Krishna Reddy Kakumanu

The stabilization value of groundwater: evidence from Indian tank irrigation systems

Groundwater is now a major source of agricultural water supply in many parts of the world. The value of groundwater as a new source of supply is well known. However, its additional buffering or stabilization value is less appreciated and even less analysed. Knowledge on groundwater’s stabilization value is advanced by developing and estimating an empirical model using the case of tank irrigation systems in Tamil Nadu, India. Unlike previous work, the model uses cross-sectional rather than time-series data. The results show that for the case-study region, the stabilization function added approximately 15% to supply value. Scenarios with surface water and electricity price were incorporated in the model. Increased surface-water supply and electricity price caused reduction in groundwater use but the percent of stabilization value of groundwater increased. The findings are used both to suggest improvements in tank irrigation systems and to further contextualize knowledge of groundwater’s stabilization value.RésuméL’eau souterraine est maintenant une source majeure d’alimentation en eau agricole dans de nombreuses régions du monde. La valeur de l’eau souterraine en tant que nouvelle source d’alimentation est bien connue. Cependant, sa valeur additionnelle liée à la stabilisation-tampon des approvisionnements en eau est moins bien évaluée et encore moins bien analysée. Les connaissances concernant la valeur de stabilisation de l’eau souterraine ont été améliorées en développant et estimant un modèle empirique utilisant le cas des systèmes d’irrigation par retenues collinaires du Tamil Nadu (Inde). A la différence des travaux précédents, le modèle utilise des données concernant différents sites d’étude plutôt que des données chronologiques. Les résultats montrent que, pour la région d’étude, la fonction de stabilisation ajoute approximativement 15% à la valeur de l’approvisionnement en eau. Des scénarios avec de l’eau de surface et le prix de l’électricité ont été intégrés au modèle. L’augmentation de l’alimentation en eau de surface et l’augmentation du prix de l’électricité entraînent une réduction de l’utilisation de l’eau souterraine, mais le pourcentage de la valeur de stabilisation de l’eau souterraine augmente. Ces résultats sont utilisés pour proposer des améliorations aux systèmes d’irrigation par retenues collinaires et pour remettre dans leur contexte les connaissances portant sur la valeur de stabilisation de l’eau souterraine.ResumenEl agua subterránea es hoy una de las principales fuentes de abastecimiento de agua para la agricultura en muchas partes del mundo. El valor del agua subterránea como una nueva fuente de abastecimiento es bien conocido. Sin embargo, su valor adicional de estabilización o de amortiguación es menos apreciado y aún menos analizado. El conocimiento del valor de la estabilización del agua subterránea es anticipado desarrollando y estimando un modelo empírico usando el caso de los sistemas de riego de tanques en Tamil Nadu, India. A diferencia de los trabajos previos, el modelo usa datos de secciones transversales más bien que de series de tiempo. Los resultados muestran que para el caso de la región de estudio, la función de estabilización adicionó aproximadamente el 15% al valor de suministro. Se incorporaron al modelo los escenarios con agua superficial y costos de la electricidad. Un incremento del suministro de agua superficial y del costo de la electricidad provocaron una reducción en el uso del agua subterránea pero el porcentaje del valor de estabilización de agua subterránea se incrementó. Los resultados son usados tanto para sugerir mejoras en el sistema de riego de tanques y para contextualizar ulteriormente el conocimiento el valor de estabilización del agua subterránea.摘要地下水在世界许多地方都是主要的农业用水来源。地下水作为一种新来源, 其价值众所周知。然而, 地下水附加的缓冲或稳定值并不被认可, 甚至缺少分析。以印度泰米尔纳德邦水池灌溉系统为例, 发展和估计的经验模型增进了对地下水稳定值的认识。与之前的工作不同, 模型使用横截面数据而非时间序列数据。结果表明研究区的稳定功能增加了大约15%的供水量。模型中包含了地表水情况及电价。增大的地表水用量及电价导致地下水使用量的减少, 但是地下水稳定值所占比例却增加了。该发现可用于建议改进水池灌溉系统, 并对地下水稳定功能有进一步的认识。ResumoEm muitas partes do mundo a água subterrânea é actualmente uma importante origem de água para a agricultura. O valor da água subterrânea como uma nova origem para o abastecimento é bem conhecido. No entanto, o seu valor de amortecimento ou de estabilização é menos conhecido e ainda menos analisado. O conhecimento acerca do valor de estabilização da água subterrânea é apresentado através do desenvolvimento e estimação de um modelo empírico, usando o caso de sistemas de tanques de irrigação em Tamil Nadu, na Índia. Ao invés do que se tem feito em trabalhos anteriores, o modelo usa dados de secções transversais em vez de séries de dados temporais. Os resultados mostram que para a região estudada a função de estabilização acrescentou aproximadamente 15% ao valor do abastecimento. Cenários que têm em consideração a água superficial e o preço da electricidade foram incorporados no modelo. O aumento do abastecimento a partir de água superficial e do preço da electricidade causaram uma diminuição do uso de água subterrânea mas a percentagem do valor de estabilização da água subterrânea aumentou. Estes resultados são usados para sugerir melhorias nos sistemas de tanques de irrigação e também para contextualizar o conhecimento acerca do valor de estabilização da água subterrânea.

