Research On Water Ecosystem Services Based On The Perspective Of Blue Water And Green Water And Typical Service Flows

The traditional assessment,planning and management of water resources in river basins pay little attention to green water resources and seldom distinguish between blue water and green water in the process of water cycle.The study on water ecosystem services in river basins is relatively weak,and the study on water ecosystem service flows is still in its infancy.Based on the analysis of the driving mechanism of the blue water and green water of the river basin on the water ecosystem service function of the river basin,the relationship matrix between the blue water and green water of the river basin and the water ecosystem service function is established,and the classification system of the water ecosystem service flow of the river basin is constructed.Taking the Lianshui river basin as the study area,this paper analyzes the spatio-temporal correlation characteristics of the supply and demand of the water production service flow and the carbon storage service flow,clarifies the spatial scope and the service flows of the river basin supply area and the beneficiary area,and reveals their spatio-temporal change characteristics,it provides a scientific basis for the water ecosystem protection,ecological compensation and scientific management of the Lianshui river basin.The specific research content and research conclusions are as follows:(1)Construction of relation matrix.By analyzing the functional characteristics of blue water and green water and the binary water cycle process,using EP-HA-HS analysis ideas and using the DPSIR theoretical framework,the response relationship of water ecosystem service functions to blue water and green water is established.The direct effect of blue water on water ecosystem services is mainly manifested in the direct use of water resources,and the indirect effect is mainly manifested in maintaining the ecological functions of aquatic ecosystems through various water bodies.The direct effect of green water on water ecosystem services is mainly to support the ecological services that can be directly used by humans,and the indirect effect is mainly to maintain the service functions of terrestrial ecosystems through water used by plants or water in the soil.(2)Construction of classification system.According to the blue water and green water characteristics embodied by the water ecosystem service flow,the blue water dependence of aquatic ecosystem and the green water dependence of terrestrial ecosystem,and combined with the direction of service flow,the classification systems of in-situ blue water service flow,omni-directional blue water service flow,directional blue water service flow,in-situ green water service flow,omni-directional green water service flow and directional green water service flow are constructed.(3)Water production service supply and demand analysis and service flow research.The supply of water resources in the Lianshui River Basin has increased first and then decreased on the time scale of the past 20 years.The water demand has shown a trend of increasing year by year.The contradiction between supply and demand in most sub-basins is more prominent,and the water resource safety index has shown a decreasing trend,water is in short supply.Four water production service flow beneficiary areas were identified,namely Louxing District,Xiangxiang City,Shuangfeng County and Xiangtan urban areas.The high-level service flow is the service flow from the 18 th sub-basin to the17 th sub-basin in the No.1 beneficiary area in 2010 and 2015.The medium-level service flow mainly refers to the service flow in the beneficiary area No.2 in 2015 and 2019.The low-level service flows are mainly the service flow in the No.1 beneficiary area in 2000 and 2005,the service flow in the No.3 beneficiary area in 2010 and 2015,and the service flow in the No.4 beneficiary area in 2015 and 2019.(4)Carbon storage service supply and demand analysis and service flow research.From 2000 to 2019,the supply of carbon storage services as a whole shows a decreasing trend,the total carbon demand shows a rising trend and then a declining trend,and the proportion of industrial carbon emissions is relatively large.The difference between the surplus of supply and demand decreases,and overall supply exceeds demand.Six carbon storage service flow beneficiary areas were identified,namely Louxing District,Xiangtan urban areas,Lianyuan City,Shuangfeng County,Shaoshan City and Lengshuijiang City.The carbon storage service in Xiangxiang City,Shaoshan City,Xiangtan County,Shaodong County and Xinshao County can basically meet their own needs,and there are surpluses that can make up for the gap in carbon storage services in other counties(cities).The high-level service flow is the service flow from Louxing District to Xiangxiang City and Lianyuan City in 2019.The medium-level service flow mainly occurs in all the service flows in 2010 and the service flow from Shuangfeng County to outside the study area in 2015.The rest The service flows are all low-level service flows.