天山北坡生态资产的动态评估及人类活动响应

Dynamic change of ecological capital and their response to human activities in the northern slope of Tianshan Mountains

在国内外有关生态资产评估研究的基础上,应用遥感技术、全球定位系统、地理信息系统技术对天山北坡的生态资产进行了评估,通过模型计算出1990、1995、2003、2008年研究区的生态资产量,分析了天山北坡生态资产的时空分布特征及其变化。结果表明:1990-2003年期间生态资产总量上升了20.7%;2008年生态资产总量比1990年上升了24%,生态资产分布的区域性差异较大,西部的发展速度大于东部,由南向北递减,与植被的地带性分布梯度基本一致;影响天山北坡生态资产发展的因素是气候因子和人类的干预,气候的变暖更促进了植被的生长,提高了生态资产单位面积的价值,国家推行的退耕还林、还草政策虽保护和发展了生态资产,但经济的快速发展增大了对自然资源的需求,在一定程度上加大了对生态环境的利益索取。

Based on a summary of the theories of ecological capital assessment, a case study on the ecological assets valuation in the Northern Slope of Tianshan Mountains was carried out by using RS, GPS and GIS. In this study, a RS valuation model was used to calculate the total ecological capital and Unit area ecological capital of this area re- spectively in the year of 1990, 1995, 2003, 2008, and their distribution and changes were primarily analyzed. The results show that the total ecological capital in the Changji Hui Autonomous Prefecture increased by 20.7% from 1990 to 2003, which is a major contribution to the total 24% of all 18 years. Meanwhile, the autonomous prefec- ture can be divided into 4 ecological areas according to the vegetation zonal distribution so as to quantitatively calcu- late the ecological capital of different ecosystems, analyze its spatial distribution and changes. The per unit area ec- ological capital performed a quite difference in the regional distribution：the growth speed in western was greater than eastern, and decreased from south to north, which was consistent with the zonal distribution of vegetation gra- dients. Cultivated land ecological assets change is mainly affected by human factors, the increase amplitude of for- est land and meadow is high, and the change rate of 27% because of the double impact of climate and human activ- ities ; Water body is not big, the ecological asset growth rate generally about 11%, because of its smaller size, even if the per unit area value varied greatly, nevertheless it is difficult to be reflected in general, on the other hand, considered the water that have buffer action to precipitation conditions; For the glaciers, bare rock and gravel non- vegetation or very sparse vegetation zones, the ecological assets showed a downward trend from 1990 to 2008, main- ly due to the climate change; Finally, the factors were analyzed by comparing the ecological capital to climate change and land type changes. Because of climate change and human activities, the vegetation growth was promo- ted and showed an increase in Unit area ecological capital. Additionally, some policies implemented by the govern- ment, such as the policy of returning farmland to forests or grassland, has protected and promoted the vegetation growth, which performs an increase in ecological capital, but on an another hand, rapid economic development has increased the demand of natural resources and exacerbated its request to ecological environment in a certain extent.