干热河谷植被覆盖对雨季地表径流和土壤水分的影响

Influence of Vegetative Coverage on Surface Runoff and Soil Moisture in Rainy Season in Dry-hot Valley

[目的]研究干热河谷植被覆盖对雨季地表径流和土壤水分变化的影响。[方法]对云南省元谋县的金沙江段干热河谷植被覆盖坡面及裸地进行雨季地表径流和土壤含水量的连续观测,并对观测数据进行统计学分析。[结果]植被覆盖能够显著减少地表径流量,对照小区（裸地）地表径流量是植被覆盖小区的22倍;植被覆盖下0-180 cm土壤含水量比裸地增加37.6%;植被覆盖提高了土壤深层含水量的稳定性,并保持土壤物理性质稳定;不同深度土壤不仅水分含量差异显著,而且土壤水分含量变化也明显不同。[结论]坡面植被覆盖能够明显改变土壤水文,维持土壤水分含量在较高水平,特别是20 cm以下的土层。

[Objective] The research aimed to study the effects of vegetative coverage on the changes of soil moisture in rainy season in dry-hot valley.[Method] The surface runoff and soil moisture of slope with vegetative coverage and bare land in rainy reason in Jinsha River at Yuanmou County of Yunnan Province were observed continuously,and the statistical analysis was made on the observation data.[Result] The vegetative coverage could decrease surface runoff and the surface runoff on bare land（CK） was 22 times as the plot with vegetative coverage.The soil water content in 0-180 cm layer with vegetative coverage increased by 37.8% than bare land.The stability of soil moisture content in deep layer was enhanced and the physical properties stability of soil was maintained.The soil moisture content in different depth of soil had significant difference and the changes of soil moisture content were obviously different.[Conclusion] The vegetative coverage of slope could change the soil hydrology obviously and keep soil moisture at the higher level,especially soil layer below 20 cm.