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一种新的水面蒸发计算方法 总被引:2,自引:0,他引:2
本文应用相似理论,提出一个考虑自由对流和强迫对流相结合的水面蒸发模式,并用实测资料对蒸发模式作了检验。 相似文献
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结合四川土壤基层分类 ,选取四川紫色雏形土的几个土系 ,对土壤的水分发性能及其与土壤结构性尤其是机械组成和微团聚体组成的相关关系分析发展 ,土壤水分蒸发具有明显的阶段性 ;土壤水分累积蒸发量与蒸发历时之间总体上符合乘幂方程 ;土壤蒸发速度与〈0 .0 0 1mm的颗粒含量呈明显相关关系 ,与 >0 .2 5mm的大团聚体含量呈明显负相关关系。 相似文献
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辽宁砖庙矿区硼矿床硬石膏的发现及成因讨论 总被引:1,自引:0,他引:1
在对辽宁砖庙矿区硼矿床的矿物学研究中发现了硬石膏。该矿物产于硼矿体中,与遂安石、菱镁矿、镁橄榄石、袁复礼石、硼铝镁石等共生。通过矿物学研究和稀土元素、硫同位素的分析表明,由于硬石膏是蒸发沉积变质成因的,所以硼矿床也应是蒸发沉积变质成因的 相似文献
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A remote sensing model for monitoring soil evaporation based on differential thermal inertia and its validation 总被引:2,自引:0,他引:2
To develop geosciences quantification and multi-dimensional researches will be an inevitable trend in the 21st century. The interaction between the land surface and the atmosphere not only serves as an important component in geosciences quantification, bu… 相似文献
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Equilibrium Evaporation and the Convective Boundary Layer 总被引:2,自引:1,他引:1
M. R. Raupach 《Boundary-Layer Meteorology》2000,96(1-2):107-142
A theory is developed for surface energy exchanges in well-mixed, partlyopen systems, embracing fully open and fully closed systems as limits.Conservation equations for entropy and water vapour are converted intoan exact rate equation for the potential saturation deficit D in a well-mixed, partly open region. The main contributions to changes in D arise from (1) the flux of D at the surface, dependent on a conductance gq that is a weighted sum of the bulk aerodynamic and surface conductances; and (2) the exchange flux of D with the external environment by entrainment or advection, dependent on a conductance ge that is identifiable with the entrainment velocity when the partly open region is a growing convective boundary layer (CBL). The system is fully open when ge/gq , and fully closed when ge/gq 0. The equations determine the steady state surface energy balance (SEB) in a partly open system, the associated steady-state deficit, and the settling time scale needed to reach the steady state. The general result for the steady-state SEB corresponds to the equations of conventional combination theory for the SEB of a vegetated surface, with the surface-layer deficit replaced by the external deficit and with gq replaced by the series sum (gq
-1 + ge
-1)-1. In the fully open limit D is entirely externally prescribed, while in the fully closed limit, D is internally determined and the SEB approaches thermodynamic equilibrium energy partition. In the case of the CBL, the conductances gq and ge are themselves functions of D through short-term feedbacks, induced by entrainment in the case of ge and by both physiological and aerodynamic (thermal stability) processes in the case of gq. The effects of these feedbacks are evaluated. It is found that a steady-state CBL is physically achievable only over surfaces with at least moderate moisture availability; that entrainment has a significant accelerating effect on equilibration; that the settling time scale is well approximated by h/(gq + ge), where h is the CBL depth; and that this scale is short enough to allow a steady state to evolve within a semi-diurnal time scale only when h is around 500 m or less. 相似文献