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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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    Subsurface drainage of valley bottom irrigated rice schemes in tropical savannah : case studies of Tiefora and Moussodougou in Burkina Faso
    Keïta, A. - \ 2015
    Wageningen University. Promotor(en): E. Schultz; H. Yacouba. - Leiden : CRC Press/Balkema - ISBN 9789462572638
    oryza - ondergrondse drainage - drainage - irrigatie - rijst - savannen - irrigatiesystemen - waterbeheer - burkina faso - oryza - subsurface drainage - drainage - irrigation - rice - savannas - irrigation systems - water management - burkina faso

    SUMMARY

    The contrasted global population growth with the multiplication of the constraints to developing new irrigation systems puts a special challenge upon human crop production systems that needs to be taken up. The populations in many countries in Asia, Middle East and Africa are expected to double in the coming 50 years. The experience of the green revolution in Asia – during which 70% of food production increase was provided by irrigated agriculture – shows that there is not only a need to strive to increase such crop production systems, but also to improve the production efficiency of existing ones. In fact, as a much worrying case, rice production in valley bottom irrigated lands of African Tropical Savannah is far to yield the expected amount of cereals. One of the major constraints to this production is iron toxicity subsequent to poor drainage conditions. According to Africa Rice, at least 60% of the Tropical Savannah swampy valley bottoms are affected by different degree of iron toxicity. The yield in many areas drops to zero, leaving behind millions of disappointed and impoverished farmers. Therefore, it is not surprising that there is strong research dynamic – ranging from agronomy to microbiology – that strives to propose alleviating solutions to rice iron toxicity. Because prevalent anoxic conditions in the soil combined with iron reducing bacteria development were found a basic contributing factor to iron toxicity,  this research has chosen to investigate subsurface drainage potential contributions to solving this issue.

    Two complementary series of operations – designed within two project- components and focused on five basic questions closely related to the contributing factors to iron toxicity development – were performed. In fact, the research project was implemented in two major components: field surveys and designed experiments. The field surveys investigated iron toxicity triggering or aggravating factors such as clay proportions, ferrous ion Fe2+ concentration, dissolved oxygen, soil acidity or water management. Drawing profit from the knowledge gained in survey research and literature review, two parallel experiments were designed using concrete microplots on one hand and buckets on the other hand, to statistically ascertain the impact of subsurface on soil acidity and ferrous iron concentration changes. All the operations performed within the two components of this research project endeavoured to answer the following five research questions:

     

    1. how is ferrous iron formed and distributed in soils invaded by iron toxicity?
    2. how is clay spread within the valley?
    3. how is soil permeability affected by clay distribution in the valley?
    4. how can water management help improve soil conditions?
    5. what is the impact of subsurface drainage on iron toxicity?

     

    The answers to these research questions – already published or in press – are exposed below, followed by the contribution of this research project in two areas: i) science en engineering, and ii) socio-economy.

    Clay and ferrous iron may deposit in strata

    High ferrous ion Fe2+ concentration, inserted into dense clay strata, constitutes an important threat to rice production in several tropical Savannah valley irrigation schemes  of  West  Africa.  Many  actions  are  currently  undertaken  to  alleviate  iron

     

    toxicity. In this study, we have investigated the presence of clay and ferrous iron stratifications within a typical flood prone valley bottom called Tiefora in Burkina Faso. Taking into account the multiple slopes of the valley, two randomized soil samplings were implemented at various depths. Samples were collected as deep as 500 cm, but especially at 30, 50 and 100 cm. The clay percentage was determined by grain size analysis. Ferrous iron concentrations were obtained through the reflectometric method. The stratifications of clay and ferrous ion Fe2+ were checked using statistical hypothesis testing (ANOVA and Welch t-Test). Clay percentage within the first 100 cm top soil – 28.9% – was found twice higher than in the layers underneath. Furthermore, ferrous iron was mainly located in the top 30 cm, with a mean concentration of 994 mg/l. This ferrous iron concentration is much higher than found at depths 50 and 100 cm underneath (73 mg/l), while the pH of all the three layers is almost neutral. This striking stratification suggests several means of alleviating iron toxicity. Among these means, we propose maintaining wet conditions during the growing period in the irrigated lands in combination with leaching by subsurface drainage in the fallow periods.

