abstract the contact between major settlements in the central plateau of iran, especially in desert areas, was not possible without having a secure communication system. in this regard, designing communication networks through constructing secure roads with halfway caravansarais in desert areas, usually without secure underground and surface water supply, needed special insights and provisions....

the present paper has determined the radioactivity concentrations, which are due to natural occurrence of radionuclides along with heavy metal concentration in water, sediment, and fish from 2 reservoirs in ghana. heavy metal concentrations in all samples were generally within the who safe limits with the average activity concentrations of 238u, 232th, and 40k in water being respectively 0.42±0...

A three-year study (1977-9) of primary biliary cirrhosis in the city of Sheffield disclosed 34 cases, a point prevalence of 54 per million population. Closer inspection showed an apparent clustering of cases, and the prevalence in relation to one water reservoir appeared to be more than ten times that of the other reservoirs. Nevertheless, analyses of the water showed no significant relevant di...

By reconstructing the history of water impoundment in the world's artificial reservoirs, we show that a total of approximately 10,800 cubic kilometers of water has been impounded on land to date, reducing the magnitude of global sea level (GSL) rise by -30.0 millimeters, at an average rate of -0.55 millimeters per year during the past half century. This demands a considerably larger contributio...

Sedimentation in reservoirs lowers the quality of consumed water, reduce the volume of reservoir, lowers the controllable amount of flood, increases the risk of water overflow during possible floods and the risk of reversal and reduction of dam's useful life. So in all stages of dam establishment such as cognitive studies, phase-1 studies of design, control, construction and maintenance, the pr...

OBJECTIVE To evaluate the microbiological quality of treated and untreated water samples came from urban and rural communities and to examine the relationship between coliforms occurrence and average water temperature, and a comparison of the rainfall levels. METHODS A sample of 3,073 untreated and treated (chlorinated) water from taps (1,594), reservoir used to store treated water (1,033), s...

The geochemical processes of mercury in Dongfeng (DF) and Wujiangdu (WJD) reservoirs, which were constructed in 1992 and 1979, respectively in Wujiang River, which is the upper branch of Yangtze River were investigated. One sampling site was chosen up river of 1 km from the dam for each reservoir. Three sampling campaigns were conducted at these sampling sites in December 2003, April 2004 and J...

The Upper Trinity River Basin (TRB) is the most populated river basin and one of the largest water suppliers in Texas. However, sediment and nutrient loads are reducing the capacity of reservoirs and degrading water quality. The objectives of this study are to calibrate and validate the Soil and Water Assessment Tool (SWAT) model for ten study watersheds within the Upper TRB in order to assess ...

The concentrations of heavy metals (mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu) and arsenic (As)) in surface water and sediments were investigated in two adjacent drinking water reservoirs (Hongfeng and Baihua Reservoirs) on the Yunnan-Guizhou Plateau in Southwest China. Possible pollution sources were identified by spatial and statistical analyses. For both reservoirs, Cd...

The article presents the results of analyses of changes in the number of ponds in the Wyskoć catchment basin carried out in the years 1980–2003 and the characteristics of ponds excavated in that period. Only water reservoirs of an area less than 2 ha were considered. Analyses were based on topographic maps in the scale of 1:10 000 and aerial photographs taken in 1996. The results indicated that...