Rivers and Discharge

Characteristics of Rivers and Discharge Comparison

• The mountains in Weaverville, California are barren on the eastern side due to a past fire and on the western side due to strip mining.
• Gold can be found in areas where water flows fast and holds onto the gold particles.
• Black sand, which contains high-density metals like iron and gold, is often found with gold.
• The presence of magnetite crystals in black sand is due to the alignment with the magnetic field of the rocks in the coast range.
• The amount of water flowing out of the Oroville Dam during the spillway incident was 110,000 cubic feet per second.
• Velocity and discharge are important factors in stream characteristics and erosion.
• Slope or gradient is a significant characteristic that influences velocity and discharge.
• The velocity of water is generally greater at the mouth of a river compared to the head due to channel characteristics and smoother flow.
• Discharge refers to the amount of water flowing through a river, and it determines the river's erosional power.
• The Mississippi River is one of the largest rivers in the United States, with a discharge of 110,000 cubic feet per second during a significant event.
• The Amazon River is the largest in the world in terms of both length and discharge.
• The Nile River, despite flowing near the equator, has a lower discharge due to passing through a desert, making it the 29th largest in terms of discharge.

River Erosion and Deposition

• Streams carry three types of loads: suspended load, dissolved load, and bed load.

• The bouncing of particles along the bottom of a river is called saltation.

• Competence refers to the maximum size of rock that a stream can carry, while capacity refers to the maximum amount of sediment it can carry.

• A river with a large capacity but low competence is a large river that is not moving very fast, like the Amazon.

• A river with a large competence but low capacity is a fast-moving, small river that can carry larger rocks.

• Deposition occurs when the velocity of a river decreases, causing sediment to drop out.

• Sediment dropped by a stream is called alluvium.

• Well-sorted deposits occur when a river is flowing fast and larger rocks settle out first, followed by smaller rocks and fine-grained sediment.

• The settling velocity of sediment determines whether it will be carried or deposited by a river.

• The longitudinal profile of a river shows its elevation changes from headwaters to mouth.

• A braided stream occurs when there is a flat slope and a large amount of sediment, causing the river to flow in multiple channels.

• Base level is the lowest point a stream can erode to, with ultimate base level being the ocean and temporary base level being a reservoir.Formation of Floodplains and River Flooding

• Floodplains are formed through downward and side erosion by rivers.

• A floodplain is a flat, fertile area that develops when rivers flood and deposit sediment.

• Natural levees form along rivers, creating boundaries for floodplains.

• Floodplains are important for agriculture and human settlements due to their fertile soil and proximity to water.

• Rivers typically exceed their banks onto the floodplain once every two years.

• Flood insurance rates are higher for areas prone to frequent flooding.

• A 10-year flood occurs when water reaches the natural levee approximately once every 10 years.

• A 50-year flood occurs when water covers the entire floodplain approximately once every 50 years.

• A 100-year flood occurs when water overflows the top of the floodplain.

• Flood insurance coverage is based on the average height the water will reach during a flood event.

• Meanders are formed when a stream valley is lifted up and cuts straight down, creating a meandering stream.

• Deposition features include deltas, which form at the mouth of a river where it meets a body of water.

Water Resources in California

• Death Valley and the Mojave Desert in California receive very little precipitation, making water availability a significant problem in the region.
• The complex system of aqueducts is used to transport water from areas with rainfall to areas with high demand.
• California faces two major problems with water: rain falls at the wrong time of year and in the wrong location.
• The Sierra Nevada mountains, covered in snow, serve as a water source for agriculture in California.
• Snowpack in the Sierra Nevada mountains helps recharge the groundwater in the Great Valley, which is crucial for agriculture.
• During a 10-year drought, California experienced high water prices and depleted aquifers.
• The Orville Dam incident filled up the aquifers to 70% in just one year, providing temporary relief.
• The hydrologic cycle involves reservoirs and pathways for water movement, including evaporation, precipitation, and transpiration from plants.
• Transpiration, the evaporation of water from plants, is significant for agriculture in California's Great Valley.
• Infiltration occurs when water seeps into the ground and reaches the water table, leading to the formation of lakes.
• Only about 3% of the planet's water is fresh water, with the majority locked up in glaciers.
• Surface water, such as lakes and rivers, accounts for around 10-12% of the total fresh water, while groundwater makes up about 20%.

Test your knowledge on the characteristics of rivers and their discharge with this quiz. Learn about factors that influence velocity and erosion, discover the largest rivers in the world, and explore the fascinating relationship between water flow and the presence of valuable minerals like gold.