基于季节特征的土壤退墒模型建立与率定

Modeling and verification of soil moisture recession curves based on seasonal variation

利用河南省南阳市2011—2015年12个墒情站的土壤水分监测资料,分析研究了无增墒情况下土壤含水量消退规律,构建出基于不同季节(夏季、春秋季与冬季)的土壤含水量与衰减系数的数学模型,运用规划求解法率定模型参数,并利用2016—2017年资料对模型进行检验。结果表明,不同季节土壤水分衰竭系数模型分别为α=1.023(1-ω^2/4353)^1/2(夏季)、α=1.013(1-ω^2/7005)^1/2(春秋季)与α=1.008(1-ω^2/9303)^1/2(冬季),所建立的数学模型适用于南阳市相应季节壤土与粘壤土小麦、水稻与休闲地土壤旱情预测,但不适用于夏季与春秋季砂土特别是休闲地砂土土壤墒情预测。

Soil moisture data collected between 2011 and 2015 from 12 soil moisture monitoring stationsin Nanyang,Henan,were used to analyze the decreasing pattern of soil moisture content without water input.Based on these data,a soil moisture recession model was constructed and the parameters were calibrated by programming solver.After being examined with soil moisture data from 2016-2017,it was found that the parameters of the model wereα=1.023(1-ω^2/4353)^1/2,α=1.013(1-ω^2/7005)^1/2,andα=1.008(1-ω^2/9303)^1/2 for summer,spring-autumn,and winter,respectively.The results suggested that the proposed model can be used to describe the decreasing pattern of soil moisture for clay and loam soil in farmland for fallow and planting wheat or rice,but not suitable for drought prediction in summer and spring-autumn for fallow sandy soil.