River hydrology

Abstract In most of the world s watercourses, dramatic modifications have occurred as a consequence of intensive use by human societies. The simplification of the channel network and the alteration of water fluxes have an impact upon the capacity of fluvial systems to recover from disturbances, because of their irreversible consequences. However, human impacts on river hydrology, such as those that derive from regulating their flow or by affecting their channel geomorphology, affect the functional organisation of streams, as well as the ecosystem services that derive from them, and lead to the simplification and impoverishment of these ecosystems. 

Keywords Dams, Flow regime, River Ebro, River hydrology, Sediment transport Contents... 

Hope, D., M. F. Billett, R. Milne, and T. A. W. Brown. 1997. Exports of organic carbon in British rivers. Hydrological Processes 11 325—344. 

As with all water quality analyses, the objective in river water quality engineering is to recognize and quantify, as much as possible, the various interactions between river hydrology, chemistry, and biology. 

Jarvis, C.S. (1943). Supplementary gleanings from the field of hydrology. Washington DC. Jarvis, C.S. (1943). Early contributions to Mississippi River hydrology. Trom. ASCitlOS 605-655... 

In hydrological studies, the transfer of water between reservoirs is of primary interest. The magnitudes of the main reservoirs and fluxes (volume per time) are given in Figure 7. The oceans hold ca 76% of all the earth s water. Most of the remainder, ie, ca 21%, is contained in pores of sediments and in sedimentary rocks. A Httle more than 1% (or 73% of freshwater) is locked up in ice. The other freshwater reservoir of significant size is groundwater. Lakes, rivers, and the atmosphere hold a surprisingly small fraction of the earth s water. 

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. 

The Willamette River Basin, Oregon serves as an excellent case study of river quality assessment for a number of reasons. First, the Willamette River has been cited internationally as a classic example of how water quality can be restored from a previously poor quality waterway (1-3). Second, excellent background data were available, particularly on hydrology. Third, at the time most of these studies were initiated, the Willamette River was the largest river in the U.S. for which all point-source discharges were receiving secondary wastewater treatment. 

The oceans are by far the largest reservoir in the hydrologic cycle, containing more than 25 times as much water as the rest of the reservoirs combined. As another means of comparison, the volume of water in the oceans is four orders of magnitude larger than that in the next most visible reservoir, the world s lakes and rivers. The oceans are also one of the Earth s primary... 

Meade, R. H., Yuzyk, T. R., and Day, T. J. (1990). Movement and storage of sediment in rivers of the United States and Canada. In "Surface Water Hydrology" (M. G. Wolman and H. C. Riggs, eds), pp. 255-280. Geological Society of America, Boulder, Colorado, The Geology of North America 0-1. 

Effects of Hydrologic Alterations on the Ecological Quality of River Ecosystems... 

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