Study On Forest Ecological Security Evaluation Of County Based On Geomatics

In recent years, as global environmental problems have become more prominent, and ecological security problems are gradually being attention. The ecological security studies have become the frontier areas and important task of resources and environmental sciences and ecology study . The forest ecological security which is the guarantee to the producture and life of people is the basis of ecological environment security and is an important part of country ecological security and fundamental that achieving sustainable development of forests. It's significant to carry out the evaluation of the safety of the forest ecosystem on the interests of national security. In this paper, The Forest Resources of Fujian Province Sanming county was taken as the research object, county forest ecological security assessment index system was built according to the impact of factors of forest ecological security, in the Geomatics technology support, using of Sanming City in 2008 ALOS image was data, combined with socio-economic statistics data of Sanming counties to give a comprehensive,systematic evaluation of Sanming counties forest and to provide a theoretical basis for the ecological environment. The main conclusions are as follows:(1)According to the forest ecological security effect factors, from the stand structure, function efficiency, natural conditions, environmental stress and social investment five areas, selecting 24 indicators such as the proportion of mixed forest, diversity index and forest cover constructed county forest ecological security evaluation index system. In the expert survey based on the AHP method to determine different levels of the index weight, the weight of a sequence of stand structure (0.5050)> Functional Efficiency (0.2648)> natural conditions (0.1306)> Environmental pressure (0.0661)> social investment (0.0334 ).(2)Based on surface features spectral characteristics, the selection of the appropriate threshold and the use of supervised classification methods, hierarchical classification method with visual interpretation of such human-computer interaction, This study has extracted the land use thematic information and the forest type thematic information of Sanming in 2008,the result showed that classification accuracy was respectively 88.54% and 83.63%.(3)In this study, the soil organic matter, N, P, K content, vegetation cover, and soil erosion intensity six factors were taken as soil quality evaluation factor, using the forest actual evapotranspiration and productivity of forest climate, combined with soil quality correction factor to estimate the area of woodland forest productivity, and established the database of Sanming city and county woodland forest productivity and forest fixed CO2 capacity.(4)In this study, combining with the actual situation in Sanming city, according to USLE equation built soil erosion model and calculated by the model of thematic maps of various factors to achieve a quantitative estimation of soil erosion of Sanming in 2008 to provide the basis for data access for forest ecological security assessment indexes.(5)According to the forest ecological security evaluation results, the forest ecological security index of Sanming city and county from high to low order is Sanming city> Jiangle > Mingxi> Shaxian> Qingliu > Taining > Yongan> Youxi> Ninghua> Jianing> Datian. Forest ecological security in good status counties are Sanming City, Jiangle, Mingxi, Shaxian, Qingliu. in general status counties are Taining,Yongan,Youxi, Ninghua. in relatively poor status is Jianing county. in poor status is Datian county.(6)Reference to previous national monitoring station based on the promulgation of the "eco-environmental quality evaluation method" in the evaluation of ecological environment quality in the Min River counties to calculate the index of vegetation cover index value, and calculated in this study all Sanming ecological security index of forest counties the correlation analysis results show that the ecological security index of forest and vegetation cover index was a strong positive correlation, correlation coefficient of 0.9112, which verifies the calculated in this study Sanming city and county ecological security index of forest is reasonable.