Drought Vulnerability In Social-ecological System And Drought Adaptation Of Farmer Household On The Loess Plateau

Research on drought vulnerability and drought adaptation is a hot issue in the field of global change and sustainability science.In the context of global climate change,drought occurrence frequency has become increasingly severe on the Loess Plateau of China,poses a great threat to sustainabl development in local district,which has influence on components of social-ecological system including social,economic,ecological and farmer households in multiple dimensions.The framework of vulnerability-adaptation contributes to understand the relationship between global climate change and sustainable development in a new viewpoint.This study constructs the framework of vulnerability and adaptation to drought regarded as disturbance to social-ecological system in Yuzhong county on the Loess Plateau.Based on meteorological site data(1960-2015a),remote sensing data(2002-2015a),statistical data(2002-2015a)and survey data,it analyses drought condition from 1960 to 2015 in Yuzhong county by standard precipitation index in different time scale,introduces mathematical model to assess the direct and indirect effect resulted by drought to social-economic components?agricultural and ecological components and farmer households.Then,it constructs drought vulnerability indicators system in three dimensions including exposure,sensitivity and adaptive capacity,calculates drought vulnerability index from 2002 to 2015 in town level in Yuzhong county and find law of temporal and spatial evolution combining GIS technique and mathematical model,checks the robustness of drought vulnerability index with robustness analysis method.In an end,it conceptualizes farmer household adaptation to drought,containing adaptive capacity,adaptation process,adaptation outcomes and adaptation mechanism.It measures adaptive capacity index of different livelihood types and different geographic location by constructing adaptive capacity indicators system from natural capital,physical capital,human capital,financial capital and social capital,and identify the factors which determine adaptive capacity of farmer household to drought.Simultaneously,it indicates adaptation process of farmer household to drought with adaptive action and adaptive strategies,characterizes adaptation outcomes to drought with coping degree,adaptation effect and adaptation paths,and combines quantitative and qualitative methods to reveal the inhere mechanism of adaptation to drought.Above all,the objective of this study is to provide theoretical basis for making economic development policy,disaster prevention and mitigation and targeted poverty alleviation.Main study conclusions contain as follows:Drought events in Yuzhong county occur in high frequency,and the higher drought severity is,the longer time scale is,which there is no significant seasonal difference characteristics.There is high match between drought identification results and historic drought events.Drought has direct influence on food production,and has no significant influence on agricultural GDP proportion,per capita income of farmers,NDVI,cultivated land area,agricultural workers,illiterate and semiliterate population and urbanization rate in period 2002-2015 a,results in economic obvious loss with high frequency,which is relatively low a majority of towns in Yuzhong county instead.However,drought severely affects household income,food security,quality of life and emotions of coping with drought.There is obvious growth trend of drought vulnerability index and its variation coefficient,indicating the degree of drought vulnerability and its spatial differences increasing in period 2002-2015 a.The number of towns in different drought vulnerability degree presents the characteristic with general drought vulnerability>higher drought vulnerability=high drought vulnerability>low drought vulnerability>lower drought vulnerability.The result and ranking of drought vulnerability index in town level is with high robustness.There is significant difference in adaptive capacity to drought among farmer household in different livelihood types,of which is comprehensive farmer > off-farm farmer >farm-off farm farmer > worker> farmer from high to low.The determinants of adaptive capacity in farmer household respectively are livelihood diversity,number of appliances and phones,economic status in village,livestock scale and agricultural inputs.So famer households make adaptive actions including laying mulch,reducing spending,working,borrowing money from friends and relatives,and irrigating by adaptation strategy with diversity,resulting that adaptation outcomes differ obviously,which farmer is worse,farm-off farmer and worker is generable,comprehensive farmer and off-farm farmer is better.