Krishna Basin Research Articles

Geological and environmental issues of the proposed link canal (Inchampalli to Nagarjunasagar) of Godavari to Krishna Rivers adopting remote sensing and geographical information system (GIS)

Extremely erratic rainfall, unevenly distributed and very heavy precipitation in short time resulting in flash floods and inundation in India became a usual phenomena in recent years. At every event, a huge quantity of water is being wasted into the sea as run-off quite frequently due to inadequate harvesting structures. This huge run-off / surplus water can be harvested through the proposed linking of river basins envisaged by National Water Development Agency (NWDA). Out of the total mega projects, the NWDA suggested three link canals from Godvari to Krishna basin, to harvest the surplus water as well as to transfer flood water from Godavari. The Godavari (Inchampalli) - Krishna (Nagarjunasagar) link canal and its possible impact on the socio-economic and infrastructural forms the present study. The link canal of length 299 km (including a tunnel of 9.150 km) is proposed in the upper reaches connecting Godavari and Krishna basins succeeded by two other links towards their downstream. It takes off from the foreshore of the Inchampalli reservoir and joins the existing Nagarjunasagar via Musi reservoir. IRS-1D, LISS-III data is analysed for morphological, geological and land use/land cover information. Geology, geomorphology and soil base maps were obtained and updated with remote sensing data and their aerial distribution in the study area was discussed. The study includes 10 km buffer area on either side of the alignment and the proposed canal command area (5157.48 Sq km) spread in Warangal and Nalgonda districts. The canal command area is occupied by dry land and wasteland classes. Pediplain weathered is the main landform that occupied major part of the study area. The study area in Warangal district is mostly occupied by unclassified crystalline rocks of Archean age. Fine to medium grained, granite gneisses and migmatities of older metamorphics from chainage 102 km to the end point of the canal. Deep loamy soil, deep clayey soil, deep clayey calcareous soil and gravelly clay soils are dominant in the canal study area. Clayey and loamy soils are suitable for wet / dry crops and gravely calcareous for plantations and dry crops. The study revealed that 23 villages are to be rehabilitated while executing the canal and about 816 villages would benefit from it by way of drinking water / groundwater in addition to crop requirements. Key words: Link canal, donor basin, command area, geomorphology.

Changes in agricultural cropland areas between a water-surplus year and a water-deficit year impacting food security, determined using MODIS 250 m time-series data and spectral matching techniques, in the Krishna River basin (India)

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 R 2-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.

Comparing irrigation management reforms in Australia and India – a special reference to participatory irrigation management

AbstractEfficient irrigation water management has become a common goal for continued growth and sustainable development in both India and Australia. The two countries have followed definite paths for achieving the best irrigation management policy. Australia has adopted irrigation management transfer (IMT) with emphasis on privatisation, while India has focused on participatory irrigation management (PIM). Australia and India have adopted these approaches in one of their main river basins, namely the Murray‐Darling Basin (MDB) and the Krishna Basin, respectively. Institutional reforms in irrigation management in the MDB developed independently of global progress in IMT as compared to the Krishna Basin where the reforms were imposed from the top. Further, irrigation management entities in the MDB, either under public or participatory domain, relied heavily on market‐based instruments to achieve efficiency in irrigation water management. In contrast, PIM in the Krishna Basin in India appears to be an experiment with command and control in diverse legal and organisational settings across time and space. In summary, in terms of the parameters chosen in their nearest proximity to measure performance, the Australian IMT programme seems to have performed better than the Indian PIM programme. Copyright © 2009 John Wiley & Sons, Ltd.

An integrated hydro-economic modelling framework to evaluate water allocation strategies II: Scenario assessment

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.

An integrated hydro-economic modelling framework to evaluate water allocation strategies I: Model development

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.

