Research On Land Suitability Evaluation For Tea-tree In Rizhao Shandong Based On DEM

The land suitability evaluation for tea-tree was carried out in Rizhao, Shandong ,china. Analyzed the relation between land conditions of warm temperate zone and tea planting, the researcher founded that the evaluating factors system meeting the demand of north tea plants, and educed the comprehensive evaluation result of which was made a map with four grades. The integration of evaluation model and GIS was used in evaluation, it is a way with great efficiency and speed and can be utilized in other land suitability evaluation.Based on the integrated study results of the theories, methods and research of land use evaluation (land suitability evaluation) at home and abroad, and according to the methods and principles of FAO"A Frame work for land Evaluation", the paper expounded the interrelation between land conditions and tea-tree growth in warm temperate zone through the investigation, analysis and evaluation of the climate, terrain, soil and consulting the tea planting farmers in tea plating samples in Rizhao, and choose the evaluation factors.In the paper, the scattered radiation and the direct solar radiation in actual landform was simulated on the base of DEM and C program, the temperature and the relative humidity was interpolated by Spline supplied by ARCGIS software, then the temperature in actual landform was corrected by air temperature lapse rate and the direct solar radiation, and the average wind speed in winter taking effect of slope, aspect into account, was simulated, and the soil pH and soil texture was readied; the date base of evaluation factors was build at last.On the base of evaluation to every factors, the weight every one was calculated by AHP(Analytical Hierarchy Process), the comprehensive evaluation was made by utilized the Fuzzy model. The result divided the evaluation region into four grades: gradeâ… ,the most suitable region; gradeâ…¡, the more suitable region; gradeâ…¢,the suitable region; gradeâ…£, the unsuitable region. The paper expatiated on the distribution law of the evaluation grades, and put forward how many limiting factors and how to deal with them.The choose factors connected with tea planting showed strong north character, and every factor has a suit rang to the tea planting which is different with south study result, so the research about the factor system achieved a breakthrough in the study of China tea planting.The achievement of the paper supplied Rizhao with a basal grade distribution for developing the teaplant rationally, and can save the waste or loss of unreasonable teaplant introducing which always happened, and can optimize the structure of land resource.The date base was build exactly by using DEM correcting technology, and the integration Fuzzy model with GIS spatial analyse achieved the evaluation result more fast and accurately, and the result more accord with the fact.