The Spatio-temporal Changes and Driving Factors of the Wetlands in Madoi, China

摘要

The first county along the Yellow river, Madoi is the key region of the state natural protective source regions of Yangtze River, Lantsang River and Yellow River, its eco-environment and function in widespread attention. In support of the hardware and software system, based on GIS and remote sensing technology, this paper combined field investigation and laboratory analysis. Around 1990, 2000 and 2010, ten-phase remote sensing images are interpreted, and it is continuously monitored that Madoi wetlands have changed in the 20 years. Using wetland interpretation results and the area of the wetland types transfer matrix, it evaluates the changes of wetland area in the 20 years. With the meteorological and statistical data, this paper discussed the reason of the wetland changing in recent 20 years. The results of remote sensing monitoring and field investigation show that the overall trend of the wetland area changing increased after the first reducing in three times. In the first 10 years, swamp changes were the largest, followed by lakes and rivers; in the next 10 years, lake changes were the largest, followed by swamps and rivers. Natural factors which resulted in wetland changes of Madoi are climate changes, the permafrost environment changes, rodent rampant; man-made factors are overgrazing, irrational mining, fishing, hunting and development of tourism.