     

    Iron toxicity risk is higher in single season irrigation schemes

     

    With the aim of finding the geochemical differences and helping to build alleviating strategies against iron toxicity, two hematite dominant valley bottoms irrigated rice soils were investigated in the Tropical Savannah region of Burkina Faso. The first site was Tiefora, a 16 ha modern double-season irrigated rice scheme and moderately affected by iron toxicity (10% of the area with a toxicity score of 4). The second site was Moussodougou, a 35 ha traditional single-season irrigated rice valley-bottom, with 50% facing more severe iron toxicity (score 7). Nine soil extracts were taken from three depths – 30,  50 and 100 cm – i.e. 27 at Tiefora  and 27 at  Moussodougou.  Five techniques were used to measure the data: i) the ferrous iron concentration was determined using a reflectometer, ii) a pH-meter yielded the pH, iii) clay-proportions were obtained by United States Department of Army (USDA) grain size analysis and densitometry, iv) the organic matter was determined by oven drying and v) the dry bulk density was determined by using undisturbed soil samples. Statistical hypothesis testing of One-way ANOVA and Welch t-test were applied to the data to isolate the similarities and the differences between the two sites. A geochemical analysis followed to find the causes of these differences. The results showed that while oxidation of pyrite leads to a simultaneous increase in Fe2+ concentrations and acidity in the soils of coastal floodplains and  mangroves,  the oxidation of hematite in  Tropical savannah valley

    bottoms decreases Fe2+ but also increases acidity during the dry season. As a consequence, it was found that the single-season irrigation scheme of Moussodougou is significantly (p-value 0.4%) more acidic (pH 5.7) than the double-season system of Tiefora (pH 6.4) with also 750-1800 mg/l higher ferrous ion Fe2+. The ferrous iron reached 3000 mg/l in some layers in Moussodougou. This result is a justification to modernize traditional single-season spate irrigation schemes into double-season irrigated rice schemes.

     

    Subsurface drainage type depends on clay distribution

     

    Waterlogged valley bottom soils of Tropical Savannah are areas where the richest traditional cropping systems are found, but they also face adverse physical and chemical conditions which can drastically drop rice yield. Subsurface drainage has been used for many areas to alleviate waterlogging. However, this drainage is dependent of clay

    distribution, type and location. The current research analysed these factors using the case of Tiefora. For this purpose nine boreholes, with depths from 2 to 6 m, were realised. Some 50 samples of soils were extracted at various depths, based on soil changes in texture and colour. These samples underwent grain-size-analysis. A comparative non-linear regression was performed on the clay distribution. Quadratic regression was the most appropriate. Clay proportions were high - 20-30% in the 2 m topsoil - in the upstream and middle areas. A more important - 30-40% - peak was reached in the downstream area at 1 m-depth, with a much smaller thickness (less than 50 cm) and higher permeability. These results suggest the application of mole drainage in the valley, except downstream where the classical Hooghoudt pipe subsurface drainage can be implemented.

     

    Subsurface drainage cost can be reduced by taking into account permeability distribution in valley

     

    In flood prone Tropical Savannah valley soils very low infiltration rates often result in acidic conditions favourable to high concentrations of metallic ions, toxic for rice. The infiltration rate determination is important in drainage design to reclaim degraded soils. Several studies have addressed the mapping of the infiltration rate. Yet its relationship with the toposequence of the valley is not clarified. This research has investigated such possibility, examining the case of the irrigated rice valley of Tiefora. Nine boreholes – 1 to 5 m deep – were implemented from upstream to downstream. The Lefranc permeability test of under phreatic conditions in waterlogged soils – used when the impervious layer is close to soil surface or absent – was conducted. First, a comparative regression was applied to the data, including all the parameters of the regression curves. In case of dissimilarity of the infiltration processes, the comparison focused on the final permeability. Our results show a permeability increase from upstream (0.10 ± 0.10 cm/hr) to downstream (greater than 20.0 ± 10.0 cm/h in some places). Taking into account such permeability increase in subsurface drainage system design would result in the implementation of more efficient and cost effective systems.

     

    Data based water management can help to reduce water losses and solve water inequity frictions between farmers

     

    Surface irrigation represents more than 99% of the irrigated area in West Africa and generally includes valley bottoms dedicated to irrigated rice production, which are often denounced as water overusing schemes. Surprisingly, there is neither follow up nor analysis of the irrigation water used in these gravity irrigation systems. Such a work was carried out in the case of the 16 ha Tropical Savannah irrigated rice valley bottom scheme of Tiefora. Using the flow equation of the concrete weir at the headwork, daily water use volumes were calculated as time series covering more than one-year period. The moving average trend analysis reveals that during both the rainy season (1200 mm of rainfall) and the dry season (no rainfall), the main canal gate is almost never closed, keeping a minimum discharge of 200 m3/day for 4 ha (50 mm/day versus. a local evapotranspiration of 7 mm/day). That stresses the necessity of a more rigorous water management. Furthermore, the autocorrelation analysis by using the ARIMA model showed that the irrigation cycle that ensures equity in water distribution among farm plots is 20 days instead of five. The knowledge of this fact can defuse potential conflicts about equity among farmers: the lack of water in day 4 may be compensated later during the 20-day cycle. It appeared that a simple water level measuring device – installed at the headwork of the main irrigation canal – can produce a time series to

    which autoregressive moving average model can be applied to yield, at low cost, a thorough assessment of water management in this surface irrigation system.