Spatial and temporal variations in the occurrences of wet periods over major river basins in India

This study highlights the hydro-climatic features of the five wet periods contributing in different percentages to the annual rainfall total over major river basins in India. Spatial and temporal variations in the parameters such as starting date, duration and rainfall intensity of these wet periods throughout India have been discussed using daily gridded rainfall data for the period 1951–2007. An attempt is also made here, to assess the impact of global SSTs on the start and duration of the wet periods in Indian river basins.It is observed that, for almost all river basins in India, the 10% wet period occurs in the months of July/August with an average duration of 1–3 days and rainfall intensity varying from 44 to 89mm/day. The duration of the wet period contributing 90% to the annual rainfall varies from 112 days in the central parts of India to 186 days in the northern parts of the country. Significant increase in the rainfall intensity has been observed in the case of some river basins of central India. The late start of 75% wet period along the West Coast and in peninsular river basins has been observed with increase in Nino 3.4 SSTs (MAM), while increase in the duration of the 75% wet period over the Krishna basin is associated with increase in Nino 3.4 SSTs (concurrent JJAS).

Beyond water, beyond boundaries: spaces of water management in the Krishna river basin, South India

As demand and competition for water resources increase, the river basin has become the primary unit for water management and planning. While appealing in principle, practical implementation of river basin management and allocation has often been problematic. This paper examines the case of the Krishna basin in South India. It highlights that conflicts over basin water are embedded in a broad reality of planning and development where multiple scales of decisionmaking and non-water issues are at play. While this defines the river basin as a disputed "space of dependence", the river basin has yet to acquire a social reality. It is not yet a "space of engagement" in and for which multiple actors take actions. This explains the endurance of an interstate dispute over the sharing of the Krishna waters and sets limits to what can be achieved through further basin water allocation and adjudication mechanisms – tribunals – that are too narrowly defined. There is a need to extend the domain of negotiation from that of a single river basin to multiple scales and to non-water sectors. Institutional arrangements for basin management need to internalise the political spaces of the Indian polity: the states and the panchayats. This re-scaling process is more likely to shape the river basin as a space of engagement in which partial agreements can be iteratively renegotiated, and constitute a promising alternative to the current interstate stalemate.

Coping with drought in irrigated South India: Farmers’ adjustments in Nagarjuna Sagar

Abstract Continuous upstream water development in the South Indian Krishna Basin has resulted in declining water availability downstream. Upstream water use is not adjusted to reflect rainfall fluctuations, and downstream farmers of the Nagarjuna Sagar irrigation project in the state of Andhra Pradesh are increasingly vulnerable to water supply shocks. Understanding the adaptive capacity of irrigated command areas to fluctuating water conditions is critical. This paper documents the wide range of adjustments adopted by managers and farmers in Nagarjuna Sagar during a period of fluctuating water availability (2000–2007). Primary and secondary data indicate managerial adjustments such as rotational and timely water supplies to meet critical water demands of standing crops. Farmers responded to changing conditions through: (a) crop diversification, (b) shifting calendars, (c) conjunctive use, (d) suspending cultivation, (e) sale of livestock, (f) out-migration, and (g) tampering with the irrigation system. Adaptive strategies are more diverse in the tail-end than in the head-end of the canal network and local adjustments are often uncoordinated and may degrade the resource base. A better understanding of the practices induced by changes in water availability is needed to refine current water allocation and management in large surface irrigation projects. Crop diversification, deficit irrigation in low-flow years, and conjunctive use are some of the practices to be promoted in a conducive agricultural environment.

Zonal estimation of probable maximum precipitation rain depths over the Krishna basin in peninsular India

