Machine learning in space and time for modelling soil organic carbon change
Heuvelink, Gerard B.M. ; Angelini, Marcos E. ; Poggio, Laura ; Bai, Zhanguo ; Batjes, Niels H. ; Bosch, Rik van den; Bossio, Deborah ; Estella, Sergio ; Lehmann, Johannes ; Olmedo, Guillermo F. ; Sanderman, Jonathan - \ 2020
European Journal of Soil Science (2020). - ISSN 1351-0754
Argentina - carbon stock - climate change - land degradation - quantile regression forest - space–time mapping
Spatially resolved estimates of change in soil organic carbon (SOC) stocks are necessary for supporting national and international policies aimed at achieving land degradation neutrality and climate change mitigation. In this work we report on the development, implementation and application of a data-driven, statistical method for mapping SOC stocks in space and time, using Argentina as a pilot. We used quantile regression forest machine learning to predict annual SOC stock at 0–30 cm depth at 250 m resolution for Argentina between 1982 and 2017. The model was calibrated using over 5,000 SOC stock values from the 36-year time period and 35 environmental covariates. We preprocessed normalized difference vegetation index (NDVI) dynamic covariates using a temporal low-pass filter to allow the SOC stock for a given year to depend on the NDVI of the current as well as preceding years. Predictions had modest temporal variation, with an average decrease for the entire country from 2.55 to 2.48 kg C m−2 over the 36-year period (equivalent to a decline of 211 Gg C, 3.0% of the total 0–30 cm SOC stock in Argentina). The Pampa region had a larger estimated SOC stock decrease from 4.62 to 4.34 kg C m−2 (5.9%) during the same period. For the 2001–2015 period, predicted temporal variation was seven-fold larger than that obtained using the Tier 1 approach of the Intergovernmental Panel on Climate Change and United Nations Convention to Combat Desertification. Prediction uncertainties turned out to be substantial, mainly due to the limited number and poor spatial and temporal distribution of the calibration data, and the limited explanatory power of the covariates. Cross-validation confirmed that SOC stock prediction accuracy was limited, with a mean error of 0.03 kg C m−2 and a root mean squared error of 2.04 kg C m−2. In spite of the large uncertainties, this work showed that machine learning methods can be used for space–time SOC mapping and may yield valuable information to land managers and policymakers, provided that SOC observation density in space and time is sufficiently large.
Arsenic in Argentina : Technologies for arsenic removal from groundwater sources, investment costs and waste management practices
Litter, Marta I. ; Ingallinella, Ana M. ; Olmos, Valentina ; Savio, Marianela ; Difeo, Gonzalo ; Botto, Lía ; Torres, Elsa Mónica Farfán ; Taylor, Sergio ; Frangie, Sofía ; Herkovits, Jorge ; Schalamuk, Isidoro ; González, María José ; Berardozzi, Eliana ; García Einschlag, Fernando S. ; Bhattacharya, Prosun ; Ahmad, Arslan - \ 2019
Science of the Total Environment 690 (2019). - ISSN 0048-9697 - p. 778 - 789.
Argentina - Arsenic - Drinking water - Mitigation - Removal technologies
An overview about the presence of arsenic (As) in groundwaters of Argentina, made by a transdisciplinary group of experts is presented. In this second part, the conventional and emerging technologies for As removal, management of wastes, and the initial investment costs of the proposed technologies, with emphasis on developments of local groups are described. Successful examples of real application of conventional and emerging technologies for As removal in waters for human consumption, for medium, small and rural and periurban communities are reported. In the country, the two most applied technologies for arsenic removal at a real scale are reverse osmosis and coagulation-adsorption-filtration processes using iron or aluminum salts or polyelectrolytes as coagulants. A decision tree to evaluate the possible technologies to be applied, based on the population size, the quality of the water and its intended use, is presented, including preliminary and indicative investment costs. Finally, a section discussing the treatment and final disposal of the liquid, semiliquid and solid wastes, generated by the application of the most used technologies, is included. Conclusions and recommendations, especially for isolated rural and periurban regions, have been added.
