摘要:

Fluid flow to wells produces strain that has been measured as horizontal, vertical, and rotational displacements of reference points fixed on the ground surface. Most linear displacements measured were between 1 and 100 microns, and angular displacements were a few microradians. Of the various devices used to make measurements, a horizontal extensometer proved to be the most accurate and versatile. Most measurements were made of effects produced by pumping wells for 5 to 30 minutes. Such effects are almost entirely elastic, except in some geologically recent materials. Deflections of the land surface resembled the theoretical deflections caused by a point load on a plate of infinite extent resting on an elastic foundation. Significant horizontal strain was measured in all materials tested, suggesting that accepted equations for fluid discharge from wells might be modified for special conditions near the wells.

ISSN:0043-1397    

DOI:10.1029/WR005i001p00129

年代:1969

数据来源: WILEY

摘要:

The coefficient of mechanical dispersion of a solute in a homogeneous porous medium saturated by a binary diluted solution is derived, taking into account nonuniform density and viscosity fields. It is shown that in the neighborhood of a vanishing macroscopic velocity, a nonuniform density field induces a macroscopic dispersion resulting from the variation of microscopic density gradients and from horizontal variations of the macroscopic density. Both together yield the macroscopic effect of density instability on solute redistribution phenomena in porous materials.

ISSN:0043-1397    

DOI:10.1029/WR005i001p00139

年代:1969

数据来源: WILEY

摘要:

The drawdown in a pumped unconfined aquifer can be analyzed by computer methods. The computer can give simultaneous solutions for flow in the saturated and unsaturated zone. The surface of seepage can also be included in the analysis.

ISSN:0043-1397    

DOI:10.1029/WR005i001p00144

年代:1969

数据来源: WILEY

摘要:

The unsaturated flow processes of infiltration and evaporation are in physical and mathematical continuity with the parallel saturated processes of recharge and discharge. Water table fluctuations result when the rate of ground‐water recharge or discharge is not matched by the unsaturated flow rate created by infiltration or evaporation. A water‐table rise provides the source of replenishment to the ground‐water zone that allows the prevailing rate of recharge to continue. This dynamic water‐table behavior can be simulated by a one‐dimensional, numerical mathematical model involving transient flow through an integrated saturated‐unsaturated system. The solutions are applicable to homogeneous, isotropic soils in which the functional relationships show hysteresis properties. The model allows upper boundary conditions of constant rate rainfall, ponded water, evaporation, and redistribution. It can be used to determine the water‐table fluctuation that will arise from a given set of initial conditions, boundary conditions, and soil type. The effects of variations in the parameters that control the flow are examined to arrive at a better understanding of the mechanism of natural ground‐water recharg

ISSN:0043-1397    

DOI:10.1029/WR005i001p00153

年代:1969

数据来源: WILEY

摘要:

Identification of parameters of an unconfined aquifer in which the dynamics of the water table are describable by a partial differential equation can be looked upon as a control system problem in distributed parameter systems. Using a maximum principle in conjunction with a steepest descent algorithm, the transmissibility of an aquifer is identified, starting from observed values of input‐output as data. This algorithmic procedure is blended with a heuristic method to identify the storage coefficient and the boundary of an aquifer. Results of computations carried out on a hybrid computer are presente

ISSN:0043-1397    

DOI:10.1029/WR005i001p00172

年代:1969

数据来源: WILEY

摘要:

The main variables affecting the fluid potential distribution are topography and geology, and the effect of topography is treated by consideration of the three‐dimensional flow net by means of fluid potential slice maps and cross‐sections and is shown to be adequate to explain the major flow net. The dominant fluid potential in any part of the basin corresponds closely to the fluid potential at the topographic surface in that part of the basin. Major recharge areas correspond to major upland areas, and major lowland regions are major discharge regions. Large river valleys commonly exert a drawdown effect on the fluid potential distribution, which may be observed to depths of up to 5000 feet. The presence of a thick sequence of highly permeable Upper Devonian and Carboniferous carbonate rocks in the medium‐depth portion of the Alberta basin has resulted in the development of a low fluid potential drain, which essentially channels flow from most of the Alberta basin towards the Athabasca oil sands and has modified the theoretical relation between local and regional flow sy

ISSN:0043-1397    

DOI:10.1029/WR005i001p00186

年代:1969

数据来源: WILEY

摘要:

The ratio of horizontal to vertical permeability may be determined by analysis of drawdown data from piezometers or partially penetrating observation wells near a partially penetrating production well. The analyses are made by comparing measured drawdowns in the piezometers to those predicted if the production well fully penetrated the aquifer. The differences between the measured and predicted drawdowns are determined, and the distances from the pumped well at which these differences would occur in an isotropic aquifer are determined from an equation. The permeability ratio is computed as the square of the ratio of actual distances to computed distances. The ratio of horizontal to vertical permeability in glacial outwash in central Wisconsin was determined from 5 aquifer tests to range from about 2 to about 20.

ISSN:0043-1397    

DOI:10.1029/WR005i001p00196

年代:1969

数据来源: WILEY

摘要:

In this paper we have two main objectives. The first of these is to outline a research and payoff (R&P) model that suggests a procedure for evaluating competing or concurrent research projects. The atmospheric sciences provide a good example for an initial application of the model. Weather modification, particularly artificial stimulation of precipitation, has been touted as an answer to many water resource problems. Alternatives to this technology have received little attention. We suggest that the R&P model could profitably be applied in this instance. The second objective of the paper is incorporated in a pilot study of the first step in such an application: namely, the determination of the estimated probabilities of success of various technologies in the atmospheric sciences. For this step, responses to a questionnaire sent to professional atmospheric scientists were examined to determine whether (a) scientists are willing to provide probability estimates of success of various technologies and whether these estimates are consistent with other estimates of success; (b) personal involvement in a field influences such estimates; (c) the probability estimates are consistent with the respondents' assignment of shares of a research budget; and (d) the estimates are generally in agreement with the reports of ‘blue‐ribbon’ panels of experts. We conclude that it is possible to obtain reasonably consistent estimates of research success from those who know most about them. The degree of optimism among those sampled is high, and it is highest for those workers involved in and having a high degree of knowledge of a particular field. Continued efforts in the determination of research success probabilities specifically tailored to the R&P model are recomm

ISSN:0043-1397    

DOI:10.1029/WR005i001p00215

年代:1969

数据来源: WILEY

摘要:

Fractional Gaussian noises are a family of random processes such that the interdependence between values of the process at instants of time very distant from each other is small but nonnegligible. It has been shown by mathematical analysis that such interdependence has precisely the intensity required for a good mathematical model of long run hydrological and geophysical records. This analysis will now be illustrated, extended, and made practically usable, with the help of computer simulations. In this Part, we shall stress the shape of the sample functions and the relations between past and future averages.

ISSN:0043-1397    

DOI:10.1029/WR005i001p00228

年代:1969

数据来源: WILEY

摘要:

Continuing the preceding paper, we shall report on computer experiments concerning the ‘rescaled range’ and the spectrum of fractional Gaussian no

ISSN:0043-1397    

DOI:10.1029/WR005i001p00242

年代:1969

数据来源: WILEY