摘要:

The relationship of formation resistivity factor to effective porosity or intergranular permeability in water‐saturated sands is shown to be best defined where the solid constituents do not contribute significantly to the conduction of applied current or where corrections for this contribution have been applied to the measured formation resistivities. It is demonstrated that, in the particular case of an argillaceous sand sorted according to its matrix conduction properties, useful relationships between formation resistivity factor and intergranular permeability can be established without any process of correction, provided that porosity and electrolyte salinity do not vary markedly within the formation. This finding is used to resolve the paradox that formation resistivity factor has been reported to increase with intergranular permeability in certain sands and to decrease with increasing values of this same hydrological parameter in other

ISSN:0043-1397    

DOI:10.1029/WR013i001p00087

年代:1977

数据来源: WILEY

摘要:

Serial correlation coefficients for the 5 years mean monthly time series of precipitationP, runoffR, change in storage ΔS, atmospheric vapor divergence ∇·Q, and evapotranspirationEare computed for 76 small and 10 large combined drainage basins of the United States. An effort is made first to explore the characteristic behavior of these serial correlation numbers and then to compare their geographic distribution with physical factors. The results suggest that the geographic variation of these statistical characteristics shows correspondence with various climatological fact

ISSN:0043-1397    

DOI:10.1029/WR013i001p00093

年代:1977

数据来源: WILEY

摘要:

A shot noise process consisting of a series of events at random times and of random magnitudes, each of which produces a fixed shaped rise and recession, is used as the basis for describing continuous time streamflows. This type of model is chosen for its ability to model recessions. Recession shapes consisting of one or two exponential curves are considered. The fitting of the models to multisite daily data and the generation of synthetic daily data are described. The application of the models to some English streamflow data is illustrated.

ISSN:0043-1397    

DOI:10.1029/WR013i001p00101

年代:1977

数据来源: WILEY

摘要:

Low‐resolution meteorological satellite data and simple photo interpretation techniques have been used to map snow‐covered areas during early April over the Indus River and Kabul River basins in Pakistan. The early spring snow‐covered area was significantly related to April 1 through July 31 Streamflow in regression analyses for each watershed (Indus River, 1969–1973,r2= 0.82, and Kabul River, 1967–1973,r2= 0.89). Predictions of 1974 seasonal Streamflow using the regression equations were within 7% of the actual 1974 flow. Because of inadequate hydrometeorological data, conventionally based Streamflow predictions are not possible in some of these remote regions, and the satellite‐derived runoff estimates have immediate applicability for improved water resources

ISSN:0043-1397    

DOI:10.1029/WR013i001p00109

年代:1977

数据来源: WILEY

摘要:

Two annual flow generation models proposed to account for the Hurst phenomenon, fractional Gaussian noise (FGN) and lag 1 autoregressive‐lag 1 moving average (Arma) models, were compared operationally by using the sequent peak algorithm (SPA). The SPA was used to determine empirical probability distributions of storage at a hypothetical single site on the basis of 1000 synthetic annual streamflow traces generated from each model, for constant demands of 0.5, 0.7, and 0.9 of the mean annual flow. The comparisons were made on the basis of population values of the lag 1 correlation coefficient, coefficient of variation, and (for the FGN sequences) Hurst coefficient. For the Arma models, large sample expectations of the Hurst coefficient (O'Connell, 1974)were used in the comparisons. The fast fractional Gaussian noise (FFGN) generator proposed by Mandelbrot (1971) was used to represent FGN. A modification of the Arma model, the annual Arma‐Markov mixture process, was developed and tested. This model has the advantage that the Hurst coefficient is an explicit model parameter. The results of the comparisons showed that at an operating life of 40 years the unskewed (normal) models gave similar storage probability distributions. The small differences between models could be explained in part by differences in equivalent independent sample sizes of the generated time series. For an operating life of 40 years andH= 0.70, tests of skewed (three‐parameter log normal) models gave substantially identical storage probability distributions. For the longer 100‐year operating life, storage distributions for the Arma model differed significantly, apparently owing to the lack of an equivalent populationHvalue for this model. The Arma‐Markov model, however, gave results nearly identical to the FFGN model at the 100‐year operating life and appears to provide a viable low‐cost alternative generation method for the preservation of long‐term persistence in hydrolo

ISSN:0043-1397    

DOI:10.1029/WR013i001p00113

年代:1977

数据来源: WILEY

摘要:

