基于TM/ETM^+和MODIS的漓江流域生态环境遥感动态监测

LONG-TERM AND SHORT-TERM DYNAMIC MONITORING OF ECOLOGICAL ENVIRONMENT VARIATION IN THE DRAINAGE AREA OF THE LIJIANG RIVER BASED ON TM/ETM^+ AND MODIS

为调查漓江流域近30 a来的生态环境变化,开展了基于TM/ETM+和MOD IS遥感长、短周期结合的动态监测研究。通过对3期Landsat-5/7 TM/ETM+遥感影像的信息提取、模式识别和实际调查,发现造成漓江上游生态环境退化的主要原因与漓江水源林遭人为破坏、城市化扩展和水质污染等因素有关。通过对MOD IS-NDVI和水体反射波谱分析,初步探明了流域区植被总量的季节变化规律和漓江水体污染的遥感反射波谱特征,确定了水质遥感监测的最佳MOD IS波段,得到了研究区的植被覆盖、城市扩展变化及河流水质变化信息。

The ecological environment of the drainage area of the Lijiang river has been degenerating rapidly in the past 30 years, and hence an experimental research on the long - term and short - term dynamic monitoring of ecological environment variation of the drainage area of the Lijiang river was carried out by using the TM, ETM^＋ and MODIS. Rapid degeneration is attributed to two aspects： the headwater forest in the upper reaches of the Lijiang river has been destroyed continually, and the riverbed sand layer has been mined out on the large scale. This conclusion is based on information extraction, pattern analysis and recognition as well as comprehensive explanation of TM and ETM ^＋ images obtained from three periods of time （ 1986, 1998 and 2002 ） together with field investigation. The variation law of water quality of the Lijiang river and the gross of the vegetation were discovered, and the optimal monitor bands of MODIS were determined by spectrum analysis of water - body based on pixels and calculation of MODIS- NDVI image data.