非饱和砂箱水汽热运移的试验研究
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摘要
非饱和土壤中水汽热运移受到水文学和土壤物理学等学科的深入关注,这一研究对于查明干旱半干旱地区地表和大气间水分和能量的交换过程十分重要。
土壤中水热运移方程能够相互耦合主要是水汽运移的结果,所以,这一研究重点就集中在对土壤中各种水汽运移机制的探讨。对于水汽扩散运移机制,国内外学者已经做了许多研究,而对水汽对流和水汽弥散机制的研究相对较少。
本文在土壤物理参数试验以及含水量观测仪器EasyAG50温度效应校正试验的基础上,利用采自巴丹吉林沙漠的细砂进行了三种不同条件下的砂箱试验,根据试验结果初步探讨了各种水汽运移机制对土壤含水量变化的影响特征。
通过密封恒温试验,得出当采用风干的沙漠细砂进行砂箱水汽热运移试验时,可以忽略液态水运移对土壤含水量的影响。
通过密封变温试验,得出土壤含水量在剧烈变温条件下的改变主要是由仪器本身的温度效应引起的,水汽扩散在此阶段不起主要作用;当土壤温度逐渐趋于稳定时,水汽扩散对土壤含水率变化的作用才和温度效应相当,甚至超过温度效应。
通过通风变温试验,得出在空气实际平均流速为0.011cm/s的条件下,水汽对流和仪器温度效应对土壤含水量变化的贡献率分别为191.2%和28.6%,而水汽弥散和水汽扩散对土壤含水量改变的贡献率分别为-25.5%和-94.1%。这表明此时,水汽对流是土壤含水量改变的最重要影响因素,而不是通常认为的水汽扩散。
Coupled water, water vapor, and heat transport in unsaturated soil has enjoyed intensive focus in hydrology and soil physics. This research plays an important role in identifying water and energy exchange process between land surface and atmosphere in arid and semiarid areas.
The coupling of the water and heat transfer equations is mainly resulting from the water vapor movement, therefore, naturally, this area research has focused on each water vapor transport mechanisms in the unsaturated soil. Domestic and foreign scholars have done a lot of research on the water vapor diffusion and yet, pay relatively little attention to the research of water vapor convection and dispersion.
Based on the soil physical parameters experiment and calibration experiment of temperature effect of the soil moisture monitoring equipment EasyAG50, this dissertation conducts sandbox experiment under three different conditions, using fine sand which is collected from the Badain Jaran Desert. Meanwhile, according to the experiment results, this dissertation preliminary probes into the impact of each water vapor transport mechanisms on the changes in soil moisture content.
Through sandbox experiment under airtight and constant temperature conditions, the author concludes that the effect of liquid water transport on changes in soil moisture content could be ignored when using air-dry desert fine sand in this sandbox experiment.
Through sandbox experiment under airtight and fluctuant temperature conditions, the author concludes that the change in soil moisture content under fluctuant temperature condition mainly results from the temperature effect of the equipment EasyAG50 itself, the water vapor diffusion plays a minor role at this stage; and that when the soil temperature gradually stabilizes, the change in soil moisture content chiefly arises from the water vapor diffusion but not the equipment temperature effect. Through sandbox experiment under ventilated and fluctuant temperature conditions, the author concludes that under the actual average air flow rate 0.011cm/s conditions, the contribution rates of water vapor convection and equipment temperature effect on changes in soil moisture content are 191.2% and 28.6% respectively, while the contribution rates of water vapor diffusion and dispersion on changes in soil moisture content are -25.5% and -94.1% respectively. This indicates that under such conditions, water vapor convection is the most important factors to the change in soil moisture content, but not the well-known water vapor diffusion.
