基于SVR的长江经济带水环境承载力评价

基于DPSIRM模型构建区域水环境承载力评价指标体系，并基于SVR模型构建了区域水环境承载力评价模型，利用交叉验证法对SVR模型参数进行优化选择，进一步提高模型预测精度.运用该模型研究了长江经济带2009~2018年的水环境承载力演变趋势及空间差异，结果表明：长江经济带水环境承载力等级整体呈现升高趋势，其中上游城市群承载等级由II级（超载）提升到了IV级（弱可承载）；中游城市群承载等级由II级（超载）提升到了IV级（弱可承载）；下游长三角区域承载等级由I级（重超载）提升到了IV级（弱可承载）.将评价结果与熵权-TOPSIS法的评价结果相比较，相同率达到91.7%，说明SVR模型评价区域水环境承载力可行，评价结果可靠.以下游区域为例，分别对其6个子系统的承载力进行剖析，并运用单因素轮换OAT法对各子系统内的评价指标进行敏感性分析，便于决策者识别指标敏感性.

Evaluation of water environment bearing capacity of Yangtze River economic belt based on SVR Model

The Water Environment Bearing Capacity Assessment Index System and Model were constructed respectively from DPSIRM and SVR Model, then parameters of the SVR Model were optimized via cross-validation methodology to further improve the accuracy of the prediction. The evolution trend and spatial differences of water environment carrying capacity of Yangtze River Economic Zone from 2009~2018 were studied using the Model. Water Environment Bearing Capacity Grade of Yangtze River Economic Belt presents an upward trend in a whole, the bearing level of the city agglomeration of upstream and midstream of the River has been improved from level II (overload) to level IV (weakly loadable), while the level of the downstream area changed from Level I (heavy overload) to Level IV (weakly loadable). By comparing the evaluation results of the Model and entropy weight-TOPSIS method, the coincidence rate reaches 91.7%, the SVR model is feasible to evaluate the water environment carrying capacity and the results are reliable. The bearing capacity of six subsystems of the downstream region was analyzed, then the sensitivity analysis on evaluation indicators in each subsystem was performed based on Single Factor Alternate Method (OAT) so as to help decision makers identify the sensitivity of indicators.