Estimation of design storm rain depths of probable maximum precipitation (PMP) magnitudes over different zones of the Krishna basin, India, was attempted by using daily rainfall data of about 570 raingauge stations in and around the basin for a 102-year period (1901–2002). By considering the geographical location, orographic features and rainfall characteristics, the entire basin was divided into nine zones. Analysis of severe rainstorms over each zone was carried out and envelope rain depths (standard project storm, SPS, rain depths) over each zone were estimated. These SPS rain depths were then adjusted with moisture maximization factors (MMFs) of respective severe rainstorms to work out the PMP design rain depths. On the basis of available hourly data, average time distribution was also calculated. The study was carried out with the aim of estimating the requisite standard projects storms and probable maximum storms or PMP depths to derive the corresponding design flood estimates. This may serve as a convenient tool for design engineers, in the estimation of design storm rain depths for different sub-basins and the entire Krishna basin while constructing any hydraulic structure connected with irrigation, hydropower generation and flood control in the homogeneous region of the basin. Citation Kulkarni, B. D., Nandargi, S. & Mulye, S. S. (2010) Zonal estimation of probable maximum precipitation rain depths over the Krishna basin in peninsular India. Hydrol. Sci. J. 55(1), 93–103.

Mapping agricultural responses to water supply shocks in large irrigation systems, southern India

Irrigated agriculture experienced a water supply shock during a drought in southern India in 2002–2003. In this paper, hotspots of agricultural change were mapped and put in the context of hydrology and water management. Time series of MODIS imagery taken every eight days before (2001–2002) and during (2002–2003) the supply shock were combined with agricultural census data to document changes in cropping patterns in four large irrigation projects in the downstream sections of the Krishna and Godavari River basins (total command area 18,287 km 2 ). The area cropped in rice in the four irrigated command areas decreased by 32% during the drought year, and rice production in the two districts that experienced the largest flow reductions fell below production levels of 1980. The irrigation project that showed the largest change in double cropped area (−90%) was upstream of the Krishna Delta. In the Krishna Delta, large areas changed from rice–rice to rice–gram double cropping. Historical water management contributed to the vulnerability of rice production to drought: the main reservoir in the system was drained to dead storage levels by the end of each growing season over 1968–2000, with little carryover storage. The land cover change maps suggested that the lower Krishna Basin has experienced a “hard landing” during basin closure, and revised management strategies that account for the new flow regime will be required to maintain agricultural production during droughts.

Determining the disaggregated economic value of irrigation water in the Musi sub-basin in India

In this paper the residual method is used to determine the disaggregated economic value of irrigation water used in agriculture across crops, zones and seasons. This method relies on the belief that the value of a good (its price by its quantity) is equal to the summation of the quantity of each input multiplied by its average value. By applying this method to the Musi sub-basin; a subdivision of the Krishna basin in India, it was found that the value of irrigation water use is not equated across the crops, zones and seasons. The reasons why there is no sinlge value of irrigation water use are suggested. As farmers do not have perfect knowledge, do not all possess the same resource base, plant different crops for a variety of reasons (some for a financial return on land instead of water and others for sustenance), possess different crop rotation practices and are possibly riks adverse, they all value water differently. However, the results need to be interpreted with care as the crop with the lowest return to water is probably not the one to be sacrificed if water is restricted, since farmers plant crops for a variety of reasons (and sometimes not for the highest return to water that they can achieve).

From global to local: Testing the potential of cross-scaling in global data sets

The present study investigates the potential of readily available and easily accessible global data sets to understand regional/local level interactions in wetland systems. The biogeographical zones of India were used a base-frame to select three sites. The study well fits the interests of National Wetland Committee of India to investigate and document fundamental information on wetland extent/distribution. The national partnership with SACON represents this interest. SACON commenced the inland wetland inventory module at national scale using geospatial data, although the provincial scale analysis is underway. In addition, the global irrigated area mapping (GIAM-IWMI) project generated multi-scalar spatial outputs for irrigated/rain-fed areas. With the existing information base, a multi-level geospatial analysis using Arc GIS algorithmic modelling was used to derive comprehensive appraisal of wetland systems complementing the data from GIAM and SACON. It was observed that the overlap between the two layers was 58 percent for Gujarat and 10 percent in Tamil Nadu. In Krishna basin the wetland’s cover 1.04 million hectare excluding the rice agro-ecosystem. The difference in the biogeography of the case sites governs the gradient of information derived from both data layers. Additionally, the global lakes and wetlands database (GLWD) database added thematic information on coastal wetlands. In summary we describe the cross-scaling the global data layers to compliment the regional/national level monitoring assignments.

