摘要:

Less65Zn is displaced from Columbia River sediments by the interaction of sea water than can be removed by leaching with solutions of certain first transition series metals. We interpret this to mean that ion exchange is not an important mechanism in the retention of65Zn in these samples. Instead, much of the65Zn is held by ‘specific sorption.’ Neither treatment displaced51Cr or46Sc from the sediments, whereas about one‐third of the54Mn was removed upon contact with sea

ISSN:0043-1397    

DOI:10.1029/WR003i001p00099

年代:1967

数据来源: WILEY

摘要:

Graph theory can be applied to the topology of river systems. Such applications, in particular, show how the possible different river systems of a given order can be enumerated.

ISSN:0043-1397    

DOI:10.1029/WR003i001p00103

年代:1967

数据来源: WILEY

摘要:

An evaluation of techniques for measuring the hydraulic and sediment transport variables in a small recirculating flume showed that (1) the average depth of flow over a ripple bed could be determined adequately by measuring the difference between the water‐surface elevation and the sand‐bed elevation at a large number of positions and averaging the results; (2) the water‐surface slope could be determined easily and accurately from a series of piezometers with taps positioned at 1‐meter intervals along the flume center line; (3) the sediment transport rate was determined by passing all the water‐sediment mixture through a trap covered with screen fine enough to hold the sand. The transport rate varied considerably (10‐fold range) with respect to time. The following transport phenomena were noted: (1) there was no particle movement on the plane bed before ripple formation; (2) the mean velocity for cessation of particle movement (on the ripple bed) was about one‐half that at which first movement occurred (on the pl

ISSN:0043-1397    

DOI:10.1029/WR003i001p00107

年代:1967

数据来源: WILEY

摘要:

Climatologic and basin characteristics affecting the annual runoff in Finland are selected by the orthogonal regression method. Climatologic variables, especially seasonal precipitation and mean annual temperature, are found to be much more important than basin characteristics such as soil type and vegetation. Frost depth is inversely related to annual runoff. The percentages of cultivated land and peat land are not significant variables in these data. The simple linear multiple regression approach was successful (R= 0.943,s0= 34 mm) in developing a reliable prediction equation. However, no statistical procedure can uncover the underlying laws governing runoff until the basic physical relationships are better understood. Furthermore, most available climatologic and basin characteristics are only indices of the combined effects of several physical factors. Hence, the utility of some of the more complex statistical approaches is questioned.

ISSN:0043-1397    

DOI:10.1029/WR003i001p00123

年代:1967

数据来源: WILEY

摘要:

There is no apparent relationship between elevation and the intensity of spring and summer rainfall in a 93‐square‐mile area with a range of 3500 feet in elevation in semiarid southwestern Idaho. Analysis covered four years' data from recording rain gages with an average density of 1 per square mile. Rainfall bursts amounting to 0.10 inch or more were considered. The maximum intensity recorded was 0.49 inch falling at 9.8 inches per hour. Rainfall in excess of 0.8 inch per hour occurred an average of once a year. The logarithm of the amount of rain falling in excess of a given intensity plots as a straight line against intensity. There is no difference in this relationship when the data are separated by elevation classes. The amount of rainfall decreases by about one‐half with each 1‐inch‐per‐hour increase in rainfall rate. This ratio may be a characteristic of the regional climate. It is suggested that data from accessible valley stations can be used to estimate the relative frequency of high intensity rains throughout an area of appreciable range i

ISSN:0043-1397    

DOI:10.1029/WR003i001p00131

年代:1967

数据来源: WILEY

摘要:

Data on hydrologic and geomorphic processes from single storm events are rare. The opportunity to make such measurements occurred on August 12, 1964. The runoff and hillslope erosion resulting from a high‐intensity thunderstorm were measured in a small basin of 12 acres in western Colorado. The maximum intensity of rainfall for a 10‐minute period was 1.98 inches per hour. The total runoff as measured in a reservoir was 0.508 inch over the basin, and 0.90 inch of precipitation had been recorded when runoff stopped. Data from measurements of erosion pins along 6 hillslope profiles indicate that approximately 0.11 acre‐foot was eroded from the basin during the storm; survey of the reservoir shows that 0.090 acre‐foot was delivered to the lower end of the basin. Estimates of soil loss using measurements of erosion pin exposure are considered to be good in basins where sediment transport from hillslopes to the measuring point is not complicated by diverse topography or intermediate areas where deposition ma