     

    Subsurface drainage alleviates iron toxicity in mean and long run

     

    Iron toxicity is one of the most important constraints that hinder rice productivity in Tropical Savannah valley bottom irrigated fields, but fortunately that can be alleviated. A too high ferrous iron level in the soil can nullify rice yield. Several research fields – agronomy, pedology through microbiology – strive to provide a solution to this issue. Up to date, the contribution of hydraulics to tackle iron toxicity remained limited. The current research addressed this aspect through controlled experiments on highly ferrous iron contaminated rice hematite soils. Twelve concrete microplots and eight buckets were used to implement two independent designed experiments during a period of 86 days. Drainage and liming were the two factors whose impacts were investigated. Drainage was used with two treatment conditions: 0 mm/day and = 10 mm/day, and liming also had two treatment conditions: Lime- = 0 kg/m² and Lime+ = 1 kg/m² per unit increment increase of the pH. Four different responses in the soil were measured: ferrous ion concentration Fe2+, pH, oxido reduction potential, and the dissolved oxygen. For the rice, toxicity scores of the International Rice Research Institute were followed

    up. The results indicate an increase of Fe2+ from 935 mg/l to more than 1106 mg/l (at 95% of confidence level), but, which is interesting, with a significant decrease of soil acidity from pH 5.6 to 7.3 (95% confidence level). Liming had the same effect in alleviating the acidity. Reduction processes were not hindered by subsurface drainage since the oxydo reduction potential dropped from 84.6 to 9.2 mV, and dissolved oxygen

    moved from 1 mg/l to less than 0.1 mg/l. Despite of the reduction of the acidity, with such a high ferrous iron level as 1106 mg/l, the iron toxicity score reached 7 in the twelve microplots and the rice died. Still, the reduction of soil acidity provides a new insight on the hematite soils behaviour, opposite to the acidification with subsurface drainage in coastal floodplains and mangrove pyrite. Furthermore, it will lead to less ferrous iron intake by rice roots and in such perspective improve the rice yield. Finally, though liming can achieve the same result, subsurface drainage takes the advantage when this mineral is not available or is expensive.

     

    Project outputs for Tiefora farmers

     

    From the investigations and their supporting activities, two major benefits were brought to the farmers of Tiefora. First, in order to alleviated iron toxicity – which is much less severe in this place than in Moussodougou – and improve rice yield (less than 4 tons/ha), it would be essential to apply according the norms of the Institute of Environment and Agricultural Research (IN.ERA) the complex fertilizer NPK. However, this application should go along with making well built bunds around the farm plots in order to confine the fertilizer and make the mineral more available for the rice roots. This  will invigorate the crop  and thus  strengthen  its resistance to iron toxicity. Secondly, the project handed to the farmers’ association of Tiefora three key documents: i) an aerial photo the environment of the valley of Tiefora, including the reservoir, the village, the roads and the irrigated valley, ii) a topographical map of the valley bottom, intended to help in potential engineering works on the irrigation system, and iii) a detailed map of the farm plot system, accompanied with the complete list of the farmers and their farm sizes, and the location of iron intoxicated plots for their daily activities

     

    Project outputs for Moussodougou farmers

     

    Based on the investigation results and due to the severe iron toxicity in Moussodougou, the project provided several advices and handed some key documents to the farmers. Ferrous iron concentration in the soil of Moussodougou can reach 3000 mg/l in many farm plots with acidity as severe as pH 4. Since its incorporation into the soil was found to induce the growth of iron reducing bacteria activity, and given the positive conservation impact of organic matter in lightening the soil structure,  the  project advised the farmers to reduce its use but not to eliminate it completely. In parallel, farmers would have to use the complex NPK as in Tiefora, according to the norms of IN.ERA, but combine it with a careful erection of plot bunds to make the mineral element more available for the rice. Due to the fact that the current single irrigation season during the year in Moussodougou is an aggravating factor of iron toxicity, the project also introduced to the  farmers association its ongoing work of developing sprinkler irrigation from groundwater during the dry season. Finally, the project handed to the farmers’ association the same set of documents as in Tiefora, but related to the valley bottom of Moussodougou.

