Study On Wetland Change In Sanjiangyuan Based On Remote Sensing And Hydrological Model

Wetlands are the most important carbon sinks in the world,and the degradation of wetlands and changes in patterns will make carbon sinks carbon sources,exacerbating the effects of global warming.Sanjiangyuan wetland is located in the "third pole",is the world’s most sensitive areas of climate change,but also vulnerable to climate,hydrological changes brought about by the impact.Wetland hydrological processes are considered to be the only and most important factor in determining wetland types formation and maintenance,as well as affecting wetland changes.In this paper,we use the decision tree classification method to extract the information from the wetland in the study area from 2002 to 2014,and obtain the wetland distribution and change of the wetland in the study area.By means of the remote sensing method and the hydrological model,the wetland rainfall,Runoff,water reserves and other hydrological elements of the distribution,analysis of the hydrological elements in different periods of change and trends.Analysis of wetland distribution shows that the average lake distribution of Sanjiangyuan is 430,000 hectares and the sloping wetland is 2.644 million hectares.Wetland distribution is mostly distributed in the valley and the glacier edge of the low-lying areas.Three rivers and regions of the annual rainfall in the northwest region between 180-360 mm,the central region between 360-600 mm rainfall,the southeast of the highest in the 600-780 mm interval.In recent years,in addition to the western edge of the rainfall showed a decreasing trend,the entire Sanjiangyuan area annual rainfall was increasing year by year trend.Sanjiang source area annual evaporation between 260-730 mm.There is a decreasing trend in the southwestern region,and there is an increasing trend in the eastern and southeastern regions.Sanjiang source water reserves change in the year with the seasonal fluctuations,in a dynamic balance.The change of monthly water volume in Sanjiangyuan area is obviously different.There are decreasing trends in the runoff of the northern part of the Three Rivers and the eastern Maqian and Jiuzhi County,and there is an increasing trend in other areas.In the quantitative analysis of theinfluencing factors of hydrological factors and wetland,the change of runoff and water reserves was most sensitive to the change of wetland distribution in the study area.The results of the study have important guiding significance for wetland investigation,wetland resource management,development and utilization,and protection and restoration work in Sanjiangyuan area.