InVEST Model Based Ecosystem Services Evaluation With Case Study In Xiaojiang Watershed

Ecosystem service could provide the natural resources and material for the human being’s production and living conditions. However, as people irrational utilization of natural resources, the ecosystem service functions have been in havoc. Therefore, evaluating the ecosystem service functions is the basic of protecting the ecological environment and using the natural resources rationally, and it is very significant for maintaining the balance of the natural systems and regional sustainable development.Based on the meteorology, hydrology, digital elevation model(DEM), soil and land use data, we used the InVEST model to quantifying and evaluating several representative ecosystem service functions, including water supply, soil conservation, carbon storage and biodiversity. Meanwhile, the spatial distribution pattern and regional disparity of ecosystem service functions were analyzed so that we could explained the effects of the Xiaojiang watershed to the provision, regulation and sustaining of resources. In addition, we used the spatial overlay analysis and the map algebra method to calculate the integrated ecosystem service functions and the spatial heterogeneity of vertical space in our study area. Our objective is to find out the key area of ecosystem service functions and to manage and protect these key services. We think that our results can make a contribution to seeking a better profit and realize the optimization of mountain ecosystem services and the sustainable development of regional economy. The main finding are as follows:1. A total of 1,110 million is the volume of water supply. The average volume of water supply is 362.4 mm and the maximum water yield is 737.84 mm in Xiaojiang watershed. The river valley is located in the dry-hot valley area with the lowest altitude, which result in the weakest ability of water supply. The eastern and western areas in the river basin have more powerful ability of water supply. In terms of carbon storage, the gross is 1.2×107 tones, the average density of carbon is 37.8 t/ha and the gross soil conservation is 2.94×107 t /hm2·a. The area of stronger ability of soil conservation is the southern upstream. On the contrary, the ability of soil conservation in the northern downstream is much weaker than other areas. Moreover, the northern and southern areas in the river basin have better habitat quality, but the middle area has lower habitat quality.2. These representative ecosystem service functions have obvious spatial heterogeneity of vertical space in the river basin. With the increase of altitude, the ability of water supply and habitat quality are getting better, the volume of carbon storage increased at first and then decreased, the ability of soil conservation is generally weak showing a trend of fluctuations.3. The integrated ecosystem service functions in river basin increase with the increase of altitude. The key areas of ecosystem service functions are located in the areas of dry-hot valley and subalpine coniferous forest. In the dry-hot valley area, the ecosystem service functions are disturbed more frequently under the anthropogenic activity. In consequence, accelerating the development of economy and society while we should pay more attention to the protection of ecosystems and the establishment of ecological protection engineering in order to mitigate and recover the condition of ecological degradation. The subalpine coniferous forest has powerful ability of integrated ecosystem service functions. We can properly develop the economy, such as the plantation of medicinal materials and industrial crop, to improve the living quality for the people in mountain areas on the premise that do not breaking ecology balance.