摘要:

The development and testing of a general purpose soil-moisture-plant model is presented. The model incorporates soil, plant and hydrometeorological factors, and simulates daily variations in both leaf suction and the soil moisture deficit in each of three soil layers. A fourth soil layer permits the simulation of deep percolation and the rise and fall of a shallow water table. Two important features of the model are its unsaturated flow and root abstraction algorithms which are essential to the accurate modelling of moisture changes within layers. Actual transpiration is automatically reduced below the potential rate by the root abstraction algorithm when flow through the soil-plant system is unable to meet the demand. The physical characteristics of the soil layers are represented by mathematical functions relating soil suction to moisture content and unsaturated hydraulic conductivity. The model is calibrated and tested against field data obtained using the neutron probe technique. It is proposed that the computed values of leaf suction provide a better index of irrigation need than soil moisture deficit.

ISSN:0262-6667    

DOI:10.1080/02626668209491081

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The quasi-translatory properties of the Muskingum flood routing methods are demonstrated. The conditions for best approximation of the pure translation model by single and multiple Muskingum models are developed. Instead of the finite difference methods used in the literature the transfer function approach is analysed, which gives a new, general insight into the problem. The impact of physical interpretation of the Muskingum model parameters upon the quasi-translatory properties of the model is outlined.

ISSN:0262-6667    

DOI:10.1080/02626668209491082

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Seasonal variations of the deuterium content in Rofenache, Vent, Oetztal Alps, are discussed and compared for the years 1972–1977. The basin covers an area of 98 km2, 44% being glacierized. The onset and course of the seasonal variations are closely connected with the snowmelt in the lower region of the basin and with the ice melt in the ablation area which sets in later. Due to the meltwater from the winter snow pack in the lower part of the basin, minimum deuterium contents are observed in the runoff, whereas progressing ice melt in the ablation area causes the deuterium concentration in the runoff to rise. If the ice melt sets in late, due to the weather, this is well reflected in a delayed increase in the deuterium concentration in the runoff.

ISSN:0262-6667    

DOI:10.1080/02626668209491083

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The author has recently shown that rainfall interstation correlation functions can be derived analytically from mathematically described storm models. In this paper the formal derivation of such correlation functions is improved. The terminology has been made more general to furnish a basis for further developments in deriving and interpreting correlation functions. One of the storm models that can be treated analytically is the exponential model, which contains a shape parameter measuring the steepness of the storm profile. Varying this parameter from zero to infinity, a family of storm profiles is obtained ranging from a flat (rectangular) type to extremely peaked types with vanishing storm width. This paper investigates how the analytical interstation correlation function behaves when varying the storm profile parameter. The results given as families of correlation curves complete the collection of the graphical representation of rainfall interstation correlation functions derived thus far. They are required in interpreting and calibrating empirically found correlation functions. Storm diameter, the length of the cross section in the gauged area across which storms pass, and the proportion of completely dry days over the gauged area, are used as further parameters.

ISSN:0262-6667    

DOI:10.1080/02626668209491084

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The steady state square node groundwater model presented is for a confined aquifer with choice of recharge/discharge and constant head boundaries. Transmissivity, recharge/discharge, constant and initial head and nodal network must be input. Output is steady state water levels to the precision desired by the operator up to calculator limit of significant figures. Forty nodes or less can be defined but depending on complexity the program can be easily modified for variable thickness and floating fresh water lens conditions.

ISSN:0262-6667    

DOI:10.1080/02626668209491085

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A method is proposed for the simulation of groundwater flow in regional aquifers dissected by dykes of low permeability or by geological faults, which act as barriers to flow and which can have a considerable influence on the available groundwater resources. The method has been verified by a comparison of numerical results with the analytical solution to a test problem. The method has been applied to an area of the Cave Sandstone aquifer in Botswana which has been affected by dyke intrusions which significantly affect its potential for large-scale groundwater development.

ISSN:0262-6667    

DOI:10.1080/02626668209491086

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626668209491087

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626668209491088

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626668209491089

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626668209491090

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor