黄土区长武塬土地利用变化对土壤水平衡的影响  

Impact of Land Use Change on Soil Water Balance in Changwu Tableland of Loess Region

作　　者：盖浩琪 石培君 李志[1] GAI Haoqi;SHI Peijun;LI Zhi(College of Natural Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《水土保持研究》2023年第4期154-159,共6页Research of Soil and Water Conservation

基　　金：国家自然科学基金“黄土区潜水补给的方式、速率与控制因素”(42071043)。

摘　　要：[目的]揭示土地利用变化对土壤水平衡中各水文变量的影响,明确黄土区水循环演变机制,进而为相似研究提供技术支撑。[方法]以黄土区长武塬为研究区,采集农地、18 a和26 a苹果园下20 m土样,测定了土壤水及其稳定性和放射性同位素含量,分解量化了土壤水平衡中各分量,评估了其对土地利用变化的响应。[结果]以农地为基准,18 a和26 a苹果园土壤水储量减少7.3%~14.3%,深层渗漏量减少41.2%~80.0%,蒸散发量增加5.0%~9.6%。蒸散发中,蒸发量减小8.6%~17.2%,而蒸腾量增加了12.9%~25.4%。[结论]3种土地利用方式下土壤水含量存在显著差异,土壤水氧同位素剖面总体呈现先减小后稳定的变化趋势,农地条件下土壤水受到的蒸发最强。深根植物苹果树主要通过增加蒸腾耗水而减少其他水文变量的通量,显著影响水文过程。[Objective]The aim of this study is to explore the impact of land use change(LUC)on various hydrological variables in soil water balance as well as the mechanism of water cycle in loess region,and then to provide technical support for similar research.[Methods]We chose the Changwu loess tableland as the study area,and then collected soil samples from the surface down to 20 m under three land use types(farmland,18-year apple orchard and 26-year apple orchard).Then,the content of soil water,stable(δ2 H andδ18 O)and radioactive(3 H)isotopes were measured.The components of soil water balance were decomposed and quantified,and their responses to land use changes were evaluated.[Results]Compared with farmland,the soil water storage under apple orchard(stand age 18 and 26 years)decreased by 7.3%~14.3%,the deep drainage decreased by 41.2%~80.0%,and the evapotranspiration increased by 5.0%~9.6%,of which evap oration decreased by 8.6%~17.2%,while transpiration increased by 12.9%~25.4%.[Conclusion]There were significant differences in soil water contents under three land use types,and the soil water oxygen isotope profiles showed a general trend of decreasing and then stabilizing,with soil water subject to the strongest evaporation under farmland.Deep-rooted fruit trees mainly reduced the flux of other hydrological variables by increasing transpiration water consumption,which significantly affected the hydrological process.

关 键 词：黄土塬 同位素示踪 深层渗漏 土地利用变化 土壤水分平衡 

分 类 号：S152.7[农业科学—土壤学]