基于遥感影像的千山风景区植被变化研究

Study on Changes of Vegetation in Qianshan Scenic Area Based on Remote Sensing Images

植被覆盖度是自然条件和社会经济活动的综合反映,研究一个区域植被覆盖度的时空变化对于认识该地区的社会发展状况、制定更加合理的生态环境政策、实现经济可持续发展具有重要意义。本文以千山风景区2003年、2010年和2017年TM、OLI遥感影像为数据源,基于归一化植被指数,应用ENVI和ArcGIS软件,采用像元二分模型对植被覆盖度进行估算,得到三期植被覆盖度等级图,并通过转移矩阵和NDVI差值计算对研究区近14年植被的时空变化特征进行分析。研究结果表明:1) 植被覆盖总体呈下降趋势,低度、中低度、中度植被覆盖面积分别增加0.5481 km2、1.5372 km2、1.0485 km2,中高度、高度植被覆盖面积分别下降1.3347 km2、1.7991 km2。2) 2003~2017年中度、中高度、高度植被覆盖转移较频繁。3) 据统计千山风景区严重退化植被占大多数且改善程度下降幅度较大。

Vegetation coverage is a combination of natural conditions and socioeconomic activities. Studying the temporal and spatial variation of vegetation coverage of a region is significant for understanding the social development in the region, formulating a more rational ecological and environmental policy and realizing sustainable economic development. The three periods of remote sensing images of TM/OLI in Qianshan (2003, 2010 and 2017) were taken as data sources. The vegeta-tion fractional coverage distribution maps in those periods were calculated by conducting the pixel dichotomy model using ENVI and ArcGIS software. Further, the temporal and spatial variation characteristics of vegetation coverage in the study area were analyzed through trasition matrix and deviation calculated method. The results are as follows: 1) The overall vegetation coverage showed a downward trend. The coverage areas of low, medium-low and medium vegetation increased by 1.3347 km2, 1.7991 km2 and 1.1799 km2 respectively. The coverage areas of medium-high and high vegetation decreased by 1.3347 km2 and 1.7991 km2, respectively. 2) From 2003 to 2017, the transition among medium, medium-high of high vegetation coverage is relatively frequent. 3) According to statistics, the degree of vegetation improvement in Qianhan scenic area has declined and is seriously degraded.