ISSN:0020-6024    

DOI:10.1080/02626666609493435

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

In the saturated zone of calcareous aquifers the process of erosion by solution proceeds at a very slow pace, and consists essentially of two correlated phenomena:

ISSN:0020-6024    

DOI:10.1080/02626666609493436

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0020-6024    

DOI:10.1080/02626666609493437

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0020-6024    

DOI:10.1080/02626666609493438

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

During the spring of 1961, evaporation from snow and soil surfaces was measured in the central Rocky Mountains near Fraser, Colorado. Measurements were made in natural forest openings at 9,000 feet elevation. Evaporation from wet soil surfaces greatly exceeded evaporation from nearby snow. There was little evidence of transfer of vapor from soil to nearby patches of snow, but as areas of bare, wet soil increased and evaporation amounts from such surfaces increased, evaporation from snow decreased. It was concluded that, as greater amounts of water evaporated from soils, the vapor pressure of the air was raised sufficiently to reduce evaporation from snow. Since transfer of vapor from soil to snow appeared small at best, evaporation losses from snow and soil surfaces essentially constituted a total moisture loss from the area.

ISSN:0020-6024    

DOI:10.1080/02626666609493439

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0020-6024    

DOI:10.1080/02626666609493440

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0020-6024    

DOI:10.1080/02626666609493441

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

ISSN:0020-6024    

DOI:10.1080/02626666609493442

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

It has always been a problem for the hydraulic engineer to obtain reasonable values for the roughness in a waterway. The writer feels that the idea put forward in this essay could help the parcticing engineer to obtain a roughness value without complicated procedure.

ISSN:0020-6024    

DOI:10.1080/02626666609493443

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The one-dimensional transient downward entry of water in unsaturated soils is investigated theoretically. The mathematical equation describing the infiltration process is derived by combining Darcy's dynamic equation of motion with the continuity and thermodynamic state equations adjusted for the unsaturated flow conditions. The resulting equation together with the corresponding initial and boundary conditions constitues a mathematical initial boundary value problem requiring the solution of a nonlinear partial differential equation of the parabolic type. The volumetric water content is taken as the dependent variable and the time and the position along the vertical direction are taken as the independent variables. The governing equation is of such nature that a solution exists for t > 0 and is uniquely determined if two relationships are defined, together with the specified state of the system, at the initial time t = 0 and at the two boundaries. The two required relations are those of pressure versus permeability and pressure versus volumetric water content.

ISSN:0020-6024    

DOI:10.1080/02626666609493444

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor