Evaluation Of Water Resources Vulnerability In Karst Area Of Southwest China

Water resources is a basic and strategic resource,but with the rapid growth of economy and population,the deterioration of water pollution and water environment,the inevitable trend of climate change,the water resources system points a serious vulnerability.Guizhou as a typical province of Karst,and its water resources system is complex and fragile,so the study on water resources vulnerability could have important implications for the safe development,utilization,protection and scientific management of water resource,and promoting the construction of natural ecological barrier in the upper reaches of the Yangtze River and the Pearl River.Guizhou province is located in the subtropical monsoon zone,the precipitation is abundant,but the role of karst is strong,the dual-structure of surface and underground is remarkable,sanshui transforms quickly,the infiltration of surface water is serious,in addition rocky desertification is widely distributed,the ecologic environment is fragile,economic and social development lags behind relatively,all these together cause serious water resources vulnerability.In this study,two kinds of methods,including the comprehensive index method and GIS and RS,were used to analyze and evaluate the vulnerability of water resources in Guizhou.The main conclusions are as follows:(1)Due to the unique natural environment and relatively backward social economy in Karst,water resources vulnerability characteristics and influencing factors are unique.The water resources vulnerability in Karst area of Guizhou province is caused by climate change,ecological environment and socio-economic.Using SPSS and Excel statistical analysis tool to analyze the temperature,precipitation and summer drought data of Guizhou Province from 1961 to 2015,the results showed that: the precipitation in Guizhou province showed a decreasing trend,the temperature showed an increasing trend,summer drought showed an increasing trend.Based on the comprehensive analysis of the changes of precipitation,temperature and summer drought,we find that the climate of Guizhou Province is warming,and the warming of climate has increased the water resources vulnerability of Guizhou Province to a certain extent.(2)Based on the analysis of the influencing factors and characteristics of water resources vulnerability in the karst area of southwest China,this paper constructs the evaluation index system.Then two kinds of methods,including the traditional comprehensive index method and GIS and RS,were used to analyze and evaluate the vulnerability of water resources in Guizhou.The results of evaluation on water resources vulnerability based on comprehensive index method show as bellow: In time dimension,the vulnerability of water resources of Guizhou Province in 2000-2015 showed a downward trend in general.Specifically,the water resources in 2000,2001,2002,2003,2006,2009,2010 and 2011 show "utmost vulnerability";Water resources in 2004,2005,2013 show a "severe vulnerability";Water resources in 2007 show a "moderate vulnerability";Water resources in 2008 and 2012 show a "mild vulnerability";Water resources system in 2014 and 2015 show "no fragile".On the whole,the vulnerability of water resources is declining,natural vulnerability is on the rise,artificial vulnerability has shown a weakening trend on the whole.In spatial dimension,the vulnerability of water resources in 2000-2015 is higher in the south than that in the north.The results of evaluation on water resources vulnerability based on GIS and RS show as bellow:The vulnerability of water resources in southern Guizhou is higher than that in the north.Specifically,there are four high value aera.The first high value aera consists of Majiang County,County,Kaili City,Duyun City,Sandu County and Dushan County,which are all in the southeast Guizhou.The second high value aera is consisted of Liuzhi Special District,Guanling Buyi and Miao Autonomous County,Qinglong County,which are all in the southwest Guizhou.The third high value aera is Jiangkou County which is located in the northeast of Guizhou.The fourth high value aera is located in the west of Xingyi City.The vulnerability assessment results of the two methods are approximately the same,and the vulnerability of water resources in southern Guizhou province is higher than that in the north.(3)Based on the comprehensive analysis of the characteristics,influencing factors and evaluation results of water resources vulnerability in Karst,this paper puts forward some countermeasures and suggestions to reduce the vulnerability of water resources: We should enhance water conservation awareness and improve water use efficiency,including improving the efficiency of water use in agriculture,industry and domestic water.To reduce the vulnerability of water resources,we should use mechanism and price to control water use.Establishing and improve the water rights trading system and implementation cascade water system to improve water use efficiency.We should improve the scientific layout and construction of water conservancy projects to improve water resources support capabilities.We should use science and technology for rainwater collection,sewage treatment and recycling,water quality protection and the use of cloud water resources,thus expanding total water resources.In order to reduce the vulnerability of water resources,we should establish a long-term monitoring and warning system for water resources and water environment and improve the capability of sustainable water resources management.In order to reduce the vulnerability of water resources from the source,we should strengthen the water and soil erosion and desertification control.