Your search found 16 records
1 Massuel, Sylvain; George, B.; Gauer, Anju; Nune, R. 2007. Groundwater modeling for sustainable resource management in the Musi catchment, India. In Proceedings of the International Congress on Modelling and Simulation, Christchurch, New Zealand, 10-13 December 2007. pp. 1425-1439.
Groundwater management ; Simulation models ; Aquifers ; Recharge ; Water budget ; Water table ; River basins ; Irrigation programs / India / Musi River / Andhra Pradesh / Nagarjuna Sagar Left Canal
(Location: IWMI HQ Call no: IWMI 631.7.1 G635 MAS Record No: H040940)
This study focuses on 11,000 km2 of the Musi River sub-basin which is one of the main tributaries of the Krishna River, located in Andhra Pradesh (South India). The basin has a semi-arid climate with precipitation occurring during the rainy season, from June to October and with a total average of 710 mm yr-1. During the past, the watershed development has led to significant changes in land use. Now, nearly 70% of the basin is cultivated of which 45% is irrigated. Around 60% of the water for irrigation is supplied by groundwater extraction. The number of bores in use has increased ten times from 1991 to 2001 and should currently exceeds 45,000 (on average, 1 active bore for 4.5 ha irrigated). The Musi Medium Irrigation project covers 12,500 ha and the Nagarjuna Sagar Left Canal supplies water for 43,000 ha downstream of the Musi sub-basin. Wastewater of mixed domestic and industrial origin is tilized to irrigate approximately >10,000 ha of paddy rice along the Musi River in peri-urban and rural Hyderabad. More than 1160 artificial percolation tanks had been built on the Musi catchment drainage network. The preliminary analysis of more than 60 groundwater level time series widespread all over the sub-basin (from 1989 to 2004) shows a general long term depletion trend of the water table while no significant rainfall deficit was observed over the same period. The average rate of depletion is estimated as 0.18 m yr-1 with maxima in some areas of up to 0.40 m yr-1 (Figure 1). This situation can be explained mainly by groundwater exploitation, a consequence of the watershed development for agriculture. The Musi sub-basin is mainly covered by Archaean granites with Deccan Traps at the Eastern edge. As in a typical hard rock aquifer region, the yield of the bores decreases with depth due to the reduction of the fracture density. Hence the risk of water scarcity in case of a drought year is exacerbated. In order to assess aquifer renewable reserves and help groundwater management authorities, a fully distributed physical model of the aquifer has been calibrated and validated for a transient state experienced during 1989-2004 by using MODFLOW. The key variables such as aquifer storativity and transmissivity ere determined by inverse fitting of simulated and observed groundwater levels. Mean annual simulated recharge is 1176 Mm3 (17% of total rainfall) while annual pumping is estimated at 1235 Mm3. Simulated base flow is 23 Mm3 while river leakage is less than 1 Mm3. Among the total simulated annual recharge, groundwater irrigation return flow to the aquifer can be estimated at 370 Mm3 (31%) and artificial recharge at 124 Mm3 (11%). Natural recharge from rainfall accounts for 652 Mm3 (55%). It is close to 9% of the total annual rainfall. The sustainable groundwater withdrawal yield over the period is around 1220 Mm3 for the total basin. A deficit of 124 Mm3 for the long term groundwater balance (16 years) justifies the observed depletion trend of the water-table of -0.18 m yr-1.