土壤中水热运移方程能够相互耦合主要是水汽运移的结果,所以,这一研究重点就集中在对土壤中各种水汽运移机制的探讨。对于水汽扩散运移机制,国内外学者已经做了许多研究,而对水汽对流和水汽弥散机制的研究相对较少。
本文在土壤物理参数试验以及含水量观测仪器EasyAG50温度效应校正试验的基础上,利用采自巴丹吉林沙漠的细砂进行了三种不同条件下的砂箱试验,根据试验结果初步探讨了各种水汽运移机制对土壤含水量变化的影响特征。
通过密封恒温试验,得出当采用风干的沙漠细砂进行砂箱水汽热运移试验时,可以忽略液态水运移对土壤含水量的影响。
通过密封变温试验,得出土壤含水量在剧烈变温条件下的改变主要是由仪器本身的温度效应引起的,水汽扩散在此阶段不起主要作用;当土壤温度逐渐趋于稳定时,水汽扩散对土壤含水率变化的作用才和温度效应相当,甚至超过温度效应。
通过通风变温试验,得出在空气实际平均流速为0.011cm/s的条件下,水汽对流和仪器温度效应对土壤含水量变化的贡献率分别为191.2%和28.6%,而水汽弥散和水汽扩散对土壤含水量改变的贡献率分别为-25.5%和-94.1%。这表明此时,水汽对流是土壤含水量改变的最重要影响因素,而不是通常认为的水汽扩散。
Coupled water, water vapor, and heat transport in unsaturated soil has enjoyed intensive focus in hydrology and soil physics. This research plays an important role in identifying water and energy exchange process between land surface and atmosphere in arid and semiarid areas.
The coupling of the water and heat transfer equations is mainly resulting from the water vapor movement, therefore, naturally, this area research has focused on each water vapor transport mechanisms in the unsaturated soil. Domestic and foreign scholars have done a lot of research on the water vapor diffusion and yet, pay relatively little attention to the research of water vapor convection and dispersion.
Based on the soil physical parameters experiment and calibration experiment of temperature effect of the soil moisture monitoring equipment EasyAG50, this dissertation conducts sandbox experiment under three different conditions, using fine sand which is collected from the Badain Jaran Desert. Meanwhile, according to the experiment results, this dissertation preliminary probes into the impact of each water vapor transport mechanisms on the changes in soil moisture content.
Through sandbox experiment under airtight and constant temperature conditions, the author concludes that the effect of liquid water transport on changes in soil moisture content could be ignored when using air-dry desert fine sand in this sandbox experiment.
Through sandbox experiment under airtight and fluctuant temperature conditions, the author concludes that the change in soil moisture content under fluctuant temperature condition mainly results from the temperature effect of the equipment EasyAG50 itself, the water vapor diffusion plays a minor role at this stage; and that when the soil temperature gradually stabilizes, the change in soil moisture content chiefly arises from the water vapor diffusion but not the equipment temperature effect. Through sandbox experiment under ventilated and fluctuant temperature conditions, the author concludes that under the actual average air flow rate 0.011cm/s conditions, the contribution rates of water vapor convection and equipment temperature effect on changes in soil moisture content are 191.2% and 28.6% respectively, while the contribution rates of water vapor diffusion and dispersion on changes in soil moisture content are -25.5% and -94.1% respectively. This indicates that under such conditions, water vapor convection is the most important factors to the change in soil moisture content, but not the well-known water vapor diffusion.
引文
A. Verhoef, J. Fernandez-Galvez, A. Diaz-Espejo, B.E. Main, M. El-Bishti. The diurnal course of soil moisture as measured by various dielectric sensors: Effects of soil temperature and the implications for evaporation estimates. Journal of Hydrology, 2006, 321: 147-162.
Baumhardt, R.L., R.J. Lascano, and S.R. Evett. Soil material, temperature, and salinity effects on calibration of multisensor capacitance probes. Soil Sci. Soc. Am. J., 2000, 64: 1940-1946.
Bouyoucos, G. T. Effect of temperature on the movement of water vapor and capillary moisture in soils. J. Agric. Res. 1915, 5: 141-172.
Buckingham E. Contributions to our knowledge of the aeration of soils. Washington D C: U.S. Department of Agriculture Bureau of Soils, 1904.
Cahill, A. T., Parlange, M. B. On water vapor transport in field soils. Water Resour. Res. 1998, 34(4):731-739.
Cary, J. W. Water flux in moist soil: thermal versus suction gradients. Soil Sci. 1965, 100, 168.
