Response Of Runoff To Climate Change And Adaptation Strategies In The Yuanjiang River Basin

Water resource is the foundation of subsistence of human beings,and is a key area which is affected by global climate change.Because of the impacts of global climate change,Water resource has received an unprecedented challenge as a human basic and strategic natural resources.Water resource problem has become a key factor of the sustainable development of social economy.As a basic subject in the study of sustainable development and water resources security,the evolution of water resources and adaptive management for climate change are important and hot issues in the current study.Yuanjiang River is a main river of Red River,which is an important international river in China.The impacts of climate change on hydrology and water resources have become a hotspot of current research.There is a study of Yuanjiang River Basin in this paper.Based on the discharge data of Manhao hydrological station and meteorological data at 30 meteorological stations in the Yuanjiang River Basin,I analyzed multi-temporal scale changes of runoff and meteorological from 1961-2012,and analyzed the influences of climate change and human activities on runoff.Then I proposed the measures of transboundary water resources adaption management.The results showed that:(1)The precipitation in the Yuanjiang River Basin had an unobvious decrease trend,with a rate of-8.2mm/10a,while the temperature had an obvious increase trend,with a rate of 0.1?/10a.And the potential evaporation had been increasing at a rate of 1.8 mm/10a.Results of wavelet analysis showed that the precipitation had a change periodicities of 8a?14a and 29a.Differently,the temperature and potential evaporation had an only change periodicities of 29a.(2)The runoff in the Yuanjiang River Basin had an unobvious decrease trend,with a rate of-3.56×108m3/10a in the last 50 years.The concentration period of the runoff at Manhao station showed an advance trend.And the inter-annual variations were acute,with significant differences between the wet year and dry year.It showed that the low water periods appeared from the mid-1950s to the mid-1960s,high water period from the mid-1960s to the mid-1970s,flat partial dry period from the mid-1970s to the mid-1990s,flat partial wet period from the mid-1970s to 2002,and low water period after 2002.The mean annual runoff decreased in the past 50 years.Results of wavelet analysis showed that the annual runoff at Manhao station had a change periodicities of 4a?6?9a and 21?22a.And a significantly change periodicities of 21?22a were found in the Yuanjiang River Basin.(3)Using the method of accumulative anomaly and the orderly cluster method,combined with human activity within a basin,the runoff series is divided into base period(1961-2002)and change period(2003-2012).Sensitivity coefficient method and BP-ANN model are used for quantifying the influnces of climate change and human activities on runoff.We found that the most important factor which caused decline of discharges in the Yuanjiang River Basin was precipitation,which had a 56?66%contribution.Human activities were also an important factor which influenced the intra-annual distribution of runoff,having a 34?43%contribution.Precipitation had a more sensitive influence to runoff variation than potential evaporation.(4)Under the background of climate change,there were many problems including drought,flood disasters,increasingly uneven spatial and temporal distribution and transboundary water resources development and utilization in the Yuanjiang River Basin.Adaptive strategies were put forward in order to enhance the adaptability of water resources,reduce the vulnerability of water resources caused by climate change,and ensure the sustainable utilization of water resources.