GIS based land suitability assessment for tobacco production using AHP and fuzzy set in Shandong province of China

Flue-cured tobacco (Nicotiana tabacum L.) production is important since there are still more than 300 millions of smokers in China. It is essential to allocate tobacco to the most suitable land areas precisely for the best production since arable land area has been decreasing. Therefore, we herein assess land suitability for tobacco production in tobacco zone of Shandong province, China. The assessment used 20 factors as suitability parameters, including climatic condition, soil type and nutrient characters, and topography data. The fuzzy set model, analytic hierarchy process (AHP) method, and GIS technique were integrated to create land suitability map. The results showed that 29.82% of the total area was highly suitable for tobacco production and 17.74% was unsuitable. Land in western part of the region had higher suitability, while the eastern region close to the Yellow Sea, had lower suitability. The most limiting factors included the number of continuous days with daily temperature ⩾20 °C and high soil exchangeable Mg. This study demonstrates that Fuzzy set is an excellent mechanism to transform numerical data with various magnitudes into grades of membership functions, and representing land suitability. AHP is an effective and superior method to determine the weights of multiple factors in a systematic and logical way. The modeling results produced are based on individual land mapping unit, which facilities the land resource allocation and management. This result is significant in that it provides effective approaches to increase land use efficiency and better management for tobacco production.