基于SIMDual_Kc模型的豫北地区麦田土壤水分动态和棵间蒸发模拟

Simulation of Soil Moisture Dynamics and Soil Evaporation of Winter Wheat Based on SIMDual_Kc Model in Northern Henan Province

利用2a实测的冬小麦田间土壤剖面含水率和棵间蒸发数据,修正了基础作物系数和土壤物理参数等指标,率定了SIMDual_Kc双作物模型,并验证了其在豫北地区冬小麦田的适用性。结果表明,修订后的SIMDual_Kc模型模拟豫北地区冬小麦有效根层的土壤含水率和棵间蒸发量与实测值具有很好的一致性,误差较小。冬小麦整个生育期的棵间蒸发量占总腾发量的比例约为35%,分时期计算,此比值在生育前期明显高于生育后期。生育前期棵间蒸发量占总腾发量的比例高达73%,快速生长期该比例降至约30%,生育中期棵间蒸发比例最低,约为7.5%,生育后期棵间蒸发比例又升至约35.5%。研究结果可为地表覆盖、节水灌溉方式和适宜灌溉频率等减少棵间蒸发的技术措施研发与应用提供必要的理论支持。

Based on 2- year soil moisture and soil evaporation data measured in an experimental field of winter wheat in the Guangli irrigation district, Jiaozuo city, Henan province, this paper revised the basic crop coefficients, soil parameters and other indexes, calibrated the dual crop coefficient model, SlMDualKc, and vertified its adaptability in the winter wheat field in the northern part of Henan province. The results showed that simulated values of soil water content and soil evaporation fitted well with observed data, and the errors between the simulated and observed values were small. The average ratio of soil evaporation to the actual crop evapotranspiration （E/ETc） over the whole growing season was about 35%, and the ratio in the early growing stages were significantly higher than those in the late stages. The ratio of soil evaporation to the actual crop evapotranspiration in the early stage of growth period could reach 73%, and in the rapid growth stage, it decreased to about 30%, while in the middle stage of growth period, the ratio was the lowest, which was about 7. 5%, and in the late growth stage, the ratio increased to about 35. 5%. The results provided the theoretical basis for developing soil evaporation reduction techniques, such as soil surface mulching, water saving irrigation and reasonable irrigation scheduling.