GIS And RS Supported Evaluation Of Cultivated Land Productivity--In Qingzhou City Of Shandong Province

The second soil investigation task have past more than 20 years, duringthis period ,the cultivated land quality of our country and soil fertility statushave changed greatly, and it has also spent a large amount of manpower,financial resources and the time to consume is quite long, so it's necessary tocarry on a new and overall investigation and evaluation. The study area lies in Qingzhou city of Shandong province .on the basisof summarizing literatures ,the study focused on the setting-up of theevaluation index system, dealing with the basic data , database setting-up,evaluation method and optimum evaluation mode . we also discussed thecharacteristic of each rank of the cultivated land and the utilization measure touse them rationally. The setting-up of the basic evaluation database : Including the methodand algorithm that the slope picture turns into, the best nutrient interpolationmethod ,and the expert classification based on knowledge to extracting thecultivated land . the Digital Elevation Model is built by using the TIN model ,then ,according to the formula of calculating slope , the digital slope matrix isderived by DEM, and then show it by picture; to choose the sampling pointsinterpolation method , the result of the Inverse Distance Weight method andthe Kriging interpolation method are compared, and the results show that theInverse Distance Weight method of index is acceptable for the availablephosphorus , quick-acting potassium , organic matter ,etc, and two indexKriging interpolation method is the better for the Iron , zinc; Utilizing expert'sclassification to extract the cultivated land information, this kind of methodhas not only fully utilized the existing datum , but need less manual revise , soit improve the efficiency of extracting work greatly. Evaluation method and evaluation modes comparision: this study bringforward three evaluation mode that is the modes based on vector data , on grid - 3 -基于 GIS 和 RS 技术的耕地地力评价研究-以山东省青州市为例data and on the mixed data. Each of them has the disadvantages and merits.tocompare them with each other,the same evaluation method is adopted :selecting identification factors by analyzing the social and natural condition,determining their weights by Analyzing Hierarchy Program, building up singlefactor model and complex evaluation model by the fuzzy evaluation methodand the evaluating land grades were derived with the Distribution plot ofintegrated fertility index of the cultivated land. Then based on those,comparedthe evaluation modes,the results show that based on vector data mode havehigh space resolution ratio , make a accurate positioning, imply the evaluationresult to the spot easily ,etc., at the same time its operation amount is great andthe operation form is comparatively complicated; Grid data mode's operationcourse is simple, the attribute is relatively high, but the data amount is heavyhaving data redundancy , and its' saw tooth form border causes the spaceresolution ratio loss, and this mode has difficult to imply the evaluation resultto the spot. The mixed mode synthesizes the advantages of the abovementioned modes , considered from the data characteristic of the study area , itis the best evaluation mode. At the end of the article , the cultivated land fertility of Qingzhou city isevaluated according to the procedure and method of the mixed evaluationmode, and the area , the space distribution characteristic and the attribute ofeach grade are analyzed on the basis of the evaluation result . and we also putforward the suggestion to utilize the cultivated land rationally.The result is accord with the local reality by investigate and analyze on thespot, this indicates that it is feasible to use this technology in evaluating thecultivated land fertility. And it is significance not only for the cultivated landsustainable utilization but for the Ministry of Agriculture to launch invest...