A framework for assessing the trade‐offs between economic and environmental uses of water in a river basin

AbstractSignificant increases in water diversion for irrigation and other uses have taken place worldwide throughout the twentieth century, often with negative consequences for environmental sustainability.In this paper a framework which can be used to undertake an assessment of this trade‐off problem is presented. The framework aims to achieve a balance between water extractions for irrigation and other uses and environmental demand. It involves, among many factors, an understanding of the hydrological, environmental, economic and social consequences of diverting water.The research component of the framework comprises three key elements: water cycle analysis, economic analysis and social analysis. At the core of the water cycle analysis is the characterisation of the water stocks and flows in the systems and a modelling framework to analyse system responses to water‐sharing policies and trade‐offs between extractive and environmental uses. The economic analysis focuses on the valuation of water allocated to each use including the environment, whilst the social analysis is centred on the relative values used to balance water extractions for society's needs and the environment. This framework is illustrated with examples from the Krishna Basin in India and the Murray– Darling Basin in Australia. Copyright © 2009 John Wiley & Sons, Ltd.

RAINFALL—RUNOFF MODELLING USING ARTIFICIAL NEURAL NETWORKS

ABSTRACT Runoff simulation and forecasting is essential for planning, designing and operation of water resources projects. In the present study, the rainfall—runoff process is modelled by coupling simple time—series (STS) and linear autoregressive (ARX) models with Artificial Neural Networks (ANN). The study uses the monthly data at Keesara, Damarcherla and Madhira gauging sites of Krishna basin. The study reveals that the performance of ANN model in the simulation and forecasting of monthly runoff during monsoon period can be improved considerably by including the residuals derived from STS and ARX models as additional inputs together with rainfall.

Influence of Resolution in Irrigated Area Mapping and Area Estimation

The overarching goal of this paper was to determine how irrigated areas change with resolution (or scale) of imagery. Specific objectives investigated were to (a) map irrigated areas using four distinct spatial resolutions (or scales), (b) determine how irrigated areas change with resolutions, and (c) establish the causes of differences in resolution-based irrigated areas. The study was conducted in the very large Krishna River basin (India), which has a high degree of formal contiguous, and informal fragmented irrigated areas. The irrigated areas were mapped using satellite sensor data at four distinct resolutions: (a) NOAA AVHRR Pathfinder 10,000 m, (b) Terra MODIS 500 m, (c) Terra MODIS 250 m, and (d) Landsat ETM 30 m. The proportion of irrigated areas relative to Landsat 30 m derived irrigated areas (9.36 million hectares for the Krishna basin) were (a) 95 percent using MODIS 250 m, (b) 93 percent using MODIS 500 m, and (c) 86 percent using AVHRR 10,000 m. In this study, it was found that the precise location of the irrigated areas were better established using finer spatial resolution data. A strong relationship (R 2 0.74 to 0.95) was observed between irrigated areas determined using various resolutions. This study proved the hypotheses that “the finer the spatial resolution of the sensor used, greater was the irrigated area derived,” since at finer spatial resolutions, fragmented areas are detected better. Accuracies and errors were established consistently for three classes (surface water irrigated, ground water/conjunctive use irrigated, and nonirrigated) across the four resolutions mentioned above. The results showed that the Landsat data provided significantly higher overall accuracies (84 percent) when compared to MODIS 500 m (77 percent), MODIS 250 m (79 percent), and AVHRR 10,000 m (63 percent).

Reconfiguration and closure of river basins in south India: trajectory of the lower Krishna basin

Agricultural and water development in the Krishna basin in south India has led to a progressive over-commitment of water resources. Based on a historical water accounting (1955–2004), this paper shows that upstream water development is the main cause for declining water availability in the lower Krishna basin (Andhra Pradesh state). But Andhra Pradesh's own policies of water resources development are also key in understanding the process of over-commitment observed in the region. To slow down basin closure (little or no discharge to the ocean), there is a need for formal and adaptive water allocation mechanisms that can internalize social and environmental objectives.

