Study On The System Of Cultivated Land Grading Based On COM-GIS

According to procedures and rules for farmland grading and regulations for technological operations of farmland (cultivated land) grading of Fujian province, taking longhai region as an example, the paper applies Esri'MapObject product to make a research about cultivated grading system on the base of COM-GIS technique under Visual Basic'programming environment for carrying out cultivated land grading quickly.Supported by the fundamental function of the Ole programmable object of MapObject and Visual Basic 'database technique, the paper constructs cultivated land grading system, which has two main module: First, GIS' fundamental function, this part mostly handles MapObject' forty programme object to realize new layer foundation , different data translation, graphic edit, multi_way zoom and translation , graph to attribute and attribute to graph'two-direction que, multi-way special topic render, layer print, layer spatial selection table structure modify , table sorting, data update in a table and between tables; Second, cultivated land grading function, this part mostly handles Visual basic' Ado database technology to realize cultivated land grading. In the first place, the system builds up indices and weight underlying database used by cultivate land grading, and then based on underlying database,the system achieves economy coefficient count, utilization coefficient count, nature quality pointvalue count, nature quality grade count, grade indices count, grade division, different lands of form output and print.The research system takes advantage of COM-GIS to solve the question that there is easy to be wrong in working process and low efficient leaded by various indices and weight, at the same time, overcome the question that integration type GIS system is too excessively enormous and to conform to cultivate land grading work flow and outcome manage. Guided by grading way and progress of rules and regulations, the research system produces intimacy and simple interfaces in VB to try to realize to proceed cultivated land quickly for land workers who are not GIS profession.At present, To all sorts of difficulties of cultivated land grading, it is necessary to found a GIS software suited to land grading. According to principle and means of GIS design, the paper uses advanced GIS component technique to design correlated modules and constructs rationally cultivated land system that is able to proceed grading progress fast followed by grading procedure.