贵州省土壤水分状况估算及分析

Estimation of Soil Moisture Regime of Guizhou Province,China

土壤水分是重要的土壤内在属性,亦是土壤系统分类工作中重要基础性诊断特征。将贵州省86个气象站点地面气候数据与土壤可能蒸散量模型、月干燥度和年干燥度计算公式相结合,依据中国土壤系统分类对土壤水分状况的分级要求,对贵州省土壤水分状况进行初步评判,同时探讨土壤干燥度与可能蒸散量、降水量及温度间的相互关系。结果表明,贵州省土壤水分状况包括湿润和常湿润两种类型,51个县（市）的土壤属于＂湿润＂水分状况,其余35个县（市）土壤属于＂常湿润＂水分状况。自西向东,贵州省土壤水分状况由＂湿润＂逐渐演变为＂常湿润＂,中部区域为两种土壤水分状况同时存在。相较于地区性降水量,可能蒸散量对土壤干燥度影响更大;与年均气温相比,年可能蒸散量与年均地表温度相关性更强。将贵州省土壤水分状况作为诊断特性应用于土壤系统分类时,应综合分析成土环境条件。

Soil moisture is not only an important part of soil properties,but also an important diagnostic characteristic in Chinese Taxonomy. Base on the meteorological data from 86 stations in Guizhou Province,China during the period from 1951/1971 to 1980,using the possible evaporation capacity model and the formulas of aridity index,and according to indexes of Chinese Soil Taxonomy,the soil moisture regime in Guizhou was estimated. Results show that Guizhou soil moisture regime can be divided into two categories of udic and perudic. Guizhou has 51 counties（ cities） in the category of udic moisture regime,and other counties（ cities） in Guizhou Province are in the category of perudic moisture regime. From the west to the east,udic moisture regime gradually evolved into perudic moisture regime. There were the two categories in the middle area of Guizhou. It seems that the influence of the possible evaporation capacity on soil aridity index is greater than the precipitation. The relationship between annual possible evaporation capacity and annual average surface temperature is stronger. It is essential to take soil forming environmental conditions into accountfor estimation of soil moisture regimes.