D’Odorico, P., A. Porporato, and R.E. Dickinson. Preferential states in soil moisture and climate dynamics. Proc. National. Academ. Sci. 2004, 101(24): 8848-8851.
Farrell D A, Greacen E L, Gurr C G. Vapor transfer in soil due to air turbulence. Soil Science, 1966, 102: 305-313.
Grifoll J, Gast JM, and Cohen Y. Non-isothermal soil water transport and evaporation. Advances in Water Resources. 2005, 28(11): 1254-1266.
Gurr, C. G., T. J. Marshall, and J. T. Hutton. Movement of water in soil due to a temperature gradient. Soil Sci. 1952, 74(5): 335-345.
Hirotaka Saito, Jiri Simunek, and Binayak P. Mohanty. Numerical Analysis of Coupled Water, Vapor, and Heat Transport in the Vadose Zone. Vadose Zone Journal. 2006, 5: 784-800.
Humphreys, W.J. Note on the movement of moisture in soils. Science. 1907, 26: 480-481.
Jackson, R. D. Diurnal changes in soil water content during drying. A R.R. Bruce et al.(Editors) Field soil water regime. Soil Sci. Soc. Amer. Proc. 1973(Special Pub. 5.): 37-55.
Jackson, R. D., R. J. Reginato, B. A. Kimball, and F. S. Nakayama. Diurnal soil-water evaporation: Comparison of measured and calculated soil-water fluxes. Soil Sci. Soc. Am. Proc. 1974, 38(6): 861-866.Joel Massmann, Daniel F. Farrier. Effects of atmospheric pressures on gas transport in the vadose zone. Water Resources Research, 1992, 28(3): 777-791.
Joshua L. Heitman. Measurement of coupled soil heat and water processes. Ph.D. thesis. Iowa State University, 2007.
Marco Bittelli, Francesca Ventura, Gaylon S. Campbell, Richard L. Snyder, Fabia Gallegati, Paola Rossi Pisa. Coupling of heat, water vapor, and liquid water fluxes to compute evaporation in bare soils. Journal of Hydrology. 2008, 362: 191-205.
Milly, P.C.D. A simulation analysis of thermal effects on evaporation from soil. Water Resour. Res. 1984, 20(8): 1087-1098.
Milly, P.C.D. Moisture and heat transport in hysteretic, inhomogeneous porous media: a matric head-based formulation and a numerical model. Water Resour. Res. 1982, 18(3): 489-498.
Molly S. Costanza-Robinson, Mark L. Brusseau. Gas phase advection and dispersion in unsaturated porous media. Water Resour. Res. 2002, 38(4): 7-1– 7-9.
Parlange, M.B., Cahill, A.T., Nielsen, D.R., Hopmans, J.W., and Wendroth, O. Review of heat and water movement in field soils. Soil & Tillage Research. 1998, 47: 5-10.
Philip, J.R., and D.A. de Vries. Moisture movement in porous materials under temperature gradients. Trans. Am. Geophys. Un. 1957, 38(2): 222-232.
Polyakov, V., Fares, A., and Ryder, M. H. Calibration of a capacitance system for measuring water content of tropical soil. Vadose Zone Journal, 2005, 4: 1004-1010.
Reda Abdu el-hay Mohamed Ali El-Damak. Analysis of water, heat, and solute transfers in unsaturated porous media. Ph.D. thesis. University of Maryland College Park, 1983.
Rollins, R. L., M. G. Spangler, and D. Kirkham. Movement of soil moisture under a thermal gradient. Highway Res. Board Proc. 1954, 33: 492-508.
Rose, C. W. Water transport in soil with a daily temperature wave, 1, Theory and experiment. Aust. J. Soil Res. 1968a, 6: 31-44.
Rose, C. W. Water transport in soil with a daily temperature wave, 2, Analysis. Aust. J. Soil Res. 1968b, 6: 45-57.
Scanlon, B. R. Water and heat fluxes in desert soils, 1, Field studies. Water Resour. Res. 1994, 30(3): 709-719.
Scotter D R, Thurtell G W, Raats P A C. Dispersion resulting from sinusoidal gas flow in porousmaterials. Soil Science, 1967, 104: 306-308.
