Analyzing Spatial-Temporal Pattern Of Saline-alkali Land Distribution In Tongyu County Basing On RS

It is estimated that there is 9.5×108hm~2 saline-alkali land on the global, accounting for7.26% of land area on the earth, with increasing 1.0×106 ～1.5×106hm~2 annually. Soilsalinization has been becoming a global issue. Soil salinization not only influences theproblems of resources, environment and zoology, but closely bound up to the sustainabledevelopment of society and economy. So it is important that monitoring soil salinizationdynamic change and analyzing spatial-temporal pattern by using modern techniques fully,such as RS and GIS.After understanding deeply the soil salinization of domestic and international relevantresearch, this dissertation analyzes comprehensively and rebuilds digitally physicalgeographical environment and social economic environment of Tongyu County. Assisting byrelief maps, the dissertation distills land use information of 1979, 1992 and 2001 thatincluding saline-alkali land from 3 Landsat images (MSS, TM and ETM respectively),analyzes spatial-temporal pattern of saline-alkali land distribution in Tongyu County in thepast 22 years. In the last, this dissertation analyzes coupling relation of spatial-temporaldistribution of saline-alkali land and distribution of main factors of environment background.Main contents and conclusions are as followed:Firstly, Tongyu County is in continental monsoon climate region in mid-temperate zone,growth period being short, and the period of heat and rain being overlapped. Further more,the research period is long. Considering quality and availability of RS data across-the-board,the dissertation chooses 3 RS images of U.S.A Landsat series as the basic datum source andchooses corresponding time phases and bands to compose the false colored picture basing onthe preceding land salinization experience and spectrum feature of every-band. After thegeometrical correcting, the dissertation distills lands use information of the three periods asthe background data of the research.Secondly, the dissertation analyzes saline-alkali land spatial-temporal pattern of Tongyucounty for 22 years by adopting many indexes and ways such as some kinds of statisticalindexes, land use change indexes, landscape indexes and barycenter, from many aspects suchas quantity,structure,transform,landscape patterns and regional difference.Thirdly, through three period's saline-alkali data land and corresponding environmentalbackground factors data overlaying analysis, the dissertation notices that there isconsanguineous coupling relation between spatial-temporal distribution of saline-alkali landand distribution of main factors of environment background. Physical geographical and socialeconomic elements affect spatial-temporal distribution of saline-alkali land together. Thespatial variety and organic combination of all environmental background factors restrict thespatial-temporal pattern of saline-alkali land.