2 Venot, Jean-Philippe; Jella, Kiran; Bharati, Luna; George, B.; Biggs, T.; Gangadhara Rao, Parthasaradhi; Gumma, M. K.; Acharya, Sreedhar. 2010. Farmers' adaptation and regional land use changes in irrigation systems under fluctuating water supply, South India. Journal of Irrigation and Drainage Engineering, 136(9):595-609. [doi: https://doi.org/10.1061/(ASCE)IR.1943-4774.0000225]
Irrigation systems ; Irrigation programs ; Water shortage ; Water scarcity ; Water availability ; River basins ; Crop management ; Productivity / India / Nagarjuna Sagar Project
(Location: IWMI HQ Call no: PER Record No: H043081)
(2.46 MB)
In closing river basins where nearly all available water is committed to existing uses, downstream irrigation projects are expected to experience water shortages more frequently. Understanding the scope for resilience and adaptation of large surface irrigation systems is vital to the development of management strategies designed to mitigate the impact of river basin closure on food production and the livelihoods of farmers. A multi-level analysis (farm level surveys and regional assessment through remote sensing techniques and statistics) of the dynamics of irrigation and land use in the Nagarjuna Sagar project (South India) in times of changing water availability (2000–2006) highlights that during low flow years, there is large-scale adoption of rainfed —or supplementary irrigated- crops that have lower land productivity but higher water productivity, and that a large fraction of land is fallowed. Cropping pattern changes during the drought reveal short term coping strategies rather than long-term evolutions: after the shock, farmers reverted to their usual cropping patterns during years with adequate canal supplies. For the sequence of water supply fluctuations observed from 2000–2006, the Nagarjuna Sagar irrigation system shows a high level of sensitivity to short-term perturbations, but long-term resilience if flows recover. Management strategies accounting for local level adaptability will be necessary to mitigate the impacts of low flow years but there is scope for improvement of the performance of the system.
3 George, B.; Malano, H.; Davidson, B.; Hellegers, P.; Bharati, Luna; Massuel, S. 2011. An integrated hydro-economic modelling framework to evaluate water allocation strategies II: scenario assessment. Agricultural Water Management, 98(5):747-758. [doi: https://doi.org/10.1016/j.agwat.2010.12.005]
Water allocation ; Models ; River basins ; Economic aspects / India / Krishna River Basin / Musi River Basin
(Location: IWMI HQ Call no: PER Record No: H043545)
(1.46 MB)
In this paper the results of an assessment of the hydrological and economic implications of reallocating water in the Musi sub-basin, a catchment within the Krishna Basin in India, are reported. Policy makers identified a number of different but plausible scenarios that could apply in the sub-basin, involving; supplying additional urban demand from agricultural allocations of water, implementing a number of demand management strategies, changing the timing of releases for hydropower generation, changing the crops grown under irrigation, reducing existing stream flows and allowing for more environmental flows. The framework chosen to undertake this assessment was a simulation model that measures and compares the economic values of water allocation scenarios determined from a water allocation model that accounts for supplies of groundwater and surface water across a number of regions and over a variety of uses. Policy makers are provided with the range of measures on the security of the supply of water and the social costs and benefits of reallocating water between sectors and across regions within the sub-basin. Taking water from agriculture to supply urban users has a greater impact on irrigation supplies during dry years. It was also found that changing the allocation of water between sectors, by taking it away from agriculture had a large positive economic impact on the urban sector. Yet the costs involved in undertaking such a strategy results in a significant loss in the net present value of the scheme. Stream flow reductions, if significantly large (at around 20%), were found to have a large physical and economic impact on the agricultural sector. Implementing water saving strategies in Hyderabad was found to be more cost effective than taking water from agriculture, if rainwater tanks are used to achieve this. Changing the timing of hydropower flows resulted in best meeting of irrigation demand in NSLC and NSRC. Under this scenario, the crops grown under irrigation were found to have a significant economic impact on the sub-basin, but not as large as farmers undertaking crop diversification strategies, ones which result in farmers growing less rice. The security of supplying water to different agricultural zones has significantly improved under this scenario. Finally, releasing water for environmental purposes was found to have only a minor impact on the agricultural sector.
