基于WPI模型的中国水贫困时空异质性研究

Spatial and Temporal Heterogeneity of Water Poverty in China:Based on WPI Model

在我国水资源约束日益严重的背景下,选取我国31个省市2005—2017年的面板数据,运用水贫困指数(Water Poverty Index,WPI)模型构建水贫困评价指标体系,进行水贫困的时空差异分析。结果显示:首先,2005—2017年我国整体水贫困指数呈上升趋势,其中宁夏、天津的水贫困指数较低,而广东、江苏的水贫困指数较高(水贫困指数越高,水安全程度越高);其次,水资源丰富且用水能力较强的长江中游区域水贫困指数明显高于其他区域,东部、南部、大西南及东北属于第二梯队,而黄河中游、北部及大西北的水贫困指数则低于全国平均水平;最后,基于泰尔指数的水贫困时空差异分析表明,地区内部差异是造成我国各省市水贫困差异的主要原因。因此,在保障我国水安全战略和实现可持续发展目标的宏观背景下,亟需通过资源、途径、能力、使用和环境五个维度改善区域水资源系统状态,减少区域内部各个省市之间的水贫困差异,从而提升我国水安全水平。

Under the background of increasingly serious water resources constraints,this paper mainly analyzes temporal and spatial differences using the WPI(water poverty index)model through panel data of China′s 31 provinces from 2005 to 2017.Firstly,an evaluation index system based on WPI was constructed and 22 indicators in 5 dimensions were selected.Next,after the weights of each indicator was calculated with entropy method,the Spearman′s rank correlation coefficient was introduced to measure the degree of information loss of the evaluation results obtained by the SAW,TOPSIS and WPI methods.Finally,spatial-temporal difference analysis of water poverty was conducted by the results of WPI method with minimal information loss.The results show that:(1)during the period of 2005-2017,the water poverty index of China showed an upward trend.The water poverty indices of Ningxia,Tianjin provinces were lower,while that of Guangdong,Jiangsu provinces were higher(the higher the better);(2)the regional WPIs in the middle reaches of the Yangtze River areas with more water resource and stronger water use capacity were significantly higher than other areas.Eastern,southern,southwest and northeast belong to second tiers,while middle reaches of the Yellow River,north and northwest were under the average level;(3)the spatial-temporal difference analysis based on the index shows that the within group difference is the main source of the total difference in water poverty among provinces in China.Therefore,improving performance of regional water system on resource,access,usage,capacity and environment,and reducing the difference between provinces within group are the keys to promote the status of water security in China.