     

    Other social impacts

     

    In an ultimate effort to share the insights gained about the iron toxicity alleviation process, this research project produced and uploaded onto the social media YouTube several useful videos. The 15 videos uploaded and accessible for everybody, deal with areas as varied as hydrometrics, microbiology, geochemistry and small scale water saving irrigation equipment assembling at village level (without electricity). Many of these videos were very appreciated by the audience. For example, the video of "Innovative irrigation systems in Sub-Saharan Africa (French)" has been viewed/downloaded 500 times/month. Similarly, the video "How to take a sample of disturbed soil or resting in soil immersed at different depths (English)", was viewed/downloaded some 45 times/month. These two videos were classified "creative common" due to their high potential appropriation by third party video productions. Hence, it is expected that the project will have an even higher social impact in the coming months or years.

     

    Effecten van onderwaterdrains in peilvak 9 van polder Groot-Wilnis Vinkeveen : modelstudie naar de effecten van onderwaterdrains op maaivelddaling, waterbeheer, wateroverlast en waterkwaliteit in peilvak 9
    Hendriks, R.F.A. ; Akker, J.J.H. van den; Jansen, P.C. ; Massop, H.Th.L. - \ 2014
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2480) - 124
    drainage - veenweiden - bodemdaling - wateraanvoer - graslanden - ondergrondse drainage - polders - modellen - utrecht - drainage - peat grasslands - subsidence - water advance - grasslands - subsurface drainage - polders - models - utrecht
    Dit rapport beschrijft een modelstudie naar de effecten van grootschalige toepassing van onderwaterdrains op de maaivelddaling, het waterbeheer, wateroverlast en de waterkwaliteit in Peilvak 9 in polder Groot-Wilnis Vinkeveen. Bijzonder en belangrijk aan deze studie is dat de effecten over vijftig jaar zijn doorgerekend. Toepassing van onderwaterdrains halveert de maaivelddalingsnelheid in de gebiedsdelen waarin de drains zijn aangebracht tot 5 mm per jaar. In de rest van het peilvak neemt op de langere termijn de maaivelddaling af met 17%. De gemiddelde maaivelddalingsnelheid in het peilvak bedraagt dan 6 mm per jaar. Veenbehoud kost water, vooral in een wegzijgingsgebied als Peilvak 9.
    Hydrologische en landbouwkundige effecten toepassing onderwaterdrains in polder Zeevang = Hydraulic and agricultural effects of applying 'submerged drains' in the Zeevang polder
    Hoving, I.E. ; Akker, J.J.H. van den; Pleijter, M. ; Houwelingen, K.M. van - \ 2011
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR, Livestock Research 449) - 64
    graslanden - veengronden - agrohydrologie - grondwaterstand - ondergrondse drainage - peilbeheer - proefprojecten - polders - noord-holland - grasslands - peat soils - agrohydrology - groundwater level - subsurface drainage - water level management - pilot projects - polders - noord-holland
    Op initiatief van LTO-Noord-afdeling Groot Waterland is in polder Zeevang onderzoek gedaan naar de praktijktoepassing van onderwaterdrains. Het doel was een veldexperiment op praktijkschaal naar het effect van onderwaterdrains op de zakking van veengrond en op de landbouwkundige productiemogelijkheden van grasland bij een slootpeil 60 cm –maaiveld (mv). In dit rapport ligt de nadruk op de invloed van onderwaterdrains op het verloop van de grondwaterstanden en op de grasproductie. De onderwaterdrains liggen onder het slootpeil en niet zoals gebruikelijk erboven. De hypothese is dat hierdoor de grondwaterstanden gedurende het jaar nivelleren: ’s winters lager en ’s zomers hoger
    Natuurboerderij Hoeve Stein : van Boeren met natuur naar Natuur met boeren
    Melman, T.C.P. ; Akker, J.J.H. van den; Schotman, A.G.M. ; Ottburg, F.G.W.A. ; Huiskes, H.P.J. ; Kiers, M.A. - \ 2011
    Wageningen : Alterra (Alterra-rapport 2203) - 84
    agrarisch natuurbeheer - agrarische bedrijfsvoering - slootkanten - ondergrondse drainage - weidevogels - natura 2000 - groene hart - zuid-holland - agri-environment schemes - farm management - ditch banks - subsurface drainage - grassland birds - natura 2000 - groene hart - zuid-holland
