River Systems earthsystem/rivers/

River Systems A river system consists of a river and all of its tributaries

Headwaters The water from which a river rises. The source of the river

River Basin A river basin is the portion of land drained by a river and its tributaries. It encompasses all of the land surface dissected and drained by many streams and creeks that flow downhill into one another, and eventually into one river.

River Basin In North Carolina there are 17 River Basins Cape Fear is the largest and Savannah the smallest. Cabarrus County is in Yadkin Pee-Dee Hiwassee Savannah Little Tennessee French Broad Watauga Broad New Catawba Yadkin-PeeDee Roanoke Lumber Cape Fear Neuse White Oak Tar-Pamlico Chowan Pasquotank North Carolinas 17 River Basins

River Basin The topography of each basin determines the area that it drains, and whether the water from creeks, rivers, springs, and aquifers flows into the Atlantic Ocean or Gulf of Mexico. Everyone Lives in a River Basin

Watershed Are smaller land areas and located within a river basin that include; creeks, streams, lakes, reservoirs, groundwater, aquifers, springs and sections of a river. We all live in a watershed. Watersheds are the places we call home, where we work and where we play. Everyone relies on water and other natural resources to exist. What you and others do on the land impacts the quality and quantity of water and our other natural resources.

Watershed Healthy watersheds generally supply people in the surrounding area with drinking water and one sign of a healthy watershed is if it supports a diverse ecological environment.

What is the difference between a river basin and a watershed? Both river basins and watersheds are areas of land that drain to a particular water body, such as a lake, stream, river or estuary. In a river basin, all the water drains to a large river. The term watershed is used to describe a smaller area of land that drains to a smaller stream, lake or wetland. There are many smaller watersheds within a river basin.

Divide Area of higher land that separates watersheds

Tributary A stream that flows into a lake or into a larger stream.

Channel The path that a stream follows

Stages of a River

Stages of River

River Delta Is a landform that forms at the mouth of a river, where the river flows into an ocean, sea, estuary, lake, or reservoir. Deltas form from deposition of sediment carried by a river as the flow leaves its mouth.

River Delta Important to both human activities and fish and other wildlife because they are normally home to very fertile soil as well as a large amount of vegetation. Examples – Nile River – Mississippi River

How a River Delta Form As rivers flow toward their outlets from higher elevations they deposit particles of mud, silt, sand and gravel at their mouths because the flow of water slows as the river joins the larger body of water.rivers flow Over time these particles (called sediment) build up at the mouth and can extend into the ocean or lake. As these areas continue to grow the water becomes more and more shallow and eventually landforms begin to rise above the surface of the water. Most deltas are only elevated to just above sea level though.sea level

Alluvial Fan A fan-shaped alluvial deposit formed by sediment being deposited at a stream where its velocity is abruptly decreased, as at the mouth of a ravine or at the foot of a mountain.

Alluvial Fan The rushing water carries alluvium(sediment) to a flat plain, where the stream leaves its channel to spread out. Alluvium is deposited as the stream fans out, creating the familiar triangle- shaped feature.

Alluvial Fan Creating a settlement on an alluvial fan can be dangerous. Alluvial fans are prone to flooding. Rushing water, mud, and debris can threaten communities many kilometers away.

Floodplain A flood plain is an area of land that is prone to flooding. People realize it is prone to flooding because it has flooded in the past due to a river or stream overflowing its banks. Flood plains can be very small or very large. Houses that are built in small flood plains often require more insurance coverage because damage due to flooding is more likely to occur there than in higher areas

Floodplains Flood plains usually are very fertile agricultural areas. Floods carry sediment rich in nutrients. They spread that sediment to a wide area. Flood plains are flat and have relatively few rocks or other large obstacles that may prevent farming. The flood plains of the Nile River have been Egypt's center of agriculture for thousands of years.

Floodplains Floods are usually seasonal and can be predicted months ahead of time. The ability to develop agriculture, the transportation allowed by rivers, and the normally stable flood season make flood plains ideal locations to develop urban areas.

Factors that affect watersheds Factors that affect the watersheds – Climate – Soil Characteristics – Human Activities – Topography of the land

Climate – Things that raise the water table: Greater precipitation Ice melt in the spring and summer High humidity – All of the above prevents water from evaporating, which can raise the water table. Things that lower the water table – Drought – Hot, dry weather that promotes evaporation

Soil Soils that help water infiltrate, raising the water table – Sandy soils allow water to pass through – Loose soils in dense, forested areas. Soils that are relatively impermeable, not allowing water into the water table – Soils with a high clay content – Compacted soils with small pores with little vegetation – Rocky areas with little soil

Human Activity Human activities have complex effects, though most end up lowering the water table – Clear cutting forests – Farming – Pumping – Irrigation – Construction

Depending on the terrain of the land, water will either have an easier or harder time infiltrating into the ground – Sloped land decreases permeability Example: Mountains – Flat lands increase permeability Land topography

Watersheds can cover HUGE areas – The Mississippi River watershed drains 41% of the continental United States 31 states and 2 provinces! Watershed Drainage Areas

Run-off: Water on the watershed that doesn’t infiltrate into the ground – Will eventually join up with a stream, river, or ocean – Does not contribute to the water table Runoff

Runoff can pick up nutrients, sediment, and pollutants – Runoff contaminated with fertilizer is a huge cause of the Gulf of Mexico dead-zone The water is so polluted, nothing can live there Problems with Runoff

If too much water becomes runoff, or if people use the water table faster than it has time to replenish, the level of the water table will fall – Wells run dry – Less water available for use – Example: Lake Mead in Las Vegas! Final notes

River System You will need to draw and label and color the river system. You will add a written definition in your own words beside each label. HeadwatersRiver BasinOcean WatershedChannel or TributaryDivide Gulf of Mexico Flood PlainRiver Mouth You need to choose one of NC river basins and complete your drawing using it as an example. You will need to incorporated 10 feature specific about your river basin in your drawing You will need explain in detail 1 environmental issue of your river basin Your work must be neat and organized