4 George, B.; Malano, H.; Davidson, B.; Hellegers, P.; Bharati, Luna; Massuel, S. 2011. An integrated hydro-economic modelling framework to evaluate water allocation strategies I: model development. Agricultural Water Management, 98(5):733-746. [doi: https://doi.org/10.1016/j.agwat.2010.12.004]
Water allocation ; Models ; Economic aspects ; River basins ; Water demand / India / Krishna River Basin / Musi River Basin
(Location: IWMI HQ Call no: PER Record No: H043544)
(1.10 MB)
In this paper an integrated modelling framework for water resources planning and management that can be used to carry out an analysis of alternative policy scenarios for water allocation and use is described. The modelling approach is based on integrating a network allocation model (REALM) and a social Cost Benefit economic model, to evaluate the physical and economic outcomes from alternative water allocation policies in a river basin or sub-basin. From a hydrological perspective, surface and groundwater models were first applied to assess surface and groundwater resource availability. Then an allocation model was applied to reconcile the calculated surface and groundwater resources. From an economic perspective initially the value of water allocated to different uses in each demand centre within the system was estimated. These values were then placed in a social Cost Benefit Analysis to assess the economic consequences of different allocation scenarios over time and space. This approach is useful as it allows policymakers to consider not only the physical dimensions of distributing water, but also the economic consequences associated with it. This model is considered superior to other models as water is increasingly being seen as an economic good that should be allocated according to its value. The framework outlined in this paper was applied to the Musi sub-basin located in the Krishna Basin, India. In applying this framework it was concluded that competition for Musi water is very high, the transfer of water from agriculture to urban users is likely to grow in future and the value of water used in different agricultural zones is very low.
5 Garg, K. K.; Bharati, Luna; Gaur, A.; George, B.; Acharya, Sreedhar; Jella, Kiran; Narasimhan, B. 2012. Spatial mapping of agricultural water productivity using the SWAT model in upper Bhima catchment, India. Irrigation and Drainage, 61(1):60-79. [doi: https://doi.org/10.1002/ird.618]
Water productivity ; Irrigated farming ; Irrigation programs ; Crop production ; Mapping ; Simulation models ; Hydrology ; Models ; Water balance ; River basins ; Economic aspects / India / Upper Bhima River Basin / Ujjani Irrigation Scheme
(Location: IWMI HQ Call no: PER Record No: H043722)
(1.99 MB)
The Upper Bhima River Basin is facing both episodic and chronic water shortages due to intensive irrigation development. The main objective of this study was to characterize the hydrologic processes of the Upper Bhima River Basin and assess crop water productivity using the distributed hydrologic model, SWAT. Rainfall within the basin varies from 450 to 5000 mm in a period of 3–4 months. The basin has an average rainfall of 711 mm (32 400 Mm 3 (million cubic metres)) in a normal year, of which 12.8% (4150 Mm 3 ) and 21% (6800 Mm 3) are captured by the reservoirs and groundwater reserves, respectively, 7% (2260 Mm 3 (exported as runoff out of the basin and the rest (63%) used in evapotranspiration. Agricultural water productivity for sugarcane, sorghum and millet were estimated as 2.90, 0.51 and 0.30 kg m¯3, respectively, which were signi cantly lower than the potential and global maximum in the basin and warrant further improvement. Various scenarios involving different cropping patterns were tested with the goal of increasing economic water productivity values in the Ujjani Irrigation Scheme. Analysis suggests that maximization of the area by provision of supplemental irrigation to rainfed areas as well as better on-farm water management practices can provide opportunities for improving water productivity.
6 Kumar, Saideepa; Pavelic, Paul; George, B.; Venugopal, K.; Nawarathna, B. 2013. Integrated modeling framework to evaluate conjunctive use options in a canal irrigated area. Journal of Irrigation and Drainage Engineering, 139(9):766-774. [doi: https://doi.org/10.1061/(ASCE)IR.1943-4774.0000614]
Canal irrigation ; Irrigated sites ; Models ; Calibration ; Water resources ; Conjunctive use ; Water use ; Surface water ; Groundwater ; Water balance / India / Andhra Pradesh / Srisailam Right Branch Canal
(Location: IWMI HQ Call no: e-copy only Record No: H046146)
(0.84 MB)
In canal irrigated areas, where interactions between surface water and groundwater are high, the conjunctive management of surface water and groundwater can play a significant role in improving water availability in time and space, thereby promoting more equitable distribution of water while maintaining long-term availability of groundwater resources. Achieving a harmonious balance between the use of surface water and groundwater requires careful consideration of the associated benefits, impacts, and trade-offs. In this study, a simple, integrated framework was developed and implemented to characterize and quantify interactions between surface water and groundwater in a canal irrigated area; this framework was used to evaluate the impacts of alternative levels of conjunctive use under varying climate and cropping conditions. Applying the model to a case study area of the Srisailam Right Branch Canal project in Andhra Pradesh, India, indicated that regulating canal supplies to optimum levels can prompt sustainable groundwater use and save up to 48% of allocated canal water; these water savings could be reallocated elsewhere within the irrigated area to promote equity.