Arsenic in Argentina: Occurrence, human health, legislation and determination
Litter, Marta I. ; Ingallinella, Ana M. ; Olmos, Valentina ; Savio, Marianela ; Difeo, Gonzalo ; Botto, Lía ; Farfán Torres, Elsa Mónica ; Taylor, Sergio ; Frangie, Sofía ; Herkovits, Jorge ; Schalamuk, Isidoro ; González, María José ; Berardozzi, Eliana ; García Einschlag, Fernando S. ; Bhattacharya, Prosun ; Ahmad, Arslan - \ 2019
Science of the Total Environment 676 (2019). - ISSN 0048-9697 - p. 756 - 766.
Analytical determination - Argentina - Arsenic - Health - Occurrence - Regulations
An overview about the presence of arsenic (As) in groundwaters of Argentina, made by a transdisciplinary group of experts is presented. Aspects on As occurrence, effects of As on human health, regulations regarding the maximum allowable amount of As in drinking water as well as bottled water, and analytical techniques for As determination are presented. The most affected region in Argentina is the Chaco-Pampean plain, covering around 10 million km 2 , where approximately 88% of 86 groundwater samples collected in 2007 exceeded the World Health Organization (WHO) guideline value. In the Salí river basin, As concentrations ranged from 11.4 to 1660 μg/L, with 100% of the samples above the WHO guideline value. In the Argentine Altiplano (Puna) and Subandean valleys, 61% of 62 samples collected from surface and groundwaters exceeded the WHO limit. Thus, it can be estimated that, at present, the population at risk in Argentina reaches around four million people. Pathologies derived from the chronic consumption of As, the metabolism of As in the human body and the effects of the different As chemical forms, gathered under the name HACRE (hidroarsenicismo crónico regional endémico in Spanish, for chronic regional endemic hydroarsenicism) are described. Regarding the regulations, the 10 μg/L limit recommended by the WHO and the United States Environmental Protection Agency has been incorporated in the Argentine Food Code, but the application is still on hold. In addition, there is disparity regarding the maximal admitted values in several provinces. Considerations about the As concentrations in bottled water are also presented. A survey indicates that there are several Argentine laboratories with the suitable equipment for As determination at 10 μg/L, although 66% of them are concentrated in Buenos Aires City, and in the Santa Fe, Córdoba and Buenos Aires provinces. Conclusions and recommendations of this first part are provided.
Participatory planning for climate resilient and inclusive urban development in Dosquebradas, Santa Ana and Santa Tomé
Hardoy, Jorgelina ; Gencer, Ebru ; Winograd, Manuel - \ 2019
Environment and Urbanization 31 (2019)1. - ISSN 0956-2478 - p. 33 - 52.
Argentina - climate resilience - Colombia - disaster risk reduction - El Salvador - inclusive urban development - Latin America - participatory planning
Urban governments need to take actions to reduce disaster risks and incorporate climate resilience into their development strategies and plans. But most local governments, particularly small- and medium-sized cities in the global South, lack the knowledge and capacity to do so. This paper presents the findings from a project that engaged local governments and other key stakeholders to develop a participatory planning process for climate resilient and inclusive urban development. The project took place in three small- to medium-sized Latin American cities: Dosquebradas, Colombia; Santa Ana, El Salvador; and Santo Tomé, Argentina. By engaging government officials and politicians, academics, technical specialists, and representatives of civil society organizations in interviews, workshops and focus group discussions, this project sought to identify a range of feasible options for climate resilient and inclusive urban development. In each city, this process provided rich, context-specific details to identify strategies and plan projects with the buy-in of city government and other key actors. The overall goal was to bring in a resilience lens to assess current and planned urban development projects in each city and reach a consensus on feasible and inclusive resilience options for development.
Agrohydrological analysis of groundwater recharge and land use changes in the Pampas of Argentina
Kroes, Joop ; Dam, Jos van; Supit, Iwan ; Abelleyra, Diego de; Verón, Santiago ; Wit, Allard de; Boogaard, Hendrik ; Angelini, Marcos ; Damiano, Francisco ; Groenendijk, Piet ; Wesseling, Jan ; Veldhuizen, Ab - \ 2019
Agricultural Water Management 213 (2019). - ISSN 0378-3774 - p. 843 - 857.
