基于气候和土壤要素的中国耕地适宜性指数构建

中国历史土地利用的重建工作主要分为数据重建和空间重建,而建立具有空间指示作用的参数对于历史土地利用的空间重建具有举足轻重的指示意义.本文基于此想法,参考前人经验,构建了一套耕地适宜性指数,作为历史土地利用空间重建的基础.首先通过分析影响耕地时空分布的多种自然要素和人文因素,从中厘定土壤和气候这2个关键要素,然后基于此构建了一套计算耕地适宜性指数的方法.通过获取的气候适宜性与土壤适宜性的空间分布图与实际土地利用的相关性分析验证了这2个要素的一定代表性.本文最终的结果代表自然状态下耕地分布的最初可能性,具体特征有:1)对耕地分布起影响的气候适宜性分为4个等级的块状分布;2)对耕地分布有影响的土壤适宜性比较零散,但是大体还是以秦岭-淮河一线为分界线,呈现北高南低的分布;3)对于不同地区耕地分布,影响的主导因素有区别,西北为土壤要素,东南为气候要素;4)耕地适宜性最高的地区基本集中在华北平原、长江中下游平原区域,而青藏高原地区的适宜性最低.结合人口、经济等因素,这样一套耕地适宜性分布图对历史土地利用空间分布有重要的空间指示作用.

Construction of cultivated land suitability index for China based on climate and soil properties

Reconstruction of historical land use includes volume reconstruction and spatial pattern reconstruction.A cultivated land suitability index (CLSI)was established in the present work to serve as distribution proxies for spatial reconstruction.Key factors of climate and soil were first identified from series of physical and anthropogenic factors.Cultivated land suitability map for climate and soil were then developed based on these two key factors.Suitability maps were validated;CLSI was then produced.CLSI reflects naturally cultivated land without human intervention.It was found that climate suitability map of China can be divided into 4 maj or parts with the largest area located in traditionally agriculture area.Soil suitability map of China is more scattered with many patches with slightly more in the north than the south along the Qinling Mountains-Huaihe River Line.There is a clear division that the northwest is more controlled by soil and the southeast is more controlled by climate.Cultivated land suitability index shows that the most suitable area mainly focuses on The North China Plain and The Yangtze Plain.The Tibetan Plateau is barely suitable for cultivation.With information of population and economy,CLSI index could be really helpful for historical land use spatial reconstruction.