7 Qadir, M.; Noble, Andrew D.; Karajeh, F.; George, B.. 2015. Potential business opportunities from saline water and salt-affected land resources. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE). 29p. (Resource Recovery and Reuse Series 05) [doi: https://doi.org/10.5337/2015.206]
Land resources ; Land degradation ; Saline water ; Sodic soils ; Soil salinity ; Desalination ; Crop production ; Ecosystems ; Aquaculture ; Water resources ; Water productivity ; Drainage water ; Water reuse ; Recycling ; Freshwater ; Soil properties ; Magnesium ; Phosphogypsum ; Energy generation ; Solar energy ; Horticulture ; Greenhouses ; Irrigation ; Deltas ; Trees ; Case studies / Egypt
(Location: IWMI HQ Call no: IWMI Record No: H046996)
(1 MB)
8 Aye, L.; Nawarathna, B.; George, B.; Nair, S.; Malano, H. 2014. Greenhouse gas emissions of decentralised water supply strategies in peri-urban areas of Sydney. In Maheshwari, B.; Purohit, R.; Malano, H.; Singh, V. P.; Amerasinghe, Priyanie. (Eds.). The security of water, food, energy and liveability of cities: challenges and opportunities for peri-urban futures. Dordrecht, Netherlands: Springer. pp.355-363. (Water Science and Technology Library Volume 71)
Greenhouse gases ; Emission ; Water supply ; Decentralization ; Periurban areas ; Effluents ; Wastewater treatment ; Water reuse ; Rainwater ; Water harvesting ; Drinking water / Australia / Sydney
(Location: IWMI HQ Call no: IWMI Record No: H047046)
Quantification of greenhouse gas emissions for decentralised water supply systems is essential for water policy development, decision making and implementation of these systems. Two potential water supply strategies ‘Effluent Reuse’ and ‘Stormwater Harvesting’ applicable for the planned growth centre development of Western Sydney were developed. The associated energy intensities and operational greenhouse gas emissions of these two strategies were quantified by using the factors and methods prescribed by the Department of Climate Change and Energy Efficiency National Greenhouse Accounts Factors, 2011. It was found that in terms of operational greenhouse gas emissions, stormwater harvesting performs marginally better than effluent reuse while the cost of stormwater harvesting is expected to be about four times cheaper than effluent reuse in Australia.
9 Davidson, B.; Malano, H.; Hellegers, P.; George, B.; Nawarathna, B. 2014. Valuing the water used in peri-urban regions of Hyderabad, India and in western Sydney, Australia. In Maheshwari, B.; Purohit, R.; Malano, H.; Singh, V. P.; Amerasinghe, Priyanie. (Eds.). The security of water, food, energy and liveability of cities: challenges and opportunities for peri-urban futures. Dordrecht, Netherlands: Springer. pp.463-474. (Water Science and Technology Library Volume 71)
Periurban areas ; Water rates ; Water use ; Waste management ; Water distribution ; Water allocation ; Economic value ; Domestic water ; Industrial uses ; Agricultural sector ; Catchment areas / Australia / India / Western Sydney / Hyderabad / South Creek Catchment
(Location: IWMI HQ Call no: IWMI Record No: H047054)
Economic theory suggests that resources should be employed in different sectors to the point where their marginal values are equal. Yet what has been observed in many instances is that the marginal values of a resource tend to differ, depending on what they are used for. While this occurs for a variety of reasons, it is argued in this paper that the observable relative differences in the marginal values of a resource are a measure of the pressures forcing a reallocation of those resources within a region. This issue is most acute in peri-urban regions (those places where cities and the rural environment meet) as the competition between a declining agricultural sector and the growing domestic and industrial sectors is most intense. The argument arises as to what extent is the pressure to transfer resources between these declining and expanding sectors. To answer that question it is necessary to value the resource in question in a consistent and comprehensive manner across all sectors. Once done, the forces exerted on the resource can be gauged by observing the relative differences in the values placed on it in each use. The purpose of this paper is to present the results of a method that has been used to undertake this task with respect to the allocation of water resources. However, analyzing this question in the water sector has been stymied by the fact that the value of water deployed cannot be compared easily with that allocated to other sectors. The approach taken is an extension of the Residual Method that is used to calculate the marginal value product of water used in each crop and then aggregated to obtain the total value of water allocated to the agricultural sector as a whole. These results are then compared to the more conventionally obtained values of water used in other sectors. The results presented in this paper were drawn from research that has been published on two very different peri-urban sites, in Western Sydney, Australia and in Hyderabad, India. It can be concluded that despite the differences in the circumstances, conditions and concerns of stakeholders, the approach is robust enough to be used in a variety of situations where the competition for water between sectors exists. It was found that the value of water used for domestic purposes is significantly greater than that deployed to the agricultural sector in both peri-urban regions. In addition, it does not matter that the quantities used in the urban areas for domestic and industrial uses are relatively small when compared to those in the agricultural sector (as is the case in Hyderabad) or not (as in the case in Western Sydney). Just like other resources (principally land) it is inevitable that in peri-urban regions water will be and should be allocated to the use that it is most valued; towards urban expansion and away from agriculture.