Shukla, J., and Y. Mintz. Influence of land-surface evapotranspiration on the Earth’s climate. Science. 1982, 215: 1498-1501.
Smith, W. O. Thermal transfer of moisture in soils. Trans. Am. Geophys. Un. 1943, 24, 511.
Taylor, S. A., and Cavazza, L. The movement of soil moisture in response to temperature gradients. Soil Sci. Soc. Amer. Proc. 1954, 18: 351-358.
Wuest, S.B., S.L. Albrecht, and K.W. Skirvin. Vapor transport vs. seed–soil contact in wheat germination. Agronomy Journal. 1999, 91(5): 783-787.
蔡树英,张瑜芳.温度影响下土壤水分蒸发的数值分析.水利学报,1992,11:1-8.
曹文炳,万力,周训,胡伏生,陈劲松.西北地区砂丘凝结水形成机制及对生态环境影响初步探讨.水文地质工程地质,2003(2):6-10.
陈振乾,施明恒.大气对流对土壤内热和水分迁移影响的数值模拟.农业工程学报,1998,14(3):117-122.
陈振乾,施明恒.大气对流对土壤内热湿迁移影响的实验研究.太阳能学报,1999,20(1):87-92.
顾慰祖,陈建生,汪集旸,等.巴丹吉林高大砂山表层孔隙水现象的疑义.水科学进展,2004,15(6):695-699.
韩晓非,柳云龙等.土壤水热耦合运移数值模型研究进展.土壤通报,2001,32(4):151-154.
胡和平,雷志栋,杨诗秀.土壤冻结时水热迁移规律的数值模拟.水利学报,1992,7:1-8.
黄兴法,曾德超.冻结期土壤水盐热运动规律的数值模拟.北京农业工程大学学报,1993,13(3):43-50.
雷志栋,杨诗秀,谢森传.土壤水动力学.北京:清华大学出版社,1988.
任理,张瑜芳,沈荣开.条带覆盖下土壤水热动态的田间试验与模型建立.水利学报,1998,2:1-9.
砂漠地区风积砂路用性能研究(研究报告简本).新疆交通科学研究院,2004.
邵明安,王全九,黄明斌.土壤物理学.北京:高等教育出版社,2006.
隋红建,曾德超,陈发祖.不同覆盖条件对土壤水热分布影响的计算机模拟:Ⅰ.数学模型.地理学报,1992,47(1):74-79.
隋红建,曾德超,陈发祖.不同覆盖条件对土壤水热分布影响的计算机模拟:Ⅱ.有限元分析及应用.地理学报,1992,47(2):181-187.
孙淑芬,牛国跃,洪钟祥.干旱及半干旱区土壤水热传输模式研究.大气科学,1998,22(1):1-10.
孙淑芬.陆面过程的物理、生化机理和参数化模型.北京:气象出版社,2005.
唐大雄,刘佑荣,张文殊,等.工程岩土学.北京:地质出版社,1999.
万力,曹文炳,胡伏生等.生态水文地质学.北京:地质出版社, 2005.
王大纯,张人权,史毅虹,等.水文地质学基础.北京:地质出版社,1995.
杨金忠,蔡树英,王旭升.地下水运动数学模型.北京:科学出版社,2009.
曾亦键,万力,王旭升,曹文炳.浅层包气带地温与含水量昼夜动态的实验研究.地学前缘,2006, 13(1):52-57.
曾亦键,万力,苏中啵,Hirotaka Saito,王旭升,曹文炳.浅层包气带水汽昼夜运移规律及其数值模拟研究.地学前缘,2008,15(5):330-343.
左强,王数. Hanks蒸发试验的模拟与分析.水利学报,1995,7:16-22.
Baumhardt, R.L., R.J. Lascano, and S.R. Evett. Soil material, temperature, and salinity effects on calibration of multisensor capacitance probes. Soil Sci. Soc. Am. J., 2000, 64: 1940-1946.
Bouyoucos, G. T. Effect of temperature on the movement of water vapor and capillary moisture in soils. J. Agric. Res. 1915, 5: 141-172.
