The Investigation And Utilization Potential Evaluation Of Low Hill Red Soil Of Lanxi City Based On 3S Technology

Agricultural land resource is decreasing rapidly in Zhejiang province because of the population explosion and economic development. The utilization of the low hill red soil is one of the key strategy to ensure the agricultural production.The thesis took Lanxi city of Zhejiang province as a case study. Based on the 3S technology , the low hill red soil resource was investigated by using the Spot5 image, 1:10000 DEM, the map of soil and land use, and the database of low hill red soil area has been established. The land utilization potential has been assessed by 3 methods based on investigation results, which provided scientific references for the rational utilization of low hill red soil. The main results were summarized:(1) Vegetation fraction estimation. On the basis of the FCD model, the study selected Modified Soil Adjusted Vegetation Index (MSAVI) and Shadow Index (SI) to establish a new vegetation index VI which can decrease the influence of shadow and soil interference. Then vegetation fraction was estimated using mixed pixel model. The results showed that: the new vegetation index was suitable for the low hill red soil area, and it can also decrease the influence of shadow and soil interference.(2) The investigation of low hill red soil area. Based on the 3S technology, the low hill red soil resource of various slope and elevation was investigated, and land use was interpreted by visual interpretation while the vegetation fraction was calculated. The effects of the slope and elevation in the area have been analyzed, and the soil erosion has been evaluated.(3) Utilization potential evaluation of low hill red soil. The index system of low hill red soil utilization potential evaluation has been constructed by using the results of investigation of low hill red soil resource, and the utilization potential has been evaluated using 3 models: exponential sum, exponential product extraction and matter-element model. The comparison of 3 models' results showed that: the matter-element model can reduce the effects of man-made factors in the process of evaluation, and the evaluation results were more precise which can show the characteristic of the land resource better. In a word, it was valuable for practical application.