    Voorde planvorming van een natuurboerderij nabij Reeuwijk is een aantal adviezen opgesteld, gericht op de versterking van het natuurresultaat in combinatie met een agrarische bedrijfsvoering. In dit geval staat het bedrijf in dienst van de natuur en niet andersom. Het bedrijf is gelegen in het Natura 2000-gebied ‘Broekvelden, Vettenbroek en polder Stein’. De adviezen gaan over aanleg en beheer van slootkanten, inrichting van sloten, weidevogelbeheer en het toepassen van onderwaterdrainage rond bedrijfsgebouwen. Bij de advisering is de te realiseren natuur randvoorwaardelijk, gestreefd is naar functionele inpassing van natuur in het bedrijf.
    Huidige en toekomstige watervraag van veengronden in het Groene Hart : verkenning naar het effect van onderwaterdrains
    Akker, J.J.H. van den; Jansen, P.C. ; Querner, E.P. - \ 2011
    Wageningen : Alterra (Alterra-rapport 2142) - 60
    veengronden - veenweiden - bodemwater - ondergrondse drainage - bodemdaling - groene hart - peilbeheer - peat soils - peat grasslands - soil water - subsurface drainage - subsidence - groene hart - water level management
    Dit rapport is onderdeel van de studie Droogtebestendig West-Nederland die is uitgevoerd in opdracht van de provincies Zuid-Holland, Noord-Holland en Utrecht, Waternet, Hoogheemraadschap van Rijnland, Hoogheemraadschap De Stichtse Rijnlanden en Hoogheemraadschap van Schieland en de Krimpenerwaard. Door het afwateren van de veenweidegebieden daalt daar de bodem. Toepassing van onderwaterdrains kan de bodemdaling halveren, maar zal door een betere infiltratie in het veenweideperceel en een doorgaande gewasverdamping in droge perioden leiden tot een grotere watervraag van het veenweidegebied. Uit dit verkennend onderzoek blijkt dat door toepassing van onderwaterdrains de watervraag tot 15% extra kan toenemen. Door slim peilbeheer kan deze toename van de watervraag echter sterk worden gereduceerd.
    Interne eutrofiering en veenafbraak; literatuuronderzoek : effect van toepassing van onderwaterdrains: literatuuronderzoek
    Kemmers, R.H. ; Koopmans, G.F. - \ 2010
    Wageningen : Alterra (Alterra-rapport 1980) - 68
    bodemchemie - fosfaat - eutrofiëring - ondergrondse drainage - veenweiden - soil chemistry - phosphate - eutrophication - subsurface drainage - peat grasslands
    Onderwaterdrains vormen een alternatief voor het verhogen van slootpeilen om maaivelddalingen te beperken, waarbij toch goede omstandigheden voor het boerenbedrijf worden gehandhaafd. Daarbij wordt via drains oppervlaktewater aangevoerd onder het maaiveld. Als bezwaar tegen onderwaterdrains wordt vanuit natuurbeschermingsorganisaties gewezen op het gevaar van interne eutrofiering en veenafbraak. Via een literatuurstudie is onderzocht welke effecten inlaat van ‘Gebiedsvreemd’ sulfaathoudend water heeft op de mobilisatie van met name fosfaat door afbraak van veentypen onder anaerobe condities zoals in het Hollandse Veenweidegebied kunnen voorkomen. Voor het onderzoek zijn zowel peer reviewed .wetenschappelijke artikelen als interne rapporten met resultaten van toegepast onderzoek geraadpleegd. Zowel empirische als experimentele studies zijn in beschouwing genomen. Naast veel overeenkomsten in effecten worden ook verschillen in resultaten gevonden. Deze verschillen zijn waarschijnlijk toe te schrijven aan het toepassen van doorstroomsystemen dan wel stagnante systemen tijdens experimenten waardoor het instellen van chemische evenwichten tussen vaste en opgeloste fase van de bodem worden beïnvloed.
    Onderwaterdrains in het veenweidegebied : de gevolgen voor de inlaatbehoefte, de afvoer van oppervlaktewater en voor de maaivelddaling
    Jansen, P.C. ; Querner, E.P. ; Akker, J.J.H. van den - \ 2009
    Wageningen : Alterra (Alterra-rapport 1872) - 56
    bodemdaling - graslanden - waterbeheer - drainage - ondergrondse drainage - veengebieden - oxidatie - grondwateraanvulling - oppervlaktewater - grondwaterstand - wateraanvoer - bodembeheer - veenweiden - groene hart - subsidence - grasslands - water management - drainage - subsurface drainage - peatlands - oxidation - groundwater recharge - surface water - groundwater level - water advance - soil management - peat grasslands - groene hart
    De toepassing van onderwaterdrains wordt gezien als een mogelijke oplossing om bodemdaling in veenweidegebieden te vertragen en te komen tot duurzaam water- en bodembeheer. Deze nieuwe techniek roept nog wel de nodige vragen op. In dit rapport wordt de extra inlaatbehoefte in de zomer en de extra afvoer in de winter plus de gevolgen voor de maaivelddaling door toepassing van onderwaterdrains gekwantificeerd voor een aantal waterbeheerscenario’s. Hiervoor wordt een hydrologisch model gebruikt dat in het kader van het project ‘Waarheen met het Veen’ voor het gebied rond de plaats Zegveld is ontwikkeld. Onderwaterdrains in combinatie met een hoger peil verminderen de maaivelddaling aanzienlijk. Nadelige effecten van onderwaterdrains zijn extra inlaatwater en meer water om uit te pompen.
