Study On Spatial Heterogeneity Of Water Supply Service Functiom In Qi River Basin

Mountain is an important part of the earth's life support system and the foundation of the survival and development of the terrestrial ecosystem.It is one of the most vulnerable ecosystems on the land surface,and is sensitive to global change.Under the background of global change,mountain ecosystem has changed significantly in recent years,mainly in forest area reduction,land degradation and desertification,soil erosion and natural disasters.Mountain ecosystem is an open giant system.The large terrain difference makes the ecosystem change dramatically in short distance,forming a significant geographical gradient difference.With the increasing awareness of the importance of the importance of mountain ecosystem services,the research on the service function of the mountain ecosystem has also developed rapidly.The sensitivity of mountain ecosystem to water is very prominent.Mountain area climate change and vegetation cover change will cause hydrological process change in mountainous area,which will have a great impact on water supply and soil erosion.The water supply service of the mountain ecosystem is an important basis for maintaining the functions of biodiversity and other key ecosystem.Mountain ecosystem is an open giant system.Mountain area,which accounts for 24% of the land area,provides 80% of the water for mankind.Therefore,the mainten ance of mountain ecosystem service function is a hot topic in the academic field.It plays a crucial role in the sustainable development of human society,economy and ecological environment.Qihe river is located in the southern part of Taihang Mountain,belonging to the second step to the third step transition region,is gradually decreased from west to East,mountainous area accounts for the total drainage area of 96%,with mountains,hills,plains and other types of landforms.Climate types belong to warm temperate semi humid continental monsoon climate,and four seasons are distinct.The annual average precipitation is 617.8mm.It is one of the rainstorm centers in China.The 2000-2015 annual rainfall,evapotranspiration,DEM,soil depth data and land use data,based on Arc GIS platform,using the transfer matrix of land use,Kriging,In VEST model and other tools,to evaluate the spatial heterogeneity of water supply service function in Qi River Basin,and analyzes the distribution and variation of water supply of Qihe River Basin 16 years service space and the change characteristics of water supply under different terrain factors,and provide scientific basis for for the ecological society Qihe River Basin construction.The conclusions of this study are as follows:(1)The nearly 16 years of water supply Qihe River Basin increased first and then decreased,and reached the peak in 2005(179 million m3).Study on the spatial distribution pattern of water supply area during 16 years is similar to that of the water supply was the highest values in the basin;with different spatial change of two adjacent water supply area of 2000-2005 years of water supply in Qihe increased more than the reduced area,water supply capacity and enhance overall water supply capacity of 2005-2010;and 2010-2015 years decreased,including 2010-2015 years of water supply reduction rate is relatively small.(2)The supply of 2000-2015 years of water supply of Qihe basin main functional areas is increasing the northwest to the southeast from the general trend,an important area to the important area change process.The spatial distribution of the important functional areas of water supply in the four phase of the study area is basically the same.(3)Qihe river basin water supply per unit area decreased with fluctuation;water supply per unit area decreased gradually with the increase of altitude,the lowest value reached an altitude of >1600m(348.05mm/km2);with the increase of slope unit area water supply decrease and then increase gradually,anticlimax in a steep peak,slope areas of low water supply capacity is relatively strong;the study area ground area water supply per unit area reached a peak(4771.98mm/km2),indicating that the region with slope to the water supply capacity is relatively strong.(4)From different terrain analysis,water supply distribution in small fluctuation,followed by micro fluctuation and flat area;from the analysis of different vertical zones,Qihe river basin water supply is mainly provided by the low altitude region;from the analysis of different slope,water supply on the whole of slope is low high slope;from different aspect analysis,water supply in the aspect of the distribution is uniform,slightly higher than that in sunny slope,consistent with the distribution of water supply quantity in the study area on the slope.(5)Land use types are mainly cultivated land,grassland and woodland in Qihe River Basin.In the past 16 years,the land use types in the study area changed to varying degrees: the area of cultivated land decreased significantly,and the area of grassland and water area increased significantly,and the expansion of construction land was obvious.There is little change in the area of woodland.2000-2015 years of total water supply of Qihe river is the smallest land type is water,tand he amount of water supply of other land use types from large to small is as follows: in 2000,grassland> land used for building > cultivated land> woodland> unused land,consistent change in 2005 and 2000;in 2010,land used for building > grassland > woodland > cultivated land > unused land,and in 2015 and 2010 the change is consistent.(6)From the analysis of land use types and the change of water supply per unit area,we can see that with the decrease of arable land on different terrain factors,the area of woodland and grassland increases,and the corresponding unit area water supply decreases.