| Reducing socio-ecological system vulnerability is not only an important basis for improving regional policy systems,but also a necessary condition for achieving sustainable development.In the face of the risk of regional environmental degradation and natural disasters caused by the interaction of human activities and the natural environment,many policies have been developed that have a positive impact on a particular element of the social system or ecosystem,but their impact on socio-ecological system vulnerability is unknown.There is an urgent need to identify the impact of policies on socio-ecological system vulnerability in order to provide a scientific basis and reference for decision making to improve the regional policy system.Under the implementation of ecological policies,Minqin County in the lower reaches of the Shiyang River Basin,a typical northwestern arid zone that combines water scarcity,poverty concentration and ecological fragility,has seen more drastic changes in the internal elements of the social-ecological system.The complexity of the ecosystem itself,the multiplicity of ecological and socio-economic relationships,and the diversity of sources,overlapping effects,integration with other policy elements,and stock of policies,lead to a number of issues that still deserve attention and resolution in the formulation and implementation of ecological policies.In view of this,this paper takes Minqin County in the lower reaches of the Shiyang River Basin as an example,and based on policy documents and statistical data,uses segmented linear regression and panel vector autoregression to analyse the ecological policies and socio-ecological system evolution stages in Minqin County since the founding of the People’s Republic of China,and takes two ecological policies,namely arable land reduction and afforestation,as examples,to analyse the intensity of arable land reduction,afforestation and The spatial and temporal changes in the intensity of cropland reduction,afforestation and socio-ecological system vulnerability in Minqin County from 2002 to 2020 were analysed.The results found that.(1)Since the founding of the People’s Republic of China,the ecological policies of Minqin County has gone through a stage of exploring governance(1949-1972),a stage of initial governance(1973-2000)and a stage of comprehensive governance(2001-2020),and has undergone a transformation from end-of-pipe governance of ecological problems,short-term governance,and governance that splits watersheds into individuals,to source-based governance of ecological problems,long-term governance,and governance that considers watersheds as a whole.(2)From 2002 to 2020,the intensity of cropland reduction and afforestation in Minqin County showed an upward trend,with the highest intensity of cropland reduction in the Quanshan District and the lowest in the Desert District,and the highest intensity of afforestation in the Dam District and the lowest in the Desert District.Spatially,the intensity of cropland reduction and afforestation are generally distributed in a pattern of "high around and low in the middle",in which the spatial distribution of cropland reduction intensity remains unchanged,while the high value of afforestation intensity gradually expands.(3)Since the founding of the People’s Republic of China,Minqin County’s social-ecological system has undergone a release-restructuring phase(1949-1972):social and economic functions slowly increased and ecological functions slowly decreased;restructuring-rapid development phase(1973-1990): social and economic functions sharply increased and ecological functions sharply decreased;rapid development-conservation phase(1991-2010): social,economic and ecological development methods sought to change;conservation-stable and conservative phase(2011-2020): social,economic and ecological functions tended to develop in harmony.(4)From 2002 to 2020,the social-ecological system vulnerability index of Minqin County shows a fluctuating decreasing trend,with the desert area being the most vulnerable and the dam area the least vulnerable.Among them,the exposure and sensitivity indices show a fluctuating downward trend,while the adaptive capacity index shows a fluctuating upward trend.Spatially,the distribution pattern of socio-ecological system vulnerability is "high around and low in the middle",and the exposure,sensitivity and adaptive capacity are "high around,low in the middle","high in the north,low in the south" and "low around,high in the middle" respectively.(5)Both the increased intensity of arable land reduction and afforestation have a positive effect on the reduction of socio-ecological system vulnerability,and both shocks show a negative cumulative effect in the form of "wave-like" changes.In particular,socio-ecological system vulnerability is more influenced by itself,but its influence gradually decreases,while the influence of arable land reduction and afforestation intensity on socio-ecological system vulnerability generally tends to increase.Afforestation intensity has a stronger impact on socio-ecological system vulnerability than does cropland intensity. |
