incorporate externalities of water extraction from agricultural wells around parishan lake, case study: wheat product

abstract irregular extraction from agricultural wells around parishan lake, moreover fall of groundwater surface and water salty, would affect the level of lake water and move lake water into wells. in this study we have evaluated the externalities of extraction from agricultural wells around the lake. therefore feedback effect is considered between agricultural activity around the lake and level of lake water by autoـ regressive distributed lag model. the results use in the ecologicalـ economic model. the results show that increase of water extraction from agricultural wells for wheat irrigation would affect the wheat yield and therefore increase farmers income. but on the other hand increase of extraction from wells, would affect the groundwater surface and increase pumping cost. by attention to effects of groundwater extraction on pumping cost are more than these effects on farmers income, so excess extraction has negative profit (loss) for farmers. in addition decreasing of the lake water duo to excess extraction from groundwater, would affect the wheat yield and decrease farmers income and would affect the groundwater surface in wells around the lake and increase pumping cost, so it decreases farmers profit. so we have offered to control of irregular extraction from groundwater for protection of lake ecosystem and groundwater surface.