Geological Survey Water-supply Paper, Issue 2013U.S. Government Printing Office, 1971 - Floods |
Other editions - View all
Popular passages
Page 2 - A station on a tributary that enters between two main-stream stations is listed between them. A similar order is followed in listing stations on first rank, second rank, and other ranks of tributaries.
Page 14 - When fluoride is naturally present in drinking water, the concentration should not average more than the appropriate upper limit in Table I.
Page 15 - Dissolved solids The reported quantity of dissolved solids — the residue on evaporation -consists mainly of the dissolved mineral constituents in the water . It may also contain some organic matter and water of crystallization. Waters with less than 500 parts per million of dissolved solids are usually satisfactory...
Page 9 - Time-weighted average is computed by multiplying the number of days in the sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the total number of days. A time-weighted average represents the composition of water that would be contained in a vessel or reservoir that had received equal quantities of water from the...
Page 20 - SodïuM-adsorptîon-rate (SAR) is the expression of relative activity of sodium ions in exchange reactions within soil and is an index of sodium or alkali hazard to the soil. Waters range in respect to sodium hazard from those which can be used for irrigation on almost all soils to those which are generally unsatisfactory for irrigation.
Page 12 - Magnesium (Mg) Magnesium is dissolved from many rocks, particularly from dolomitic rocks. Its effect in water is similar to that of calcium. The magnesium in soft waters may amount to only 1 or 2...
Page 18 - The use of hard water is also objectionable because it contributes to the formation of scale in boilers, water heaters, radiators, and pipes, with the resultant decrease in rate of heat transfer, possibility of boiler failure, and loss of flow. Hardness is caused almost entirely by compounds of calcium and magnesium. Other constituents- -such as iron, manganese, aluminum, barium, strontium, and free acid- -also cause hardness, although they usually are not present in quantities large enough to have...
Page 7 - For periods when no samples were collected, daily loads of suspended sediment were estimated on the basis of water discharge, sediment concentrations observed immediately before and after the periods, and suspended-sediment loads for other periods of similar discharge.
Page 4 - Decade (IHD) River Stations provide a general index of runoff and materials in the water balance (discharge of water, and dissolved and transported solids) of the world. In the United States, IHD Stations provide indices of runoff and of the general distribution of water in the principal river basins of the conterminous United States and Alaska.
Page 14 - Nitrate in water is considered a final oxidation product of nitrogenous material and may indicate contamination by sewage or other organic matter . The quantities of nitrate present in surface waters are generally...