10 Acharya, S.; George, B.; Aye, L.; Nair, S.; Nawarathna, B.; Malano, H. 2015. Life cycle energy and greenhouse gas emission analysis of groundwater-based irrigation systems. Irrigation and Drainage, 64(3):408-418. [doi: https://doi.org/10.1002/ird.1896]
Greenhouse gases ; Emission ; Energy consumption ; Life cycle analysis ; Irrigation systems ; Groundwater irrigation ; Pumping ; Water distribution ; Flood irrigation ; Drip irrigation ; Centre pivot irrigation ; Tube wells ; Drilling equipment ; Models / India / Australia
(Location: IWMI HQ Call no: e-copy only Record No: H047438)
(0.45 MB)
The reliance on groundwater for irrigation is increasing in Australia and India, which is causing concerns to policy makers about energy consumption and greenhouse gas (GHG) emissions. Therefore, it is important to quantify the GHG emissions of all components of the groundwater-based irrigation systems, over the entire life cycle to develop more environmentally friendly groundwater management strategies. This study identified and analysed energy use and GHG emissions associated with different components in the supply chain of groundwater-based irrigation systems. An existing GHG emissions and energy-accounting framework was adapted to enhance its capabilities by considering drilling techniques, water distribution and irrigation application methods. The results of this study highlighted that embodied and direct GHG emissions from drilling tube wells were higher in the Musi catchment, India, compared to South Australia. The study also highlighted that GHG emissions associated with water conveyance were higher for concrete and plastic-lined channels than unlined channels. Drip irrigation systems in both countries were found to have more GHG emissions than gravity-fed systems. Centre pivot systems were found to be emitting more than the drip systems in South Australia. We conclude that different components of the system have an impact on total GHG emissions and energy consumption for both countries. Any change in the most commonly used methods of drilling bore wells, water distribution in channels, and the irrigation methods, will have distinct impacts on energy consumption rates and GHG emissions. The developed conceptual framework provided a systematic complete analysis of the energy-consuming and GHG-emitting components associated with groundwater-based irrigation systems. Policy makers and decision makers may use the developed framework to compare different system components to develop strategies that have minimal impact on the environment.
