The survey of energy subsidies reduction on water resource stability in northern Mahyar Plain aquifer: positive-stochastic dynamic programming approach

Although government’s supportive payments to agricultural activities is fulfilled for the purpose of increasing of social benefits, but it will cause some economic and environmental externalities. So that today the development of agricultural activities lead to decline in groundwater level in most of these aquifers. This topic has increased the interest of related governmental sectors in developing and application of water conserving policies in aquifers. The objective of this study was to analyze and evaluate the outcomes of energy subsidies decline as specified water conservation policy alternatives on groundwater consumption and cropping patterns on the aquifer of Mahyar plain in Isfahan province, using non-linear optimization model. A Positive Mathematical Programming (PMP) model was developed and calibrated to land and water usage data for a base period of 2004-2005. The PMP approach produces a constrained non-linear optimization model that mimics the land and water allocation decision facing producers each year. The choice variables in the model are the acreages planted to each of the major crops and the water use by crop. The result showed that water application per acre decreased significantly under the high price scenarios, during the early years of the simulated period. This suggests that high energy prices have a significant effect on the rate of increment of the Mahyar aquifer stability.