【摘要】 建筑用地规模的扩大,在很大程度上影响着区域生态质量,制约了区域的可持续发展,利用遥感对地观测技术及时监测区域生态质量具有十分重要的意义。以敖江流域为例,重点研究该流域中的贵安开发区建设项目引发的建筑用地变化及其对区域生态质量的影响。选取2010年建设前的ALOS影像和2016年建设后的GF-1影像,构建基于ALOS和GF-1影像的建筑用地提取模型;采用遥感生态指数(RSEI)来对生态质量进行综合评价,并构建了ALOS和GF-1影像的湿度分量,在此基础上定量分析了区域建筑用地变化及其生态效应。研究表明:2010—2016年间,研究区建筑用地面积显著增加,其中有86%是由于贵安开发区建设引起的。贵安开发区建筑用地的增加导致了区域生态质量的总体下降,其遥感生态指数RSEI均值从建设前的0.787下降到建设后的0.689,降幅达12.4%,生态优良等级所占面积的比例从2010年的91%下降到2016年的79%。定量分析表明,区域建筑用地面积比例与生态质量呈显著负相关关系,建筑用地面积占比每增加10%,其RSEI值将下降0.041。因此,应加强敖江流域生态环境的保护与治理,严格控制沿江的建设开发项目,切实保护好流域的生态环境。更多还原

【Abstract】 Regional ecological environments have been frequently affected by expansion of built-up land, which inhibits regional sustainable development. Therefore, it is of great significance to timely and precisely monitor regional ecological quality using remote sensing techniques. Using the Gui′an Development Zone(GDZ) in the Aojiang River Watershed as a case, this study investigated the regional ecological quality changes due to increased construction project-induced built-up land. Two rule-based algorithms were developed to obtain built-up land information from the Advanced Land Observing Satellite(ALOS) image in 2010(before construction started) and the Gaofen-1(GF-1) image in 2016(after the construction). The remote sensing based ecological index(RSEI) was further employed to evaluate the ecological quality changes of the study area before and after the construction. As there are only four bands ranging from visible-near infrared wavelengths in the ALOS and GF-1 images, it is difficult to obtain the wetness and dryness components, which are needed for computing RSEI scores. To meet this requirement, the models of the wetness components specifically for ALOS and GF-1 images were developed. Two synchronous image pairs of GF-1 and Landsat 8 Operational Land Imager(OLI) were used to derive the coefficient of the wetness component of GF-1 by relating GF-1 data with the Landsat 8 wetness component based on selected pixel samples(i.e., 40384 samples). In addition, a soil salinity index was introduced to represent the component. The results showed that the area of built-up land of the study area increased notably over the six study years. The increase in the GDZ-induced built-up land represented 86% of the total increased built-up land in the study area. The overall ecological quality of the study area showed a trend of decline associated with the expansion of the built-up land in GDZ. The mean RSEI declined from 0.787 in 2010 to 0.689 in 2016, representing a 12.4% drop over the six study years. The area proportion of high ecological-quality grades also significantly declined from 91% in 2010 to 79% in 2016. Obviously, built-up land has a negative effect on ecological quality. Indeed, quantitative analysis indicated that a 10% increment in built-up land can cause a decline of RSEI by 0.041. Therefore, we suggest that green planning and development should be taken into consideration by regional planners during the forthcoming construction practice in the Aojiang River Watershed.更多还原