Researches On Wetland Information Extraction And Landscape Change Of Yellow River Delta Based On RS/GIS

Taking Yellow River deltaic wetland as the main study area, based on extensive data collection such as TM digital data, land use field data of Dong-Ying city, soil data, hydrologic data and social economy data, we extracted the Yellow River deltaic wetland information on August 24,1992 and May 24,2005 using knowledge-based remote sensing classification. Then we analysis the change of Yellow River deltaic wetland landscape with two model of Transfer Matrix and The dynamic variation rate, and analyze the main problems Yellow River Deltaic wetland (in Dong-Ying City) are facing to and propose relevant countermeasure. This study can not only provide the decision basis for the wetlands protection and administration in the Yellow River deltaic wetland, but also offer references for protection, exploitation and utilization effectively in the resources and environment of this delta, and provide theoretical instructions and technical support for the research of global climatic change. This study has universal-environment significances.This research disposes the Yellow River deltaic wetland (in Dong-Ying City) remote sensing image by Geometric rectification, location, enhancement and edit and revise pictures of the land use map for Dong-Ying City in 1996, soil map, traffic map of administration etc. On those bases and using knowledge-based, wetland remote sensing information is extracted. Firstly following wetland sort system in China Wetland Research Brief as a premise, combine with the actual instance of Yellow River Delta (in Dong-Ying City), wetland landscape classification system which not only accords with national demand of wetland landscape classification system but also reflects characteristic distributing of the wetland style in this district is formulated. Then each style of wetland is deeply analyzed, and extracting rules of wetland landscape information is formulated. After precision evaluation, we found the knowledge-based remote sensing classification is appropriate in extracting the wetland landscape information in the Yellow River delta. This classification method can overcome the shortcomings of time and energy consuming in visual interpretation and the poor precision in the supervised and non-supervised classification and has the characteristic of saving time and high precision. Without any person's revising, the precision of the classification has reached 83.7%.Though introducing method of counting transferring matrix of all kinds of wetland landscape from 1992 to 2005, using dynamic variation rate of change analyze the changes of all kinds of acreage, it is found by the research that:The whole acreage of Yellow River Deltaic wetland (in Dong-Ying City) decreases largely from 306699.08 hm2 in 1992 to 227550.7 hm2 in 2005, decreased by 79148.41 hm2. Wetland is in a serious degenerate status, effective measures should be taken to strengthen wetland protection.Natural wetlands largely decreases, the extent of man-made wetlands is heavier. The activist evolvements among natural wetland and man-made wetlands are foreshore wetlands and shrimp fields and salt fields distinctively. Natural wetlands decreases 76168.87 hm2 in all in 13 years during the period of 1992-2005, transferred to non-wetlands style. Thereinto, river and lake wetlands decrease by 2191.21 hm2, foreshore decrease by 36376.19 hm2, swamp decrease by 2033.31 hm2, meadow decrease by 35568.16 hm2. While the man-made areas in all do not change largely, but in and out changes are obvious, the contrast between increasing of wetlands of shrimp fields and salt fields of 18217.07 hm2 during 13 years and decreasing of natural wetlands is very brilliance, which proves the extent of man-made wetlands becomes heavier.Arrayed the condition wetlands transferred to non-wetland in acreage during 13 years from 1992 to 2005: saline land > arid lands > oil fields > sandy lands > constructive lands > forest land. Unreasonable exploitation of resource by human results in a lot of wetlands transferring to salt fields and arid lands with less contribution to ecological environment, many saline land are wild without anything growing in, becoming Bare-Land.Basing on RS and GIS methods, research the change of Yellow River deltaic wetland landscape (in Dong-Ying City). The research shows that method of combination RS with GIS can not only overcome the shortcomings such as waste of time and energy, limit of research range, influence by man-made active, but also can extract wetland landscape distribution information rapidly and exactly, and can make use of GIS space analysis to get the circumstance of transform among wetland landscape, supply for protection and reasonable use of wetland resource with scientific basis.