comisiones de Regantes . The Comisiones , however, generally comply with the cropping plan to avoid claims of water users for water they are entitled to. Apart from the permanent water rights ( licencia ) there are also water titles for excess water ( permiso ). This institution was already known in the pre-Inca times. It is an adaptation to the ever fluctuating river supplies. In Chancay-Lambayeque water is scheduled in ' riegos' . One riego is one hour of water delivery with 160 l/s at field level. The water users pay in advance and get the hours the next day. In Jequetepeque the turns are only scheduled at the beginning of the rice-growing season. During the remainder of the rice-growing season the water flows continuously from field to field.

    In water scarce periods, when supply is less than expected, the Junta de Usuarios together with the ATDR adjust the water allocations. In Chancay-Lambayeque all water users then get scheduled a fixed number of hours each 15 days. The number of riegos per hectare is proportionally less the bigger the landholding of the farmer. This results in plots only party planted with rice, but more often in plots completely planted, but deficiently irrigated. In Jequetepeque water scarcity comes less unexpected, because the reservoir has sufficient capacity for an irrigation season. Here certain campos (small clusters of fields) are excluded from rice growing when the reservoir is low.

    In Chapter 5 an assessment is made of the volumetric water delivery. First a framework for understanding delivery performance is given. In this framework three main factors are central: the physical infrastructure, the operators, and the water users. However, in the first place the Relative Water Supply (RWS) should be looked at. The RWS is the ratio of the delivered water and the crop water requirements. If the RWS at field level is higher than 1.5 water can be used as a substitute for control. An intensive water flow measurement programme was executed to assess the performance of the water delivery service. Water flows were measured at all levels of the canal system: from offtakes from the main canal to deliveries at field level. The Chancay-Lambayeque system with its manually operated undershot gates, few measurement structures, open and unlined canals, its irregular river supply, and complicated on-request scheduling for 22,000 water users is a 'nightmare' system. Nevertheless, the Delivery Performance Ratio (DPR) was remarkably close to 1.0 at different levels of the system, indicating that the actually delivered flows were as programmed. This together with a RWS of between 0.6 and 0.8 at field level leads to a high water productivity. The remarkably good water delivery performance was explained by the skills of the operators and the accountability of the boards of the Comisiones towards the water users. This accountability was a result of the board members wanting to win the next elections to remain in the position to make money from illegal water selling. Also radio and newspapers were used to exert pressure on the boards to perform well. In Jequetepeque the DPR was almost always above 1.0 indicating that there was more water distributed than programmed. This was explained by the fact the in Jequetepeque the RWS was about 2.

    Chapter 6 focuses on the financial conduct of the two irrigation systems. The charge for the water delivery service is set by the General Assemblies of the water users. They prioritise the expenditures of the Comisiones and therewith set the fee. The fees are recovered by the Junta de Usuarios (or its private company) and then distributed over the different organisations that manage the systems. The fee recovery was high. In Chancay-Lambayeque from 1993 to 1998 more than ninety percent of the distributed water was paid for (per volume). Users paid per riego , thus recovery was spread throughout the irrigation season. The advance payment could be enforced quite well because o social and technical control over the water. Only the sugarcane co-operatives in the head-end of the system took water without paying. A drawback of volumetric charging is that less river supply means less income for the organisations. Also in Jequetepeque the fee recovery was high. Here the farmers did not pay per volume and the recovery was harder to enforce because of abundant water availability. Therefore, the Junta collected the fees at the beginning of the irrigation season when the system was still dry but the rice farmers need to start their nurseries. By strict control over the water to only those users who had paid the fees of last year the Junta recovered the fees. The farmers could not wait with their nurseries until water would be available abundantly because a later start would mean a yield reduction due to low temperatures at the end of the season. This construction of technical, environmental and institutional elements that enforces the payment was called an 'obligatory point of passage'.

    Between 1.5 to 3.0 million dollars were collected each year in each system. This was more or less sufficient for operation and maintenance and paying taxes. The distribution of the

    Chapter 7 evaluates the functioning and effects of volumetric water allocation, scheduling, delivery and charging. It is concluded that water control in Chancay-Lambayeque is volumetric. In Jequetepeque water allocation and distribution is only volumetric to a certain extent, and charging is not related to the volume actually applied to the field. In both systems there are two important factors shaping water management. First, the history of the institutions and physical infrastructure. Despite the many abrupt changes in the institutional setting the continuities in the long history contributed to the legitimacy of the rules and the functionality of the infrastructure. Second, the contemporary institutions bring about a power balance among the various organisations involved in irrigation management. The governance of the organisation follows surprisingly strictly the National Water Law. Only some minor rules are not complied with. Rule-compliance is partly enforced by social control among 'equal' parties: e.g. farmers in the tertiary block guard their water against theft, and engineers of the Comisiones ensure they get allocated water for their Subsector according to the rules. Rules are also enforced by the governmental organisations ATDR and AACH. They judge about certain types of conflicts (on rule violation) inside the users' organisations. Punishment of rule violation is also used in political ways: a fine by the ATDR implies exclusion of the involved water user from the next election of the board of the Comisión .

