金沙江干热河谷冲沟发育区不同部位土壤水分的时空变化特征  

Spatial and Temporal Change of Soil Water in Different Sections of Gully in Dry-hot Valley Region of Southwest China

作　　者：吴汉[1,2,3] 熊东红 张宝军[1,2,3] 郭敏[1,2,3] 杨丹 张素[1,2,3] 校亮 方海东[4] 

机构地区：[1]中国科学院山地灾害与地表过程重点实验室,四川成都610041 [2]中国科学院水利部成都山地灾害与环境研究所,四川成都610041 [3]中国科学院大学,北京100049 [4]云南省农业科学院热区生态农业研究所,云南元谋651300

出　　处：《西南农业学报》2018年第2期384-392,共9页Southwest China Journal of Agricultural Sciences

基　　金：中国科学院"西部之光"重点项目(Y4R2060060);国家重点基础研究发展计划(973)项目(2015CB452704);国家自然科学基金项目(41571277)

摘　　要：【目的】为了研究干热河谷冲沟不同部位(集水区、沟头和沟床)土壤水分时空变化特征。【方法】基于元谋干热河谷典型冲沟不同部位土壤水分的长期监测,分析冲沟不同部位土壤水分(10~100 cm)时空变化特征。【结果】(1)冲沟不同部位土壤平均含水量随时间变化可划分为土壤水分消耗期(2-6月)、土壤水分积累期(7-10月)和土壤水分消退期(11-12月)等3个变化阶段;冲沟不同部位不同深度土壤水分年内变化特征不同,其中集水区20、30和40 cm土层,土壤水分年内分配差异不明显,其他部位不同深度土壤水分均表现明显的干湿季变化。(2)冲沟不同部位年内土壤水分含量及变异系数随着土层深度的增加均表现出先减小后增加的分布特征,其中40~60 cm土层土壤水分变异系数较低且土壤水分亏损表现明显,表明表层(10~30 cm)和深层(60~100 cm)土壤水分年内含量高且分配不均,而中间(30~60 cm)土层土壤水分含量相对较少且分配相对均匀。(3)不同深度的土壤水分日变异系数表明,集水区和沟床在干季,不同深度土层间土壤水分差异较小,雨季差异较大,分配不均,而沟头土壤水分在春季土壤水分分配较均匀,其他时间均出现分配不均现象;冲沟不同部位土壤水分含量差异显著,表现为沟头(9.98%)>沟床(9.65%)>集水区(6.64%)。【结论】在进行植被恢复时,应该考虑冲沟不同部位、季节性以及剖面土壤水分变化规律,因时因地进行植被恢复。【Objective】The aim of this study was to understand spatial and temporal change of soil water in different sections of gully in Dryhot Valley Region of Southwest China. 【Method 】Based on the long-term soil water monitoring at different positions of the typical gully（drainage,gully head and gully bed）,we analyzed the seasonal variations and depth discrepancy of soil moisture.【Result】（i） Three stages of soil moisture variation,including consuming period,accumulative period and decreasing period,could be divided based on the monitoring data. The seasonal change characteristics in different depth of soil water was different,for example,the soil water distribution had no seasonal change in drainage area about 20 cm,30 cm and 40 cm soil layer,and the other layers all showed obvious dry-wet season change.（ ii）The soil moisture content and coefficients always firstly decreased then increased with depth＇s increasing,and soil subsurface（40-60 cm）presented relatively low variation and significant moisture shortage among all layers,in which high soil water content and high variation coefficients revealed uneven soil moisture distribution,vice versa.（ iii） The soil profile water variation coefficient in every day showed that the soil water difference between different depth of soil layer in drainage area and gully bed,and showed relative relatively large difference; And the coefficients of soil profile in gully head revealed that the soil water distribution was only uniform; soil moisture of gully positions showed significant difference,following the order： gully head gully bed drainage area. 【Conclusion】In the vegetation restoration,we should take the soil water characteristics of different positions of the gully,season and profile water distribution into account to select planting vegetation.

关 键 词：土壤水分 动态变化规律 冲沟 干热河谷 

分 类 号：S15[农业科学—土壤学]