| As populations grow and economic develops, the shortage of water resources are increasingly prominent. Hydrological responses which are result from the change of land use and land cover during the process of the river basin hydrological cycle has become an advanced research hotspot of hydrological cycle under the changing environment. The change of runoff of basin outlet is intuitive behavior of LUCC hydrological responses. Our country is agricultural country, and irrigation water accounts for 65 percent of annual water supply. As a result, reducing the agricultural water will be an important approach of achieving water resource sustainable utilization. As the important means of water resources allocation, optimization design of irrigation and water price control are playing an important role in increasing river runoff.In this paper, Wohushan basin will be introduced. By using 3S technology and a distributed hydrological model named SWAT, we can analyze hydrological responses which are result from land use and land cover change from 1988 to 2014. After optimizing the irrigation resign, we can simulate the change of basin runoff and analyze the influence of raising water price on basin runoff and national economy. The specific research content are as follows:(1) After a full investigation of researched region and collection of data, we can finish calibration and verification of SWAT model. As a result, we can get the conclusion that R2 =0.73, Ens=0.66.(2) After analyzing the land-use maps of 1988、1996、2002、2009 and 2014, we can find change characteristics of all types land utilization: as time goes by, the magnitude of change in land utilization of Wohushan basin has been reduced during our study period. The area of residential land and traffic land have increased by plunder of grass land and farm land, meanwhile, forest lands has little change. We can assume that the climate condition is unchanged, and then inputting the climate data of 2009 which is a typical year when using SWAT model, we can get the result of basin runoff of five periods which are mentioned above. At last, we find an increase trend in basin runoff.(3)Winter wheat of Wohushan basin is irrigated in the reference of the irrigation quota in Shandong province, when guarantee rate is 50%, irrigation quota in growth period is 288m3 per Mu, considering crop water requirement and the randomicity of rainfall, we reduced the irrigation quota in typical year of 2009 to 248 m3 per Mu when optimizing the irrigation scheme so that we can reduce the irrigation quota. Then, we put the data we optimized into the SWAT model, then we can find that the basin runoff increased 0.31% after optimizing the scheme.(4)The water price has a direct influence on water resources demand, price flexibility coefficient of irrigation water demand is 0.2, that means we raise water price by 50% and 100%, irrigation water will reduced by 10% and 20%. When we raise the water price by 50% and 100%, the basin runoff will increase by 0.19% and 0.44%. From the output table of cyclic economy, we can conclude that if there is a water price increase of 50%, the average price of agricultural products、industrial products and public service will increase by 0.061%、0.053% and 0.072%,even if the water price doubles, the average price will only increase by 0.123%、0.105% and 0.143%. So we can conclude that the influence of raising water price on Hydrological positive effect is larger than the influence on economic negative effect. Because the water price is low now, the proportion of water price in cost of production is small, so there is plenty of room for improvement in water price. |
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