Comprehensive Evaluation of Tobacco Ecological Suitability of Henan Province Based on G IS

The growth of tobacco is sensitive to environment conditions. The tobacco production is strictly restricted by regional cultivated land. Based on the principal of hiberarchy analysis and fuzzy mathematics and the technique of geographic information system （GIS）, the comprehensive evaluation of tobacco ecology suitability were studied according to the actual circumstances of the whole Henan tobacco planting regions, China. The evaluation index system of tobacco ecology suitability of Henan tobacco planting regions was established by choosing 17 evaluation indexes from 3 respects of climate, soil and landform with Delphi method. Furthermore, the membership function was set up according to the effects of each ecology factors on the growth and quality of tobacco suitability. And the analytical hierarchy process （AHP） was used to determine the weight of indexes by using quantitative analysis. Then the tobacco ecology suitability map of Henan tobacco plantation was drawn with GIS software mapGIS. It is found that the most areas of the western and southern parts of Henan Province, China, are the highly suitable regions, accounting for 22.52% of Henan tobacco planting areas. It is because that there are medium air temperature, sunshine and rainfall, medium soil pH value, and high contents of soil organic matter in the regions. Moreover, the topography is hill and massif, and the height above sea level is between 150-800 m there. Some areas of the southern and middle parts of Henan Province are the suitable ones, accounting for 34.99% of Henan tobacco planting areas. It is because that there are enough rainfall, medium air temperature, high contents of available N and available K in the soil in these regions. There are less suitable regions in the northern and eastern parts of the investigated regions because of drought, too high pH value and CI in the soil and irrigation water, accounting for 35.54% of the whole areas. It can be conducted rapidly and correctly by combining AHP and membership function for comprehensive evaluation of tobacco ecological suitability supported by GIS. There are above moderate ecological suitability for most part of tobacco planting fields in Henan Province. The distributions of tobacco ecological suitability calculated are identical with actual tobacco productivity completely.