11 Perera, K. C.; Western, A. W.; George, B.; Nawarathna, B. 2015. Multivariate time series modeling of short-term system scale irrigation demand. Journal of Hydrology, 531(Part 3):1003-1019. [doi: https://doi.org/10.1016/j.jhydrol.2015.11.007]
Irrigation systems ; Water demand ; Forecasting ; Performance evaluation ; Multivariate analysis ; Time series analysis ; Models ; Weather ; Precipitation ; Irrigation canals ; Flow discharge ; Farmers attitudes / Australia / Goulburn-Murray Irrigation District
(Location: IWMI HQ Call no: e-copy only Record No: H047570)
(6.17 MB)
Travel time limits the ability of irrigation system operators to react to short-term irrigation demand fluctuations that result from variations in weather, including very hot periods and rainfall events, as well as the various other pressures and opportunities that farmers face. Short-term system-wide irrigation demand forecasts can assist in system operation. Here we developed a multivariate time series (ARMAX) model to forecast irrigation demands with respect to aggregated service points flows (IDCGi, ASP) and off take regulator flows (IDCGi,OTR) based across 5 command areas, which included area covered under four irrigation channels and the study area. These command area specific ARMAX models forecast 1–5 days ahead daily IDCGi,ASP and IDCGi,OTR using the real time flow data recorded at the service points and the uppermost regulators and observed meteorological data collected from automatic weather stations. The model efficiency and the predictive performance were quantified using the root mean squared error (RMSE), Nash–Sutcliffe model efficiency coefficient (NSE), anomaly correlation coefficient (ACC) and mean square skill score (MSSS). During the evaluation period, NSE for IDCGi, ASP and IDCGi,OTR across 5 command areas were ranged 0.98–0.78. These models were capable of generating skillful forecasts (MSSS P 0.5 and ACC P 0.6) of IDCGi, ASP and IDCGi,OTR for all 5 lead days and IDCGi, ASP and IDCGi,OTR forecasts were better than using the long term monthly mean irrigation demand. Overall these predictive performance from the ARMAX time series models were higher than almost all the previous studies we are aware. Further, IDCGi, ASP and IDCGi,OTR forecasts have improved the operators’ ability to react for near future irrigation demand fluctuations as the developed ARMAX time series models were self-adaptive to reflect the short-term changes in the irrigation demand with respect to various pressures and opportunities that farmers’ face, such as changing water policy, continued development of water markets, drought and changing technology.
12 Rejani, R.; Rao, K. V.; Rao, C. H. S.; Osman, M.; Reddy, K. S.; George, B.; Kranthi, G. S. P.; Chary, G. R.; Swamy, M. V.; Rao, P. J. 2017. Identification of potential rainwater-harvesting sites for the sustainable management of a semi-arid watershed. Irrigation and Drainage, 66(2):227-237. [doi: https://doi.org/10.1002/ird.2101]
Rainwater ; Water harvesting ; Structures ; Planning ; Sustainability ; Watershed management ; Semiarid zones ; Water conservation ; GIS ; Models ; Spatial database ; Remote sensing ; Soil conservation ; Surface runoff ; Land use ; Land cover ; Identification / India / Goparajpalli Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H048128)
(0.98 MB)
In the present study, the potential locations for constructing different water-harvesting structures in a semi-arid watershed located at Goparajpalli, in southern India, were derived using GIS in three stages. The locations were first identified based on land use land cover, land slope, rainfall characteristics, soil texture and soil depth. Then a number of structures and suitable semi-arid rainfed regions have limitations in their runoff potential availability; these locations were further optimized based on the runoff available after in situ water conservation and storage in existing water-harvesting structures. The surplus runoff volume available in a normal year after storage was estimated to be 870 000 m3 . Suitable locations for 25 rock fill dams (RFD), 74 farm ponds and 5 check dams were identified. These derived sites were validated by exporting to Google Earth and investigated for their suitability with ground truth information. At present, the number of structures existing is more than the optimum number of structures derived, but they have less storage capacity. Hence those structures such as farm ponds located at potential sites are recommended for desiltation and renovation by increasing their size along with lining so that they can be utilized for rainwater harvesting and supplementary irrigation. This methodology for identification of potential locations for water-harvesting structures is less time-consuming, more precise and can be utilized for the planning of large catchments to improve the water availability and productivity.
13 Reddy, V. R.; Saharawat, Y. S.; George, B.. 2017. Watershed management in South Asia: a synoptic review. Journal of Hydrology, 551:4-13. [doi: https://doi.org/10.1016/j.jhydrol.2017.05.043]
Watershed management ; Evolution ; Sustainability ; Hydrology ; Rainwater ; Water harvesting ; Soil conservation ; Moisture conservation ; Environmental effects ; Economic impact ; Social impact ; Living standards ; Equity ; Corporate culture / South Asia / Afghanistan / Bangladesh / Bhutan / India / Nepal / Pakistan / Sri Lanka
(Location: IWMI HQ Call no: e-copy only Record No: H048240)
(0.97 MB)
Watershed management (WSM) is the most widely adopted technology in developed as well as developing countries due to its suitability across climatic conditions. Watershed technology is suitable to protect and enhance soil fertility, which is deteriorating at an alarming rate with agricultural intensification in high as well as low rainfall regions. Of late, WSM is considered as an effective poverty alleviation intervention in the rain fed regions in countries like India. This paper aims at providing a basic watershed policy and implementation framework based on a critical review of experiences of WSM initiatives across South Asia. The purpose is to provide cross learnings within South Asia and other developing countries (especially Africa) that are embarking on WSM in recent years.
