Study On Evaluation And Prediction On Forest Carrying Capacity Of Minjiang River Basin

The sustainable development is now the subject and direction of economics development of the world, and is the basis to instruct people to make full use of the natural resource reasonably. The forest carrying capacity is an important constituent of each kind of natural resource in the carrying capacity sustainable developing process of a national or in the erea. It has an important influence on synthesis development and developing scale of a nation or an area. It has caused the academic circles high attention and became the current research key and the hot spot. As a special region, Minjiang river basin has abundant natural resource, especially forest resource, and has an unique regional advantage on the construction of west-strait economic zone and the development of Fujian province economic from it's geographical position. The construction of economic zone certainly will require for abundant resource, especially forest resource, and the requirement should be lay on strategic height. To realize the sustainability of forest and of social-economic, the problem should be concerned between the requirement of social-economic for forest and the total amount and carrying capacity of forest. It is urgent to study on forest carrying capacity of Minjiang river basin, and it's evaluation and prediction are key and difficulty. The evaluation index system, the method for evaluation and for prediction is key to the research.This article carried on the summary about present situation and the progress of reseach of forest carrying capacity. Taking the regionality and adaptablity as guiding ideology, it proposed the main research object and content based on research results. And it revolved the forest carrying capacity appraisal and the forecast question to limit the forest carrying capacity concept. It analyzed its connotation and the primary factors that influence forest supporting capacity and established the forest carrying capacity evaluation index system. The index system covers indexs of the requirement of forest struct, the requirement of forest fucntion, the requirement of social system and the economical system.In view of the question that the forest carrying capacity appraisal method research was less, this article proposed and discussed comprehension index method, Fuzzy synthesis appraisal method, set pair analytic method and the application of RBF network method in forest supporting capacity appraisal. Based forest resource continuously- checked data about 1998 and social economics department's data, the paper used comprehension index method to analyze the Minjiang river basin forest carrying capacity. After being evaluated, its composite index is 0.769 and lies in medium of the load bearing rank. The appraisal result is similar to the result studied formerly. Then fuzzy synthesis appraisal method, set pair analytic method, RBF network method, matter element method and projection pursuit method were used to analyze forest carrying capacity of Minjiang river basin. The results are all III level, namely the load bearing rank in medium.The article analysed the order of evaluation results by using Spearman rank correlation. Under the confidence level of 0.99, the comprehension index method, fuzzy comprehensive evaluation, RBF newwork and projection pursuit were highly related, and these evaluation results were consistent. The set-pair analytic and matter-element extension were independent, and had large differences in the results. According to theory of serial number summation and Spearman rank correlation, the best evaluation method for forest carrying capacity of Minjiang river basin was RBF network, and then projection pursuit, comprehension index, fuzzy comprehension evaluation, set-pair analytic, matter-element extension in turn.This article used the comprehension index method to separately appraise forest carrying capacity of Minjiang River basin about 1988, 1993 and 2003. The results are 0.691, 0.673 and 0.809. Based on the composite index evaluated as the primary data, it used the grey system theory to establishe the Minjiang river basin forest carrying capacity grey forecast model. The average precision of the model is 98.21%. It predicted that the composite index forest carrying capacity of Minjiang river basin in 2008 shall be 0.893. According to analyzing forecast results, it gived suggestions on enhancing the basin forest supporting capacity.It completed the forest carrying capacity evaluation and prediction information subsystem based on former theory study, by using the forestry information technology, and combining with the pattern of forest resource management under the information time. The functions of subsystem contained many modules such as index data management, index reference value management, index classification management, index weight computation, comprehension index method module, fuzzy comprehension evaluation module, set pair analytic module, RBF network module, grey prediction module, and so on. The complement on the subsystem provided the possibility of fast policy-making, and the scientific of policy-making, and it also supply the necessary system basis of forest resource decision-making management system.In a word, according to the problem of research on forest carrying capacity, and to the requiremtent of region social-ecomic development for forest, the paper took the Minjiang river basin as research object, built evaluation index system according to the regionality and adaptablity. It first time applied comprehension index method, fuzzy comprehension evaluation method, set-pair analytic method, RBF network method, matter-element extension method and projection pursuit method to evaluat forest carrying capacity of Minjiang river basin, and then analysed concordance and discordance coefficients. The paper also constructed prediction model to forecast short-term about Minjiang river basin. Last, it completed a forest carrying capacity evaluation and prediction information subsystem.