Research And Development Of Site Quality Evaluation Methods And System

Site quality evaluation is an accurate and timely evaluation of the future production potential of the site.It is the prerequisite for carrying out all follow-up forest management.This paper studies the quality evaluation methods of forest land and non-forest land.Taking the Pinus massoniana in Guangxi Gaofeng Forest Farm as an example,the site index table was compiled and the expert scoring model was established.Achieved the unification of the quality evaluation of forest land and non-forest land.A general system for site quality evaluation based on secondary development of ArcGIS Engine was designed and constructed.The main research contents and results are as follows:(1)For the evaluation of the quality of forest land.Seven common tree growth equations were chosen for fitting according to the least squares method.The Korf equation with the smallest error and the largest decision coefficient is selected as the basic steering curve.Determine the base age 20a and the site index level by lm.Using the comparative advantage high method,the status index of Pinus massoniana in Guangxi Gaofeng Forest Farm was compiled.And use the drop test to verify its accuracy.The results show that 96.49%of the dominant wood falls in the position index curve.It can well represent the site quality of Pinus massoniana in the Gaofeng forest farm in Guangxi.(2)Evaluation of the quality of land without site.Expert scoring and grey correlation analysis were used.Each site factor is scored based on expert experience.The gray correlation analysis method is used to calculate the weight and the expert scoring model is established.Thereby an evaluation value is obtained.The evaluation value ranges from 1 to 5 points.Finally,the site quality level is divided by the mean value and standard deviation of the evaluation values.The results showed that the quality of the small class with an evaluation value greater than 3.75 was "good" and it was suitable for planting Pinus massoniana.The site quality of the site factor is greater than 2.49 and less than 3.75.The site quality is"medium",which is more suitable for planting Pinus massoniana.The site quality of the small class with a site factor evaluation value less than 2.49 is "poor" and it is not suitable for planting Pinus massoniana.Finally,the expert scoring model is compared with the site index table.The correlation coefficient between the site factor evaluation value and the position index is 0.772,which is significantly correlated.It shows that the two evaluation indicators have the same trend and can be applied to practical work.(3)Based on the above research on site quality evaluation method,this paper designs and implements the site quality evaluation system.The system can perform targeted modeling of different tree species according to the above method.Thereby achieving the evaluation of the site quality of different tree species.In order to evaluate the quality of forest land,it is necessary to add data and select the tree species to be evaluated.The fitting is arbitrarily selected among the seven commonly used growth equations.Output error and goodness of fit.Determine the optimal equation as the basic steering curve.Using the comparative advantage high method,the status index table of the tree species in the study area is output.Click on the small class to query the basic information of the small class and the evaluation results of the site quality.No forest land uses the expert scoring method.After clicking on the small class,the background gets the small class information.The ground factor weights are calculated using grey correlation analysis.Finally,the score value and the site quality level are output.