Surface Water Movement Surface Water What types of

Surface Water Movement

Surface Water �What types of bodies of water constitute surface water? �River, lakes, streams, ponds, and seas �Where does surface water come from? �Rain, Ice, Snow, and Under the ground

Hydrologic Cycle �Earth’s water supply is recycled in a continuous process

Hydrologic Cycle �Evaporation-Movement of water from Earth’s surface to atmosphere �Condensation- Movement from water vapor to clouds �Precipitation- water falls back on Earth �Infiltration- Water soaking into the Earth �Runoff- water on earth’s surface that flows downslope into lakes, streams, rivers, oceans, or puddles �Transpiration- water vapor from plants; Similar to evaporation

Runoff �A number of conditions determine whether water on Earth’s surface will infiltrate the ground or become runoff. �Vegetation �causes the soil to hold more water � water flows slower down plants allowing the ground to soak in more �Rate of Precipitation�More water enters ground if rainfall is gentle �During heavy downpours , the rate of precipitation may exceed the rate of infiltration

Runoff �Soil Composition: Determines how much water soil can hold �Slope: the steeper the slope, the less water is allowed to soak into the ground

Stream Systems �Stream System- Large river and all of its tributaries �Water flows downslope to lower elevations �Can flow into lakes, oceans and other streams

Stream Systems �Tributaries �Rivers that flow into other streams �Example: Missouri river is a tributary for the Mississippi

Stream Systems �Water Sheds �All of the land whose water drains into a stream �Divide �A high land that separates one watershed from another

Stream Systems �Stream Load: the material that a stream carries. Stream load is carried in 3 ways: 1. solution: material dissolved in water 2. suspension: particles small enough to be held up by the turbulence of moving water (silt, sand, clay) 3. bed load: sand pebbles and cobbles that are rolled and pushed along the stream bed by water

Stream Velocity and Carrying Power �Carrying power: streams ability to transport material; this is dependent on stream velocity and volume �Stream velocity: effected by slope, depth, width of the stream �Discharge: width x depth x velocity �When discharge increases, carrying power increases �Increases during heavy rain, rapid snowmelt, and flooding

Floodplains �Flood- water spills over the sides of stream banks and onto adjacent lands �Floodplain- the area of land covered with stream water during times of floods �When water recedes off the floodplain, sediments are deposited on the land making the soil very fertile

Floods �Upstream flood: the flooding of a small area caused by a sudden rainstorm dropping large amounts of time (flashflood) �Downstream flood: heavy accumulation of excess water from large regional drainage

Streams, Wetlands, and Lakes

Stream Development �Stream formation relies on adequate water supply �As a stream develops it changes width and size, and shapes the land over which it flows

Formation of Stream Valleys �Driving force of a stream- gravity �Stream actively erodes a path through the sediment or rock, a V-shaped channel develops

Meander �As stream channels develop into broader valleys , the volume of water and sediment that they can carry increases. �Sometimes the water begins to erode the sides of the channel in such a way that the overall path starts to bend and wind. �A bend or curve is called a meander.

Meander

Origins of Lakes �Lakes can form from many different sources �Stream flows become blocked �Glacial origins �Melted glaciers �Water from precipitation , runoff, and underground sources can maintain a lake’s water supply

Lakes Undergo Change �Eutrophication: when watershed enriches bodies of water with nutrients that stimulate excessive plant growth �Can be positive or negative

Wetlands �Wetland: low lying area that is periodically saturated with water and support a specific plant species �Areas include bogs, marshes, or swamps