水利学报2025，Vol.56Issue(3)：411-422,12.DOI:10.13243/j.cnki.slxb.20240351
考虑降雨和气温变化对土壤热通量估算模型的修正
Enhancing soil heat flux estimation with the consideration of precipitation and air temperature influences
摘要
Abstract
Soil heat flux is an important element of surface energy balance,holding a significant role in accurately estimating water budget during eco-hydrological processes in farmland and region.In estimating soil heat flux,the estimated daily-scale soil heat flux values in crop growth season by the conventional semi-theoretical and semi-em-pirical methods are always positive that do not align with the field observations.In this study,the soil heat flux model based on vegetation growth was revised by quantifying the influence of precipitation and air temperature chan-ges expressed using special design factors.Utilizing the measurements from the Hetao irrigation district in Inner Mongolia for sunflower and Beijing's Daxing district for winter wheat and summer maize,the parameters of the re-vised model were calibrated and validated.Then,the revised model was tested and applied using data obtained from the global flux network(FLUXNET)sites in the United States for maize-soybean rotation and in South Korea for rice,combined with the fractional vegetation cover from remote sensing satellites.Results showed that:(1)By incorporating precipitation and air temperature factors,the revised model effectively accounted for the influence of meteorological variations on soil heat flux and could accurately estimate the negative values of daily-scale soil heat flux during crop growth season.(2)Compared to observations,the revised model provided accurate estimates of soil heat flux across different regions and crop types for years,with the ranges of determination coefficient,root mean square error,the index of model agreement,and mean relative error of 0.54-0.63,3.30-11.70 W/m2,0.82-0.88,and-13.4％-11.70％,respectively.(3)Based on the Monte Carlo method,the key coefficients αand z in the revised model were determined as 0.1 and 10-20,respectively.(4)The sensitivity analysis of factors revealed that the air temperature had a more important influence on the revised model.A change of 1 ℃ in air tem-perature could result in a 10％-25％variation in estimating soil heat flux.These findings serve as a beneficial ref-erence for mitigating the surface energy imbalance and provide valuable technical support for precise soil heat flux estimation in large-scale remote sensing inversions.关键词
土壤热通量/灌区/空气温度/降雨/能量平衡Key words
soil heat flux/irrigation district/air temperature/precipitation/energy balance分类
农业科技引用本文复制引用
常宏芳,蔡甲冰,肖春安,张宝忠,许迪..考虑降雨和气温变化对土壤热通量估算模型的修正[J].水利学报,2025,56(3):411-422,12.基金项目
国家自然科学基金项目(52130906,51979286) （52130906,51979286）
内蒙古科技兴蒙项目(NMKJXM202208-3,NMKJXM202301-3) （NMKJXM202208-3,NMKJXM202301-3）
