Rs And Gis-based Wetland Ecosystem Health Evaluation

Wetland is a particular ecosystem between land and sea. It is one of the most important environment capitals. Wetland is considered as the kidney of earth because of huge function on water and element cycle. Wetland, which has tremendous food chains and various biology, is taken for the supermarket of biology.The ecosystem health of wetland is that substance recycle and energy flow are not destroyed, elasticity and stability are retained; system can fight against disturbance of nature and people, function of which is various.Ecosystem, health evaluation on wetland refers multi-subject, multi-method and multi-scale. The paper is based on the theories and approaches of the ecosystem, the landscape ecology, the ecosystem health and the regional sustainable development. The model of the paper is the pressure-state-response model built by the Organization for Economic Co-operation and Development of the United Nation. The datum of the paper includes RS datum and statistic inspecting datum. The paper adopts many advanced technologies such as RS, GIS, GPS, and combines some new methods such as measurable geography, mathematical statistic and mathematical model. The paper distills many kinds of datum such as: land use/land cover, wetland type, small watershed, landscape index of wetland, initial productivity of wetland, population pressure index of wetland, deposited quantity of water, pollution charges of wetland, wetland change, and so on. The study builds the database of wetland ecosystem health in Panjin City. Meanwhile, according to the assessment cell of small watershed, the paper evaluates each index and compositive index. The paper can provide scientific bases for both protection and use of wetland by disclosing the spatial distributing rules and analyzing the impact on environment brought because of exploiting.The study shows that 1) in the structure of wetland ecosystem health of Panjin city in 2000, better area accounts for 22%, generic area 52%, worse area 26%; 2) in Shuangtaizi National Wetland Nature Reserve, the health of many regions is better, the one of partial regions is threaten, the area of wetland is decreasing; 3) in the period from 1986 to 2000, paddy field, shrimp and crab pool were increased, swamp and biodiversity were decreased gradually, and the environment of wetland was polluted gradually.