Countries in the region accord differential policy priority and are at different levels of institutional arrangements for implementing WSM programmes. The implementation of watershed interventions is neither scientific nor comprehensive in all the countries limiting the effectiveness (impacts). Implementation of the programmes for enhancing the livelihoods of the communities need to strengthen both technical and institutional aspects. While countries like India and Nepal are yet to strengthen the technical aspects in terms of integrating hydrogeology and biophysical aspects into watershed design, others need to look at these aspects as they move towards strengthening the watershed institutions.
Another important challenge in all the countries is regarding the distribution of benefits. Due to the existing property rights in land and water resources coupled with the agrarian structure and uneven distribution and geometry of aquifers access to sub-surface water resources is unevenly distributed across households. Though most of the countries are moving towards incorporating livelihoods components in order to ensure benefits to all sections of the community, not much is done in terms of addressing the equity aspects of WSM.
Countries in the region accord differential policy priority and are at different levels of institutional arrangements for implementing WSM programmes. The implementation of watershed interventions is neither scientific nor comprehensive in all the countries limiting the effectiveness (impacts). Implementation of the programmes for enhancing the livelihoods of the communities need to strengthen both technical and institutional aspects. While countries like India and Nepal are yet to strengthen the technical aspects in terms of integrating hydrogeology and biophysical aspects into watershed design, others need to look at these aspects as they move towards strengthening the watershed institutions.
Another important challenge in all the countries is regarding the distribution of benefits. Due to the existing property rights in land and water resources coupled with the agrarian structure and uneven distribution and geometry of aquifers access to sub-surface water resources is unevenly distributed across households. Though most of the countries are moving towards incorporating livelihoods components in order to ensure benefits to all sections of the community, not much is done in terms of addressing the equity aspects of WSM.
14 Ibrakhimov, M.; Awan, U. K.; George, B.; Liaqat, U. W. 2018. Understanding surface water–groundwater interactions for managing large irrigation schemes in the multi-country Fergana Valley, Central Asia. Agricultural Water Management, 201:99-106. [doi: https://doi.org/10.1016/j.agwat.2018.01.016]
Surface water ; Groundwater recharge ; Irrigation schemes ; Large scale systems ; Irrigation management ; Water balance ; Groundwater table ; Discharges ; Crops ; Water requirements ; Water user associations ; Evapotranspiration ; Precipitation ; Models / Central Asia / Uzbekistan / Fergana Valley / Oktepa Zilol Chashmasi Water Consumers Association
(Location: IWMI HQ Call no: e-copy only Record No: H048584)
(0.97 MB)
Traditionally, surface water supplies are the sole sources to satisfy crop water requirements in large irrigation schemes such as those in the Fergana Valley, Central Asia. Recent studies indicate that 23–30% of these requirements are met from shallow groundwater, but this is not usually quantified. To manage favorable groundwater levels – i.e., without increasing soil salinity and nutrient leaching and reducing crop yields – information on, and quantification of, groundwater recharge and discharge rates at large spatial and temporal scales, as well as understanding their mechanisms of interaction, is indispensable. With the aim to quantify groundwater recharge, discharge and their interaction, a conceptual water balance model at a scale of a Water Consumers’ Association was established on a monthly basis for a 10-year period. Average groundwater recharge was estimated as 780 ± 75.7 mm, representing 62% of surface water supplies. The highest average annual recharge (930 mm) driven by excessive precipitation and water supply was in 2010 and the lowest (667–726 mm) was in years of lower water availability: 2006–2008 and 2012. The net groundwater recharge was 82.4 ± 79 mm, and determined the groundwater level fluctuations. The highest positive net groundwater recharge rate (247 mm) and the shallowest groundwater level (123 cm) also occurred in 2010. The negative net recharge in 2006 (–11 mm), 2008 (–41 mm) and 2012 (–5 mm) indicated deeper groundwater levels during these periods. The groundwater recharge values were excessively high even for this large irrigation scheme. To save limited freshwater resources, groundwater discharge should be reduced, with one option being to reduce excessive drainage outflow.
