基于遥感生态指数的吐哈地区生态环境变化研究

以吐鲁番市和哈密市（简称吐哈地区）为研究对象,基于MODIS多光谱传感器2000、2006、2012年和2018年的遥感数据,采用4个表征湿度、干度、热度和绿度的指数,建立和绘制吐哈地区多个时期的遥感生态指数（Remote sensing ecology index,RSEI）,并对该地区的生态环境质量及土地利用转换情况进行了定量分析。结果表明：近20 a来,吐哈地区的绿度指数平均增加0.0244,热度指数平均降低0.0241,而湿度和干度指数整体的变化接近于0;其中,热度指数与RSEI具有负相关性。总体而言,2000—2018年吐哈地区的生态环境质量表现为略微下降的趋势;其中,吐鲁番市的鄯善县RSEI变化幅度最大,环境质量表征数据在区域下降幅度中排列首位,哈密市的巴里坤哈萨克自治县环境质量减少的幅度最小。近20 a来,吐哈地区的草地面积有明显增加,但需控制草地开垦及过度放牧,防止区域生态环境恶化。

Change of ecological environment in Turpan and Hami cities based on remote sensing ecology index

It is important to make an objective and comprehensive evaluation of the quality of the ecological environment for ecological civilization construction. Using four indicators of humidity, dryness, heat, and greenness, the remote sensing ecology index (RSEI) was established and plotted to characterize Turpan and Hami cities of Xinjiang, China in 2000, 2006, 2012, and 2018, based on the multispectral sensor, moderate resolution imaging spectroradiometer. Additionally, the ecological environment quality and land use conversion in the region were quantitatively analyzed. The spatial-temporal variation changes in the ecological environment and land use in Turpan and Hami cities were analyzed and evaluated using the principal component analysis method to construct remote sensing ecological indices and statistical analysis. The results show that in the past 20 years, the greenness index of Turpan and Hami cities has increased by 0.0244 on average, the heat index has decreased by 0.0241 on average, and the overall changes in humidity and dryness index are close to 0. Among them, the heat index has the strongest negative correlation with RSEI. In general, the eco-environmental quality of Turpan and Hami cities showed a slight downward trend from 2000 to 2018. Among them, the change range of RSEI in Shanshan County of Turpan City was the largest, and the environmental quality decreased the most, while the range of the decrease in environmental quality in Barkol Kazak Autonomous County of Hami City was the smallest. Although the grassland area in this area has expanded significantly in the past 20 years, it is still necessary to control grassland reclamation and overgrazing in the future.