Quantitative Assessment Of Ecological Effects Of Land Use Change In Zarapshan River Basin Based On 3S

Land resource is the most important resource for people to survive, and it is the best gift that nature has given to people. With the survival and development of human beings and the basis of social progress is the ecological environment. With the increase of human activities, the ecological environment has been seriously affected and destroyed. Thus, ecological security has become important questions faced by the human world to study, Yarkant River Basin in the past 25 years ecosystem happened great changes, the ecological service functions have also been changed. In this paper, based on the theory of ecological service value calculated in Yeerqiang River Basin nearly 25 years of different land use / cover changes in the various types of ecosystem service function value, and analyze the characteristics of temporal and spatial variation of the ecosystem service value and the ecological footprint. Then the ecological security of the study area was evaluated by using the ecological pressure index, and the ecological security status of each area in the next 20 years was predicted. The main conclusions are as follows:(1) using remote sensing image information source, supplemented by other related thematic information and field investigation, the establishment of a land use type remote sensing interpretation signs, gets the Yeerqiang River Valley, 1989, 1999, 2009 and 2014 four periods of land use data. Analysis of the Yarkant River Basin in 1989 and 2014 land use / cover change. The results show that the 1989- 2014, Yarkant River Basin, the land use / cover types have undergone significant changes, the cultivated land area increased the fastest, in local human irrational use of the various land use types to 31.3922% change range of the growth of the 229875.4hm2; second is water area increased by 24016.84hm2 and amplitude variation 14.6707% is because the area of cultivated land within the study area increased in order to irrigate farmland and the construction of the reservoir.(2) according to the characteristics of natural environment in the study area, on ecosystem service value of quantitative evaluation method were calculated in different periods of the service value of the ecosystem types and the ecosystem service value value and its change. The results showed that: 1989-2014, Yarkant River basin ecosystem total service value by reducing the 26460 million yuan was reduced trend. Average annual loss of $. The service function of the ecosystem is reduced.(3) the Yarkant River basin all kinds of ecosystem services value size of each ecosystem type land area change. During the study period, the ecological service value of arable land area in the eight kinds of ecosystem is the largest contribution to the total value of ecosystem services in the study area, and the second is the area of the wetland. Although both area accounts for the total land in the study area using area ratio was 32%, provide the value of ecosystem services is accounted for 59.9% of the total value of ecosystem services; and unused land area accounts for the total land use proportion of the area for more than 43%, but the value of ecosystem services accounted for the proportion of study area, the ecosystem services value is below 1%.(4) in Yeerqiang River Basin in different land use type of ecological services value sensitivity index change is based on the determined value of ecosystem services and ecosystem service value coefficient depends on the degree of estimation. It is an application of the concept of elasticity coefficient in the applied economics to verify the sensitivity index of different ecosystem types in the study area to the representative value coefficient of the land use / cover type. In 1989- 2014 years, the area of arable land, water, desert, wetland(ESV, ecosystem service value) of CS(sensitivity) sensitivity index is greater than 1, the rest of saline alkali soil, high-density grassland, dense grass, low grass sensitive index less than 1, suggesting that research of ecosystem services value of the study the ecological service value coefficient of elasticity.(5) is introduced in this paper in ecosystem service function based on the theory of ecological footprint model, calculated the Yeerqiang River Valley, 1989- 2014 ecological footprint and ecological capacity. 1989- 2014, the ecological footprint per capita in the Yarkant River Basin presented a gradually increasing trend and from 1989 1.9543hm2/ to 2014 7.8086hm2/ increased 3.9 times in Yeerqiang River basin ecological footprint per capita in the main part of the per capita arable land and per capita grassland ecological footprint and accounted for more than 85% of the ecological footprint per capita, and the ratio is further increased.(6) in Yerqiang River Basin in 1989- 2014 the ecological capacity per capita showing an overall decreasing trend; ecological capacity per capita in Yeerqiang River basin composed of uneven, which occupies a large quantity of water ecological carrying capacity, ecological carrying capacity of cultivated land, accounting for the proportion of the ecological capacity in more than 75%. Ecological capacity per capita in the present law gradually reduced, from the point of view of the size of the ecological capacity per capita, the waters of the ecological capacity > ecological carrying capacity of cultivated land > unused ecological capacity > grassland ecological capacity further down is the construction with ecological capacity and woodland ecological capacity.(7) in 1989- 2014 in Yeerqiang River basin ecological pressure index on the whole was rising trend, from 1989-0.45299 rise to 1.831626 2014. Yarkant River Watershed characterization of state in 1989 for safer, in 1999 and was slightly insecure, 2009 slightly insecure, 2014 is not safe. Safety level of decline shows that the study area in nearly 25 years of social economy rapid development, the population increased dramatically, the pace of urbanization accelerated to the ecological environment damage degree on the rise, the ecosystem itself recovery capability by the severe challenges. In addition, the water resource distribution is not uniform, serious damage to vegetation, forest degradation of natural ecological environment changes in the ecological system vulnerability and ecological security in the study area level decline of another important reason.