| Ecosystem services are closely related to human well-being,so people pay more and more attention to them.The degradation of ecosystem services directly threatens the sustainable development of regional,national and global social economies.It is of great significance to clarify the temporal and spatial changes of ecosystem services for maintaining and improving regional ecosystem services,preventing ecosystem risks and alleviating regional ecological pressure.The Central Yunnan Urban Agglomeration is the key urban group in Southwest China,and is the most developed,densely populated and the highest degree of urbanization in Yunnan Province.With the rapid development of industrialization and urbanization of urban agglomeration,the Central Yunnan Urban Agglomeration is facing great ecological environment pressure.On the one hand,the Central Yunnan Urban Agglomeration is facing a serious shortage of water resources.On the other hand,the Central Yunnan Urban Agglomeration is mainly mountainous and hilly areas,with concentrated annual rainfall,leading to serious regional soil erosion.Therefore,based on GIS spatial analysis and ecosystem service evaluation model In VEST,this paper evaluates the water yield service and soil conservation service of the Central Yunnan Urban Agglomeration from 1980 to 2018,and analyzes the spatiotemporal variation of water yield service and soil conservation service of the Central Yunnan Urban Agglomeration in recent 38 years.And on the basis of this study,exploratory spatial analysis and geographic detector were used to further analyze the spatial and temporal distribution pattern of water yield service and soil conservation service and the influencing factors of their spatial differentiation.The main research contents and conclusions are as follows:（1）The spatial and temporal characteristics of water yield service.From 1980to 2018,the water yield of central Yunnan Urban Agglomeration showed a trend of"increase-decrease-increase".From 1980 to 2000,the annual water yield increased by1.07×1010 m3.From 2000 to 2015,the annual water yield decreased by 1.75×1010m3.From 2015 to 2018,the total annual water yield showed an increasing trend,with an increase by 1.58×1010 m3.In terms of the time change,the highest water yield in2000 was 5.55×1010 m3,and the lowest water yield in 2015 was 3.80×1010 m3.In terms of spatial distribution,the east of the Central Yunnan Urban Agglomeration is the region with the highest water yield and abundant water resources,and the northwest of it is the region with the lowest water production and water resources shortage.On the whole,there are significant differences in the distribution of water yield in Central Yunnan Urban Agglomeration,and the spatial distribution of water yield is high in the east and low in the northwest.（2）The spatial and temporal characteristics of soil conservation service.From1980 to 2018,the soil conservation in Central Yunnan Urban Agglomeration showed a trend of"increase-decrease-increase".From 1980 to 2000,soil conservation increased by 1.64×109t.From 2000 to 2015,soil conservation decreased by 1.56×109t.From2015 to 2018,soil conservation increased by 1.10×109t.In terms of the time change,the highest soil conservation in 2000 was 7.87×109t,and the lowest soil conservation in 1980 was 6.23×109t.In terms of spatial distribution,the north and southwest of the Central Yunnan Urban Agglomeration is the region with the highest soil conservation,and the northwest of it is the region with the lowest soil conservation.On the whole,the spatial distribution of soil conservation in the Central Yunnan Urban Agglomeration is significantly different,and the spatial distribution of soil conservation is low in the east and high in the north and southwest.（3）The influencing factors of spatial heterogeneity of water yield service and soil conservation service.From 1980 to 2018,the geographic detector results of the spatial heterogeneity of water yield service and soil conservation service of the Central Yunnan Urban Agglomeration showed that:In different years,the explanatory power of the same factor to the spatial differentiation of water yield service and soil conservation service changed little and was relatively stable.There were significant differences in the explanatory power of different factors to the spatial differentiation of water yield service and soil conservation service.The factors of land use,rainfall,potential evapotranspiration and soil type have high explanatory power for water yield service,while NDVI,altitude,and slope have low explanatory power for water yield service.The factors of land use,slope,soil type and altitude have high explanatory power for soil conservation service,while rainfall erosivity and NDVI have low explanatory power for soil conservation service. |
