基于改进TOPSIS的水资源承载力动态评价

Dynamic Evaluation of Water Resources Carrying Capacity Based on Improved TOPSIS

为进一步研究水资源的动态性,并针对传统TOPSIS评价水资源承载力存在的问题,如评价值临近分级区间边界时,等级区分度不高,从而难以形成客观有效评价。利用D-S证据理论能有效降低数据差异性带来的损失,融合结果客观准确的优势,改进TOPSIS方法进行水资源评价。通过融合TOPSIS方法中的指标向量与正负理想解的距离,获取水资源承载力各等级合成信度,基于具有较大区分度的合成信度值判断水资源承载力等级。在此基础上,引入指标增量计算历年水资源承载力的变化情况,利用时间权向量组合历年变化情况,分析水资源承载力发展趋势。算例结果表明:改进TOPSIS方法后,2018、2020年的水资源承载力评价值与区间边界的区分度,由0.0003、0.0011提升到0.019、0.3367。同时,利用提出的趋势分析法计算2020年水资源承载力趋势,与实际结果差距仅为0.0019,验证了方法的有效性。最后根据本文方法预测2021年水资源承载力为负向变化趋势,并采用障碍因子模型诊断主要影响指标为年降水量及人均水资源量,提出加强生态环境建设及优化水资源合理配置的建议。利用本文方法进行水资源承载力评价具有更高的等级区分度,评价结果合理客观,符合实际情况,并且能综合利用历年动态数据,较为准确的描述水资源承载力的变化情况,可为水资源的开发保护提供科学依据。

In order to study the dynamics of the water resources system and to solve the problems existing in traditional TOPSIS evaluation of water resources carrying capacity,for example,when the evaluation values are close to the interval classification boundary,the grade differentiation is not high,thus it is difficult to form an objective and effective evaluation.In this paper,due to the advantage that D-S evidence theory can effectively reduce loss caused by data variability and fuse the results objectively and accurately,it is used to improve TOPSIS method for water resources carrying capacity evaluation.By fusing the distance between the indicator vectors in TOPSIS method and the positive and negative ideal solutions,the synthetic confidence of each grade of water resources carrying capacity is obtained,and the grade of water resources carrying capacity is judged based on the synthetic confidence value with greater differentiation.On this basis,the indicator increment is introduced to calculate the changes in the water resources carrying capacity over the years,and the time power vector is used to combine the changes over the years to analyze the trend of water resources carrying capacity.The results show that:the discriminations between the evaluation value and the interval boundary are improved from 0.0003,0.0011 in 2018 and 2020 to 0.019 and 0.3367 respectively by improved the TOPSIS.Meanwhile,the error between the predicted trend using the proposed trend analysis method and the actual result is 0.0019 in 2020.Finally,it is predicted that the water resources carrying capacity will have a negative trend in 2021.The main impact indicators are annual precipitation and per capita water resources by the obstacle factor model.The suggestions are put forward to strengthen the construction of the ecological environment and optimize the rational allocation of water resources.The method in this paper has higher grade distinction,and the evaluation results are reasonable and objective,in line with the actual situation.And it can also make comprehensive use of the dynamic data of the past years so that it can accurately describe the changes in water resources carrying capacity,which can provide a scientific basis for the development and protection of water resources.