    The effect of volumetric water control on productivity of water is small. It is much more the water availability per hectare that determines the productivity of water. The water in Chancay-Lambayeque is 'stretched' over a much bigger area compared with Jequeteque making water more productive per volume of water applied. The volumetric charging affected livelihoods of poor farmers because it was difficult for them to find the money to pay the water turns when the crops required water. However, as the production system is high input - high output, the farmers invest much money anyway and the water fee is only 5 to 10 percent of the total input costs. The payment per volume made the board and staff of the Comisiones somewhat more accountable in water delivery to the water users.

    It is concluded in Chapter 8 that the power balance between the water users, different water users' organisations, private company and different public agencies shaped a well functioning entity. The general governance regulations were complied with, but locally rules on allocation, scheduling, maintenance and fee setting were refined and negotiated. It was also concluded that the analytical framework and research methods used in the comparative study were useful in revealing the complex nature of the irrigation management.

    Water rights and empowerment
    Boelens, R.A. ; Hoogendam, P. - \ 2002
    Assen : Koninklijke Van Gorcum BV - ISBN 9789023237648 - 255
    irrigatie - waterverdeling - waterbeheer - waterbeleid - boerenorganisaties - plattelandssamenleving - zuid-amerika - waterrechten - andes - irrigation - water distribution - water management - water policy - farmers' associations - rural society - south america - water rights
    Intervention processes and irrigation institutions : sustainability of farmer managed irrigation systems in Nepal
    Pant, D.R. - \ 2000
    Agricultural University. Promotor(en): D.B.W.M. van Dusseldorp; L.F. Vincent. - S.l. : S.n. - ISBN 9789058082787 - 285
    irrigatie - waterbeheer - waterverdeling - ontwikkelingsplannen - boeren - nepal - irrigation - water management - water distribution - development plans - farmers - nepal

    With the support from various donors, His Majesty's Government of Nepal has implemented support programmes with a view to transform water availability, improve production, and increase the institutional capabilities of farmers to develop and sustain efficient, fair and reliable irrigation management practices in irrigation systems in Nepal. In this respect, this study aimed to understand the social, administrative and political processes involved in the social and institutional changes brought about by development interventions at local level. This study focused mainly on the physical aspects of the interventions, the way they were implemented and the consequences for local institutions.

    The study consists of seven chapters. The first chapter consists of the nature of the problem, research focus and research objective. The various concepts and the theoretical framework along with the various methods used in generating information are presented in the second chapter. The socio-political and administrative environment of the country along with government policies and the priority in irrigation and agriculture development in different plan periods are discussed in the third chapter. The four case studies are discussed in chapters four to six. The case studies consist of the description of the general environment along with the presentation of the cases. The presentation is followed by an analysis of the case. The final chapter includes major findings of the case studies and conclusions. The changes in the government policy at various times have resulted in differences in the intervention strategies designed for various programmes. Moreover, there was no consistency in the intervention policies for various programmes at the same time. The government policy of seeking users' participation in the decision making of project design and implementation was mixed during the 1980s, as indicated by the interventions under different programmes. For example, small-scale financial support for the improvement of the FMIS was implemented with a more or less 'participatory approach'. The processes followed in new construction projects were not based on a 'participatory approach'. However, users' participation in the decision making since the early 1990s was a precondition for the initiation of intervention processes.

    The study shows that the initiation of interventions is complicated and not always very transparent due to the different objectives and hidden agendas of all the actors involved such as: the users, local leaders, local and regional institutions, government agencies, and external donors. The initiative for interventions started at the local level. The users, local leaders and VP officials formed a linking loop to obtain the resources from in which, they were successful. The VP acted as intermediary between the users and the government agencies in the initiation process of the intervention. However, the linking loop did not function well during the design of the project, as the government officials designed the interventions and great emphasis was placed on the financial and technical aspects, which were not discussed at length with the users. As a result the knowledge of the users' was not fully utilised by the agency officials. The cases indicate that the interface between the users and the other actors were not so intensive to reflect a 'participatory approach'.

    The implementation of the intervention could be categorised into three types. They are the new construction, rehabilitation and improvement. The objective of the intervention determined the type and scale of financial, technical and the institutional involvement in its implementation. The cases indicate that most of the UCs formed for the purpose of the intervention acted as 'construction committees' and failed to function after the completion of the intervention. In this respect the objectives of creating institutions for the implementation were partially achieved, but they could not ensure the complete participation of the users. Thus, the linking loop formed to obtain the government resources disintegrated during the implementation of the project. However, users with the help of the VP/VDC were quick to form a linking loop to obtain resources for other interventions.

    The analysis of the cases reveals that four institutions a) the Ditthawal system, b) DIO, c) VP/VDC and d) UC were important for the governance and the management of irrigation systems. The cases also indicate that the legitimacy of the institutions was established through the confidence of the users. The formal or informal status of the institution is secondary. The cases indicate that the fundamental reform of collective-choice rule due to the changes effected by the irrigation intervention in the governance structure contributed to increasing anarchy in 'rules in use'. Besides, there was little contribution in the design by the users due to an absence of constitutional-choice rule. The study also shows that many aspects of 'conditions for successful schemes' were violated due to changes in village administration. The study also shows that agency taking over constitutional-choice rule (policy) without adequate understanding of the village needs.

