In-VEST Model Hanjiang River Ecosystem Services And Dynamic Evaluation Research

To fully disclose the pattern, quality and dynamic spatial change of ecosystem service in upper Hanjing, this paper selected upper Hanjing in Shaanxi province as its research object, then evaluate ecosystem service in this area, such as biological diversity maintenance function, soil conservation function, water source conservation function, carbon fixation and releasing oxygen, the capabilities provided by products by using the major function modules of In-VEST Model. The results show that:(1) Because of its special geographical location and Complex and diverse geographical features, upper Hanjing in Shaanxi province played a huge ecosystem services. By calculation, the total value of the above five functions in study were1577.72,1588.87and1651.08billion yuan, respectively. There was a big difference in different value of service function, which arrayed with the order: carbon fixation and releasing oxygen>biological diversity maintenance function> water source conservation function>the capabilities provided by products> soil conservation function. All kinds of cosystem service played a huge ecosystem services, which showed that the study area is one of the most abundant in biodiversity resources, water resources and carbon storage region. The ecosystem services in upper Hanjing plays an important role in this area and the national ecological environment protection. Also, plays an irreplaceable role in our protection of biodiversity and ensure water security diversion.(2)Affected by vegetation type, topography condition and climate differences and stress from human activities, ecosystem service terms differentiate in region. Apart from a few strong regional human disturbance, biodiversity keeping of ecosystem has higher value volume. Water conservation and soil retention terms mainly distributed in the southern slope of Qinling and Bashan North Slope. Distribution of carbon storage has significant relationship with vegetation condition. Products offer services are more concentrated in the plains and hilly areas. Except Products offerings, all ecosystem service terms have a high value, beyond region mean value, in north slope region of qinba mountain. The area has a small effect by human activities, better to keep the original ecosystem status. Apart Products offerings, ecosystem service terms have a low value at low mountain region in central basin. (3)Various types of ecosystem services both have increased in Shaanxi section of Hanjiang River Basin at the past ten years. Services of biodiversity maintenance and Products offerings have a significantly increase, the change above showed that the quality of the regional ecological environment have a significantly improving trend with low affecting by human activities. what’s the above showed that though all functions of ecosystem service have an actively change, but the trade of value increasing and the quantity of changes has a big difference. Where the function of biological diversity maintenance, water source conservation and the capabilities provided by products showed a trend of sustained growth, and was apparently enhanced with a large variations during10years, while the function of soil conservation and carbon fixation and releasing oxygen showed a trend of decreased at first and increased later.(4)The assessment of functional recovery and biodiversity of ecological system in the area of upstream of Han River, Xi’an part, will be a tremendous reference for the economic development. In the future research, we should focus on how to protect and recover the economic system function on the area mentioned above. especially the areas which have been seriously interferenced by mankind, the areas which has exceeded the threshold of ecological system, the areas which ahs been badly destroied, the ecological systems which are losing their service functions. The recovery of the service funtions of ecological system have significant implications to the whole upstream of Han River, Qinling Mountains, and Ba Mountain. For now, researches on the recovery of service funtion of ecological system is still mature, thus we should the future reaches should base on long-term oberservation and dynamic detection on ecological system within some limitations.And, we need also get a more thorough understanding of the affect to ecological system under the interference of mankinds, and a the influence to mankinds by changes of the ecological service funtion.