    Conceptualisatie en parameterisatie van landgebruik, bodem, beregening en buisdrainage in het NHI
    Veldhuizen, A.A. ; Bakel, P.J.T. van; Kroon, T. ; Vries, F. de; Massop, H.T.L. - \ 2008
    Stromingen : vakblad voor hydrologen 14 (2008)4. - ISSN 1382-6069 - p. 47 - 62.
    veldgewassen - ondergrondse drainage - bodemtypen - modellen - agrohydrologie - field crops - subsurface drainage - soil types - models - agrohydrology
    Bij de modellering van de hydrologie van de bodem en het landgebruik in het NHI (Nationaal Hydrologisch Instrumentarium) is voortgebouwd op de hydrologie voor STONE 2.3. Bij STONE is Nederland landsdekkend gemodelleerd met behulp van een beperkt aantal (6405) plots. Een plot is een unieke combinatie van gewastypen, en geclassificeerde hydrologische eigenschappen en bodemchemische eigenschappen. Bij het bouwen van het NHI is deze piotbenadering verlaten. Dit betekent dat voor elke gridcel van 250 bij 250 m een model moet worden gebouwd van het gewas-onverzadigde zone deelsysteem.Daarbij is gebruik gemaakt van de modelcode metaSWAP, de onverzadigde zone module van SIMGRO. In dit artikel wordt zowel de conceptualisatie als de bijbehorende parametrisatie en de daarvoor gebruikte bestanden in meer detail beschreven
    Onderwaterdrains in het veenweidegebied : toelichting op de methode en meetinrichting
    Pleijter, M. ; Akker, J.J.H. van den - \ 2007
    Wageningen : Alterra (Alterra-rapport 1586) - 58
    drainagesystemen - drainage uitrusting - moldrainage - drainage door leidingen - ondergrondse drainage - methodologie - veenweiden - meetsystemen - meettechnieken - drainage systems - drainage equipment - mole drainage - pipe drainage - subsurface drainage - methodology - peat grasslands - measurement systems - measurement techniques
    Drains wordt doorgaans gebruikt voor het afvoeren van overtollig water. De onderwaterdrains kunnen echter ook gebruikt worden om water aan te voeren (infiltratie). Door de dubbele functie van de drains ontstaat een grondwaterregiem met een relatief lage hoogste grondwaterstand en een relatief hoge laagste grondwaterstand. Hierdoor wordt oxidatie van veen in de zomermaanden zoveel mogelijk tegengegaan, terwijl het landbouwkundig beheer niet negatief wordt beïnvloed dankzij een lagere grondwaterstand vroeg in het voorjaar. Deze proef bekijkt op verschillende locaties (Zegveld, Linschoten en in polder Zeevang) wat het effect is van de onderwaterdrainsdrains op de grondwaterstanden en de maaiveldligging
    Performance assessment of subsurface drainage systems : case studies from Egypt and Pakistan
    Ritzema, H.P. - \ 2007
    Wageningen : Alterra-ILRI - 137
    ondergrondse drainage - monitoring - egypte - pakistan - agrohydrologie - subsurface drainage - monitoring - egypt - pakistan - agrohydrology
    A case study set-up for the performance assessment of subsurface drainage systems for agricultural land drainage has been developed and 76 case studies from Egypt and Pakistan have been prepared. Based on these case studies, performance indicators for subsurface drainage systems have been derived and the main lessons learned to assess the performance of these systems have been summarized.
    Subsurface drainage practices : Guidelines for the implementation, operation and maintenance of subsurface pipe drainage systems
    Nijland, H. ; Croon, F.W. ; Ritzema, H.P. - \ 2005
    Wageningen : ILRI (ILRI publication 60) - ISBN 9789032703400 - 608
    ondergrondse drainage - buisdrainage - drainagesystemen - handboeken - subsurface drainage - tile drainage - drainage systems - handbooks
    Drainage goed voor veenweiden
    Bokma, B. - \ 2005
    Oogst : weekblad voor de agrarische ondernemer. Landbouw 18 (2005)12. - ISSN 1566-2616 - p. 8 - 8.
    drainage - ondergrondse drainage - drainagesystemen - bodemdaling - graslandverbetering - weiden - geïrrigeerde weiden - graslanden - irrigatie - infiltratie - veengronden - veengebieden - melkveehouderij - grondwaterstand - grondwateraanvulling - drainage - subsurface drainage - drainage systems - subsidence - grassland improvement - pastures - irrigated pastures - grasslands - irrigation - infiltration - peat soils - peatlands - dairy farming - groundwater level - groundwater recharge
