Peak discharge

Global warming would also be expected to influence surface waters such as lakes and streams, through changes induced in the hydrologic cycle. However, the last published report of the IPCC states no clear evidence of widespread change in annual streamflows and peak discharges of rivers in the world (IPCC, 1995, p. 158). Wliile lake and inland sea levels have fluctuated, the IPCC also points out that local effects make it difficult to use lake levels to monitor climate variations. 

Stallard, R. F. and Edmond, J. M. (1981). Geochemistry of the Amazon 1. Precipitation chemistry and the marine contribution to the dissolved load at the time of peak discharge. /. Geophys. Res. 86, 9844-9858. 

Cenderelli DA, Wohl EE (2001) Peak discharge estimates of glacial-lake outburst floods and normal floods in the Mount Everest Region, Nepal. Geomorphology 40 57-90... 

Pinder, G. F. Jones, J. F. 1969. Determination of the groundwater component of peak discharge chemistry of total runoff. Water Resouces Research, 5, 438-445. 

Mulhsouive 1000 Peak discharge currents from 5 to in excess of 500 A at time constants ranging from 8 to less than 1 ms. Sensitive and precise. Parameter selection allows wide variety of controlled unidirectional and oscillatory charges variable from arc-like 10 spark like in spectral excitation. 

The decrease in silica concentration during rising discharge, rapid rise in silica near the discharge peak, and leveling off in silica concentration 18-24 hours after peak discharge are easily seen in the case of an isolated runoff event. However, when one storm follows another in rapid succession, the pattern of variation in silica and the ratio Si02 Spec. Cond. with time becomes complex. Nevertheless, if one keeps in mind the basic pattern outlined above, the reasons for the observed silica concentrations become evident. 

Sediment concentration and silica concentration show a consistent inverse relation during periods of storm runoff, and silica minima commonly tend to precede peak discharge by 2-4 hours, depending on how fast a rise occurs. Sediment concentration varies much more than does any of the dissolved constituents. 

Suspended-sediment concentrations increased sharply on rises and reached a maximum at or, commonly, shortly before peak discharge (Figures 6 and 7). Peak sediment concentrations consistently occurred at times of minima in silica concentration. This is to be expected if minimum silica and maximum sediment concentrations coincide with maximum contribution of overland runoff to stream flow, for at that time maximum dilution of silica-rich subsurface flow by direct runoff would occur and maximum erosive capability of direct runoff would exist. If this reasoning is correct, peak stream discharge would coincide with peak contribution from overland flow only when rainfall was intense or the surface soil was of very low permeability. Normally, peak direct runoff would precede peak stream discharge because of the significant contribution of subsurface flow at maximum stream discharge. 

Because the minimum in silica concentration and maximum in sediment concentration normally precede peak discharge, peak overland flow probably also precedes peak discharge. Therefore, runoff that has spent an appreciable period of time in soil pores contributes a major part of the stream flow at peak discharge. The rather small decrease in silica concentration during a stream rise supports this interpretation. Because little silica can be obtained by interaction between water and stream sediment... 

If it can be shown that silica minima and sediment maxima mark peak overland flow elsewhere and that the end of overland flow is marked by a leveling off in silica concentration after peak discharge in stream flow, then monitoring of these parameters should be very helpful in separating storm runoff into the various components of flow. 

Totally (as of 1/11/97) 36 reactor core reloads have been carried out at peak discharge bumup of 10% h.a. and experimental fuel bumup of 11.8% h.a. 

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