基于SMMI的红碱淖湖区面积遥感分析

红碱淖是我国最大的沙漠淡水湖,在当地气候的调节、水资源的平衡及生物多样性的保持等方面发挥着非常重要的作用。以2000~2014年MODIS陆地植被数据产品MOD13Q1为数据源,在提取NIR和Red波段反射率的基础上,利用土壤湿度监测指数(SMMI)提取红碱淖年内和年际面积数据,并对其15 a间变化趋势进行分析。结果表明:红碱淖面积年内变化规律为每年4月开始缓慢增大,至7月~8月间达到最大,而后逐渐减小;红碱淖湖区面积总体呈线性减少趋势(R~2=0.884 7),由2000年的49.63 km~2减小到2014年的31.88 km~2,变化率为36%,平均缩减速度为1.18 km~2/a。相比较气象因子而言,人类活动是影响红碱淖面积变化的主要因素。

Analysis of Hong jiannao Lake Area Based on SMMI

The Hong jiannao Lake is the largest fresh water lake in China and it plays an important role in the adjustment of local climate, water balance and maintain biodiversity. Using vegetation indices products MOD13Q1 of MODIS from 2000 to 2014 as data sources, Soil Moisture Monitoring Index (SMMI) was applied to extract lake area based on the reflectance of NIR and Red bands and the area change trend of Hong jiannao Lake was analyzed. Results showed that the intra-annual change trend of lake area was slowly increasing in April each year, reaching the maximum between July and August and then gradually decreased. The area of Hong jiannao Lake was shrinking gradually from 2000 to 2014 (R₂ = 0.8847) and the average shrinking speed was 1.18 km₂/a. The area of Hong jiannao Lake was 49.63 km₂ in 2000 while it was shrunk to 31.88 km₂ in 2014, decreasing by 36%. Compare meteorological factors, human activities like underground mining, irrigation or reservoir construction are the main factors leading to area change of Hong jiannao Lake.