    Onderwaterdrainage remt de bodemdaling in het veenweidegebied af. Veldproeven van Praktijkcentrum Zegveld (U) zijn veelbelovend - een flinke opsteker voor de melkveehouderij op laagveen. In Noordbeemster (NH) sleutelt loonbedrijf De Vlijt intussen aan een eenvoudige drainlegger achter de tractor
    Materials for subsurface land drainage systems
    Stuyt, L.C.P.M. ; Dierickx, W. ; Martínez Beltrán, J. - \ 2005
    Rome (Italy) : FAO (FAO irrigation and drainage paper 60) - ISBN 9789251054277 - 183
    ondergrondse drainage - drainagesystemen - drainage uitrusting - draineerbuizen - waterstroming - omhullingsmaterialen - drainage - subsurface drainage - drainage systems - drainage equipment - drain pipes - water flow - envelope materials - drainage
    The purpose of this Paper is to provide this practical information to drainage engineers and contractors. The Paper is based on the current knowledge of water flow into drain pipes and envelopes, their properties and applicability. It also contains guidelines for the selection of drainage materials and practical guidelines for the implementation of laboratory and field investigations to evaluate the performance of drainage materials. The selection of the materials must also consider the required specifications, their availability, durability and cost. Guideline for selection of the most appropriate envelope material, as related to local conditions
    Hoe de kartering van de grondwaterstand (nog) beter kan
    Hoogland, T. ; Brus, D.J. ; Heuvelink, G.B.M. ; Knotters, M. - \ 2004
    Wageningen : Alterra (Alterra-rapport 1032) - 88
    bodemwater - grondwaterspiegel - monitoring - bemonsteren - tijdreeksen - ondergrondse drainage - soil water - water table - subsurface drainage - monitoring - sampling - time series
    De afgelopen jaren ontwikkelde Alterra een methode voor kartering van grondwaterstandskarakteristieken (de Gd-karteringsmethode). Deze methode, die met behulp van tijdreeksanalyse, lineaire regressie en geostatistische interpolatie ruimtelijke beelden van grondwaterstandskarakteristieken produceert, is de ontwikkelfase inmiddels ontstegen en al een aantal keren in de praktijk toegepast. Op onderdelen is aanpassing, verfijning, correctie en verbetering van de methode mogelijk. Daarom is in dit project de Gd-methodiek grondig onder de loep genomen en is een uitgebreide lijst gemaakt van mogelijke verbeterpunten. Op basis hiervan zijn belangrijke en kansrijke verbeterpunten onderzocht in drie deelonderzoeken. Het eerste deelonderzoek, naar tijdreeksmodellering van grondwaterstandsreeksen voor de predictie van klimaatsrepresentatieve GxG (GHG, GVG en GLG), gaf geen aanleiding de Gd-methode aan te passen. Op het gebied van zowel stambuisregressie voor de omzetting van gemeten grondwaterstanden naar klimaatsrepresentatieve GxG als van vlakdekkende predictie van klimaatsrepresentatieve GxG zijn echter wel mogelijke verbeteringen gevonden. De voorstellen betreffen vooral kleine veranderingen die relatief eenvoudig te implementeren zijn en die de uitgangspunten en globale werkwijze van de Gd-methode intact laten.
    Drainage for a secure environment and food supply : 9th international drainage workshop, September 10-13 2003, Utrecht, The Netherlands
    Zeeuw, C.J. de; Vlotman, W.F. - \ 2004
    Wageningen : Alterra (Alterra-rapport 998) - 128
    drainage - ondergrondse drainage - zoute gronden - irrigatie - conferenties - wereld - drainage - subsurface drainage - saline soils - irrigation - conferences - world
    The 9th International Drainage Workshop; building blocks for Dutch and Global Water Policy. From September 10 - 13, 2003 Alterra-ILRI organised an international workshop where by means of Open Space Technology fifteen action plans were formulated by more than 115 participants to enhance integration of drainage into Integrated Water Resource Management. These action plans need to be elaborated for possible inclusion with Dutch and International water management plans. The main theme of the IDW was `Drainage for a secure environment and food supply`. A total of 85 papers and 30 posters were submitted, and these, including this report are presented on CD-ROM. This report contains the results of the first round of discussions; a total of 45 topics were identified by the participants for further discussion. On the thrid day finally 15 action plans emerged. The conclusions of the workshop are reflected in the Utrecht Declaration. This report is only digitally distributed and the information is also available via the website.