Buckingham E. Contributions to our knowledge of the aeration of soils. Washington D C: U.S. Department of Agriculture Bureau of Soils, 1904.
Cahill, A. T., Parlange, M. B. On water vapor transport in field soils. Water Resour. Res. 1998, 34(4):731-739.
Cary, J. W. Water flux in moist soil: thermal versus suction gradients. Soil Sci. 1965, 100, 168.
D’Odorico, P., A. Porporato, and R.E. Dickinson. Preferential states in soil moisture and climate dynamics. Proc. National. Academ. Sci. 2004, 101(24): 8848-8851.
Farrell D A, Greacen E L, Gurr C G. Vapor transfer in soil due to air turbulence. Soil Science, 1966, 102: 305-313.
Grifoll J, Gast JM, and Cohen Y. Non-isothermal soil water transport and evaporation. Advances in Water Resources. 2005, 28(11): 1254-1266.
Gurr, C. G., T. J. Marshall, and J. T. Hutton. Movement of water in soil due to a temperature gradient. Soil Sci. 1952, 74(5): 335-345.
Hirotaka Saito, Jiri Simunek, and Binayak P. Mohanty. Numerical Analysis of Coupled Water, Vapor, and Heat Transport in the Vadose Zone. Vadose Zone Journal. 2006, 5: 784-800.
Humphreys, W.J. Note on the movement of moisture in soils. Science. 1907, 26: 480-481.
Jackson, R. D. Diurnal changes in soil water content during drying. A R.R. Bruce et al.(Editors) Field soil water regime. Soil Sci. Soc. Amer. Proc. 1973(Special Pub. 5.): 37-55.
Jackson, R. D., R. J. Reginato, B. A. Kimball, and F. S. Nakayama. Diurnal soil-water evaporation: Comparison of measured and calculated soil-water fluxes. Soil Sci. Soc. Am. Proc. 1974, 38(6): 861-866.Joel Massmann, Daniel F. Farrier. Effects of atmospheric pressures on gas transport in the vadose zone. Water Resources Research, 1992, 28(3): 777-791.
Joshua L. Heitman. Measurement of coupled soil heat and water processes. Ph.D. thesis. Iowa State University, 2007.
Marco Bittelli, Francesca Ventura, Gaylon S. Campbell, Richard L. Snyder, Fabia Gallegati, Paola Rossi Pisa. Coupling of heat, water vapor, and liquid water fluxes to compute evaporation in bare soils. Journal of Hydrology. 2008, 362: 191-205.
Milly, P.C.D. A simulation analysis of thermal effects on evaporation from soil. Water Resour. Res. 1984, 20(8): 1087-1098.
Milly, P.C.D. Moisture and heat transport in hysteretic, inhomogeneous porous media: a matric head-based formulation and a numerical model. Water Resour. Res. 1982, 18(3): 489-498.
Molly S. Costanza-Robinson, Mark L. Brusseau. Gas phase advection and dispersion in unsaturated porous media. Water Resour. Res. 2002, 38(4): 7-1– 7-9.
Parlange, M.B., Cahill, A.T., Nielsen, D.R., Hopmans, J.W., and Wendroth, O. Review of heat and water movement in field soils. Soil & Tillage Research. 1998, 47: 5-10.
Philip, J.R., and D.A. de Vries. Moisture movement in porous materials under temperature gradients. Trans. Am. Geophys. Un. 1957, 38(2): 222-232.
Polyakov, V., Fares, A., and Ryder, M. H. Calibration of a capacitance system for measuring water content of tropical soil. Vadose Zone Journal, 2005, 4: 1004-1010.
Reda Abdu el-hay Mohamed Ali El-Damak. Analysis of water, heat, and solute transfers in unsaturated porous media. Ph.D. thesis. University of Maryland College Park, 1983.
Rollins, R. L., M. G. Spangler, and D. Kirkham. Movement of soil moisture under a thermal gradient. Highway Res. Board Proc. 1954, 33: 492-508.
Rose, C. W. Water transport in soil with a daily temperature wave, 1, Theory and experiment. Aust. J. Soil Res. 1968a, 6: 31-44.
