黄河中下游影响区生态空间和生态指数变化评估

Abstract

黄河中下游影响区人地关系复杂，受到自然和人类活动交叠影响，厘清该区域的生态空间及其生态指数变化对实现黄河流域生态保护与高质量发展这一国家战略具有重要意义。对黄河中下游影响区的生态空间时空格局演化和生态状况进行定量分析，具体包括基于土地利用遥感监测数据的生态空间演变分析和基于纯遥感驱动的遥感生态指数RSEI （Remote Sensing Ecological Index）分析，从而完整刻画了2000-2020年黄河中下游影响区生态环境的动态变化格局。研究结果显示：（1）从土地利用类型变化来看，黄河中下游影响区主要土地利用类型是耕地，占研究区的70%；近20年以来耕地和建设用地变化明显，耕地面积减少了2.15%（约9849km²），建设用地增加了30.75%（约11146km²），且建设用地的扩张主要以侵占耕地为主；（2）从生态空间类型变化来看，研究区半生态用地面积变化较大，主要向弱生态用地转变，发生在城市地区；天津市、河北省以及山东省的沿海地区生态空间类型由弱生态用地转为生态用地；黄河流域河南段可以明显看出半生态用地向生态用地的转变；（3）从生态级别来看，近20年来生态级别为"差"和"较差"的面积有所减少，由2000年的38.85%减少至2020年的23.01%，生态级别为"中等"和"良"的面积有所上升，由2000年的45.54%增加至2020年的73.71%，生态级别为"优"主要分布在河南省、江苏省和安徽省周边；黄河滩区内外生态环境质量相当，均呈缓慢上升趋势。本研究利用遥感大数据完整地对黄河中下游影响区的生态空间及其对应生态状况进行了长时间序列的监测与评估，为总体认知和把握该区的生态状况提供了基础支撑。;The human-land relationship in the affected area of the middle and lower reaches of the Yellow River is complex, and it is affected by overlapping natural and human activities. Clarifying the ecological space of the region and its ecological changes is of great significance to achieve the national strategy of ecological protection and high-quality development for the Yellow River Basin. In this study, we made a quantitative analysis on the evolution of ecological pattern and ecological status in the affected area of the middle and lower reaches of the Yellow River. Specifically, by analyzing the spatio-temporal evolution of ecological space with the data of land use and Remote sensing ecological index (RSEI) derived by remote sensing products, this study completely depicted the dynamic change pattern of ecological environment in the affected area of the middle and lower reaches of the Yellow River from 2000 to 2020. The results showed that:(1) from the perspective of the land use change, the main land use type in the study area was cultivated land, accounting for 70% of the study area. Over the past 20 years, cultivated land and construction land changed significantly. The area of cultivated land decreased by 2.15% (9849km²), and the construction land increased by 30.75% (11146km²), and the expansion of construction land was mainly by occupying cultivated land. (2) In terms of the ecological space, the areas of semi-ecological land changed greatly, mainly to weak-ecological land, which occurs in urban areas. The ecological space type in the coastal areas of Tianjin, Hebei, and Shandong changed from weak-ecological land to ecological land. The transition from semi-ecological land to ecological land appeared obviously in the Henan section of the Yellow River Basin. (3) For the RSEI, the area proportion with low level RSEI decreased from 38.85% in 2000 to 23.01% in 2020 while the area proportion with high level RSEI increased from 45.54% to 73.71% in recent 20 years. Relatively good ecological environment was mainly distributed around Henan, Jiangsu, and Anhui. The eco-environmental quality inside and outside the Yellow River beach area was similar, showing a slow upward trend. In this study, ecological space and its corresponding ecological status in the affected areas of the middle and lower reaches of the Yellow River were monitored and evaluated over a long time series based on the remote sensing big data, which provided the foundation support for the overall cognition and characterization for the ecological dynamics of the study area.