    Zegveld gaat zakken veengrond te lijf
    Hoving, I.E. ; Akker, J.J.H. van den; Hendriks, R.F.A. - \ 2004
    Praktijkkompas. Rundvee 18 (2004)1. - ISSN 1570-8586 - p. 6 - 7.
    veengronden - moldrainage - grondwaterspiegel - bodemdaling - graslanden - ondergrondse drainage - watervoorziening - utrecht - peat soils - subsurface drainage - water supply - mole drainage - water table - subsidence - grasslands - utrecht
    Praktijkcentrum Zegveld onderzoekt of het zakken van veengrond sterk verminderd kan worden door de bodem te infiltreren met slootwater via drainagebuizen of moldrains. Deze 'onderwaterdrains' liggen daarbij onder het slootpeil en niet zoals gebruikelijk erboven. In de zomer zakt de grondwaterstand in het veenweidegebied vaak enkele decimeters onder het slootpeil. Door deze nieuwe vorm van infiltratie blijft naar verwachting de grondwaterstand op of iets onder het slootpeil, waardoor meer veen volledig verzadigd blijft.
    Soil heterogeneity
    Dam, J.C. van; Hendriks, R.F.A. - \ 2003
    In: Reference Manual SWAP; version 3.0.3 / Kroes, J.G., van Dam, J.C., Wageningen : Alterra (Alterra-rapport 773) - p. 91 - 113.
    bodemwater - infiltratie - hydraulisch geleidingsvermogen - modellen - ondergrondse drainage - ruimtelijke variatie - soil water - infiltration - hydraulic conductivity - subsurface drainage - models - spatial variation
    Soil water - surface water interaction
    Dam, J.C. van; Kroes, J.G. ; Groenendijk, P. ; Walsum, P.E.V. van - \ 2003
    In: Reference Manual SWAP; version 3.0.3 / Kroes, J.G., van Dam, J.C., Wageningen : Alterra (Alterra-rapport 773) - p. 51 - 83.
    bodemwaterbeweging - oppervlakkige afvoer - ondergrondse drainage - modellen - soil water movement - runoff - subsurface drainage - models
    Drainage and infiltration are described by Hooghoudt and Ernst equations;
    Managing salinity for sustainability of irrigation in areas with shallow saline ground water
    Ayars, J.E. ; Soppe, R.W.O. ; Christen, E.W. - \ 2003
    drainage - bodemchemie - zoutgehalte - grondwaterspiegel - ondergrondse drainage - californië - drainage - subsurface drainage - soil chemistry - salinity - water table - california
    Irrigation will be required to meet the demands of the world population for food. Water will also be needed to meet the municipal, industrial, and environmental demands of the growing population. As a result irrigation water supplies will be reduced and irrigators will probably be forced into using degraded water as part of the supply and the possibility for increased salinity in the soil profile will occur. Drainage will be required to assist in the management of the water needed for leaching to prevent soil salinisation. Drainage water containing salt and other contaminants creates a water quality problem for the water body receiving the drainage water. The paper presents the results of three cases studies that address the issue of disposal of saline drainage water through reuse for supplemental irrigation, water table control, and changing the design criteria for subsurface drainage as methods to reduce the drainage volume. The first study demonstrated that over 50% of the crop water requirement can be met with saline drainage water and that salinity in the soil profile can be managed to not adversely affect yields. This is not the case if the drainage water contains high levels of boron. The second study demonstrated that the water table can effectively be manipulated if the drainage system is properly installed. The third study showed the reduction in salt load as a result of implementing drainage control on deep drains or installing shallow drains. The results from these studies demonstrate that irrigated agriculture is sustainable in arid and semi-arid areas through improved management of the subsurface drainage system.
    Subsurface drainage research on design, technology and management : drainage research project I & II, final report Dec 1994 - June 2001
    Anonymous, - \ 2001
    Cairo : DRI [etc.] - 172
    ondergrondse drainage - projecten - internationale samenwerking - egypte - nederland - subsurface drainage - projects - international cooperation - egypt - netherlands
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