Impacts of irrigation and anthropogenic aerosols on the water balance, heat fluxes, and surface temperature in a river basin

Changes in both land cover and the atmosphere have impacted the heat fluxes of south Asia in ways that may have altered the timing and magnitude of the monsoon. Century‐long budgets of water and energy in the Krishna Basin (258,948 km2) in southern India demonstrate that irrigation impacted the sensible heat flux of the land surface (H) as much as or more than did the atmospheric brown cloud (ABC) over 1960–2005. Annual discharge of the Krishna River fell from 226 mm during pre‐irrigation land cover (1901–1960) to 64 mm by 1990–2005, when 14–20% of the basin area was irrigated. Over the same period, annual evaporation increased by 166 ± 32 mm (+28%) causing H to decrease by 12.7 ± 2 W m−2 (−18%) compared to a decrease of 11.2 ± 1.8 W m−2 caused by the atmospheric brown cloud (ABC). The rate of change in H during irrigation expansion (1960–1990) was between −3.4 and −5.0 W m−2 per decade (da−1) due to irrigation expansion and −1.8 to −2.3 W m−2 da−1 due to the ABC. The trend in H caused by irrigation was negligible over 1990–2005 as irrigated area and evaporation stabilized. Previous work using the Parallel Climate Model estimated that the ABC decreased the latent heat flux by 2.4 W m−2; this decrease was more than offset by irrigation, resulting in a net increase in the latent heat flux of 12.9 W m−2. The maximum surface air temperature (Tmax) either decreased or remained the same in areas experiencing irrigation expansion but increased in a majority of unirrigated areas during the post‐monsoon season. The results provide observational evidence that irrigation changed both the basin‐scale sensible heat flux and surface air temperatures.

Urban and industrial water use in the Krishna Basin, India

AbstractRegional urbanization and industrial development require water that may put additional pressure on available water resources and threaten water quality in developing countries. In this study we use a combination of census statistics, case studies, and a simple model of demand growth to assess current and future urban and industrial water demand in the Krishna Basin in southern India. Water use in this “closed” basin is dominated by irrigation (61.9 billion cubic metres (BCM) yr−1) compared to a modest domestic and industrial water use (1.6 and 3.2 BCM yr−1). Total water diversion for non‐irrigation purposes is estimated at 7–8% of available surface water in the basin in an average year. Thermal power plants use the majority of water used by industries (86% or 2.7 BCM yr−1), though only 6.8% of this is consumed via evaporation. Simple modelling of urban and industrial growth suggests that non‐agricultural water demand will range from 10 to 20 BCM by 2030. This is 14–28% of basin water available surface water for an average year and 17–34% for a year with 75% dependable flow. Although water use in the Krishna Basin will continue to be dominated by agriculture, water stress, and the fraction of water supplies at risk of becoming polluted by urban and industrial activity, will become more severe in urbanized regions in dry years. Copyright © 2008 John Wiley & Sons, Ltd.

Krishna Basin Development

Since India gained Independence, the Krishna basin has seen an increasing mobilization of its water resources. Warnings of basin closure (minimal flow to the ocean) emerge during dry periods. Basin water development and local rural dynamics have led to a degradation of downstream ecosystems manifesting itself by salinizing soil and groundwater, increasing pollution, making mangroves disappear, and desiccating wetlands. Reversing this evolution requires the formal recognition of the environment as a water user in its own right and the implementation of an environmental water provision. This provision should be based on a two-tier allocation system with assured discharges in the irrigation canals of the delta and to the ocean. This will lead to further commitment of water resources, but this is needed to reconcile the social, economic, and environmental objectives of sustainable development. Other measures facilitating integrated natural resources management from the local to the basin level are needed too.

Water Scarcity Effects on Equitable Water Distribution and Land Use in a Major Irrigation Project—Case Study in India

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.