PERFORMANCE EVALVATION OF CANAL IRRIGATION SYSTEM USING REMOTE SENSING AND GIS

Abstract

To face the challenge of satisfying the food requirements of increasing population, the rain fed agriculture was switched over to irrigated agriculture. But the continuous increase in population calls for improvements in irrigated agriculture by optimal utilisation of available land and water resources. Water and land resources being finite, their over exploitation in an unplanned manner has worsened the situation. The existing irrigation systems need to be analysed for their performance in order to evaluate whether the desirable objectives are met and to explore the horizon of improvements in structural and managerial aspects for increasing the productivity of available land and water resources. The present study was carried out for a period of 2012-2018 to evaluate the performance of irrigation system at tertiary level based on the various performance indicators. In this study, seventeen performance indicators were utilised for evaluation i.e. system performance, agricultural productivity and financial aspects. Water delivery capacity index (WDCI) for Harchandpur minor (HM) and Naserpur minor (NM) were found to be 1.34 and 1.8 respectively suggesting sufficient capacity of the systems for increasing the discharge of canals. The average values of relative irrigation supply (RIS), which is the ratio of irrigation water supply to water demand of a crop, for paddy, wheat and sugarcane in HM were found to be 0.45, 1.24 and 1.62, respectively and for NM were found to be 0.32, 0.94 and 1.01 respectively. This indicates good RIS for wheat and sugarcane and poor for paddy. The average values of relative water supply (RWS), which is the ratio of sum of irrigation water supply and rainfall to the crop water demand, for paddy, wheat and sugarcane in HM were found to be 3.5, 1.32 and 1.8, respectively and for NM were found to be 3.22, 0.95 and 1.48 respectively indicating good RWS for all the crops. The average values of depleted fraction (DF), which is the ratio of the actual water used by the crop to the sum of irrigation water supplied and total rainfall, for paddy, wheat and sugarcane in HM were 0.29, 0.80 and 0.54 respectively and for NM were found to be 0.32, 1.02 and 0.56 respectively. The average values of relative evapotranspiration (RET), which is the ratio of actual water use to the potential water use, for paddy, wheat and sugarcane in HM were found to be 1.00, 0.96 and 0.91 respectively and for NM the values of RET were 1, 0.88 and 0.82 respectively indicating good RET values for all the crops. The average values of crop water deficit (CWD), which is the difference in potential water use and actual water use, for paddy, wheat and sugarcane in the HM were found to be 1.00, 0.96 and 0.91 respectively and for NM the values of RET were found to be 1, 0.88 and 0.82 respectively indicating good CWD values for paddy and wheat, and poor for sugarcane. The average values of productivity of irrigation water supplied (PIW), which is the ratio of yield to the irrigation water supplied, for paddy, wheat and sugarcane in HM for paddy, wheat and sugarcane were found to be 0.4, 1.2 and 6.2 respectively and for NM were found to be 0.5, 2.2 and 9.9 kg-m-3 respectively indicating poor PIW values for paddy in HM and good for other crops in both HM and NM. Productivity of actual water consumed (PAW), which is the ratio of yield to the actual water consumed by the crop, for paddy, wheat and sugarcane in HM were found to be 0.5, 1.0 and 5.9 respectively and for NM were found to be 0.6, 1.0 and 6.5 kg-m-3 respectively indicating good PAW for both HM and NM, and comparatively more in NM than in HM for wheat and sugarcane. Average revenue per cubic metre of irrigation water supplied were found to be 0.13 and 0.20 ₹/m3 for HM and NM respectively. It was found that water supplied is more than the required quantity. Productivity of rice, wheat and sugarcane is within the range suggested by FAO. xiv In spite of supplying more water than required, the tail end users are not receiving the due share which calls for proper management and distribution of water. This can be achieved by creation of water user’s association and awareness among the farmers about the judicious use of water. Indicators also suggested for implementation of agricultural extension programmes for improved agricultural practices and inputs. Analysis also demands for improvement in irrigation schedule and earmarking of suitable period of least water requirement for carrying out the annual maintenance. This study suggests that optimum utilisation of land and water resources for increasing the productivity cannot be achieved by providing or improving the structural components only but can be achieved by combination of proper structural inputs, efficient management and agricultural extension programmes. For sustainable development, the Food – Energy – Water Nexus (FEW) has been utilised as a conceptual tool. Land and water being limited, increased population and food demand has resulted in increased stress on water and demand for energy. The demand for food has resulted for increased demand for land from 85 hectares in 1981 to 91 hectares in 2011. The demand for energy from outside boundary has increased from 0 in 1981 to 4798 Tera Joules (TJ) in 2011. The demand for water within (for domestic purpose) and across the boundary (for agricultural purpose) has also increased. Therefore, the food, energy and water nexus at micro level is required to be understood for adapting an integrative approach for sustainable management and development of available resources.