Dynamic Monitoring Of Maqu Wetland Based On3S Technology

Maqu wetland is located at the eastern margin of Qinghai-Tibetan Plateau, which is the largest, most characterized, most primeval and representative alpine wetland in Tibetan Plateau as well as is the most well-preserved natural wetland. It is crucial for water supply of Yellow River, overwintering of rare wild animals, animal husbandry production and grassland ecological security.The wetland change of Maqu based on ETM data in2001and TM data in2006and2010during the period from2001to2010in this study was extracted and classi-ficatied by integrating visual interpretation and computer automatic classification methods. The variation conditions in temporal and spatial, landscape index, vegetation index and wetland types of Maqu wetlands were also analyzed. The main results are as follows:1) Based on present wetland classification systems, the wetland classification system of Maqu was established by using remote sensing technology platform. In this system, Maqu wetland was divided into4categories (marsh wetland, river wetland, lake wetland, artificial wetland) and9types(peat wetland, marsh wetland, tundra wet-land, spring wetlands, river body wetland, river heart island wetland, permanent lake, oxbow lake and reservoir).2) Based on the result of visual interpretation in2001, the accuracy of Maqu wetland extracted by the supervised classification, decision tree classification and ob-ject-oriented technology classification approaches were comprehensively compared. The object-oriented technology classification could reduce the phenomenon of the same object with different spectrum and the same spectrum corresponding to different objects in the wetland classification to some extents, and can improve the accuracy of Maqu wetland classification, and its classification accuracy reached by86%.3) The area of total wetland of Maqu County was1254hm2,54909hm2and 47124hm2respecticely in2001,2006and2010m2, which was mainly composed by peat wetland and swamp wetland, and occupted37.9%-39.3%and48.0%-52.4%of the total wetlands, while the river heart island wetland, tundra wetland, lakes wetland was5.6%-10.3%,0.9%-1.5%and1.0%-1.7%of the total. The wetlands of Maqu dis-tributed at Man Rima and Cai Rima towns, which accounted for more than70%of the totalwetlans and also was the key protection areas of Maqu wetlands.4) During the period from2001to2010, the wetlands of Maqu declined by23053hm2and33.1%. The decrease area was14963hm2for Marsh wetlands and9583hm2for peat wetlands. The decrease area of wetlands in Cai Rima, Man Rima and Qi Hama was highest, totally declined by17332hm2from2001to2010.5) he number of patches and the landscape indices of diversity and evenness of Maqu wetlands showed a degradation trend.6) The conversion trend of Maqu wetlands was from peat wetlands to non-wet, from peat wetlands firstly to swamp wetland and then to non-wetland, and from lakes wetlands firstly to swamp wetland and then to non-wetlands. The conversion from peat wetlands to non-wetlands was noreversible.