optimal sustainable use of groundwater in agricultural sector: case study subsector in qazvin basin

abstract surface water restriction and supply variation of these resources causes of over extraction of groundwater and unbalance between feed and extraction of groundwater in iran. agricultural sector as the biggest consumer of water resources has the most share of this unsustainability. this paper studies the conjunctive use of surface and groundwater in agronomy production in qazvin basin, one of the most important areas of water crisis in iran. for this, we used an intertemporal mathematical programming model to determine optimal cropping patterns of the crops for ten years period in qazvin. for constructing the model, the duration of growth, water requirement of the crops, accessible surface water and exhaustible groundwater in qazvin has been considered, and finally the cropping patterns was recommended. according to groundwater resources restrictions, it is suggested that cucumber and sugarcane is excluded, and cultivated area of maize and barley is increased in cropping pattern.