ISSN:0043-1397    

DOI:10.1029/WR003i001p00139

年代:1967

数据来源: WILEY

摘要:

This small plot study shows how ground cover, furrowing, and the presence of frost in soils of the Sierra Nevada affect infiltration from prolonged simulated winter rains. A rapidly melting snowpack over soil containing dense frost may accelerate on‐site runoff. The presence of stalactite soil frost promotes rapid absorption of snowmelt and reduces overland flow. Conversely, porous concrete frost usually reduces infiltration capacity and increases overland flow on burned or sparsely vegetated sites but does not impair infiltration where plant and litter cover are appreciable. Snow cover, by cooling rain water, tends to preserve soil frost and keep it visibly intact. Snow absorbs raindrop energy much as dense vegetation does. Soil losses from snow‐covered plots, regardless of vegetative cover, are practically nil. Generally, plants, litter, and snow cover dissipate raindrop energy and increase infiltration, but exposed rock usually accelerates overland flow and erosion. Shallow contour furrowing seemed to facilitate infiltration and controlled overland flow adequat

ISSN:0043-1397    

DOI:10.1029/WR003i001p00145

年代:1967

数据来源: WILEY

摘要:

Bouchet's theory on actual and potential evaporation can be used as a basis to develop semi‐empirical relationships between precipitation, actual evaporation, and radiation. These relationships are curvilinear, and the derived precipitation‐runoff relationships are also curvilinear. Since the variation of annual radiation from one year to another in tropical‐equatorial regions is not very significant, the average value of annual radiation can be approximated using direct measurements or indirect estimates from data taken over a period of from two to five years. This value can be used with the semi‐empirical relationship developed in the paper to obtain fair estimates of the annual variation of actual evaporation and runoff from data on annual precipitation and good estimates of the long‐term averages of these hydrologie characteristics. Bouchet's theory can be used to analyze evaporation and runoff for periods of less than one year and for estimating lake and reservoir evaporation. However, in this case, the assessment of the effect of heat and moisture storage requires further inve

ISSN:0043-1397    

DOI:10.1029/WR003i001p00163

年代:1967

数据来源: WILEY

摘要:

Data collected specifically to evaluate the increase in the water temperature in a reservoir due to the presence of a monolayer showed an increase in temperature not only at the surface but also at greater depths. This increase in temperature must be accounted for in predicting the reduction in evaporation by monolayers. Use of values for the increase in temperature predicted from the combined energy‐budget mass‐transfer method indicates a decrease of 8 to 14% in values for evaporation reduction as estimated by the simplified Bureau of Reclamation method, which does not account for the rise in temperature. An approach to predicting the increase in reservoir temperature and the reduction in evaporation as applied to one reservoir gave values for the temperature increase close to those measu

ISSN:0043-1397    

DOI:10.1029/WR003i001p00173

年代:1967

数据来源: WILEY

摘要:

Derived insolation and water budget evaporation data for Lake Superior and Lake Ontario are analyzed in terms of both the regional and the water surface energy balances. The results indicate that the seasonal pattern of evaporation is governed by heat storage changes, and that these changes are closely associated with atmospheric energy export from the lake. This finding provides a physical basis for the simple empirical relationships between monthly evaporation and island‐to‐mainland temperature differentials that are developed from the water budget evaporation data. Substantial atmospheric energy export, a concomitant of heat storage changes, reduces the energy available for evaporation. Therefore, evaporation from a large deep lake is less than that from a large shallow lake under comparable climatic conditions. The analysis also provides speculative reasoning and evidence to indicate that evaporation from a large deep lake is closely related to the radiant heat transfer to the

ISSN:0043-1397    

DOI:10.1029/WR003i001p00181

年代:1967

数据来源: WILEY