Case Study On The Assessment Of Ecosystem Health Based On Remote Sensing

Ecosystem health is an emerging field of environmental protection science. Different scholars have different views on the status of ecosystem health and ecosystem health discipline system, but in general they can be summarized as follows:Ecosystem Health (Science) is the integrated science which study the human activity, social organization, natural systems and human health and ecosystem health means there is no pain response in ecological systems, stable function and sustainable development. As time goes on the ecosystem can maintain its organization and autonomy, restore easily in the external stress.As environmental management and sustainable development goals, ecosystem health has become a fever field of Eco-Environmental research and it has important theoretical and practical value. Research for the ecological system protection and recovery process of prairie ecosystem has become more and more important.This study select PSR (Pressure-State-Response) mode established by the United Nations Department as indexes system of ecosystem health assessment. As the model has a very clear causal relationship (the human activities exert a certain pressure on the study area, the health status of the study area have some changes taken place; the human society should make some response to the changs of ecosystem health to restore environmental quality and prevent ecological degradation) has been accepted and used.On the basis of the selection of evaluation indicators. Both from natural and social side, this study select multiple indicators to evaluate the ecosystem health of different regions of Ordos City.Pressure indicators include:land reclamation rate, population density and population disturbance degree; state indicators include:carbon density, diversity index, dominance index, evenness index, fragmentation index and the ecological flexibility; forest coverage rate and per capita GDP belong to response indicators.The information of land use is the basical spatial information data for the research and analysis of the ecological environment. it could fully reflect the distribution of surfacial natural resources and the number and spatial distribution of the human activities.Surveys of the current usage of land with remote sensing is the process of extraction the remote sensing information and inversion of the ground prototype from the analog image of true ground with remote sensing. Current methods for extracting remote sensing information can be divided into two ways:visual interpretation and computer automatic interpretation.According to the signs of interactive interpretation of the land resources established by 96-B02-01-02 thematic groups of Chinese Academy of Sciences, selecting 2009 TM image and derived data as basical information sources, landscape interpretation software and Excel Software were used to calculate the value of the state, pressure, response indicators. The standardized value was analysisde by PCA (principal component analysis) through SPSS,comprehensive score can be divided into five different classifications,and the classification was expressde in the ArcGIS.Specific process is as follows:(1)attribute table exported from ArcGIS, was carried out by statistical analysis with the landscape interpretation software. Specific informations of different land types, as basic information of the extraction of indicators, (size, proportion of area of different land types and the total number of patches, etc.) were obtained.(2)the actual value of the pressure, state, response indicators were calculated in Excel software, extreme standardized methods were used to unify the unit of the data. The standardized value was analysisde by PCA (principal component analysis) through SPSS to get the composited indicator value of pressure state response.(3)Each indicator was graded, grading standards are:fine, relatively good, ordinary, relatively poor, ill.The composite value of different indicators was assigned and expressed in ArcGIS.The results show that,overall,ecosystem health of Ordos City distinguish significantly from west to east.and from west to east,ecosystem health was gradually getting better.The ecosystem health of Dalate district, Dongsheng district,and Yijinhuoyi district were relatively good, Etuoke district and Etuokeqian district are relatively poor.