半干旱地区不同森林类型土壤水分动态模拟  

Modeling soil moisture dynamics in different forest types in semiarid areas

作　　者：王晓学[1,2] 沈会涛[3] 周玥[4] 景峰[5] 李叙勇[1] 陈国鹏 

机构地区：[1]中国科学院生态环境研究中心城市与区域国家重点实验室,北京100085 [2]中国科学院大学研究生院,北京100049 [3]中国科学院遗传与发育生物学研究所农业资源研究中心,石家庄050021 [4]北京林业大学水土保持学院,北京100083 [5]中国国际工程咨询公司,北京100048 [6]甘肃省白龙江林业管理局林业科学研究所,武都746010

出　　处：《生态学报》2015年第19期6344-6354,共11页Acta Ecologica Sinica

基　　金：中国科学院生态环境研究中心"一三五"项目(YSW2013B02-4);中国科学院生态环境研究中心城市与区域生态国家重点实验室自主项目(SKLURE2013-1-05);海河流域水资源调蓄区水质保障及生态修复关键技术研究与示范(2014ZX07203010)

摘　　要：采用暖温带落叶阔叶次生林、油松人工林和华北落叶松人工林样地土壤水分的生长季内观测数据和其他辅助观测数据,检验了Georgakakos等提出的土壤水分模型在半干旱林地的适用性。结果表明,该模型用于模拟半干旱林地日尺度土壤水分动态具有一定的可信度,且能够较好的反映不同森林类型的水文效应。模型参数的敏感性分析表明,不同目标函数的参数敏感度信息反映了该模型"异参同效"现象不显著,模型结构不确定性也较小。各参数的敏感度结果揭示了各参数在降雨入渗、深层渗漏和蒸散部分中的控制作用。从模型模拟的土壤水分变化通量来看,油松人工林地实际年蒸散发量大于其他林地,落叶阔叶林地年入渗量大于其他林地,而3种森林类型林地深层渗漏所占生长季降雨量的比例都较小。研究半干旱地区多年生人工林土壤水分的情况,不仅有助于从根本上认清半干旱地区土壤-大气-植被连续体的复杂作用关系,也为半干旱地区树种选择及造林后的生态水文效应研究提供理论依据。Soil moisture is widely recognized as an important variable in studies related to ecology, meteorology, hydrology, agriculture and climate change. From a hydrological viewpoint, soil moisture content controls the partitioning of rainfall into runoff and infiltration, thereby affecting the runoff response in catchment areas. In recent decades, the role of soil moisture in a number of hydrological processes has been extensively studied on slope or catchment areas and has received increasing attention from the hydrological community. However, soil moisture is one of the most difficult variables to estimate because of factors such as vegetation, soil and topography. Accurate estimation of spatial and temporal variation in soil moisture is therefore required to improve both the predictive capabilities of runoff models as well as to validate representations of hydrological processes. Datasets of observed in situ moisture measurements are crucial. Unfortunately, measured soil moisture time series are not widely available and therefore simulated soil moisture series are used. We apply and test a simple parametric water balance model to simulating soil moisture conditions in different forest types （ natural secondary forest, evergreen needleleaf and deciduous/coniferous plantation forest） in semiarid regions of southwestern Beijhag, China. Model calibration and validation were performed using a dataset comprising averaged soil moisture content measured at depths of 0-75 cm in the growing seasons of 2006, 2007, and 2010. The models performed reasonably well in simulating the patterns and magnitudes of daily average soil moisture content in the upper 75 cm soil layer in all three forest types. Using different parameters in the model did not significantly alter the results and the model structure exhibited a relatively small amount of uncertainty. Sensitivity analysis revealed that four parameters （ Wmax （the maximum water capacity of the soil layer）, m （a parameter linked to the non-linearity of the infiltration

关 键 词：土壤水分模型 蒸散发 水量平衡 林下土壤含水量 半干旱 

分 类 号：S714.2[农业科学—林学]