    The construction of permanent headworks and the canal lining has facilitated the operations of the system and the task of the users has been made easier. As a result, less participation of the users was needed for the system development, regular repair and cleaning of the canal. The users however lost the social control of the irrigation system due to the introduction of new technology and their dependence on outside resources was increasing. The user allocation of water in the case study area is based on irrigable land. Three types of water distribution practices are prevailing in the case study area. They are rotation, field to field and unregulated allocation. The cases indicate that the contributions in the operation and maintenance of the irrigation system are not the sufficient condition for a fair access to irrigation water. The degree of social control on which the institutions would rely was an important factor for ensuring fair distribution of water resources among the members.

    Three types of conflicts have been identified from the analysis of the cases. They are the conflict between the irrigation systems over the use of a single water source. However, the construction of the permanent weir did facilitate in defining the water rights between the irrigation systems. The second type of dispute is among the users due to weak institutional arrangements for the distribution of water. The third type of conflict is between the agency and the users due to lack of intensive interfaces during the planning and implementation of the intervention, which had implications on turning over the management of the irrigation system.

    The nature and extent of the participation by the users reflects that the interventions were not successful in seeking the active participation of the people in decision making due to a lack of an intensive interface between the actors involved in the design and implementation of the interventions. The analysis of the cases suggests that the most common form of participation for resource mobilisation was labour, land and time. The pattern of resource mobilisation shows that the newly introduced irrigation technologies such as permanent structures of the irrigation systems make the user more dependent on the external resources. The cash contribution was almost negligible. The complexity of the technology has considerable consequences for the need for external resources and expertise. The increasing dependence on external agencies for the sustenance of the irrigation system reflects that new linking loops are emerging through interfaces between the actors involved in irrigation development. This indicates that the technical intervention is demanding new organisational control.

    In all the four case studies, the maintenance of the system after the interventions depended largely on external resources when it came to cash contributions. The newly introduced UCs were only functioning during the time of the intervention but were not functional in mobilising resources for the maintenance of irrigation system. This means a greater dependence on government support. When this is not forthcoming the sustainability of the FMIS is questionable. It is therefore necessary that in the future more attention be given by the government to the institutional aspects of intervention that aims at the improvement of rehabilitation of FMIS. However it was not only the intervention and the way they were implemented that led to a diminishing participation of the users in the maintenance of their irrigation system. The changes in the local, political, and administrative institutions, the opening of the villages via new roads lessened cohesion of the rural communities and opportunities were created or made accessible what led among others to a diminished social control. The provision of all kinds of facilities (school, health-posts) led farmers to look for new roles for the government e.g. to support them with the maintenance of the irrigation system.

    Huishoudwater in Wageningen Noord-West
    Vliet, B.J.M. van - \ 2000
    S.n. - 28
    drinkwater - waterbeheer - watervoorraden - stedelijke gebieden - nederland - kraanwater - watervoorziening - waterverdeling - watergebruik - huishoudens - consumenten - perceptie - consumentengedrag - interviews - waterkwaliteit - hydrologie - gemeenten - gelderland - tap water - drinking water - water supply - water distribution - water use - water quality - households - consumers - perception - consumer behaviour - water management - water resources - urban areas - netherlands - hydrology - municipalities
    Huishoudwater : een nieuwe standaard?
    Burg, S. van der; Buuren, J.C.L. van; Vliet, B. van - \ 1999
    H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 32 (1999)19. - ISSN 0166-8439 - p. 17 - 20.
    water - kraanwater - watergebruik - hergebruik van water - watervoorziening - waterverdeling - kosten - kostenanalyse - kosten-batenanalyse - milieu - milieubeheer - milieubescherming - kwaliteit - natuurlijke hulpbronnen - watervoorraden - hulpbronnenbeheer - hulpbronnengebruik - gebruiksefficiëntie - watergebruiksrendement - schadepreventie - stedelijke gebieden - huisvesting - huishoudens - netwerken - woningbouw - waterzuivering - water - tap water - water use - water reuse - water supply - water distribution - costs - cost analysis - cost benefit analysis - environment - environmental management - environmental protection - quality - natural resources - water resources - resource management - resource utilization - use efficiency - water use efficiency - loss prevention - urban areas - housing - households - networks - house building - water treatment
    Een vergelijking van drie huishoudwatersystemen (hemelwater-, oppervlaktewater- en grijswatersysteem) met het gangbare enkel-net-systeem op de punten economische rendabiliteit, milieurendement en maatschappelijke effecten. Behalve in het oosten van het land, waar de noodzaak van grondwaterbesparing het grootst is, zullen omvangrijke huishoudwaterprojecten er waarschijnlijk niet komen
    Sediment transport in irrigation canals
    Mendez V., N.J. - \ 1998
    Agricultural University. Promotor(en): E. Schultz; L.C. van Rijn. - Rotterdam etc. : Balkema - ISBN 9789054104131 - 285
    irrigatiewater - transport - waterverdeling - hydrodynamica - hydraulica - suspensies - sediment - irrigation water - transport - water distribution - hydrodynamics - hydraulics - suspensions - sediment

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high crop production. Irrigation has been the largest recipient of public agricultural investment in the developing world. Hence, continued investment in irrigation along with reforms in institutional arrangements for management of water are very much necessary to ensure adequate supply of food. Simultaneously, water requirements for other purposes, domestic, industrial and hydropower will steadily increase as well. Under this competing situation irrigation will have to become increasingly more efficient in the future.

