摘要
使用高精度土壤水分测量仪ML2X测定元阳梯田水源区林地不同深度(10、20、30、40、60、100cm)的土壤容积含水率,分析其土壤水分时空变异规律。结果表明:林地土壤水分垂直分布规律显著,土壤含水率随土层深度的增加而递增,且雨季大于旱季,变异系数随土层深度的增加而递减。土壤含水率在同一坡面存在差异,坡中位置均大于坡上和坡下位置;其中,变异系数表现为坡下>坡上>坡中,雨季>旱季。季节、土层深度及坡位等因素均对土壤含水率有较大影响。土壤水分的平均值具有明显的时间变异规律,不同层次土壤含水率变化不同,表层土壤水分与降水变化基本一致,深层土壤受降雨和蒸腾作用的影响较小,土壤水分时序变幅不大。各土层土壤蓄水量均表现为雨季大于旱季,且随着土层深度的增加呈递增的趋势。研究揭示了林地土壤水分的分布特征,为今后梯田灌区土壤水分的有效利用提供一定参考依据。
The volumetric water contents （VWC） in different depths （10, 20, 30, 40, 60, and 100 cm, re- spectively） of the forest soil which serves as the water source for the agricultural terrace fields nearby in Yuanyang, Yunnan Province, China were measured by high-precision soil moisture measurement instru- ment ML2x. Rules of temporal and spatial variations of VWC were analyzed. Significantly regular distri- bution patterns of VWC in soil profile were observed. The VWC increased with the soil depth, and it was higher in rainy season than in dry season. The variation coefficients increased with the soil depth. In the same slope, it was higher the middle part than those in lower and upper parts, in which the values of varia- tion coefficients in different positions of a slope were in the order of low 〉 up 〉 middle, and similarly, rain season 〉 dry season. Factors such as season, soil depth and slope positions all had significant influ- ences on VWC. The average value of VWC presented obvious variations with time. Different variation pat- terns were found in different soil layers, the changes of VWC in surface soil were the same as precipitati- on, it almost was not affected by rainfall and transpiration in deep soil, and the variation range of the time series was small. The water demands in the soils with different depths in wet season were more than in dry season, and with the increase of soil depth, VWC presented the trend of increase.
出处
《西北林学院学报》
CSCD
北大核心
2014年第2期49-53,60,共6页
Journal of Northwest Forestry University
基金
国家自然科学基金项目(31070631
41371066)
关键词
土壤水分
林地
时空变异
元阳梯田水源区
soil moisture
forest
spatial and temporal variation
water source area of Yuanyang terrace
