近30年天山北坡生态环境质量时空演变分析

Analysis of the Spatial and Temporal Evolution of the Ecological Environment Quality on the Northern Slope of Tianshan Mountain in the Last 30 Years

天山北坡是我国西部经济最发达的区域之一,是我国向西开放的重要门户,属于生态环境脆弱的干旱区。探究天山北坡生态环境质量动态演化规律,对于维持区域经济发展与生态环境保护之间的平衡具有重要意义。因此,本文基于GEE平台的Landsat数据进行波段运算与主成分分析构建遥感生态指数,探究天山北坡生态环境质量时空分布特征。结果表明:1) 天山北坡生态环境质量具有明显的时空分异特征。时间尺度上,1990~2020年间研究区生态环境质量呈现出“下降–上升–下降”的波动变化,总体呈现略微下降的趋势。在空间尺度上,天山北坡生态环境质量以中等与较差为主,生态环境质量差和较差的区域主要集中在研究区的东部和北部。生态环境质量为中等及优、良的区域主要集中在研究区中部和南部。2) 生态环境质量的变化与等级转移有关,以中等及以下的等级往更下一级的转移为主。1990~2000年间,生态环境质量等级发生恶化的区域大于改善的区域,这一时期生态环境质量快速变差,与这一时期生态环境质量等级较差转为差、中等转为较差、良转为中等为主。2000~2010年间,生态环境质量等级发生改善的区域明显扩张,而恶化的区域明显萎缩,这一时期生态环境质量在变好,与这一时期生态环境质量等级较差转中等、较差转良、中等转良有关。2010~2020年间,生态环境质量等级发生改善的区域明显萎缩,而恶化的区域明显扩张,这一时期的生态环境质量在变差,与这一时期生态环境质量等级较差转为差、中等转为较差有关。

The northern slope of Tianshan Mountain is one of the most economically developed regions in the west of China, an important gateway for China’s opening to the west, and belongs to the arid region with a fragile ecological environment. Exploring the dynamic evolution law of ecological environment quality on the northern slope of Tianshan Mountain is of great significance to maintaining the balance between regional economic development and ecological environment protection. Therefore, this paper constructs a remote sensing ecological index based on Landsat data of the GEE platform by wave operation and principal component analysis to explore the spatial and temporal distribution characteristics of ecological environment quality on the northern slope of Tianshan Mountain. The results show that 1) the ecological environment quality of the northern slope of Tianshan Mountain has obvious spatio-temporal differentiation characteristics. On the time scale, the ecological environment quality in the study area showed a fluctuation of “decreasing-rising-decreasing” between 1990 and 2020, with an overall slightly decreasing trend. On the spatial scale, the ecological environment quality of the northern slope of Tianshan Mountain is mainly moderate and poor, and the areas with poor and poor ecological environment quality are mainly concentrated in the east and north of the study area. The areas with moderate, excellent and good ecological quality are mainly concentrated in the central and southern parts of the study area. 2) Changes in the quality of the ecological environment are related to the transfer of grades, with the grades of medium and below shifting to the lower grades. Between 1990 and 2000, the areas with deteriorating ecological quality were larger than those with improving ecological quality, and the rapid deterioration of ecological quality in this period was mainly related to the shift of ecological quality grades from poor to worse, medium to poor, and good to medium;During the period from 2000 to 2010, the areas with improved ecological environment quality significantly expanded, while the areas with deteriorating quality significantly declined, indicating an overall improvement in the ecological environment. This improvement is mainly attributed to the transition of ecological environment quality from poor to medium, from poor to good, and from medium to good during this period. Between 2010 and 2020, the areas with improved ecological environment quality significantly shrank, while the areas with deteriorating quality expanded notably, indicating a decline in the overall ecological environment quality during this period. This deterioration is mainly associated with the transition of ecological environment quality from poor to worse and from medium to poor.