    Improved management and operation activities must be implemented to prevent recurring degradation of irrigation projects. Clogging of turnouts and reduction of the conveyance capacity of canals by siltation are problems frequently met in irrigation systems. Annually, high investments are required for rehabilitation of irrigation systems in order to keep them suitable for their purposes. New development of irrigation projects or upgrading of existing schemes will require a better understanding of the sediment transport process under the prevailing flow conditions in irrigation canals. Applicability of the existing sediment transport relationships on irrigation canals has to be better understood. In this way predictions on sediment deposition in irrigation canals will be more reliable.

    The present study is focused on sediment transport in irrigation canals which may have a serious impact on the operation and maintenance activities. The design of the canal system either should be based on the transport of all the in the water present sediment to the fields or to places in the canal system, where the deposition can be removed with least costs. Sedimentation should be prevented in canals and near structures, as it will hamper and endanger a proper irrigation management. In the design and operation of irrigation canals with sediment-laden water several aspects related to irrigation criteria and sediment transport must be taken into consideration. The need for conveying different discharges at a required water level to meet the irrigation requirement and at the same time to convey the sediment load with a minimum deposition and/or erosion in the canal system should be the main criteria for the canal design. Irrigation canals are generally designed upon the assumption of uniform and steady flow.

    It is also assumed that there exists an equilibrium situation where the sediments entering into the irrigation canals will be transported without settling or erosion. However, uniform and steady flow are seldom found in reality. In the operation of an irrigation system the flow is predominantly non-uniform. While the sediment transport is highly dependent on the flow conditions it is obvious that the sediment transport capacity of the canals varies as well.

    Development on sediment transport in open channels have been mainly focused on river engineering. Even though certain similarities between rivers and irrigation canals are present, these concepts are not fully applicable to irrigation canals. A description and analysis of the sediment transport concepts under the specific conditions of irrigation canals will contribute to improve the understanding of these concepts and will help to decide on the applicability of them on simulation of the sediment transport processes for particular conditions of water flow and sediment inputs. A mathematical model which includes sediment transport concepts for the specific conditions of irrigation canals will become an important and timely tool for designers and managers of those systems.

    The aim of this research is to present a detailed analysis of the sediment transport processes, a physical and mathematical description of the behaviour of sediment transport under flow conditions encountered in irrigation canals and to develop a model to predict sediment transport and the deposition or entrainment rate for various flow conditions and sediment inputs.

    Sediment transport processes

    Sediment transport and water flow are interrelated and cannot be separated. From a mathematical point of view the interrelation can be described for a one-dimensional phenomenon without changes in the shape of the cross section by the following equations:

    • governing water flow equations : continuity and dynamic equations;
    • governing sediment equations : resistance to flow, sediment transport equations, continuity equation for sediment mass.

    Water flow equations : although one-dimensional flow hardly can be found in nature, water flow in an irrigation canal will be considered to be one-dimensional. Under this assumption, the general equations for one dimensional flow can be described by the Saint Venant equations. The amount of water flowing into irrigation canals during the irrigation season and moreover during the life time of irrigation canals is not constant. For the time depending changes in the bottom of the canal the water flow can be easily schematized as quasi-steady which means that the time depending factors in the Saint Venant equations can be neglected.

    Resistance to flow : the resistance to flow in open channels is affected by several factors, among which the development of bed forms play an important role. Determination of the friction factor of a movable bed is a complex problem that requires knowledge of an implicit process of flow conditions and bed form development. In order to predict the type of bed forms in irrigation canals the theories developed by Liu, Simons and Richardsons, Bogardi and van Rijn were compared to a selected set of laboratory and field data. Also a comparison of the most widely used methods to predict the resistance to flow with field and flume data has contributed to select an appropriate method for similar situations. The selected methods for predicting the resistance to flow were: White, Bettes and Paris (1979), Brownlie (1983) and van Rijn (1984c).The objective was to find the appropriate theories to describe the bed form and to estimate the resistance to flow (friction factor) in irrigation canals.

    From the performance of each predictor of bed form type and friction factor method when compared with selected field and laboratory data some conclusions can be drawn:

    • the theories of van Rijn and Simons and Richardson behave as the best to predict the bed form in irrigation canals;
    • all the bed forms described for the lower regime (ripples, mega-ripples and dunes) can be expected in irrigation canals;
    • the prediction of the friction factor by using the previously described methods takes only into account the bottom friction;
    • the van Rijn method for predicting the friction factor shows the best results when compared with the selected data.

    Another important feature related to the resistance of water flow in irrigation canals is the estimation of the friction factor of a irrigation canal with composite hydraulic roughness. The development of bed forms on the bottom, different material on the bottom and side of the canal or vegetated side banks are typical situations for the composite roughness conditions in irrigation canals. The most common cross sections in irrigation canals are the trapezoidal and rectangular cross section with a relatively small value for the bottom width-water depth ratio. In these cross-sections the velocity distribution is strongly affected by the varying water depth on the side slope and the boundary condition imposed to the velocity at the side wall. A method to estimate the effective roughness in a trapezoidal canal with composite roughness along the wetted perimeter which uses the theoretical velocity distribution in the cross section, is proposed.

    In order to predict the effective roughness in irrigation canals with composite roughness, the existing methods for predicting the effective roughness and the proposed method in this study have been compared with a selected set of laboratory data, which has been collected in the hydraulic laboratory of the Wageningen Agricultural University. The aim of the experiments has been to investigate the friction factor in a trapezoidal canal having varying roughness on side and bottom and to find an appropriate method to estimate the friction factor in a non-wide canal with different roughness along the wetted perimeter. From the comparison the main conclusion can be drawn that the proposed method gives better results than the other methods.

