Impact Studies Of Climate Change On Water Resources Security In The Zhangweinan River Basin

As an indisputable scientific facts, global climate is undergoing changes in thecharacteristic of warming according to a large amount of observation data. Climate changehas severe impact on natural environment such as water conservancy and ecology, as well aseconomic and social development, among which, water, as the final area in the chain, isaffected in the most direct way. Zhangweinan River basin is heavily affected by humanactivities and sensitive to climate change. Water resourcess security in this basin would bethreaten directly by climate change. Hence, the impact research of climate change onZhangweinan River basin is significant in the way of providing scientific basis for rationalplanning and sustainable utilization of water resourcess in this basin. In this thesis, the changetrends of hydrological and meteorological elements in the last50years are analyzed firstly.Then, water supply and demand situation and socio-economic index values in2030arepredicted, seven evaluation scenarios are set in accordance with this analysis. After thoseabove, evaluation index system and criteria of water resources security are established. Twoevaluation methods are adopted to evaluate the safety of water resourcess respectively underseven scenarios in five regions. Finally, the results are compared with each other and thecorresponding adaptive strategies are given.The main conclusions are as follows:1、The nonparametric Mann-Kendall statistical test method was adopted to analyse thelong-term trend of hydrological and meteorological changes in Zhangweinan River basinduring the past50years form1957to2009, results show that the warming trend is moresignificant in tempreture, while the annual mean precipitation has shown a decrease trend,especially in summer. Decreaseing trend is also significant in runoff.2、 According to Hurst Index calculation results, the annual mean temperature，precipitation and runoff series have shown strong continuity in the Zhangweinan River Basin,indicating that the future trend will be consistent with that of the past. Climate warming alongwith decreasing precipitation will inevitably lead to a reduction in runoff; therefore, droughtwill be intensified in the Zhangweinan River Basin. From the above, it is predicted that the climate in Zhangweinan River basin will become warmer and drier in the future. Meanwhile,the hydrological cycle may also be changed. All of these effect factors threaten the security ofwater resources.3、According to the runoff change under future climate, which was provided by NanjingHydraulic Reserach Institute, as well as the comprehensive water resourcess planning inHaihe River basin, water resourcess quantity, economic and social development indicators,situation of water supply and demand as well as waste water discharge indicators inZhangweinan River basin in2030were predicted.4、Water resources security evaluation index system and evaluation criteria wereestablished, seven scenarios were set according to climate change and socio-economicscenarios, evaluation index values were calculated respectively under the seven scenarios,Fuzzy comprehensive evaluation method and improved TOPSIS method were adopted tomake a quantitative evaluation on water resourcess security under seven scenarios in fiveregions, and the comparative analysis about evaluation results was carried out at last. Theresults indicate that: under the scenarios5,6and7, in which only climate will change in thefuture, water resources security comprehensive evaluation value has present a descendingtrend. While as the water resources security ratings in scenarios2,3and4are adaptabilityevaluation, which are made under considering of cliamate change and the adjustment onsocio-economic as well as supply and demand situation in the basin, the water resourcessecurity comprehensive evaluation scores of these five regions score are slightly higher thanthat in present situation. These results demonstrate that: climate change has exacerbated thesecurity situation of river basin water resources. The situation can be improved after propercomprehensive management, however, the grim situation of water resources in this river basinhas not been changed. Under climate change scenarios, this thesis has put forward adaptivestrategies for water resources security in Zhangweinan River basin, with a view to providescientific basis for rational water resources planning and sustainable utilization.