云南西双版纳热带季雨林土壤水分运动模拟及参数变化特征

Simulation of Soil Water Movement and Variation Characteristics of Soil Hydraulic Parameters in Tropical Monsoon Forest in Xishuangbanna,Yunnan Province

因气象、植被等因素的季节周期特征,土壤水分运动规律及参数可能存在季节差异。以西双版纳季雨林通量站的观测数据为基础,运用Hydrus-1D模型,分别采用整时段、分时段策略率定土壤水力学参数,并分析参数的季节性特征,根据土壤含水量的模拟结果统计不同参数化方案下的模拟精度。结果表明,研究区在干热季、雨季的气象条件具有分明的季节性特征,进而影响土壤水分特征曲线和土壤非饱和导水率。相比于单组参数整时段模拟方法,依照客观存在的季节规律采用分时段、分季节的土壤水力学参数设定可明显提高土壤含水量的模拟精度,更准确地描绘土壤水动力过程。

Due to the seasonal cycle characteristics of meteorological and vegetation factors,there are seasonal differences in law of soil water movement and parameters.Based on the observed data of monsoon forest flux stations in Xishuangbanna,this paper used the HYDRUS-1 D model to simulate the soil water content and calibrate the soil hydraulic parameters by using the strategy of which is simulation with one set of parameters during the whole period and which adopt multiple sets of parameters for different periods.The accuracy of simulation under different parameter schemes were calculated according to the simulation results of soil moisture content.The results show that the study area has distinct seasonal characteristics in dry hot season and rainy season,which affects the soil water characteristic curve and unsaturated hydraulic conductivity.The simulation accuracy of soil water content could be obviously improved by using the way of simulation with multiple sets of parameters in different period according to the objective seasonal law,and the soil hydrodynamic process could be described more accurately.