    For rectangular cross sections with composite roughness the existing methods for estimating the effective roughness can not explicitly be used. Therefor it is proposed to estimate the composite roughness in rectangular cross sections by the same principle as used for the side wall correction. The procedure to estimate the effective roughness in rectangular cross sections has been tested with a selected set of laboratory data used by Krüger. The proposed method predicts more than 95% of the measured values of the composite roughness within a range of error of 15%.

    Sediment transport equations : sediment transport equations are related to the way in which the sediment is transported: namely in equilibrium and non-equilibrium condition.

    Sediment transport predictors for equilibrium conditions have been established for different conditions. The use of those equations should be restricted to the conditions for which they were developed. However a comparison of the different equations under similar flow and sediment characteristics, both in irrigation canals and from field and laboratory data will be a useful tool to evaluate the suitability of each equation under these particular flow conditions. In this study, five of the most widely used equations to compute sediment transport have been compared, namely the Ackers and White, Brownlie, Engelund and Hansen, van Rijn and Yang equations. These equations have been compared with field and laboratory data. The objective was to find more reliable predictors of the sediment transport capacity under the flow conditions prevailing in irrigation canals. From that evaluation some remarks can be drawn:

    • prediction of the sediment transport in irrigation canals within an error factor less than 2 is hardly possible;
    • based on an overall evaluation of all performance criteria for each equation, the Ackers and White and Brownlie equations seem to be the best to predict the sediment transport rate in irrigation canals.

    Sediment transport theories have been developed for wide, open channels. Most of the man-made irrigation canals are not considered as wide canals. Recommended values for the ratio of bottom width and water depth (B/h) in those canals are smaller than 8. Existing methods for calculating the total sediment transport capacity for the entire cross section of a non-wide canal do not take into account the velocity distribution over the cross section. A new method to compute the total sediment transport by using a cross section integrated method is proposed, which is based on the assumption of a quasi two-dimensional model. The objective is to consider the effect of the side banks on the distribution of velocities and to adapt the sediment transport predictors for computing the sediment transport for the entire cross section of a non-wide canal. The existing methods and the proposed method to compute the total sediment transport in non-wide canals were compared with a selected set of laboratory data. Based on the overall comparison the proposed method gives better results than the existing methods for computing the sediment transport capacity for the whole cross section.

    An interesting phenomenon of the non-equilibrium sediment transport in irrigation canals is the adjustment of the actual sediment transport to the sediment transport capacity of the irrigation canal. To simulate the sediment transport under non-equilibrium conditions, the Gallapatti's depth integrated model for adaptation of the suspended load has been used. It has been assumed that the adaptation length for bed load is the same adaptation length for suspended load. Therefore the Gallapatti's depth integrated model can be used to describe the approach of the total sediment concentration to the transport capacity of the irrigation canal.

    Application of mathematical modelling of sediment transport in irrigation canals

    In order to simulate the sediment transport in irrigation canals, a computer program (SETRIC) has been developed. The computer program can simulate water flow, sediment transport and changes of bottom level in a network composed by a main canal and several laterals with/without tertiary outlets. Also some hydraulics structures are included in the program: overflow and undershot type, submerged culverts and inverted siphons, flumes and drops.

    The computer program is based on a sub-critical, quasi-steady, uniform or non-uniform flow (gradually varied flow). The water flow can be simulated in open channels, with a rectangular or trapezoidal cross section with single or composite roughness. Only friction losses are considered. No local losses due to changes in the bottom level, cross section or discharges are taken into account. However, changes in the bottom level are included.

    Sediment characteristics are defined by the sediment concentration at the head of the canal and sediment size is characterized by the mean diameter d 50 . The range of values is 0.05 mm≤d 50 ≤0.5 mm. A uniform sediment size distribution has been assumed.

    The simulation periods take into account the variation of the irrigation water requirement during the growing season. The growing season is divided into four stages depending on the crop development and climate conditions. The program assumes a maximum of four different periods in which the discharges along the system can be varied.

    Maintenance activities can also be included into the program. Those maintenance activities are referred to the obstruction degree due to weed growth on the banks and by its effect on the roughness condition of the canal. From that point of view three types of maintenance are included in the program: ideal maintenance, well maintained and poor maintained.

    Some applications of the model to simulate sediment transport in irrigation canals are shown. The results can not be generalized so that they can only be applied for the local flow conditions and sediment characteristics of each application. The applications are meant to show the applicability of the model and to improve the understanding of the sediment transport process for situations usually encountered in irrigation systems. The sediment deposition in an irrigation canal during a certain period will be simulated for each of the different applications. The sediment transport capacity of the irrigation canal is computed according to the Ackers and White's predictor method. The adjustment towards the sediment transport capacity is according to the Gallapatti's depth integrated model. A sediment mass balance in each reach of the canal will give either the net deposition or net entrainment between the two boundaries of a specific canal reach. From the application cases some conclusions are drawn:

    Changes of discharges : during the simulations for reductions of discharge to 80% of the design value (equilibrium condition), more than 40% of the incoming sediment load was deposited.

