Levels of cemented silts, clayish silts, and clays that intercalate with fine, medium, and coarse sands and gravel lenses may be distinguished.
The flow of the Yongding is irregular; in the rainy season it rises rapidly, carrying with it large quantities of silt, which raise the level of the riverbed considerably.
Mann (1990) stressed that filter substrates are more advantageous to use due to their high hydraulic conductivity, e.g. they are less likely to clog or block than are systems based on soil containing high levels of clay or silt.
The new standard lowers the acceptable level of cancer-causing PCB's in silt to 113 parts per billion from 400 parts per billion.
As the river deposited alluvial silt, raising the level of the floodplain, and land was reclaimed from marsh, the area available for cultivation in the Nile valley and delta increased, while pastoralism declined slowly.
Similarly, the content of silt did not vary in both locations and invasion levels.
Heavy rains covered Hewanorra International Airport with 2 inches of silt, and in Anse La Raye, floods reached waist-deep levels.
The factors used in this study consisted of silt content, slope, aspect and vegetation cover, each of which had four levels in the study area in Lar Township, Iran.
The river carries a heavy load of silt, and the volume of water varies greatly from season to season; the maximum level is attained during the summer.
Then there is the problem of silt.
Accumulation of silt has narrowed many sewer channels.
