| China is a vast agricultural country with a large population in the world. Today, with the development of urbanization and industrialization, a large number of cultivated land is turned into construction land while the arable land is now in shortage. In order to ensure grain self-sufficiency and the security of food, a more effort should be made to increase the yield of the low and middle yield lands. As a kind of low-yielding fields, waterlogged field widely spread in the major agricultural provinces of our country do not draw enough attention due to its slow process and low magnitude relative to flood. However the survey of waterlogging fields is an important issue. In the past, the survey mainly relies on manual surveys. Due to involving so many factors, it is not conducive to conduct a wide range of investigation, monitoring and forecasting. In recent decades, With the development of remote sensing technology, a wide range of investigation of waterlogging fields becomes reality.In this paper, Anhui province is chosen as the study area. The distribution characteristics and the inducement of waterlogged field have been analyzed based on the remote sensing technology and multiple source information. In addition, different control strategies are proposed according to different waterlogging. The content and conclusions of the thesis work are as follows:(1) The research background and significance are firstly analyzed. Through the analysis of the research progress at home and abroad, the issue is found as a hot topic in the field of waterlogged fields. Although the mechanism research on this issue is abundant, but most of them are limited to a single discipline. As the starting point and the innovation, this paper attempts to find a method applies to a wide range of identification.(2) This paper focuses on the induced factors of waterlogged fields such as topographic factors, soil type, rainfall, runoff, crop type, groundwater levels and soil moisture content. Then the classified analysis is used on above factors. Through a number of comparisons on the current standard of waterlogged fields, the factors can be combined and the method of identification, monitoring and prediction of waterlogging fileds can be drawn. (3) The geography and hydro meteorology condition combined with the cause and distribution regulation of watrelogging are analysed in detail. In addition, we also applied analysis and summaries on the data source. On the basis of the above study, we analyzed the specific methods of Modisand data preprocessing. Obtained the DEM including SRTM90and DEM30(ASTER) covering the AhHui province and fill the holes in SRTM90. Finally the DEM is used to get the topographic factors.(4) Using the Landsat-8sixth/seventh band data to generate normalized soil moisture index. Combined with soil type data, the moisture data is spatial analyzed, amd accprdomg tp the result of spatial analysis soil moisture data are grouped. Establish the regression model based on data above, and extract spatial distribution of the soil moisture(5) Extract the suspected waterlogging area according to the results above and the Soil moisture time series data would be used as reference to check the data. Then the space-time characteristics relationship between factors of waterlogged fields and waterlogging area are analyzed and the distribution characteristics in AnHui province are determined. In addition, the spring waterlogging phenomenon in Huaibei region have been also emphatically analyzed and the Envisat data is collected to verify this. |
PDF Full Text Request