A Study On Returning Cultivated Land Into Forest And Grass Project Evaluation Information System Based On ComGIS

With the development of economy, human beings have strengthened the natural resources exploitation; at the same time more and more ecological environment problems are found. Water and soil loss is intensified because of the unreasonable land use structure, such as forest destroys and cultivating in slop field, etc, which has badly threatened the harmonious development of the economic and social in China. On the one hand, returning farmland into forest and grass project to control water and soil loss has entirely started in the background of three years experimental projects. On the other hand, the programming, supervising and evaluating of returning cultivated land into forest and grass project are becoming more objective, timelier and exacter because of the information development. 3S technology is wildly used in the fields such as land use and land cover, resources management, environment supervising, etc, which offers theories and fact experiences for GIS applied in the evaluation of returning cultivated land into forest and grass project. So 3S technology, in which GIS is the core technology, becomes the main technology support in the evaluation. It is significant to study the theories, methods and technologies of GIS application in the returning cultivated land into forest and grass project evaluation.This paper, using comprehensive evaluation method, establishes project evaluation model; from the point of project evaluation method realization, minutely designs returning cultivated land into forest and grass project evaluation information system; discusses the theories and methods to establish returning cultivated land into forest and grass project evaluation information system, using the integration technology between GIS and application models in the VB environment. Combining to the practice in developing cultivated land into forest and grass project evaluation information system, using GeoMap in the VB platform, this paper also discusses a few of main secondary development technologies. And some advantages and shortcomings of secondary development using GeoMap are brought forward in this paper. The concept and realization ways of 2D visualization in the returning cultivated land forest and grass project evaluation information system are stressed, and 3D visualization technologies are studied in theory.Based on the theory study, relating to returning cultivated land into forest and grass project construction in the middle of Gansu province, primarily develops returning cultivated land into forest and grass project evaluation information system of Tianzhu county in VB environment integrating GeoMap; taking Tanshanling's returning cultivated land into forest and grass project as an example tests the functions of the returning cultivated land into forest and grass project evaluation information system , completes the application of the returning cultivated land into forest and grass project evaluation information system.Study results show: the first, to establish returning cultivated land into forest and grass project evaluation information system, it is the demand of the information development, and it is the foundation and guarantee of scientific management and evaluation of returning cultivated land into forest and grass project; the second, 3S as the delegate of modern spatial technologies is the important technology support of establishing returning cultivated land into forest and grass project evaluation information system; the third, based on ComGIS, developing returning cultivated land into forest and grass project evaluation information system has some advantages; the forth, object oriented method makes project evolution's model and visualization easier. Study results also show: the project evaluation indexes study is in the just stage; the project evaluation method and model are single; some functions can't directly be finished using national GIS software to develop returning cultivated land into forest and grass project evaluation information system. In the future, the accumula...