Fluvial sediment transport can result in the formation of ripples and dunes, in fractal-shaped patterns of erosion, in complex patterns of natural river systems, and in the development of floodplains.

Water can wash sediment, such as gravel or pebbles, down from a creek, into a river, and eventually to that river’s delta. Deltas, river banks, and the bottom of waterfalls are common areas where sediment accumulates.

Sediment delivery to the shoreline can be intermittent, mostly occurring during floods. In some locations, as much as 90 percent of coastal sediment comes from rivers. The origin of the sediment is the erosion of inland areas by ice, wind and water as well as sub-aerial processes such as mass movement and weathering.

Sedimentary rocks are formed on or near the Earth’s surface, in contrast to metamorphic and igneous rocks, which are formed deep within the Earth. The most important geological processes that lead to the creation of sedimentary rocks are erosion, weathering, dissolution, precipitation, and lithification.

When a river enters standing water, its velocity slows to a stop. The stream moves back and forth across the region and drops its sediments in a wide triangular-shaped deposit called a delta. If a stream falls down a steep slope onto a broad flat valley, an alluvial fan develops.

Most sediments settle out of water (Figure 4.11). For example, running water in rivers carries huge amounts of sediments. The river dumps these sediments along its banks and at the end of its course. When sediments settle out of water, they form horizontal layers.

The two main sources of the sediment carried by the streams and rivers are from the mass movement and runoff.

There are a total of three natural sources of water. They are categorized as: rain water, underground water and surface water. Here is a look at each and what supplies these sources. Rain water includes other sources such as snow and additional types of precipitation.

The largest natural source of water is none other than glaciers. They are melting at each and every point of time thus contributing a lot in maintaining the overall level of rivers as well as dams.

4.3 Sources of water. Our main sources of water for drinking, washing, agriculture and industry are surface water, groundwater and collected rainwater, all of which are dependent on rain and snow falling on the Earth’s surface.

Tap water comes from one of two sources: surface water (including reservoirs, rivers, and lakes) or groundwater (from artesian and deep wells).

Although it’s true that the water in some cities contains trace amounts of pollutants, most healthy adults can still safely drink from the tap in most areas—and, in fact, tap water remains the most cost-effective, convenient way to stay hydrated.

Overall, both tap and bottled water are considered good ways to hydrate. However, tap water is generally a better option, as it’s just as safe as bottled water but costs considerably less and has a much lower environmental impact. Plus, with a reusable water bottle, tap water can be just as convenient as bottled.