渭干河流域农田生态系统服务价值变化及其影响因素分析

Service values change of farmland ecosystem and its influence factors analysis in Weigan River Basin

以渭干河流域为例,计算了2000—2010年间上游山区、中游山间盆地、下游冲洪积平原的农田生态系统服务价值变化,并采用多元逐步回归模型分析了人类活动对流域不同区域农田生态系统服务价值的影响。结果表明:渭干河流域农田生态系统综合服务价值呈中游山间盆地>上游山区>下游冲洪积平原的空间分异特征,单位面积农田生态服务价值则表现为上游山区>下游冲洪积平原>中游山间盆地;流域农田生态系统综合服务价值呈增长趋势,其中上游山区增加了3.86亿元、中游山间盆地增加了2.26亿元、下游冲洪积平原增加了6.02亿元;农田生态系统基本服务价值,上游山区、中游山间盆地及下游冲洪积平原年均分别增加0.56亿元、0.61亿元和0.75亿元;使用化肥等导致农田环境污染损失的价值表现出不同程度的增大趋势;农业耗水损失价值方面,上游山区和中游山间盆地年均分别减少0.19亿元和0.35亿元,下游冲洪积平原变化较小;回归分析结果显示渭干河流域农田生态系统服务价值的变化主要是由农业现代化以及种植结构调整引起的,流域不同地貌单元主要影响因子及影响程度具有较大差异性。

Taking Weigan River Basin（WRB） as an example ,calculated the service value change of farmland e-cosystem 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 comprehen-sive 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 up-stream 〉 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 up-stream ,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 consump-tion 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 im-pact factors and the degree of influence in different geographical unit in river basic will be had great difference .