    Changes in the incoming sediment load : the effect of changes in the incoming sediment load on the sediment transport include the effect of variations in the incoming sediment concentration and in the median sediment size during the irrigation season and/or the lifetime of an irrigation canal. For 100% of variation in the incoming sediment concentration about 30% of the incoming sediment load is expected to settle into the canal. A similar behaviour is observed for the case of changes in the design value of the median size of the incoming sediment. For instance a total of about 45% of the incoming sediment during the simulation period is deposited when the sediment size deviates 100% from the equilibrium size.

    Controlled sediment deposition : two scenarios to concentrate the sediment deposition at the head reach of a canal were simulated. They can be described as: widening (scenario 1) and deepening (scenario 2). No additional considerations for optimizing economical cost and sediment deposition were done. For the specific flow and sediment transport conditions scenario 2 trapped 4 times more sediment than an irrigation canal without control and 1.3 times more than scenario 1.

    Sediment transport predictor : large differences in the computed sediment deposition were observed among the sediment transport predictors. The hydraulic conditions during the simulation period gave a low sediment transport capacity for the Engelund and Hansen predictor and larger for Brownlie and Ackers and White predictors. By using the Engelund and Hansen's predictor the sediment deposition was 2 and 3 times more that the Brownlie and Ackers and White's predictors respectively.

    Flow control structures : two types of flow control structures were compared: overflow type and undershot type. The observed total deposition in both cases is rather similar. A larger difference was observed in the distribution of the sediment deposition along the canal. That difference was mainly concentrated in the upstream part of the structure.

    Maintenance activities : maintenance was related to weed infestation and it was simulated by assuming optimal maintenance and no maintenance at all during the irrigation season. No direct effect of the growth of the weed on the sediment transport is considered. More sediment deposition was observed in the ideally maintained canal than the non-maintained canal. Due to the constant water level at the downstream side of the irrigation canal the flow condition within the canal behaved as: in the ideally maintained canal a gradually varied flow (backwater curve) remained constant during the simulation period. A continuous deposition was observed during all the time along the irrigation canal. In the non-maintained canal the initial flow condition changed in time from a backwater curve to a drawdown curve due to the constant water level at the downstream end and due to the variation of the water level within the canal imposed by the variation of the roughness condition. A sediment deposition period followed by an entrainment period was observed during the irrigation season.

    Operation activities : for simulating the effect of the operation procedures on the sediment deposition in the main canal four scenarios were investigated. The four scenarios are: scenario 1 (continuous flow); scenario 2 (rotational flow by hour); scenario 3 (rotational flow by day); scenario 4 (rotational flow by week). From the comparison the following conclusions can be drawn:

    • the largest total sediment deposition was observed in scenario 1. Total sediment deposition in scenarios 2, 3 and 4 was rather similar;
    • large differences were observed in the distribution of the sediment deposition within the reaches of the main canal.

    By considering the results of the applications of the mathematical modelling, it can be concluded that model is a useful tool for assessing the sediment deposition within irrigation canals under different flow conditions and sediment characteristics. Nevertheless, the mathematical model's performance can most probably be improved when it is applied in more situations. Monitoring of the sediment deposition in irrigation networks is required to evaluate the model under specific conditions and to investigate the response in time and space of the bottom level to determined water flows and sediment characteristics. Influences of the type and operation of flow control structures, geometrical characteristics of the canals, water flow and incoming sediment characteristics on the deposition, which the mathematical model predicts, will contribute to a better understanding of the sediment transport processes in irrigation canals.

    On the waterfront : water distribution, technology and agrarian change in a South Indian canal irrigation system
    Mollinga, P.P. - \ 1998
    Agricultural University. Promotor(en): L. Horst; B. Crow. - S.l. : S.n. - ISBN 9789054859277 - 307
    irrigatiewater - waterverdeling - boeren - kanalen - watervoorziening - watertoewijzing - bedrijfsvoering - india - irrigation water - water distribution - farmers - canals - water supply - water allocation - management - india

    This book discusses water distribution in the Tungabhadra Left Bank Canal irrigation system in Raichur district, Karnataka, India. The system is located in interior South India, where rainfall is limited (approximately 600 mm annually) and extremely variable. The region suffered from failed harvests and famines in the past. A large scale irrigation system was constructed to solve these problems. The system is operational since 1953 and was completed in 1968. The area to be irrigated is 240,000 ha.

    The Tungabhadra Left Bank Canal is a protective irrigation system. It has been designed to spread available water thinly over a large area. It involves supplementary or partial irrigation. Crop water requirements are not fully met. In a particular agricultural season only part of the area is irrigated. Not production per unit area is maximised, but production per unit water.

    The last point implies a fundamental contradiction inherent to protective irrigation. For a farmer with a given landholding maximisation of production per unit land is the obvious strategy, instead of contributing to the maximum total product given the volume of water. The most remunerative crops, rice and sugarcane, demand a lot of water. Farmers who have the opportunity therefore appropriate more water than their protective share. As a result others do not get their share. Irrigation water in the Tungabhadra Left Bank Canal, like in many other systems, is unequally distributed.

    The central theme of the thesis is the day to day occurrence of this unequal distribution of water. The book attempts an interdisciplinary analysis of `water control' at different levels: the tertiary unit, the secondary canal and the main (primary) canal. The technical/physical, organisational and socio-economic/political dimensions of water control are related. The central research question is the following.

