南瓮河自然保护区生态环境质量遥感评价

运用遥感技术,科学、快速地评价区域生态环境质量,能够为区域生态环境的保护、治理和规划等提供科学依据.本研究以1990、2000和2015年的Landsat TM/OLI/TIRS为数据源,使用主成分分析方法确定湿度分量、归一化植被指数、地表温度和干度指数4个指标的权重,运用遥感生态指数(RSEI)评价模型,对南瓮河自然保护区1990—2015年的生态环境进行评价.结果表明: 遥感生态指数能够较好地反映研究区生态环境质量状况及其时空分异;1990—2015年,保护区 RSEI均值由0.55上升至0.83,生态环境质量优良以上区域面积所占百分比逐年增加,这与该等级中森林所占比例增加有关;保护区生态环境质量变好的区域所占比例高达91.4%,这与保护区的建立及相关工程与非工程防护措施的实施密切相关;核心区、缓冲区北部生态环境质量下降的主要原因是火灾的发生导致森林植被遭到破坏,而道路附近和试验区的东南部生态环境质量的下降与人类活动的干扰密不可分.

Assessment of the eco-environmental quality in the Nanweng River Nature Reserve,Northeast China by remote sensing

Scientific and rapid assessment of the ecological environment quality based on remote sensing can provide basis for regional protection, management and planning. In this study, using Landsat TM/OLI/TIRS in 1990, 2000 and 2015 as data sources, four indices including the wetness component of the tasseled cap transformation (WET), normalized difference vegetation index (NDVI), normalized difference built-up and soil index (NDSI), and land surface temperature (LST) were derived, with the weights being determined by principal components analysis (PCA). Remote sensing ecological index (RSEI) was used to evaluate the eco-environmental quality of Nanweng River Nature Reserve from 1990 to 2015. Results showed that RSEI was an effective indicator for evaluating spatio-temporal dynamics of eco-environmental quality. From 1990 to 2015, the mean value of RSEI of Nanweng River Nature Reserve increased from 0.55 to 0.83, the proportion of area with excellent and good levels of RSEI trended to increase, probably due to the increase of forests at those levels. Meanwhile, 91.4% of the total land area in the reserve had an improved eco-environmental quality. Such improvement was attributed to the establishment of the reserve and implement of a series of engineering and non-engineering protection measures. In the north of core area and buffer area, decrease of eco-environmental quality was due to forest fires which destroyed a large area of forest vegetation. In the road side and southeast of the experimental area, intensified human activities led to the decrease of regional eco-environmental quality.