Farm-level cost of adaptation and expected cost of uncertainty associated with climate change impacts in major river basins in India

Purpose – Researchers and policymakers are figuring out the adaptation technologies to cope with the changing climate. Adaptation strategies for crop production followed by the farmers at selected study locations had ranged from 6-30 per cent only, and this was mainly due to lack of awareness about the actual cost associated with adaptation and non-adaptation of these strategies. Design/methodology/approach – Hence, this study aims to address the cost of adaptation for rice using joint probability distribution of rainfall and crop prices. Findings – Cost of adaptation varied from INR2,389 to 4,395/ha for System of Rice Intensification (SRI); INR646 to 1,121/ha for alternate wetting and drying (AWD) and INR8,144 to 8,677/ha for well irrigation (WI), whereas expected cost for not using these technologies has ranged from INR6,976 to 9,172/ha for SRI; INR4,123 7,764/ha for AWD and INR10,825 to 17,270/ha for WI. Hence, promotion of the adaptation technologies itself will minimize the income losses to the farme...

Policy Support: Challenges and Opportunities in Abiotically Stressed Agroecosystem

Abiotic stress causes more than 50% losses in crop productivity and hence got major concerns for food and nutritional security. Two case studies addressing the impacts of abiotic stress on agricultural sector, adaptation measure taken up and needed policy options are included. The first case addresses the impact of climatic variables in Godavari River basin of Telangana where the impact of climate change on yield of paddy, groundnut and maize crops had been assessed using the Just-Pope production function. Climate change has serious effect on groundnut (with high yield variation of 69–90%), rice (with moderate yield variation of 23–38%) and maize (with negligible yield variation). Case two discusses about different adaptation strategies followed by agro-silvipastoral farmers to manage the abiotic (drought) stress in Tamil Nadu where among the 17 strategies identified, 12 were indexed as important strategies undertaken. At the time of severe drought stress, farmers used cotton waste as livestock feed, gave vaccination and added shade to protect the livestock from cold and heat stress. Majority of the farmers are only medium adopters, and hence there is an increasing need for creating awareness among the farmers on latest stress management practices by strengthening the extension services and capacity building programmes.

Water Pricing Experiences in India: Emerging Issues

The debate on growing water scarcity and the need to use the available water more efficiently among different sectors has once again brought in renewed focus in India. In this debate, a large part of the emphasis has been on the pricing of irrigation water, the sector which accounts for almost 80 % of the total water use but for which water is charged at a fraction of the supply cost. Low water rates, apart from encouraging the inefficient use of water, result in low revenue collections and contribute to the growing burden of government subsidies. Efforts to increase revenue collection through institutional reforms motivated mostly by international lending agencies have yielded mixed results. However, given the increasing demand for water and the resulting competition among sectors, there is scope to price water. In this context, the chapter aims to examine the issues relating to water pricing in India with a case study from Andhra Pradesh.