    • How do the pattern of commoditisation, the form of state regulation and the characteristics of the technical infrastructure shape, and how are they in turn shaped by, the forms of organisation of water distribution in the Tungabhadra Left Bank Canal irrigation system?

    The method is that of an intensive case study. The research started at the local level with the study of water distribution in a number of tertiary units (local irrigation units in which farmers distribute water among themselves), which were located in the upstream and downstream part of the irrigation system, and with a certain degree of water scarcity. The assumption was that scarcity would induce organisation.

    After research at this level the investigations gradually moved against the current onto the canal system and the distribution points located there, to the offices of the officials of the Irrigation Department who manage this part of the system, to the houses of politicians, to the shops of traders in seeds and fertiliser, and even to the High Court and Parliament of Karnataka. Mainly social-anthropological research techniques were used.

    The book has ten chapters. After an introduction chapter 2 discusses the theoretical framework of the analysis. Chapters 3 to 5 give background information on the phenomenon protective irrigation, the design of the system, and the socio-economic development in the region as a result of the introduction of irrigation. Chapters 6 to 9 are the core of the thesis. They discuss water distribution practices at different levels. Chapter 10 presents the conclusions and discusses the possibility of reform of the present situation with regard to water management.

    Chapter 2 introduces the two central concepts of the book. The first is the notion that irrigation systems are sociotechnical systems. They are heterogenous and complex because they consist of many different types of elements, which are related to each other in multifarious ways. The second concept is water control. Three dimensions of water control are distinguished: the technical/physical dimension, the organisational dimension and the socio-economic/political dimension. The central assumption is that these three dimensions are intimately related. Water control in irrigation is described as an example of politically contested resource use. With this description the importance of the social relations of power in the use of irrigation water is emphasised.

    Chapter 3 explains the meaning of protection and localisation. The notion of protection originated in British colonial irrigation policy. Three meanings of it are identified: 1) the general meaning of the function of irrigation to protect against drought/crop failure and famine), 2) protective irrigation as a financial-administrative class of irrigation works in the colonial period, and 3) protective irrigation as a specific type of irrigation in the technical, organisational and socio-economic/political sense. In South India, localisation is part of protection. Localisation is a form of land use planning in which the government legally prescribes which crops farmers can and cannot grow with the irrigation water.

    It is remarkable that the protection objective has remained a central element of Indian irrigation policy, also after independence, despite the (recognised) practice of unequal water distribution. The explanation of this persistence is found is the populist nature of the Indian political system. Politicians act as resource brokers who can secure their political support, among other ways, by getting canals constructed to their constituencies. At the same time they depend primarily on the category of large farmers within their constituency, who are the ones who tend to appropriate water above their protective share. For this reason politicians do not take action against unequal distribution. Because of the influence of politicians on their work, the officials of the Irrigation Department also find themselves in a difficult position.

    The genesis of the Tungabhadra Left Bank Canal is described in chapter 4. The history of the system starts in the period 1850-1860. The implementation of the plans made in that period and after it for a canal in Raichur district, was complicated by the relationship between Madras Presidency, directly ruled by the British, and the Nizam's Dominions, a formally independent Princely State. The Tungabhadra river was the border river of these two territories. The construction of a dam across it for creating a reservoir required agreement of both governments. Prolonged political negotiation was necessary to come to an agreement on the sharing of the available water. Despite the dominance of Madras presidency it was finally decided to share the water on a 50/50 basis. In 1944 an agreement was signed that allowed the start of the project, but negotiation protracted till 1976, among other things as a result of the reorganisation of the Indian States after independence.

    In 1945 construction of the project started. Once the available volume of water had been agreed, the further design was mainly done by engineers with little external influence. The cropping pattern was protective from the beginning, and in choice of canal alignments cost of construction was the major consideration. Social boundaries, like those of villages and farms, were not taken into consideration; topography and soil type have determined the design. The explanation of this lies in the very high social status of engineers in this period which made doubting their decisions impossible, and in the absence of institutions for discussion and negotiation regarding design elements.

    The introduction of irrigation in Raichur district has resulted in rapid economic development, which is described in chapter 5. Irrigation has induced the occurrence of intensive commercialised agricultural cultivation with high productivity. The migration of farmers from the neighbouring state of Andhra Pradesh to the new irrigation system has played a key role in this development. The migrant farmers came with sufficient investment capital and knowledge of irrigated agriculture, and started a farming system based on rice cultivation, and sugarcane to a lesser extent. Initially the local population had insufficient means for investment. The migrants bought land from local farmers. The larger local farmers used the returns of their land sales to invest in the development of their remaining land for irrigation (levelling, making field bunds). There has been a massive transfer of land to migrant farmers. In the course of time migrant as well as local farmers started to invest in pump irrigation, lifting water from the river and natural drains.

    A geographical pattern has emerged in which rich and middle peasants mainly have land in the upstream reaches of the canals, and small and poor peasants mainly in the downstream parts (the chapter first develops a typology of these four categories of farmers). Notwithstanding this general correlation of location and socio-economic class, the exact relationship differs from locality to locality. Migrant farmers could not always obtain land in the geographically most favourable locations. Sometimes water scarcity developed in areas where sufficient water was available earlier. The process of the relocation of farms in relation to access to water, continues to this day through the mechanisms of purchase and sale of land, the transfer of land in dowries, and through the acquisition of land by extending loans with land as collateral. The process of agrarian change can not be fully understood without incorporation of this inherent spatial dimension.

