摘要:

The estimation of recharge and boundary flux is an important problem in deterministic groundwater modelling since these quantities are often difficult to measure directly in the field. A new method (inferred recharge) is proposed for this estimation, based upon water level and transmissivity observations; it is particularly applicable to those semiarid regions where a steady state formulation can be used and recharge is confined to certain known areas. The inferred recharge method which assumes that recharge occurs in these areas only is compared with an alternative method which does not use this information, and is found to be superior. In the example of the inferred recharge method applied to the Oman coastal plain, random normal errors have been added to both water levels and transmissivities in simulation experiments to assess the effect of errors in the data. The results of the simulations have been used to test the reliability of variance estimates derived from the theory. In addition, statistical tests have been used to examine the inferred recharge results.

ISSN:0303-6936    

DOI:10.1080/02626668109490870

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Many basins in nature diverge or possess diverging elements. This study formulates a diverging flow model utilizing kinematic wave theory. The kinematic equations are solved using a first order explicit finite difference scheme. The model is tested using data on a number of laboratory basins reported in the literature. A comparison of this model with the plane model shows that they yield different concentration times and hydrographs that differ in shape, depending upon the degree of divergence.

ISSN:0303-6936    

DOI:10.1080/02626668109490871

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A study of the water balance of a basin in India, where the annual monsoon season of water surplus contrasts with a longer period of deficit, shows that estimates of soil moisture recharge and groundwater recharge may be obtained in these circumstances by comparing seasonal net rainfall with runoff on two assumptions: soil moisture recharge is constant from year to year, and groundwater recharge is proportional to runoff.

ISSN:0303-6936    

DOI:10.1080/02626668109490872

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

From a series of 83 daily heat balances for the lake la Godivelle (France), daily estimates of the rate of heating S (or variation in the heat content) of the lake are analysed by the methods of Edinger et al. (1968), Keijman (1974) for equilibrium temperature. This enables the calculation procedure and the formulation of the exchange coefficient K, and the equilibrium temperature Te, to be distinguished which give the best estimate of the rate of heating. In addition the data are used to describe the daily and seasonal behaviour of K and Tefor the summer and autumn stratification phases of the lake.

ISSN:0303-6936    

DOI:10.1080/02626668109490873

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Chow's hydrological frequency factor, K, is used to compare and relate results and attach probabilities to several sets of maximum rainfall data. K is primarily a function of the recurrence interval for a particular probability distribution. K is displayed as a function of the mean of the annual maxima for both official and unofficial rainfall observations and the probable maximum precipitation (PMP) and PMP/2 for the 6 and 24 h durations. The magnitude of the unofficial observations appears to have a strong influence on the level of PMP. The geographical distribution of K for the latter is displayed on maps for the eastern US and ranges from about 20 in the south to more than 35 in the north for PMP and from about 7.5 to more than 17.5 for PMP/2. Probability seems to have very little meaning for PMP or for the largest unofficial observations because these values are so rare that their return periods are several orders of magnitude greater than the length of record upon which they are based.

ISSN:0303-6936    

DOI:10.1080/02626668109490874

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

With the increasing use of telemetry in the control of water resource systems, a considerable amount of effort is being devoted to the development of models and parameter estimation techniques for on-line use. A variety of models and parameter estimation algorithms have been considered, ranging from complex conceptual models of the soil moisture accounting type, which are traditionally calibrated off-line, to state-space/Kalman filter models which, perhaps, have enjoyed undue popularity in the recent literature due to their mathematical elegance. The fundamental assumptions underlying the various approaches are reviewed, and the validity of these assumptions in the hydrological forecasting context is assessed. The paper draws on some results obtained during a recent workshop at the Institute of Hydrology in making assessments of the relative merits of different models and parameter estimation algorithms; these results have been derived from an intercomparison of a number of real time forecasting models.

ISSN:0303-6936    

DOI:10.1080/02626668109490875

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0303-6936    

DOI:10.1080/02626668109490876

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0303-6936    

DOI:10.1080/02626668109490877

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0303-6936    

DOI:10.1080/02626668109490878

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0303-6936    

DOI:10.1080/02626668109490879

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor