黄土丘陵区柠条人工林土壤水分动态变化特征及降雨特征对其影响  

Dynamic Variation Characteristics of Soil Moisture in Caragana korshinskii Plantation in Loess Hilly Area and the Influence of Rainfall Characteristics on It

作　　者：孙亚荣 陈云明[1,2] 王亚娟 刘少华 赵敏 刘乐 卢森堡 SUN Yarong;CHEN Yunming;WANG Yajuan;LIU Shaohua;ZHAO Min;LIU Le;LU Senbao(Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100)

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《水土保持学报》2023年第1期272-279,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41771556);国家重点研发计划项目(2016YFC0501703);宁夏回族自治区重点研发计划项目(2020BCF01001)。

摘　　要：明确黄土丘陵区降雨对土壤水分影响,对准确评估降雨格局变化对生态系统结构和功能的影响具有重要意义。以陕北黄土丘陵区退耕地栽植后自然撂荒23年的柠条人工纯林为研究对象,通过土壤湿度传感器监测不同土层土壤体积含水量,探讨不同土层土壤水分补充增量对降雨特征(降雨量、降雨历时和降雨强度)的响应。结果表明:(1)土壤水分消耗和补充主要集中于0-500 cm土层,其月变化在垂直剖面呈“双峰”(4—5月)、“单峰”(6月)和“双峰”(7—10月),随土层深度增加变化率减弱;(2)当降雨量>4 mm时表层土壤水分得到有效补充,当其超过142.8 mm时补充深度可到达200 cm土层,其中长历时强降雨较短历时强降雨对土壤水分补充增量小,但其补充深度较深,达到峰值时间长,但小降雨长历时则土壤水分补充增量较小;(3)降雨特征对土壤水分影响随土层深度增加而减弱,其中降雨量和降雨历时对土壤水分影响主要在0—50 cm土层,而降雨强度对其影响主要在0—30 cm土层。降雨量(降雨历时)和土壤水分补充增量对数拟合最优,而降雨强度与其则表现为幂函数拟合最优,其可分别解释土壤水分补充增量的39%~76%(降雨量)、0~97%(降雨历时)和1%~91%(降雨强度)。综上所述,降雨量越大,降雨历时越长,对深层土壤水分补给增量越大,且土壤水分消耗和降雨对其补充分别在0—500 cm土层和0—200 cm土层。Clarifying the impact of rainfall on soil moisture in the loess hilly area is great significance to accurately assess the impact of rainfall pattern changes on the structure and function of ecosystem.In this study,the artificial pure forest of Caragana korshinskii that had been abandoned for 23 years after being planted in the abandoned farmland in the loess hilly area of northern Shaanxi was taken as the research object.The soil moisture sensor was used to monitor the soil volume water content in different soil layers,and the responses of soil water supplement increment in different soil layers to rainfall characteristics(rainfall,rainfall duration and rainfall intensity)were discussed.The results showed that:(1)Soil water consumption and replenishment were mainly concentrated in the 0-500 cm soil depths,and the monthly variation in the vertical profile were“double peak”(April-May),“single peak”(June)and“double peak”,and the change rate decreased with the increasing of soil depth.(2)When the rainfall was more than 4 mm,surface soil moisture could be effectively replenished.When it exceeded 142.8 mm,the replenishment depth could reach 200 cm soil layer.The soil moisture replenishment increment of the long-duration heavy rainfall was less than that of short duration heavy rainfall,however,the replenishment depth of long-duration heavy rainfall was deep and the peak time was long.(3)The influence of rainfall characteristics on soil moisture decreased with the increasing of soil depth.The influence of rainfall and rainfall duration was mainly in 0-50 cm soil layer,and the influence of rainfall intensity was in 0-30 cm soil layer.The logarithmic fitting of rainfall(rainfall duration)and soil water replenishment increment was the best.While the logarithmic fitting of rainfall intensity and soil water replenishment increment was the best,which could explain 39%~76%of soil water replenishment increment(rainfall),0~97%(rain duration)and 1%~91%(rain intensity),respectively.To sum up,the greater the rainfall an

关 键 词：黄土丘陵区 土壤水分补充 降雨特征 柠条人工林 

分 类 号：S157.2[农业科学—土壤学]