湖南省水资源脆弱性时空演变研究

Spatial-temporal evolution of water resources vulnerability in Hunan province

为研究湖南省水资源脆弱性动态演变问题,利用GIS和RS技术,基于PSR概念模型构建水资源脆弱性评价指标体系,采用改进的主成分分析法和熵值法确定水资源脆弱性指标综合权重,对2005—2013年湖南省水资源脆弱性的时空演变特征和脆弱性成因进行分析与探讨。结果表明:(1)研究区水资源脆弱性时空分布格局呈现"中高周低,东强西弱"之势;(2)重度和极度脆弱区域团聚在东部和北部,微度和轻度脆弱区域呈阶梯状分布在西南两翼,中度脆弱区域如星罗棋布般分布在各个州市;(3)从时间变化上看,大体呈现"首尾时段波动明显,中间时段相对稳定"的特征;(4)从演化的空间分异特征看,其脆弱性变化大致分为2种类型:持续增速型和低速稳定型。由此可见,近9年来,湖南省水资源脆弱性具有明显的时空分异特征。人类活动的影响是水资源持续脆弱的主导因素;强降雨事件发生的频率是区域水资源系统性增强与减弱并存的直接原因。

In order to study the dynamic evolution of the water resources vulnerability（ WRV） in Hunan province. By using GIS,RS technology and based on the water resources pressure-sensitivity-applicability（ PSR）conceptual model,an evaluation index system for WRV was constructed. Meanwhile,principal component analysis（ PCA） and entropy method was adopted to determine the weight of WRV index from 2005 to 2013.Then the spatiotemporal characteristics of WRV and its reasons was analyzed as well. The results show：（ 1）during the study period,the spatiotemporal distribution pattern of WRV is low in the border regions and high in central regions,strong in the east and weak in the west;（ 2） Severe vulnerability of WRV centralizes along the north and east,while the slight and moderate vulnerability is ladder-like distributed along the south and west. Meanwhile,the areas of moderate vulnerability disperse all over the study area;（ 3） the feature of time series of the WRV typically present fluctuated at the begin and end of the study period,and relatively stabilized in the middle period;（ 4） from the spatial differentiations of evolution,the vulnerability changes are broadly divided into two types： continuous growth and low speed stability. In recent nine years,WRV of Hunan province had an strong spatial and temporal variability. The impact of human activities is the dominant factor that drives water resources continue to be fragile. Meanwhile,the frequently heavy rainfall events is the direct causation of the coexistence of increased and weakened WRV.