摘要:

Several optimization procedures have been proposed for the analysis of complex water resource planning problems. One of these techniques, dynamic programming, has been limited in its applicability to river basin systems, because these systems are nonserial and dynamic programming is by nature a serial procedure. Recently developed methods are discussed and illustrated with example problems for decomposing the nonserial river basin system into equivalent serial systems amenable to analysis by the dynamic programming method.

ISSN:0043-1397    

DOI:10.1029/WR003i003p00645

年代:1967

数据来源: WILEY

摘要:

An extension to an algorithm for the sequential generation of nonhistoric stream‐flow, previously used by Thomas and Fiering, is suggested. The distinguishing features of this model are preservation of (1) normal distribution of annual flows; (2) log‐normal distribution of monthly flows; (3) correlation between annual flows; and (4) correlation between monthly flows. This model has been applied to two representative Pacific Northwest rivers. A graphical examination of the results suggests that this model provides an authentic representation of streamf

ISSN:0043-1397    

DOI:10.1029/WR003i003p00653

年代:1967

数据来源: WILEY

摘要:

The exact equations for the mean range of some normal but autocorrelated variables, of known population means and known linear dependence, are developed. The basic hypothesis was that the exact expression in the general form for the mean range of linearly dependent normal variables is the same as for the normal independent variable, which form was derived from the mean range given by Anis and Lloyd. The data generation method (with a large sample of 250,000 random numbers) was used to assess the differences in mean ranges between the developed equations and the computer results. For three cases—the first‐and the second‐order Markov linear dependence and the simple moving average scheme—these differences are very small, and they are of the order of magnitude of the sampling errors for the data generation method. The expressions for exact values of mean range are derived for: (1) the general Markov linear dependence model; (2) the first‐order Markov linear dependence; (3) the general linear moving average scheme; and (4) the simple linear moving avera

ISSN:0043-1397    

DOI:10.1029/WR003i003p00663

年代:1967

数据来源: WILEY

摘要:

Temporal allocation of groundwater is analyzed for quadratic measures of economic net output from a basin. The two variables of the net output function are rate of use and quantity of stocks. It is shown that an optimal policy for groundwater utilization over time is dependent upon the mean recharge rate but not on higher moments of its probability distribution for the case of quadratic criterion functions, provided that inequality constraints on rate of use are unnecessary. The optimal policy is derived, and some analysis of the probability distribution of groundwater stocks is made. Some consideration is given to approximately optimal policies for the situation arising when inequality constraints on rate of use are binding.

ISSN:0043-1397    

DOI:10.1029/WR003i003p00673

年代:1967

数据来源: WILEY

摘要:

Preliminary studies indicate that the underground storage of fresh water in saline aquifers may be feasible from a technical viewpoint. Such a process would involve injection of fresh water, storage until needed, and subsequent production from the same well. This work, based upon theoretical considerations and model studies, leads to a computer technique by means of which the recovery of stored fresh water may be estimated. Calculations involving five hypothetical aquifers indicate recoveries ranging from 25 to 85%, depending upon aquifer and fluid properties. Loss of fresh water as a result of both dispersion (mixing) and gravitational segregation was considered. Results obtained in porous flow models indicate that gravitational segregation is significantly retarded by the development of a mixed zone. Such a zone is developed naturally during injection and production as a result of fluid movement and to a lesser degree during the storage portion of the cycle as a result of diffusion. Economic considerations and well problems were not treated in the study.

ISSN:0043-1397    

DOI:10.1029/WR003i003p00683

年代:1967

数据来源: WILEY

摘要:

From analysis of the water profiles obtained by gamma ray absorption during infiltration into soil columns, and of the wetting branch of the soil water‐suction water content relation, this paper suggests a method for checking the validity of the generalized Darcy's law and for computing the values of the hydraulic conductivity at various water contents. Tests have been made for horizontal infiltration and for capillary rise. In both tests, for a given water content, the capillary conductivitykis constant, and the generalized Darcy's law is valid and may be used to describe a transient flow in unsaturated soil

ISSN:0043-1397    

DOI:10.1029/WR003i003p00697

年代:1967

数据来源: WILEY

摘要:

Average annual precipitation in western Oregon and Washington varies from less than 20 inches to over 150 inches, in obvious general relation to the topographic influences of the Coast and Cascade mountain ranges. If these influences could be isolated and measured, it would result in better definition of the precipitation resource in the mountainous areas of sparse measurements. Testing of the parameters and methods used by investigators in other regions led to the development of simple indexes to terrain elevation and barrier elevation. Together with a latitude index, they explain most of the variation in precipitation among the more than 280 stations. The key to the method is in the empirical definition of the contours of ‘effective’ barrier elevation. The pattern of residual errors from the graphical correlation shows no need for the usual zone parame

ISSN:0043-1397    

DOI:10.1029/WR003i003p00707

年代:1967

数据来源: WILEY

摘要:

The meteorology of a mountainous watershed in the Alberta Rockies is shown to be strongly influenced by upslope‐downslope diurnal wind circulations during rain‐free periods of observation in August, 1965. The evapotranspiration from the forest is inferred from measurements of net radiation above the canopy and from vertical temperature gradients obtained from an 80‐ft tower. The forest water loss during August rain‐free periods is estimated to be between 0.15 and 0.6 gm/cm2/day with high confidence, or between 0.25 and 0.48 gm/cm2with somewhat less confidence. A ‘best’ engineering estimate of evapotranspiration is 0.3

ISSN:0043-1397    

DOI:10.1029/WR003i003p00713

年代:1967

数据来源: WILEY

摘要:

Measurements of gross rainfall, throughfall, stemflow, and litter interception in three eastern white pine stands, age 10, 35, and 60 years, in the Southern Appalachians of western North Carolina, were used to derive regression equations for estimating throughfall, stemflow, and the sum of throughfall and stemflow from measurements of gross rainfall. Equations for total interception loss were derived by algebraically combining losses from the canopy and litter. These equations were used to predict total seasonal interception loss (I) from measurements of total seasonal rainfall (ΣP) and number of storms (N). Equations for the 10‐, 35‐, and 60‐year‐old stands areI= 0.05(N) + 0.08 (ΣP),I= 0.05(N) + 0.12(ΣP), andI= 0.06(N) + 0.18(ΣP), respectively. Total interception loss in white pine increased with stand age, and total loss from all pine stands studied exceeded losses calculated for mature hardwoods. During the dormant season, calculated monthly interception loss from mature hardwoods and white pine exceeded potential evapotranspiration calculated by the Thornthw

ISSN:0043-1397    

DOI:10.1029/WR003i003p00723

年代:1967

数据来源: WILEY

摘要:

In a pine‐hardwood stand in the Ouachita Mountains of Arkansas, throughfall was strongly correlated with gross rainfall and long‐term mean temperature on the calendar day of the storm, whereas stemflow was closely related to gross rainfall, crown diameter (or basal area at breast height), tree height, and minimum temperature on storm date. Total interception averaged 15.1% of average annual gross rainfall and stemflow 2.4%. Thus, average annual interception loss was 12.7%. Nearly 75% of total stemflow was from hardwoods, which were primarily understory tr

ISSN:0043-1397    

DOI:10.1029/WR003i003p00731

年代:1967

数据来源: WILEY