干旱荒漠区生态环境质量遥感动态监测——以古尔班通古特沙漠为例

Dynamic monitoring of eco-environmental quality in arid desert area by remote sensing: Taking the Gurbantunggut Desert China as an example

利用遥感生态指数(RSEI)对区域生态变化进行评价,可以快速、高效、客观地获取研究区生态环境变化状况.本研究以两期Landsat数据为数据源,计算研究区绿度、湿度、热度、干度4个生态因子的遥感生态指数,并基于主成分分析法确定其权重,对古尔班通古特沙漠2006—2017年间的生态环境时空格局进行定性和定量评价.结果表明:湿度和绿度对古尔班通古特沙漠生态环境质量起正面作用,而热度和干度对生态环境质量起负面作用,其中代表绿度指标的归一化植被指数(NDVI)的贡献最大.2006—2017年间,古尔班通古特沙漠的RSEI有所下降,其均值从0.294下降至0.243,降幅达20.1%,研究区的生态环境状况呈现整体变差的趋势.古尔班通古特沙漠中部生态环境较为稳定,东北部植被覆盖密集区及南缘灌溉区生态环境质量变好,沙漠南部及西北部区域生态环境质量变差.

Using remote sensing ecological index (RSEI) to evaluate regional ecological changes can obtain the ecological environment changes quickly, efficiently, and objectively. In this study, RSEI of four ecological factors, greenness, humidity, heat, and dryness were calculated using the Landsat data and the spatial and temporal patterns of ecological environment in the Gurbantunggut Desert from 2006 to 2017 were qualitatively and quantitatively evaluated, based on the weights determined by principal component analysis. The results showed that humidity and greenness played a positive role in the eco-environment quality of the Gurbantunggut Desert, whereas heat and dryness had negative effects. Normalized vegetation index (NDVI) representing the greenness was the top contributor among those four factors. The RSEI of the Gurbantunggut Desert declined from 2006 to 2017, with a 20.1% decrease of the mean value from 0.294 in 2006 to 0.243 in 2017. The ecological environment of the study area showed a deterioration. The eco-environmental quality of the central part of the Gurbantunggut Desert was relatively stable. The eco-environment quality of the dense vegetation areas in the northeast and the irrigated areas in the south was getting better, but that of southern and northwestern parts of the desert was getting worse.