青藏高原湖泊和NDVI变化反映的生态地质环境问题

Ecological-Geological Environment Problem Indicated by Monitoring Lakes and NDVI with Remote Sensing in QingZang Plateau

分析湖泊源区生态地质环境对湖泊变化的影响,建立湖泊变化、源区归一化植被指数(NDVI)变化与生态地质环境演变的关系,提出"湖泊、NDVI遥感动态监测的生态地质环境评价"方法("L-N")。基于20世纪90年代初(TM)至2000年初(ETM)的湖泊遥感调查数据,结合相应NOAA/AVHRR NDVI数据,利用L-N方法完成青藏高原生态地质环境评价。研究结果表明:青藏高原生态地质环境总体呈恶化趋势,高原北部的边缘地带、长江水系上游、特别是柴达木盆地较为明显,雅鲁藏布江流域、高原东南部情况较好;L-N方法有助于提高遥感环境监测效率,湖泊、NDVI遥感监测具有重要的生态地质环境意义。

There are many problems in eco-geological environment evaluation,such as being short of macro,difficulty of data acquisition,trouble of indicator quantitative analysis and operation.Consequently,eco-geological environment evaluation and its dynamic monitoring is influenced by them.In order to solve this problem,this paper discusses the feasibility of eco-geological environmental evaluation with NDVI and lakes changes and open out practice in QingZang Plateau.Firstly,analyzing lake changes by considering the influence of eco-geological environment in lake source area,the relationship among eco-geological environment,lake change and NDVI change in lake source area are established.Secondly,a method of eco-geological environment assessment which is named as 'Assessment of eco-geological environment base on Remote Sensing Dynamic Changes Information of Lakes and NDVI',for short 'L-N',is given.Finally,based on the survey data of lake by Remote Sensing technique with Landsat TM in 1990's and Landsat ETM in 2000's,with contemporaneous NDVI data from NOAA/AVHRR sensor,the eco-geological environment assessment of QingZang Plateau is accomplished by 'L-N'.The results show that: The eco-giologic environment of QingZang Plateau has been worsening,it is obvious in the fringe area of north Plateau,Rivers Sources of Yangtze River,specially Qaidam Basin.On the contrast,environment situation is preferable in southeast of the Plateau and Yarlung Tsangpo river basin.From the evaluation result of QingZang Plateau,'L-N' way obtains closely consilient outcome and its needful index is consumedly decreasing,at the same time,with nicer and easy operation.Ulteriorly,in virtue of powerful monitoring ability of Remote Sensing technology,it is beneficial to develop dynamic eco-geological environment evaluation investigating in QingZang Plateau.In conclusion,it is helpful to promote efficiency of environment monitoring by 'L-N' with Remote Sensing technology,having the characteristic of reducing many evaluating index,expediently being investigated by Remote Sensing technology and feasibility.In addition,it is a significant for eco-geological environment to monitor lake and NDVI data in QingZang Plateau.If correlative theory can be advanced,ploting out fixed area and surveying lakes will change by Remote Sensing image processing technique.Therefore,it is possible that we can improve,eco-geological environment status of a region in macroscopical scale.