A preliminary study on the agricultural water resources balance and eco-agriculture program in a semiarid regi0n— A case study from the west area of Jilin Province

According tO the balance condition between supply and demand of agricultural water resources ，in order tO improve the agricultural water resources balance and rise the ecological benefit of the agriculture ecological system ，the struc-tttre of the system WaS regulated by using linear programming．The results show that the shortage of the water resources and the agricultural coo-environment can be improved and the ecological benefit of the system can be risen obviously by cutting down the farmland area suitably and expanding the artificial grass，forest and waters area，and the stability of the grain output and agricultural economic benefit at present may be kept．