摘要:

The Bundelkhand area of central India consists of weathered granitic bedrock. The aim of the present study was to identify the effects of surface water irrigation on groundwater quality in shallow aquifers used for domestic supply. A set of 37, 58 and 17 samples were collected, respectively, from the non-irrigated area, the irrigated area and surface waters. Concentrations of major ions (including NO3−), PO4= and Fe++were determined. A statistical comparison of the data groups was carried out assuming that the only difference between the two areas was in agricultural practice. It was discovered that, despite the better quality of the surface waters, the irrigated area groundwaters were higher in concentration than those of the non-irrigated area. The main causes for that appear to be evaporation/transpiration and fertilizer application, modified by calcite precipitation and ion exchange. The proposed approach is simple enough to be used routinely in monitoring.

ISSN:0262-6667    

DOI:10.1080/02626669209492598

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Over-exploitation of an alluvial aquifer in India has occurred since tubewells were drilled into deeper aquifers. Field information concerning-the fall in both the water table and the piezometric heads in the deeper aquifers has been examined and a numerical model has been developed to represent a heavily exploited area. Predictions using the model suggest that the annual declines in the water table and the piezometric heads are accelerating as the water table moves into a zone having a lower specific yield. Careful monitoring of the movement of the water table is proposed.

ISSN:0262-6667    

DOI:10.1080/02626669209492599

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

One of the scale problems in hydrology is to relate nonlinearity in basin response to size and other factors. On the Sputka basin (103.4 km2), three groups of unit hydrographs were identified, each group having a common shape parameter, N, of the Nash model and each, therefore, representing one dimensionless response. The existence of the three dimensionless responses can be explained in the first place by there being different spatial rainfall patterns for the events from which they were derived. The time parameter, K, within the individual groups depends primarily on the initial flow and on the skewness of the rainfall time pattern. However, when the conditions of rainfall uniformity and of a minimum depth are strictly met, and the initial flow is in a certain range, the basin behaves in a linear fashion.

ISSN:0262-6667    

DOI:10.1080/02626669209492600

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The baseflow characteristics of some of the numerous small basins in southeastern Nigeria have been analysed to estimate the developable groundwater in the basins. It is shown that from 5.62 × 104to 1.59 × 106m3of groundwater can be developed per square kilometre of basin per annum. The relationship between the baseflow characteristics and other attributes of the basins, such as geology and stream density, were studied statistically, leading to the development of empirical equations for predicting the hydrological features of the several ungauged streams in the region. It is shown, for example, that the basin geology (represented as the percentage of sands), the drainage density, the basin area, the baseflow depletion rate and the total groundwater stored in the basin, Qtp, are related by the equation:

ISSN:0262-6667    

DOI:10.1080/02626669209492601

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper presents the program KALMOD which has been developed to enable the execution of the integration of the Kalman filtering and the numerical groundwater flow model MODFLOW on microcomputers. The program can be applied to quantify and reduce the uncertainty of the groundwater flow model, and to analyse and design groundwater monitoring networks. KALMOD consists of a preprocessor, a processor and a postprocessor. The preprocessor acts as an interface between the user and the processor. The processor manipulates the measurement processes and carries out the filtering tasks. The filtering algorithm is implemented so that it is relatively efficient with respect to computer memory and execution time. The postprocessor was designed to present the model results in graphics. The program is suitable for small scale problems and for educational purposes.

ISSN:0262-6667    

DOI:10.1080/02626669209492602

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The cause of negative or reduced outflow formation at the beginning of a Muskingum solution is examined in two steps. The first step involves a physical interpretation of the Muskingum weighted discharge and the storage equation, using theory based on an extension of the Kalinin-Milyukov method. The second step involves the derivation of an analytical solution for the weighted discharge based on linear systems analysis theory, and then subsequently the Muskingum solution from that analytical solution using the assumption of linear variation of discharge within the reach. It is proved that this assumption causes the formation of negative or reduced outflow at the beginning of a Muskingum solution.

ISSN:0262-6667    

DOI:10.1080/02626669209492603

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669209492604

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669209492605

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669209492606

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669209492607

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor