| The terrain of northeast Sanjiang Plain is relatively flat,full of water resources and nutrient-rich soil,its natural factors are very conducive to agricultural production.After years of development and utilization,it becomes to China's major commodity grain production base.As we all know,wetlands and forests,oceans and are known as the Earth's three major ecosystems.The important role of wetlands is not only about rich natural resources,but also has a strong environmental regulation and ecological functions.Protecting the natural ecological environment of the region plays a significant role in protecting China's food security.Based on the northeastern part of Sanjiang Plain in China chose as the object of study,using SPOT-5 in 2009 and ZY-3,GF-1 and GF-2 high resolution remote sensing data in 2014,The characteristics of wetland types in the study area from 2009 to 2014 were analyzed by means of artificial visual interpretation,and the characteristics of wetland types in the study area were analyzed according to the characteristics of feature features and color representation of remote sensing images.And the influencing factors of wetland change were analyzed according to the annual average temperature,annual average precipitation,population quantity,GDP and slope data in the study area.The high-resolution remote sensing image is used to analyze the change of wetland in this area,not only in the data source,but also in the visual interpretation of the object,greatly enhance the spatial recognition of the target features.The relatively low resolution of remote sensing images,and difficultly distinguished can be more clearly demonstrated.In order to ensure the maximum amount of data in the process of data processing and selection,the information in the remote sensing image of the remote sensing image is better retained by the combination of the?band,the ? band and the ? band.Down,so that the characteristics of the wetlands can be reflected more obviously.At the same time,combined with the relevant data of field investigation and verification,the classification system and interpretation mark of the wetland were studied by using the processed remote sensing image data.The total area of wetland in the northeastern part of Sanjiang Plain in 2009 was 16332.21 km2,and the total area of wetland in the study area was 23284.46 km2,a total of 6952.25 km2.The species includes artificial wetland,river wetland,lake wetland and swamp and marsh wetland.Among the four types,the increase of artificial wetland is 7360 km2,and the distribution of most constructed wetlands is mainly distributed in Tongjiang City,Huachuan Town and Suibin nearby.The proportion of four types of wetland,wetland,swamp wetland and wetland in the wetlands,lakes,wetlands and constructed wetlands were 25.22%,0.25%,5.11%,69.41% and 16.28%,0.13%,3.27% and 80.32 respectively %.In the past six years,the dynamic degree of constructed wetland was higher than that of other wetlands(10.83%),which was mainly reflected in the increase of paddy field(10.91%).It can be seen that the artificial wetland shows an increasing trend,which makes the degree of artificialization of wetland in the study area aggravate,confirming that the research area is one of the largest commercial grain production bases in China.In the multiple linear regression model,the selected human and social factors(GDP,population)and natural environmental factors(annual average precipitation,annual mean temperature,slope slope)as independent variables,the wetland changes as the dependent variable,the analysis of the relationship between the change of wetland and the selected influencing factors in the area.From the analysis,we can see that the effect of GDP on the wetland change is the most obvious in the study area,followed by the slope factor,then is the annual average precipitation and he population,and finally is the annual average temperature. |
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