| In order to understand the condition of forest resource objectively and exactly, it is very important for us to conduct comprehensive analysis and evaluation of forest reasonablely, which can supply reliable scientific data for government's policy-making and production & operating activities. Based on Forest Management Inventory data of Yanqing county of Beijing in 1999 and 2004, this research used the theories and techniques of Geographic Information System (GIS), landscape ecology and fuzzy evaluation, and carried out the Spatial-temporal dynamic analysis quantificationally at the aspect of composition, structure, landscape pattern and ecological effect of forest resource. A system of evaluation index and evaluation model was also established. At the same time, the computer software was developed successfully under the support of develop-kit ArcGIS Engine, which realizes some helpful functions, like forest resource statistics, landscape ecology analysis, and ecological effect calculation.This research results indicate,①The condition of forest resource in Yanqing county took on a prosperous developing trend, and its green ratio and forest coverage have reached 66.13% and 55.75% by 2004. The area of forest land increased with the promotion of quality and structure, which profits from the projects of artificial afforestation, Young-middle aged stands tending and rebuilding of low-efficiency forest.②Under the two-level-classification of landscape component(land use type and dominant species group), the landscape pattern which is based on the landscape matrix of woodland shows great heterogeneity with increasing trend, by means of calculation and analysis of 13 landscape metrics, such as Shape Index, Diversity Index, Contagion,etc. The patch shape of non-forest land shows more irregular due to human activities.③The evaluation of forest ecological effect have carried out in Yanqing at the aspect of water conservation, soil conservation, biomass and air purifying. The result shows the forestry in Yanqing performs fairly powerful in the field of ecological construction.④Each subarea have classified into 3 levels according to its forest condition, using the method of analytic hierarchy process(AHP), ladder-shaped membership function of homogeneous distribution, and fuzzy comprehensive evaluation. The whole forest develops steady and have the trend of going better.⑤As for the generic technology, a relatively excellent index system of forest evaluation was built based on Forest Management Inventory data, including forest land use rate, volume, crown density, DBH, age index, decrement of direct runoff and soil erosion, etc. At the same time, under the support of ESRI ArcGIS Engine, a computer software named Forest Resource Analysis and Evaluation System(FRAES) was developed successfully using.NET(C#) programming, which can realize some helpful functions, like forest resource statistics, landscape metrics calculation, ecological benefit calculation, map operation, thematic map making, etc. |
