南方红壤侵蚀区土壤肥力质量与人为活动可达性的空间关系——以福建长汀县朱溪流域为例

Spatial relationship between soil fertility quality and human activities accessibility in the red eroded area of southern China: A case study in Zhuxi Watershed,Changting County,Fujian Province

人为活动可达性对土壤肥力质量具有重要影响。以南方红壤侵蚀区典型流域福建省长汀县朱溪流域为研究区,选取10个土壤肥力质量因子,基于"3S"技术并结合野外调查,对10个土壤肥力质量因子进行叠加,生成土壤肥力质量等级图;根据相对高度、DEM生成的坡度、SPOT影像提取的土地利用图、距居民点和交通用地的远近,创建人为活动可达性综合评价指数,整个研究区可达性由最难到达至最易到达可分为5级。结果表明:1)人为活动可达性从"中等"到"困难"到"很困难",土壤肥力质量总体呈上升趋势,可达性难度逐渐增大导致开发利用难度增大,人为活动的干扰程度相对减少;2)在人为活动可达性"容易"和"很容易"2个级别,分布着所有的"很好"和大部分"好"2个土壤肥力质量级别,并与流域下游的耕地地类对应,同时"容易"和"很容易"2个级别所在区域自然条件较好,人类开发利用强度大,导致部分区域土壤肥力质量级别较低;3)人为活动可达性是土壤肥力质量的重要但不是唯一影响因素;4)今后相关研究应加强土壤肥力质量综合评价模型中人为活动的定量表达,从而深入解释南方红壤侵蚀区人为活动与土壤肥力的复杂关系。

Human activities accessibility plays an important role in soil fertility quality.This study were conducted in Zhuxi Watershed of Changting County,Fujian Province,the typical representative area of red eroded soil in Southern China.The spatial relationship between human activities accessibility and soil fertility quality was evaluated.After selecting ten soil fertility factors,the soil fertility quality was generated by overlaying ten factors based on 3S technique and field investigation.A compound-accessibility evaluation index was created based on relative altitude,slope from DEM,land use from SPOT images,distance to residential point and road extracted from land use,and the whole study area can be divided into 5 accessibility grades from the least reachable area to the most easily reachable area.The following conclusions were drawn from this research： 1） Soil fertility quality had an increasing tendency with the level of human activities accessibility from Medium,Difficult to Very difficult.The more frequent human activity,the relatively higher the disturbance of human activities.2） All Very high and most of High grades distributed on the level of human activities accessibility Very easy and Easy on the lower reaches whose corresponding land use types were cropland,while other soil fertility quality exited because of violent development and utilization for good natural conditions.3） Human activities accessibility was an important but not unique influencing factor to soil fertility quality.4） The quantitative expression of human activities should be strengthened in the model of soil fertility comprehensive evaluation to explain the complex relations between human activities and soil fertility in red eroded soil in Southern China.