Rose, C. W. Water transport in soil with a daily temperature wave, 2, Analysis. Aust. J. Soil Res. 1968b, 6: 45-57.
Scanlon, B. R. Water and heat fluxes in desert soils, 1, Field studies. Water Resour. Res. 1994, 30(3): 709-719.
Scotter D R, Thurtell G W, Raats P A C. Dispersion resulting from sinusoidal gas flow in porousmaterials. Soil Science, 1967, 104: 306-308.
Shukla, J., and Y. Mintz. Influence of land-surface evapotranspiration on the Earth’s climate. Science. 1982, 215: 1498-1501.
Smith, W. O. Thermal transfer of moisture in soils. Trans. Am. Geophys. Un. 1943, 24, 511.
Taylor, S. A., and Cavazza, L. The movement of soil moisture in response to temperature gradients. Soil Sci. Soc. Amer. Proc. 1954, 18: 351-358.
Wuest, S.B., S.L. Albrecht, and K.W. Skirvin. Vapor transport vs. seed–soil contact in wheat germination. Agronomy Journal. 1999, 91(5): 783-787.
蔡树英,张瑜芳.温度影响下土壤水分蒸发的数值分析.水利学报,1992,11:1-8.
曹文炳,万力,周训,胡伏生,陈劲松.西北地区砂丘凝结水形成机制及对生态环境影响初步探讨.水文地质工程地质,2003(2):6-10.
陈振乾,施明恒.大气对流对土壤内热和水分迁移影响的数值模拟.农业工程学报,1998,14(3):117-122.
陈振乾,施明恒.大气对流对土壤内热湿迁移影响的实验研究.太阳能学报,1999,20(1):87-92.
顾慰祖,陈建生,汪集旸,等.巴丹吉林高大砂山表层孔隙水现象的疑义.水科学进展,2004,15(6):695-699.
韩晓非,柳云龙等.土壤水热耦合运移数值模型研究进展.土壤通报,2001,32(4):151-154.
胡和平,雷志栋,杨诗秀.土壤冻结时水热迁移规律的数值模拟.水利学报,1992,7:1-8.
黄兴法,曾德超.冻结期土壤水盐热运动规律的数值模拟.北京农业工程大学学报,1993,13(3):43-50.
雷志栋,杨诗秀,谢森传.土壤水动力学.北京:清华大学出版社,1988.
任理,张瑜芳,沈荣开.条带覆盖下土壤水热动态的田间试验与模型建立.水利学报,1998,2:1-9.
砂漠地区风积砂路用性能研究(研究报告简本).新疆交通科学研究院,2004.
邵明安,王全九,黄明斌.土壤物理学.北京:高等教育出版社,2006.
隋红建,曾德超,陈发祖.不同覆盖条件对土壤水热分布影响的计算机模拟:Ⅰ.数学模型.地理学报,1992,47(1):74-79.
隋红建,曾德超,陈发祖.不同覆盖条件对土壤水热分布影响的计算机模拟:Ⅱ.有限元分析及应用.地理学报,1992,47(2):181-187.
孙淑芬,牛国跃,洪钟祥.干旱及半干旱区土壤水热传输模式研究.大气科学,1998,22(1):1-10.
孙淑芬.陆面过程的物理、生化机理和参数化模型.北京:气象出版社,2005.
唐大雄,刘佑荣,张文殊,等.工程岩土学.北京:地质出版社,1999.
万力,曹文炳,胡伏生等.生态水文地质学.北京:地质出版社, 2005.
王大纯,张人权,史毅虹,等.水文地质学基础.北京:地质出版社,1995.
杨金忠,蔡树英,王旭升.地下水运动数学模型.北京:科学出版社,2009.
曾亦键,万力,王旭升,曹文炳.浅层包气带地温与含水量昼夜动态的实验研究.地学前缘,2006, 13(1):52-57.
曾亦键,万力,苏中啵,Hirotaka Saito,王旭升,曹文炳.浅层包气带水汽昼夜运移规律及其数值模拟研究.地学前缘,2008,15(5):330-343.
左强,王数. Hanks蒸发试验的模拟与分析.水利学报,1995,7:16-22.