Somes River

Data on selenium in water are limited. The drinking water content is usually less than 1 )-lg/L, and seldom exceeds the 50 )-lg/L upper limit estabhshed in 1993 by the U.S. EPA (23). It may be higher in wells in seleniferous areas, and markedly higher in some river waters where irrigation drainage from seleniferous soil contains up to 2680 )-lg/L. 

In this work ion-exchange and gel-permeation chromatography coupled with membrane filtration, photochemical oxidation of organic metal complexes and CL detection were applied to the study of the speciation of cobalt, copper, iron and vanadium in water from the Dnieper reservoirs and some rivers of Ukraine. The role of various groups of organic matters in the complexation of metals is established. 

Significant levels of herbicides have also been detected in rivers, although these are usually transitory. Heavy rainfall can move herbicides from agricultural land to nearby ditches and streams due to runoff, and in soils that are high in clay, percolation of water occurs through deep fissures with consequent movement into neighboring water courses. Such events under extreme weather conditions are likely to have contributed to the pulses of herbicide contamination observed in some rivers. Questions have been asked about possible effects of such episodic pollution on populations of aquatic plants. 

Throughout the ages humans have used sand for many and the most varied uses. Some river sand, known as auriferous sand, contains native gold... 

The most recent research results show that it is difficult to detect formerly liquid water on Mars. Pictures of what are assumed to be seafloors and riverbeds are no longer considered to be certain evidence that flowing water was always present in all the regions of Mars. Critical examination of some landscapes indicates that they were carved by lava flows and not by water. Only in the case of the edges of craters, and some river gullies, does it appear quite clear that they were formed by liquid water. However, at the time of writing, the Mars Reconnaissance Orbiter mission is only a few weeks old, so further important results (and perhaps surprises) on the surface and mineralogy of Mars can be expected (Baker, 2007). 

Also, Amie and Alberto [22] obtained good correlations between mean annual water temperatures, mean annual water temperature ranges and heights for the rivers of the Ebro River basin. Comparing the actual water temperature with the estimated water temperature they observed that some rivers (rivers Jalon, Jiloca, Martin) showed higher temperatures than expected. However, although the authors formulated some hypothesis for such alterations (reservoirs, thermal sources) the available data did not suffice to isolate the actual cause. 

Chaco-Pampean plain, Argentina 1.2 million <1-11 500 Holocene and earlier loess with rhyolitic volcanic ash Oxidizing, neutral to high pH, high alkalinity, groundwaters often saline. Arsenic mainly as As(V), accompanied by high B, V, Mo, and U. Also high arsenic in some river waters 1955... 

In rivers and streams heavy metals are distributed between the water, colloidal material, suspended matter, and the sedimented phases. The assessment of the mechanisms of deposition and remobilization of heavy metals into and from the sediment is one task for research on the behavior of metals in river systems [IRGOLIC and MARTELL, 1985]. It was hitherto, usual to calculate enrichment factors, for instance the geoaccumulation index for sediments [MULLER, 1979 1981], to compare the properties of elements. Distribution coefficients of the metal in water and in sediment fractions were calculated for some rivers to find general aspects of the enrichment behavior of metals [FOR-STNER and MULLER, 1974]. In-situ analyses or laboratory experiments with natural material in combination with speciation techniques are another means of investigation [LANDNER, 1987 CALMANO et al., 1992], Such experiments manifest univariate dependencies for the metals and other components, for instance between different metals and nitrilotriacetic acid [FORSTNER and SALOMONS, 1991], but the interactions in natural systems are often more complex. 

One of the best and most widely used formulas for open-channel flow is that of Robert Manning, who published it in 1890. Manning found from many tests that the value of C varied approximately as Ry< and others observed that the proportionality factor was very close to the reciprocal of n, the coefficient of roughness in the classical Kutter formula. The Kutter formula, which was for many years the most widely used of all open-channel formulas, is now of interest principally for its historical value and as an outstanding example of empirical hydraulics. This formula, which may be found in several handbooks, included terms to make C a function of S, based on some river flow data that were later proved to be in error. This led to the Manning formula, which has since spread to all parts of the world. In metric units, the Manning formula is... 

Odontoceti Beaked whales, beluga whales, narwhal, sperm whale, dolphin, porpoise 32 64 2% All oceans, and some rivers and estuaries... 

Many natural aqueous systems have ion combinations in solution that allow them to function as buffers. Other aquatic systems (e.g., some rivers and lakes) lack such ions or have a poor buffering capacity, and therefore they are vulnerable to acid or basic inputs. 

Increased arsenic concentrations are also found in some river waters dominated by base flow in arid areas. Such waters often have a high pH and alkalinity. For example, surface waters from the Loa River Basin of northern Chile (Atacama desert) contain naturally occurring arsenic in the range 190-21,800 p,g L (Caceres et al., 1992). The high arsenic concentrations correlate with high salinity. While geothermal inputs of arsenic are likely to be important, evaporative concentration of the base-flow-dominated river... 

Calcification and deposition of carbonates in rivers are uncommon but may be found in some stagnant parts, and in the upper reaches, when the deposits may occur as calcareous tufas, travertines, and sinters (Golubic, 1967,1973). In some rivers, oncoids and algal balls are formed. 

Before discussing in detail any of the fate and transport processes occurring in surface waters, the major characteristics of surface waters must be defined. As illustrated in Fig. 2-1, rivers and streams are relatively long, shallow, narrow water bodies characterized by a pronounced horizontal movement of water in the downstream direction. Often the water flow is sufficiently turbulent to erode the stream channel and carry sediment for considerable distances. Due to this movement of sediment, some river channels are constantly shifting in geometry. Compared with rivers, lakes tend to be deeper and wider and are not dominated by a persistent downstream current (Fig. 2-2). Lakes are often vertically stratified for part of the year, with two distinct layers of water whose temperatures and chemistries are markedly different. Estuaries (Fig. 2-3), the interfaces between rivers and the ocean, also are often vertically stratified, due to the denser saline seawater sinking beneath the freshwater discharged from the river. Estuaries have tides due to their connection to the ocean, and they tend to be rich in nutrients. 

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