2005-2015年三江源地区玛沁县植被覆盖度变化分析

基于美国Landsat TM卫星遥感影像数据,通过ArcGIS10.0与ENVI5.1软件,提取并分析了玛沁县不同时期的植被覆盖度动态变化总体特征。分析结果表明:2005年、2010年、2015年的平均植被覆盖度依次为72.53 %、65.76 %、68.27 %,植被覆盖度fc>0.65的区域面积占总面积的比例达到60 %以上,植被覆盖总体情况良好;植被覆盖变化面积转移矩阵表明,近10年来植被覆盖度呈现出下降趋势,各级植被覆盖度减少面积近4 000 hm²,自然生态环境退化程度明显;玛沁县植被覆盖度减少区面积占比20.96 %,比重较大,植被覆盖不稳定并呈现退化趋势,自然生态环境亟待保护。

Changes of Vegetation Coverage from 2005 to 2015 of Maqin County in Three-river Headwater Region

Based on the remote sensing data of US Landsat TM satellite, using ArcGIS 10.0 and ENVI 5.1 software, we extract and analyze the dynamic changes of overall characteristics of vegetation coverage of Maqin County in different periods. The results show that: in 2005, 2010 and 2015, the average vegetation coverage were 72.53 %, 65.76%, 68.27 % respectively. Vegetation coverage area ratio which are more than 0.65 are over 60 % of the total area. The overall situation of the vegetation cover is good. The transition matrix changes of vegetation coverage area over the past decade showed that vegetation coverage showed a downward trend, reducing the levels of vegetation coverage area of nearly 4 000 hm². The degree of degradation of the natural environment is significant. The reducing of Maqin county vegetation coverage area accounted for 20.96 %, which is a large proportion. Because the vegetation cover showed an unstable and degraded trends, we should protect the natural environment.