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This document provides an overview of how water resource software’s (WRS) are used to manage water resources issues, criteria for WRS selection, and a high level review of WRS currently available that central and state governments of India can use for water management. The water resource issues covered include water allocation and planning, flood management, groundwater management, conjunctive use, water quality, and sediment transport.

The objective of this study was to investigate the changes in cropland areas as a result of water availability using Moderate Resolution Imaging Spectroradiometer (MODIS) 250 m time-series data and spectral matching techniques (SMTs). The study was conducted in the Krishna River basin in India, a very large river basin with an area of 265 752 km2 (26 575 200 ha), comparing a water-surplus year (2000-2001) and a water-deficit year (2002-2003). The MODIS 250 m time-series data and SMTs were found ideal for agricultural cropland change detection over large areas and provided fuzzy classification accuracies of 61-100% for various land-use classes and 61-81% for the rain-fed and irrigated classes. The most mixing change occurred between rain-fed cropland areas and informally irrigated (e.g. groundwater and small reservoir) areas. Hence separation of these two classes was the most difficult. The MODIS 250 m-derived irrigated cropland areas for the districts were highly correlated with the Indian Bureau of Statistics data, with R2-values between 0.82 and 0.86. The change in the net area irrigated was modest, with an irrigated area of 8 669 881 ha during the water-surplus year, as compared with 7 718 900 ha during the water-deficit year. However, this is quite misleading as most of the major changes occurred in cropping intensity, such as changing from higher intensity to lower intensity (e.g. from double crop to single crop). The changes in cropping intensity of the agricultural cropland areas that took place in the water-deficit year (2002-2003) when compared with the water-surplus year (2000-2001) in the Krishna basin were: (a) 1 078 564 ha changed from double crop to single crop, (b) 1 461 177 ha changed from continuous crop to single crop, (c) 704 172 ha changed from irrigated single crop to fallow and (d) 1 314 522 ha changed from minor irrigation (e.g. tanks, small reservoirs) to rain-fed. These are highly significant changes that will have strong impact on food security. Such changes may be expected all over the world in a changing climate.

To keep pace with population and economic growth, the city of Hyderabad, India, will need to identify and develop new supply sources almost continually. Increasing population growth rate, declining surface water resources, overexploitation of groundwater, deterioration of ground water quality and poor sewage treatment are the major water-related issues in Hyderabad. This paper reviews the current situation facing policy makers who need to come to terms with the problem of restricted water supply and increasing demand in an urban centre such as Hyderabad, India. The City Water Balance model developed in this study can be used to analyse different scenarios that include water conservation, urban wastewater reuse and improvement of distribution and conveyance efficiency. Water conservation programs, which include a 5% conveyance efficiency improvement, reusing 90 million cubic metres (MCM) of urban runoff and adoption of water harvesting by 0.5 million households together with recycling 120 MCM of wastewater recycling wastewater would be sufficient to meet the water demand by 2031, if the population grows at a rate of 2.5%.

In many river basins, upstream development and interannual variations in rainfall can cause both episodic and chronic shortages in water supplies downstream. Continued rapid development of surface and groundwater throughout the Krishna Basin in southern India resulted in historically low inflows to the main canals of the Nagarjuna Sagar irrigation project 8,955 km 2 during a recent drought 2002-2004. This paper presents an integrated approach to assess how cropping patterns and the spatial equity of canal flow changed with water supply shocks in the left canal command area 3,592 km 2 of Nagarjuna Sagar. We combined 3 years 2000-2003 of canal release data with census statistics and high temporal resolution 8-10 days moderate resolution imaging spectrometer MODIS 500-m resolution satellite imagery. The impact of water scarcity on land use pattern, delineated by MODIS images with moderate spatial resolution, was comparable with the census statistics, while the MODIS data also identified areas with changes and delays in the rice crop area, which is critical in assessing the impact of canal operations. A 60% reduction in water availability during the drought resulted in 40% land being fallowed in the left-bank canal command area. The results suggest that head reach areas receiving high supply rates during a normal year experienced the highest risks of fluctuations in water supply and cropped area during a water short year compared to downstream areas, which had chronically low water supply, and better adaptive responses by farmers. Contrary to expectations, the spatial distribution of canal flows among the three major zones of the command area was more equitable during low-flow years due to decreased flow at the head reach of the canal and relatively smaller decreases in tail-end areas. The findings suggested that equitable allocations could be achieved by improving the water distribution efficiency of the canal network during normal years and by crop diversification and introduction of alternative water sources during water shortage years. The study identified areas susceptible to decreases in water supplies by using modern techniques, which can help in decision-making processes for equitable water allocation and distribution and in devel- oping strategies to mitigate the effects of water supply shocks on cropping patterns and rural livelihoods.