    Chapter 6 is the first chapter on day to day water distribution practices. It analyses events at the level of the tertiary unit, within which farmers distribute water among themselves. It was found that in many cases detailed systems of rules existed for rotational water distribution. These are based on the principles of zoning of the irrigated command area, and on a fixed irrigation time per unit area. The rules are used in periods of water scarcity. Outside these periods irrigation takes place on the basis of mutual agreement.

    Despite the fact that these rules incorporate equity principles, strongly unequal water distribution can be observed. The reasons for this are that the rules only refer to the supply of water, and that they are not applied continuously. The demand for water is differentiated. Small, downstream farmers adjust their crop choice to the anticipation that they will lose conflicts with large farmers on the distribution of water. Small farmers grow crops that demand less water, and thus avoid conflicts. However, these crops are also less remunerative. The anticipation is the product of the dependence of small farmers on large farmers for obtaining credit and for employment for themselves and their family members. Large farmers also act as representatives of the local irrigation unit in discussions with the Irrigation Department and in other activities to safeguard water supply.

    Water distribution at the level of the secondary canal, called distributary in India, is discussed in chapter 7 (organisational aspects) and chapter 8 (technical aspects). Chapter 7 describes which rules for rotational water distribution have emerged in the interaction of the Irrigation Department officials who manage these canals, and the water users. In many secondary canals rules for rotation exist, which are, like those at tertiary level, mobilised in times of scarcity. At this level the rules also do not accomplish equity in water distribution. They express the power balance between users in different parts of the irrigated area, and that between water users and the government administration.

    In contrast to what is often assumed, corruption is not the dominant mechanism in water distribution at secondary level in the Tungabhadra Left Bank Canal. The problematic relationship between government managers and water users are not translated into financial transactions, but into political mediation. In certain circumstances local politicians (members of parliament) can play an important role in water management. Politicians depend on the political support of farmers. In exchange for their votes farmers can ask the politician to influence the behaviour of Irrigation Department staff. The local members of parliament's power over the Irrigation Department staff is based on their influence on the three-yearly (or more frequent) transfer of government officials. In this way a `triangle of accommodation' emerges, in which none of the parties involved (farmers, officials and politicians) has absolute control, and in which continuous negotiation is necessary about the distribution of water.

    Chapter 8 concentrates on the structure that links the secondary canal with the local irrigation unit: the pipe outlet structure. Because the discharge that flows from the secondary canal to the field channel through the pipe of the pipe outlet structure, depends on the upstream as well as the downstream water level, and on the cross section of the pipe (which can be adjusted with a shutter), it is practically impossible to regulate the discharge with any degree of precision. As a result it is unknown how much water is exactly diverted by the pipe outlet structures. Why this type of outlet structure remains in use, and have not been replaced by outlet structures used elsewhere in India that are more fit for the task of equitable distribution, is not completely clear.

    In practice there is substantial variation in the precise characteristics of the pipe outlet structure: the robustness of construction (concrete, stones and mortar), the location of the shutter (visible or non-visible, accessible or non-accessible), the type of lock or locks, and other characteristics. This variation expresses water distribution practices and problems along the canal. The characteristics and the state of the outlet structures are an expression of the relationships between different groups of farmers along the canal and between farmers and the Irrigation Department.

    The last chapter on water distribution practices, chapter 9, discusses the process of institutional change within the Irrigation Department in relation to main canal management. In a period of two years with extreme water shortage (1988-1990) a number of institutional changes took place that have improved water supply to the downstream parts of the canal. The original rules for distribution of water based on the localisation pattern have been abandoned. To replace these, new rules have been adopted that on the one hand consolidate inequality, but on the other hand provide a more realistic basis for negotiating water supply to the downstream part of the canal. As a result of the introduction of these new rules water supply to the downstream part has been improved, particularly it has become more stable.

    The concluding chapter, chapter 10, gives a summary reply to the central research question, and discusses the implications of the analysis for reform of irrigation management. It is argued that the analysis has identified both a number of structural limitations or hurdles for reform, and has shown that the day to day practice of water distribution provides opportunities for change. The opportunities are related to the capacity for self-management of water users, the joint formulation of rules for distribution by farmers and Irrigation Department staff, and the technical creativity and the possibility of institutional change within the Irrigation Department.

    After this the different perspectives that exist on the generally felt need for reform are discussed. These perspectives vary from technical and managerial arguments for `good management', economic arguments for `efficient management', ecological arguments for `sustainable management', to political arguments for `egalitarian and democratic' management. An attempt is made to describe a comprehensive approach in which technical, organisational, economic and political elements are intertwined.

    As regards the irrigation policy reform situation in Karnataka it is argued that more attention for the participation of water users and other interest groups in the formulation of policy is necessary. At present, efforts to change policy and practice take place in a rather isolated manner at high levels in the government, or in individual, local situations in irrigation systems. The creation of a broad support base for reform in society is considered a priority.

    Finally a number of research topics are listed and briefly discussed that could contribute to the reform agenda. These are the design process of canal irrigation technology, the political dimension of irrigation, and the issue of use(r) rights. This research should be situated in the daily practice of water management, that is, on the waterfront.

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