沣河流域生态环境质量的遥感评价及影响因子分析

Remote Sensing Evaluation and Influence Factor Analysis of Ecological Environment Quality in the Fenghe River Watershed.

通过遥感数据准确评估生态环境质量,对区域生态环境保护和可持续发展决策指导具有重大意义。以沣河流域为研究对象,采用Landsat遥感影像提取绿度、湿度、干度和热度指标并耦合成遥感生态指数(RSEI),分析沣河流域近20年生态环境时空变化特征,并通过空间自相关分析研究区生态环境质量空间聚类分布模式,同时采用地理探测器对影响区域生态环境的主导因子和交互因子展开探究。结果表明:(1)2001、2005、2011、2015和2021年沣河流域RSEI均值分别为0.543、0.600、0.634、0.668和0.649,说明研究区生态环境在2001—2015年有所改善,在2015—2021年发生轻微退化。(2)全局莫兰指数(global Moran′s I)值范围为0.767~0.887,表明沣河流域生态环境质量空间分布呈现显著正相关性,且高-高(H-H)聚集区分布在滦镇街道等研究区南部地区,低-低(L-L)聚集区主要分布在王寺街道等城市化水平较高的北部地区,近20年L-L聚集区面积呈先明显减少后轻微增加趋势。(3)沣河流域生态环境质量并不是单一因素作用的结果,而是多种因素交互后增强的结果,其中,2015年干度指标与其他因子交互后,其协同作用明显加强,说明地表裸土和建筑面积对沣河流域生态环境影响最大。在未来发展中,沣河流域应合理规划土地利用方式,实现流域经济与自然环境协同发展。

It is essential to accurately assess the quality of ecological environment through remote sensing data,which is of great importance to decision-making guidance for regional ecological environmental protection and sustainable development.Taking the Fenghe River watershed as the research object,the indicators of greenness,humidity,dryness,and heat were extracted from the Landsat remote sensing images and coupled into the remote sensing ecological index(RSEI)to analyze the spatio-temporal variation characteristics of the ecological environment in the Fenghe River watershed over the past 20 years.Then,the spatial clustering distribution pattern of the ecological environment quality in the study area was analyzed through spatial autocorrelation analysis.At the same time,geographic detector was used to explore the dominant and interactive factors affecting the regional ecological environment.The results show the following,(1)The mean RSEI values of the Fenghe River watershed in 2001,2005,2011,2015,and 2021 were 0.543,0.600,0.634,0.668,and 0.649,respectively,indicating that the ecological environment in the study area improved during 2001-2015 and slightly degraded during 2015-2021.(2)The value of global Moran′s I ranged from 0.767 to 0.887,showing that the spatial distribution of the ecological environmental quality in the Fenghe River watershed had a significant positive correlation.In addition,the high-high value(H-H)agglomerations were distributed in the southern part of the study area such as Luanzhen subdistrict,while the low-low value(L-L)agglomerations were mainly distributed in Wangsi subdistrict and other northern areas with high urbanization levels.Over the past 20 years,the area of the L-L agglomerations decreased obviously at first and then increased slightly.(3)The ecological environment quality of the Fenghe River watershed was not the result of the action of a single factor,but the result of enhancement after the interaction of multiple factors.For enample,the synergistic effect was significantly strengthened after the dryness indicator interacted with other factors in 2015,suggesting that the bare soil and building area had the greatest impact on the ecological environment in the Fenghe River watershed.In future development,land-use should be rationally planned to realize the coordinated development of the river watershed economy and the natural environment in the Fenghe River watershed.