运用中分辨率成像光谱数据对塔里木河流域植被覆盖度动态变化分析

Dynamic Changes of Vegetation Coverage in Tarim River Basin with MODIS Data

为加快塔里木河流域植被的保护、恢复进程,运用2007—2017年塔里木河流域遥感影像和基础数据,利用“3S”技术平台,系统分析了塔里木河流域11a年间植被覆盖度年内、年际变化特征以及空间变化,并进行了实地调查和检验。结果表明:(1)2007—2017年,塔里木河流域的植被覆盖度总体趋于好转,11a间研究区年平均植被覆盖度增加3.29%;2017年塔里木河流域植被覆盖度与2007年相比,上游增加了30.8%,中游增加了29.4%,下游增加了53.2%。(2)塔里木河流域植被覆盖度变化与植被的生长季相一致,年内植被覆盖度最大值出现在8月份,最小值出现在4月份,上游河段2017年两者相差21.39%。(3)塔里木河流域植被覆盖度空间差异明显,呈现从上游向下游递减的趋势,上游植被覆盖度是下游的4.51倍。

In order to accelerate the process of vegetation protection and restoration in the Tarim River Basin based on the remote sensing image and basic data of the Tarim River Basin from 2007 to 2018, the “3S” technology platform was used to systematically analyze the Tarim River Basin for 12 years. During the year, the annual and interannual variation characteristics of vegetation coverage and the spatial changes in the Tarim River Basin were investigated and tested. The vegetation coverage of the Tarim River Basin tended to improve from 2007 to 2017. The annual average vegetation coverage growth rate in the study area was 3.29% in the past 11 years. In 2017, the vegetation coverage in the upper reaches of the Tarim River increased by 30.8% compared with 2007;the vegetation coverage in the middle reaches of the Tarim River increased by 29.4%;and the vegetation coverage in the lower reaches of the Tarim River increased by 53.2%. Vegetation coverage in the Tarim River Basin was consistent with the growing season of the vegetation. The maximum vegetation coverage during the year appeared in August, and the lowest value appeared in April. Take the upstream section as an example, the difference between the two was 21.39% in 2017. The spatial difference of vegetation coverage in Tarim River Basin is obvious, showing a decreasing trend from upstream to downstream, and the difference between upstream and downstream reaches 4.51 times.