This paper compares the efficiency of line successive overrelaxation (LSOR) with a two‐dimensional correction procedure (2DC), the iterative, alternating direction implicit procedure (ADI), and the strongly implicit procedure (SIP) to solve finite‐difference equations used to simulate several groundwater reservoirs. Three of the reservoirs are linear, two are isotropic areal problems, and the third is an anisotropic cross‐section simulation. The fourth is a nonlinear water table aquifer with areas of thin saturation. SIP is generally the best method for the linear simulations and with the addition of another iteration parameter is the only method that gives an adequate rate of convergence for the water table problem. LSOR with 2DC is competitive with SIP on isotropic and anisotropic linear problems that are dominated by no‐flow boundaries. ADI is generally more efficient than LSOR if a good set of iteration parameters are used, but this advantage is offset by the relative ease of finding the best acceleration parameter f

ISSN:0043-1397    

DOI:10.1029/WR013i001p00125

年代:1977

数据来源: WILEY

摘要:

The present emphasis on Great Lakes water quality studies requires a knowledge of the average and variability of the net flow between Lakes Michigan and Huron. Average annual and average monthly flows through the Straits of Mackinac were computed for the 1950–1966 period by use of a water budget technique applied to Lakes Michigan and Huron. In addition, water budget computations were compared with a 100‐day period of current meter observations taken in 1973. The computations and measurements agreed quite closely, within approximately 2%. A variation of greater than 500% was found between the maximum and minimum annual flows observed during the 17‐year computation period. The gross residence or flushing time for Lake Michigan was determined by two methods. The first determination used the mean annual flow through the straits, resulting in a flushing time of 137 years. The second procedure using the results of the current study, which found a deep return flow into Lake Michigan through the straits during stratification, gave a flushing time of 69

ISSN:0043-1397    

DOI:10.1029/WR013i001p00137

年代:1977

数据来源: WILEY

摘要:

The evapotranspiration (ET) of a 28‐m Douglas fir in a weighing lysimeter located on the Cedar River watershed near Seattle, Washington, was determined during the summer and fall of 1972, 1973, and 1974. Average ET rates from the area of the crown projection were 1.8 mm d−1(55.8 1 d−1or 14.7 gal. d−1) in 1972, 2.0 mm d−1in 1973, and 2.5 mm d−1in 1974. The range for monthly periods was 1.3–3.6 mm d−1. During 1972, ET was 46% of precipitation plus irrigation (P + I), and evaporation of interception (i) was 36% of ET. Comparable values for 1973 were 51% and 37% and for 1974 were 69% and 24%. The lower ET/(P + I) values in 1973 and 1974 were associated with soil moisture depletion studies and longer periods of clear skies. The relatively highi/ET percentages suggest the need for more interception studies. Problems such as irrigation, drainage, listing, wind, rainfall interception, and the translation of data to an area basis that are associated with large plants in lysimeter

ISSN:0043-1397    

DOI:10.1029/WR013i001p00145

年代:1977

数据来源: WILEY

摘要:

In explicit stochastic dynamic programing optimization of storage reservoirs the ‘curse of dimensionality’ dictates the adoption of the smallest possible number of discrete states to represent the range of reservoir storage. This pressure makes it imperative to understand clearly the consequences of pushing the limit too far. It is shown that the number of storage states is subject to some absolute constraints and that it must increase linearly with the reservoir storage capacity in order that comparability of results be assured. It is demonstrated, both theoretically and with the aid of a numerical example, that a too coarse discrete storage representation can not only impede accuracy but may completely distort reality in most unexpected ways. Finally, charts are presented giving the numbers of storage states necessary to obtain stationary probabilities of reservoir emptiness and/or fullness with an error e ≤ 0.1% for log normal and normal input distribu

ISSN:0043-1397    

DOI:10.1029/WR013i001p00149

年代:1977

数据来源: WILEY

摘要:

Differences in the relationships between the mean and standard deviation of regional estimates of skewness for historical flood sequences and the relations derived from several well‐known distribution functions may be explained in terms of spatial or temporal distribution of values of skewness. Unless skewness is large, variations in estimates of skewness for different time periods are unlikely to be ascribable to chanc

ISSN:0043-1397    

DOI:10.1029/WR013i001p00159

年代:1977

数据来源: WILEY