Argentina - Capillary rise - Groundwater recharge - Land use - Pampas - Soybean - SWAP - WOFOST
This paper studies the changes of groundwater, climate and land use in the Pampas of Argentina. These changes offer opportunities and threats. Lowering groundwater without irrigation causes drought and successive crop and yield damage. Rising groundwater may alleviate drought as capillary rise supports root water uptake and crop growth, thus narrowing the difference between potential and actual yields. However, rising groundwater may also limit soil water storage, cause flooding in metropolitan areas and have a negative impact on crop yields. Changing land use from continuous soy bean into crop rotations or natural vegetation may decrease groundwater recharge and thus decrease groundwater levels. In case of crop rotation however, leaching of nutrients like nitrate may increase. We quantified these impacts using integrated dynamic crop growth and soil hydrology modelling. The models were tested at field scale using a local dataset from Argentina. We applied distributed modelling at regional scale to evaluate the impacts on groundwater recharge and crop yields using long term weather data. The experiments showed that threats arise from continuous monotone land use. Opportunities are created when a proper balance is found between supply and demand of soil water using a larger differentiation of land use. Increasing the areas of land use types with higher evapotranspiration, like permanent grassland and trees, will contribute to a more stable hydrologic system with more water storage capacities in the soil system and lower groundwater levels. Modelling tools clearly support the evaluation of the impact of land use and climate change on groundwater levels and crop yields.
The moving frontiers of genetically modified soy production : shifts in land control in the Argentinian Chaco
Goldfarb, Lucía ; Haar, Gemma van der - \ 2016
The Journal of Peasant Studies 43 (2016)2. - ISSN 0306-6150 - p. 562 - 582.
Argentina - enclosure - land control - land grab - soy
This article attempts to understand how control over land (power in practice) is built, achieved and contested in the context of land transfers involving pressures over possession rights in Santiago del Estero in northern Argentina. Here new forms of land control – due to expansion of the speculative, soy and cattle frontiers – are changing and involve new relationships while using novel mechanisms to gain and maintain control. The article adopts the notion of shifting ‘frontiers of land control’ as an analytical lens, following Lund and Peluso (2011). We can say that the process of soy and cattle expansion into the new frontiers happens through a group of different mechanisms which range from voluntary purchase to violent evictions. As shifts in land control in the frontier involve pressures on possession rights, we observe different mechanisms of control, mainly in the direction of dispossession and enclosure. The paper adds to the debate on ‘land grabbing’ by (a) showing how domestic investors operate to advance industrial agriculture and (b) showing how this frontier advances in a context of (rather unsecured) possession rights where rights are being shifted through transfers (sales, leases, evictions) and compensation mechanisms as well as conflict and judicial procedures.
Epidemiology, infection dynamics and effective control of Bovine Leukemia virus within dairy herds of Argentina: a quantitative approach
Monti, G.E. - \ 2005
Wageningen University. Promotor(en): Mart de Jong, co-promotor(en): Klaas Frankena. - Wageningen : S.n. - ISBN 9789085042341 - 164
melkveestapel - runderleukemievirus - epidemiologie - simulatiemodellen - ziekteoverdracht - diagnostische technieken - ziektebestrijding - Argentinië - dairy herds - Bovine leukemia virus - epidemiology - simulation models - disease transmission - diagnostic techniques - disease control - Argentina
Bovine Leukemia Virus (BLV) is a retrovirus that causes lymphomas (leucosis) and other disorders in cattle and it has a large economical impact on the livestock sector of many countries around the world. BovineLeukemia has been reported in
The use of hydrological models in the irrigated areas of Mendoza, Argentina
Querner, E.P. ; Morábito, J.A. ; Manzanera, M. ; Pazos, J.A. ; Ciancaglini, N.C. ; Menenti, M. - \ 1997
Agricultural Water Management 35 (1997)1/2. - ISSN 0378-3774 - p. 11 - 28.
hydrologie - evapotranspiratie - irrigatie - bodemwaterbalans - modellen - analogen - Argentinië - hydrology - evapotranspiration - irrigation - soil water balance - models - analogues - Argentina
A proper understanding of the interaction of irrigation and drainage canals with an aquifer system is necessary to improve the performance of irrigation. This mechanism must be studied with a detail sufficient to identify operational guidelines for specific portions of an irrigation and drainage system. Numerical simulation models provide a useful support since specific operational procedures of irrigation and drainage canals can be evaluated in this way. Regional hydrological models of surface water and groundwater have been applied to an irrigated area of 36,000 ha in the province of Mendoza, Argentina. The use of such models can support decision-making on water management aspects. The benefit of a physically-based model is its use in situations with changing conditions affecting the hydrological system. An important aspect is the need to simulate the hydrological processes as accurately as possible and to include operational irrigation practice. The drawback of a modelling approach is the great demand for reliable input data.