冻融期不同覆盖和气象因子对土壤导热率和热通量的影响

发布时间：2018-05-12 23:18

本文选题：秸秆 + 土壤　；参考：《农业工程学报》2017年20期

【摘要】：为了研究冻融期不同覆盖和气象因子对土壤导热率和土壤热通量的影响,在2015年11月-2016年4月期间,设置了裸地(BL)、自然积雪覆盖(SC)、6 000 kg/hm~2秸秆+积雪覆盖(SM1)、12 000 kg/hm~2秸秆+积雪覆盖(SM2)和18 000 kg/hm~2秸秆+积雪覆盖(SM3)5种不同的处理,测定了20、40、60和100 cm土壤含水率和温度,并计算出土壤导热率和土壤热通量。研究结果发现:在土壤冻结期,土壤导热率随着土壤的冻结而增大,直至完全冻结后基本保持不变,而在土壤融化期则逐渐减小。冻融阶段,积雪和秸秆覆盖会延缓土壤导热率的变化,减小土壤导热率的变化。冻结期,裸地处理的土壤导热率最大,平均为1.55 W/(m×K);融化期,裸地处理的土壤导热率最小,平均为0.79 W/(m×K)。在冻结期,土壤热量向上传递,传递量先增加后减小;在融化期,土壤热量向下传递,传递量逐渐增加。积雪和秸秆覆盖可以减小土壤热通量及其变化。积雪和秸秆覆盖条件下的土壤热通量比裸地少4.73~8.84 W/m~2。裸地处理的土壤导热率与水汽压的相关性最好,相关系数为-0.84,与风速的相关性最差,相关系数为-0.43。积雪和秸秆覆盖条件下的土壤导热率与环境温度的相关性最好,相关系数为-0.67~-0.73,与风速的相关性最差,相关系数为-0.18~-0.25。土壤热通量与太阳辐射的相关性最好,相关系数为-0.88~-0.91,与风速的相关性最差,相关系数为-0.44~-0.53。整体而言,积雪和秸秆覆盖会减小大气环境对土壤导热率和热通量的影响。
[Abstract]:In order to study the effects of different mulching and meteorological factors on soil thermal conductivity and soil heat flux during freezing and thawing period, from November 2015 to April 2016, The soil moisture content and temperature of 20 ~ 4060 cm and 100 cm soil were measured under 5 different treatments, I. E. natural snow cover, 6 000 kg/hm~2 straw mulch, 12 000 kg/hm~2 straw snow cover (SM2) and 18 000 kg/hm~2 straw snow cover (SM3). The soil thermal conductivity and soil heat flux were calculated. The results showed that during the period of soil freezing, the soil thermal conductivity increased with the freezing of the soil, and remained basically unchanged until it was completely frozen, but gradually decreased during the period of soil melting. In freezing and thawing stage, snow cover and straw mulch could delay the change of soil thermal conductivity and decrease the change of soil thermal conductivity. During freezing period, the soil thermal conductivity of bare land treatment was the highest, with an average of 1.55 W / m 脳 K ~ (2 +), and that of bare land treatment was the lowest, with an average of 0.79 W / m 脳 K ~ (-1) during melting period. During the freezing period, the heat transfer increased first and then decreased, while in the melting period, the heat transfer gradually increased. Snow cover and straw mulch can reduce soil heat flux and change. The soil heat flux under the condition of snow cover and straw mulch was 4.73 ~ 8.84 W / m ~ (-1) less than that of bare land. The correlation between soil thermal conductivity and water vapor pressure was the best, the correlation coefficient was -0.84, and the correlation coefficient with wind speed was -0.43. Under the condition of snow cover and straw mulching, the correlation between soil thermal conductivity and environmental temperature was the best, the correlation coefficient was -0.67 ~ 0.73, and the correlation coefficient was -0.18 ~ (-0.25) with wind speed. The correlation between soil heat flux and solar radiation was the best, the correlation coefficient was -0.88 ~ 0.91, and the correlation coefficient with wind speed was -0.44 ~ 0.53. As a whole, snow cover and straw mulch can reduce the influence of atmospheric environment on soil heat conductivity and heat flux.
【作者单位】：东北农业大学水利与土木工程学院;
【基金】：国家自然科学基金(51679039) 黑龙江省杰出青年基金(JC201402)
【分类号】：S152.8

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