Assessment Of The Productivity Of Regional Cultivated Dryland In Northern China Supported By GIS

In northern China, dry land covers a large area in the north of Kunlun Mountain, Qinling Mountain and Huaihe River, including 966 counties of 17 provinces, about 56 percent of area of national territory. The area of cultivated land in this region is approximately 55.4 percent of national total arable land, and dry land is 73 percent of dry land in our country. Considered as one of the most-potential area, it has been an important base of foodstuff production in China with over 85 percent of the quantity and quality of unused land. The assessment of regional cultivated dry land fertility aims to provide theory support in using glebe properly, preventing land deteriorated, improvement and utilization of cultivated land, protecting and conducting the quality of cultivated land, food security and agriculture structure adjustment, etc.According to the condition of Shouyang county in Shanxi province, 10 indicators have been chosen to evaluate cultivated lands by the Delphi method. And then the weight of each factor is determined by AHP. The paper sets up subjective functions in terms of their characteristics and different influence on the quality of cultivated land with the fuzzy mathematics method. Based on above GIS platform, the database was constructed. Meanwhile, applying the accumulated mode, the paper calculates the integrated fertility index of cultivated land between 0.35 and 0.48. Thus the appraisal is completed by dividing the fertility of cultivated lands into six grades in Shouyang with a satisfactory conclusion in line with the realities. The first and second grade cultivated lands distribute on the hilly and river valley region of Baima River. The third grade cultivated lands distribute on the second grade ladder of Xiaohe River and Baima River. The fourth grade cultivated lands distribute on the girder and slope part of the hilly and river valley region. The fifth and sixth grade cultivated lands distribute on the hilly country of above 1200m region. At last the model for utilizing cultivated lands and improvement measures are discussed in the paper.In conclusion, the paper has managed to put forward GIS flow which is applicable to build database, and given an efficient technique process and working method for cropland capacity survey and quality evaluation by calculating parameter and exporting result map automatically supported by GIS...