大田县近22 a环境变化遥感监测研究

Monitoring the Ecology and Environment Change of Datian County Using Remote Sensing in Recent 22 Years

利用1992、2004、2014年3期Landsat遥感影像反演得到绿度、湿度、干度和热度因子后,基于主成分分析法生成遥感生态指数(RSEI),对大田县生态环境质量时空变化情况进行分析.结果表明:大田县三时期RSEI平均值分别为0. 673,0. 663,0. 735,表明近22 a以来,整体生态环境呈现先略有下降后小幅增加的变化趋势,以2004年为中间年份,前后变化幅度分别为-1. 49%与10. 86%.大田县近22 a生态环境改善总面积为955. 12 km2,占比42. 43%;生态环境退化总面积为173. 01 km2,占比7. 69%,改善面积显著大于退化面积,表明大田县政府一系列整治环境的政策对改善境内生态起到关键作用.

This paper used 1992,2004 and 2014 Landsat remote sensing images to retrieve four indexes which were greenness,wetness,dryness and heat. Then,based on principal component analysis method,remote sensing based ecological index（ RSEI） was obtained to analyse the temporal and spatial variation characteristics of Datian county＇ s ecological environmental quality.The results shows： The Datian county＇ s mean RSEI value of three period is 0. 673,0. 663 and0. 735 respectively. It notes that overall ecological environment in recent 22 years shows first slightly decreased and then minor increased trend. Set 2004 as the middle period,the range of variation was-1. 49% and 10. 86% respectively. In recent 22 years,the total ecological environment improved area of Datian county was 955. 12 km2,accounting for 42. 43%; Opposite,the total ecological environment degraded area of Datian county was 173. 01 km2,which accounted for 7. 69%. The improved area was significantly greater than the degraded area,which shows that the a series of Datian county government policies play a key role in improving the ecological environment.