Study On The Identification Of Conservation Priorities For Protected River Area Based On Ecosystem Integrity And Authenticity:A Case Study Of Sichuan Province

Protected area（PA） is important for maintaining ecological security worldwide.Protected river area（PRA）is the essential component of PA.However,river are often ignored in PA’s construction.In essence,freshwater ecosystem that includes river,are one of the most threatened habitats in the world.Against this backdrop,this research selects Sichuan Province as the study case,which is known as the"Province of Thousand Rivers".According to the spatial determination criteria of PRA,the Ecosystem Approach is applied to develop a model for identifying conservation priorities for river（CPR）of Sichuan Province.This research extracted representative freshwater species,vegetation in basin and human activitity influence in basin as constituent elements of the model from river ecosystem.Then,the paper selected four indicators of Irreplaceability,Ecological Integrity,Wilderness Index and Dendritic Connectivity Indices as the model’s indicator system.Next,each indicator is caculated and their spatial pattern map are overlaid with different weights to obtain a distribution layer(map S_CPV)of Comprehensively Protected Value（CPV）.Lastly,by comparing S_CPV and existing PAs’distribution map,CPR are identified in Sichuan Province,which include priority conservation area for river（PCAR）and priority conservation reach（PCR）.PCAR are the areas with high-value CPV falling outside of existing PAs and PCR are the rivers with high-value CPV falling out existing PAs.The conclusions are as follows:（1）There are still large conservation gaps in Sichuan Province and a certain proportion of CPRs still exist.As to the existing PAs,their conservation degree to CPV high value areas are insufficient.According to the statistics,PCARs total area is about 131,162km~2,accounting for26.99%of the PA-alternative-region’s area.About 74.92%of CPV high value areas aren’t protected at present.PCRs total length is about 9190.72km,accounting for 26.84%of PA-alternative-river’s length in Sichuan Province.（2）CPR spatial distribution aggregation characteristic is outstanding in Sichuan Province.PCARs and PCRs both have good connectivity,and only a small amount of CPRs are scattered.It is conducive to the PA’s construction in the future and realization of protection effects.CPR aggregation areas are mainly located in the Jinsha River basin in the west and south of Sichuan,Yalong River basin,part of lower basin of Dadu River,the southern part of Yangtze River basin east of Yibin City,part of Yellow River basin,upper basin of Fu River and Qingzhu River basin that is a tributary of Bailong River.（3）After verifying,the model is reasonable and validated.At theoretical perspectives,the selection of the model’s constituent elements and indicator system are all based on existing researches.In terms of calculation results,CPV high value area accounts for about 36%of province’s area.The establishment of PA in these areas in the future can effectively protect more than 50%of freshwater species in Sichuan Province.On a practical level,CPR aggregated regions are mostly far away from densely populated regions,possessing rich species,lush vegetation,and high integrity and authenticity of river ecosystem,which is consistent with region’s current situation.Besides,these CPR areas are mostly forest land,grassland and swamp,and there is almost no conflict with urban land,rural land and cultivated land,which is conducive to the actual construction of PA.To sum up,the model has good general applicability to other regions,such as basins,provinces and even countries.Our research can provide reference for PRA’s planning and construction in Sichuan Province and even in China.In addition,it can also provide a scientific basis for PA’s optimization/integration and national territory development planning in China.