| Taking Weigan River Basin(WRB) as an example, calculated the service value change of farmland ecosystem for mountainous areas in upstream, intermountain basin in midstream and alluvial-proluvial plain in downstream during 2000—2010, and adopted the multiple stepwise regression model to analyze the impacts of human activities on the service value of farmland ecosystem(SVFE) for different areas in river basin. The results showed that: The comprehensive SVFE in WRB assumed the characteristics of spatial heterogeneity as intermountain basin in midstream＞mountainous area in upstream＞alluvial-proluvial plain in downstream. The SVFE per unit area are shown as mountainous area in upstream＞alluvial-proluvial plain in downstream＞intermountain basin in midstream; The comprehensive SVFE in whole river basin was shown the increase trend, among them the mountainous area in upstream was increased 386 million yuan, the intermountain basin in midstream was increased 226 million yuan and the alluvial-proluvial plain in downstream was increased 602 million yuan. The basic SVFE was yearly increased 56 million, 61 million and 75 million yuan in upstream, midstream and downstream, respectively. The loss values of farmland environmental pollution caused by using chemical fertilizer was showed increasing trend in different degrees. The yearly loss values of agricultural water consumption was reduced 19 million and 35 million in upstream and midstream, respectively, but it was small change in alluvial-proluvial plain of downstream. The results from regression analysis were shown that change of SVFE in Weigan River Basin was mainly caused by the agricultural modernization as well as the adjustment of planting structure, the main impact factors and the degree of influence in different geographical unit in river basic will be had great difference. |