| This paper adopted Bayi Area of Hainan State Farm as studying area, based on the current status of cultivated resource utilization, utilized the technologies of geographic information system (GIS), remote sensing (RS) and global positioning system (GPS), combined analytic hierarchy process and Delphi method (expert evaluation method), and finally put forward a natural productivity evaluation method for rubber plantation basing on the fuzzy mathematical model.Firstly, according to the resource status of rubber plantation, relevant maps, resources, and sampling analysis data were collected to establish the cultivated land resources'information database basing on the 3S technology; then land-use map, land-type map and soil map were utilized to stacked-form evaluation unit, twelve factors out of four aspects, including nutrients status, physicochemical characters, site conditions, and profile characters of the cultivated layer, were selected to as the evaluation factors of rubber plantations; meanwhile, Delphi method was adopted to assess the weight of these factors; fuzzy mathematical model, combing with analytic hierarchy process (AHP) was mainly used to calculate comprehensive index of rubber plantation Bayi Area's productivity; finally, through statistics of evaluation results, the main conclusion were drawn as follows:With the total area of 99572.1 hectares, Bayi Area possesses 38428.21 hectares rubber plantations. The rubber plantations of Bayi Area are mainly cultivated lands ofâ…¢,â…£class, the cultivated land ofâ…¢class covers 15207.61 hectares, taking up 39.57% of the total area, and theâ…£class covers 8526.45 hectares, taking up 22.19%; the cultivated lands ofâ…¡,â…¤class cover 6039.14 and 5877.33 hectares, taking up 15.72% and 15.29% respectively; Theâ… class covers the smallest area of 2777.67 hectares, taking up 7.23%. The different classes of lands'order presentsâ…¢>â…£>â…¡>â…¤>â… The rubber plantations of Bayi Area mainly distribute in four geomorphological types including plain, platform, low and high hilly regions; and most of the plantations locate in low hilly regions, with the areas of 24585.64 hectares, taking up 63.98% of rubber plantations'total area; terrace and terrace plain comes next, with the areas of 10198.59 and 2782.35 hectares respectively, taking up 26.54% and 7.24% of the total areas; the terrain rises from north to east. The soil texture types are mainly medium and heavy loam, with the areas of 9876.60 and 9198.60 hectares, respectively taking up 25.70% and 23.94% of the total rubber plantations'soil area; light and sandy loam come the next, with the areas of 6691.85 and 5840.74 hectares, respectively taking up 17.41% and 15.20% of the total rubber plantations'soil area; light clay takes up 201.23 hectares, with the ratio of 7.82%; loose sandy soil takes up 2923.39 hectares, with the ratio of 7.61%; tight sandy soil takes up the smallest area of 893.54 hectares, with the ratio of 2.33%.According to the soil nutrient classification standard, and the results of the soil nutrients'preliminary evaluation showed that the overall level of organic matter and macro elements in Bayi Area's soil were relatively low, and the phenomenon of nitrogen and phosphorous deficiency was obvious; among the middle elements of soil, the content of available calcium and magnesium were lacking; and among micro elements of soil, the content of available iron located in the middle upper level, while those of available manganese, cuprum and zinc were relatively lacking.During the study, the paper preliminarily exploited a set of efficient methods and process flow for natural productivity investigation and evaluation utilizing GIS, which vital significance to the scientific management and sustainable utilization of the rubber plantations.
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