长江中游四湖流域湖泊变迁与湖区土壤空间格局的关联分析

分析了20世纪20年代以来长江中游四湖流域湖泊阶段性变化特征,并结合湖区土壤空间分布数据,重点探讨现代土壤空间格局与湖泊的阶段性变化是否存在关联。研究结果表明,从20世纪20年代至今,江汉平原四湖流域湖泊经历了由扩大到缩小至稳定的阶段性变化过程;通过湖泊变迁序列与湖区土壤格局的综合分析,发现四湖流域湖泊变化范围内的土壤空间分异与20世纪20年代以来湖泊变化历程具有密切关系。20世纪20年代以来,四湖流域湖泊变化范围集中分布了全流域67%以上的潜育型水稻土和沼泽型水稻土;在四湖流域自20世纪40年代起的湖泊萎缩阶段,湖泊变化时间距今愈近,相应湖泊变化范围中沼泽型水稻土和潜育型水稻土面积比例愈大,淹育型水稻土和潴育型水稻土面积比例则愈小。在湖泊变化不同时间组合所对应的空间范围中,各类型水稻土所占面积比例随时间变化而表现的规律性,在一定程度表现出人为耕作及土壤性质改良对土壤性质转变的影响作用;而根据沼泽型水稻土转变速率的空间差异性,可推测湖区脱沼泽过程与地形地貌分异相关。

Analysis of Relation between Change of Lakes and the Spatial Pattern of Soils in the Lake District in Sihu Drainage Basin,Middle Reaches of Yangtze River

The purpose of this study is to analyze whether the spatial pattern of soils in the lake district has some relationships with the course of change of lakes at the lakes’fluctuation extent in Sihu drainage basin, middle reaches of Yangtze River.Information of lakes’distribution in Sihu drainage basin from 1920s to 2005 was collected from historical topographic maps,lake maps,water resources maps,and remotely sensed images.Afterwards,the time series of lake maps were imported into GIS software and characterized into several stages by decade according to the collected data.Then,overlay analysis were used to detect and test the relationships between the spatial changes of the lakes among different time intervals and the spatial patterns of the soil types.From the spatial analysis of the lakes changes,it turned out that the lakes in the study area changed from spread to shrink and to stabilization.The period from 1920s to 1940s is the lake spread stage.After this stage,lakes in the study area shrunk continuously.Between the middle of 1950s and 1960s,shrink speed of the lakes reached its maximum level.Area of the lakes was steadying after the end of the 1970s,and remained basically unchanged after 2000.The results of overlay analysis showed that the current spatial pattern of soil types was correlative with the course of lakes changes from 1920s to 1970s at the lakes’fluctuation regions. The whole lakes’fluctuation regions concentrated more than 67%gleyed paddy soil and swamp paddy soil of all the Sihu drainage basin.During the lakes’shrunk period since 1940s,the percentage of the gleyed paddy soil and swamp paddy soil in the lake fluctuation regions increased following the time of the lakes’changes, whereas the percentage of submergic paddy soil and hydromorphic paddy soil decreased along with the time of the lakes changes.At the different spatial ranges corresponding with the stages of lakes’changes,the relevance between the proportion of paddy soils and the periods of lake changes reflected the influence of the soil amelioration and utilization to some extent.It also could presume that the topography has distinct effects to the deswamping process according to the spatial differences of the transformation rate of the swamp paddy soil.