15 Davidson, B.; Hellegers, P.; George, B.; Malano, H. 2019. The opportunity costs of increasing reliability in irrigation systems. Agricultural Water Management, 222:173-181. [doi: https://doi.org/10.1016/j.agwat.2019.03.005]
Irrigation systems ; Opportunity costs ; Cost benefit analysis ; Water use ; Water resources ; Water management ; Water supply ; Catchment areas ; Flow discharge ; Case studies ; Models / India / Andhra Pradesh / Musi Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H049403)
(0.80 MB)
Increasing water reliability in a catchment requires reducing the total quantity of water available to users in some years in order to supply it in more years when its supply is constrained. Thus, the more reliable the supply the more water that needs to be withheld. Consequently, increased levels of water reliability to a catchment, which reduces the costs associated with an unreliable supply, often comes at an incremental increase in costs that researchers do not consider; that of the water foregone that could be have been used productively if the system had been run less reliably. In this paper the trade-offs between the costs of water foregone to maintain a level of reliability and the costs associated with an unreliable supply of water at different levels of reliability in an irrigation system are discussed. The concepts developed are applied to the irrigation sector in the Musi catchment in Andhra Pradesh, India from 2011 to 2040. In this catchment it was found that the costs of water foregone to increase reliability rise as the level of reliability rises, while the benefits generally fall. When the level of reliability exceeded approximately 85% (where water is so scarce that it is used on only the most valuable output), the costs of greater reliability exceed the benefits resulting in net losses to the system. These results were found to vary in each demand centre across the catchment. These results have implications for those considering innovations that improve the level of reliability in a catchment.
16 Joseph, N.; Ryu, D.; Malano, H. M.; George, B.; Sudheer, K. P. 2020. Investigation into sustainable water use in India using combined large-scale earth system-based modelling and census-based statistical data. Journal of Hydrology, 587:124930. [doi: https://doi.org/10.1016/j.jhydrol.2020.124930]
Sustainable Development Goals ; Water use ; Modelling ; Groundwater extraction ; Groundwater recharge ; Water scarcity ; Water stress ; Water availability ; Surface water ; Water demand ; Irrigation water ; Domestic water ; Environmental flows / India
(Location: IWMI HQ Call no: e-copy only Record No: H049846)
(16.20 MB)
Sustainable water use and water scarcity are major concerns in developing countries such as India. Rapidly growing population along with increasing economic and technological development in India have resulted in increased water use leading to severe water scarcity. The present study aims to quantify and assess sustainable water use and water scarcity in India. A data-intensive approach is employed at a State spatial resolution and monthly temporal scales during the period 1991–1999. The Water Stress Index (WSI), which is defined as the ratio of total water use to available water, is used as a measure of blue water scarcity. The total available water includes surface water and groundwater while the total water uses include irrigation, industrial, domestic and environmental uses. A Community Land Model (CLM 4.0) developed by the National Centre for Atmospheric Research (NCAR), is used to quantify the total available water in India. Water uses in India are reconstructed using a census-based statistical database while the environmental water demand is modelled following the hydrology-based approach, which allocates environmental flows as a proportion of the available water, with seasonally defined environmental flow thresholds. Further, the excess water component, defined as the amount of water remaining after meeting the demands at each time step, is incorporated into the modelling framework by adding it to the available water pool. The study estimates that 60% of the population in India faces severe water stress during the analysis period, and is more predominant in the States of Rajasthan, Gujarat, Uttar Pradesh and Maharashtra. Moreover, non-renewable groundwater abstraction, which is defined as the amount of groundwater abstraction more than the groundwater recharge, is also quantified. This study identifies severe groundwater depletion in the north-western parts of India, consistent with the current estimates from GRACE satellite observations.
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