Running Water

Rivers Systems

Watershed  Land from which water runs off into streams (drainage basin)

Tributaries Feeder streams that flow into a main river.  Where were these located on our watershed diagram?

A few terms to know….. Divide -ridges or elevated regions of high ground that separate watersheds. Headwaters - Beginning of a stream Velocity - Distance water travels over time.

More terms to know…. Discharge - volume of water moved by a stream within a given time. Gradient - steepness of a stream’s slope

Stream Erosion

channel The path that a stream follows

headward erosion  process of lengthening and branching of a stream

How old is that river?  Youthful river   straight   erodes rapidly   V-shaped   few tributaries   has waterfalls and rapids

Mature river  meandering (winding)  slow erosion  U-shaped  lots of tributaries  holds lots of water

Old river  gradient and velocity decreases  no more erosion  more meandering

River Basins  A river basin is the land that water flows across or under on its way to a river.  Large river basins are made up of many smaller watersheds

Lakes A depression in the surface of the earth that collects and holds water  Which material would collect and hold water better: clay, sand, or gravel?

Lake Origins  Natural lakes originate in different ways in surface depressions and low areas. Oxbow Lakes Form when streams cut off meanders and leave isolated channels of water

Lake Origins Landslide Lake Stream flow is blocked by sediment from landslides

Lake Origins Prehistoric Lakes   Remnants of prehistoric lakes that have receded to lower-lying areas Glacial Lakes   Basins of these lakes formed as glaciers gouged out the land during the ice ages. Glacial moraines dammed the depression = moraine-dammed lakes

Lake Origins Cirque Lakes Circular depression carved out by a glacier carved high in the mountains by valley glaciers. Kettle or Pothole Lakes Blocks of glacial ice left behind/blocked by rocks that melt and leave a depression

Man Made Lakes (Reservoirs)  Dammed rivers that create lakes  Used to create Hydroelectric power!

Amount of dissolved oxygen helps determine quality of lake water and its ability to support life

Eutrophication Process by which lakes become rich in nutrients from the surrounding watershed

Eutrophication  Sources  Wastes from Industry  Wastes from Sewage Systems  Pesticide/herbicide runoff from farms  Illegal dumping  Leaking of storage tanks  Types  Copper = leaching from rock weathering, corrosion of piping  Nitrates = Most common! Septic tanks, fertilizers, organic wastes (poop)  Phosphates = fertilizers, industrial wastes  Chlorine = from disinfection

What this mean for people…  Copper = Can lead to liver damage or anemia  Nitrates = starve body of oxygen – “cyanosis” = “blue baby syndrome” = occurs in infants who drink water contaminated with nitrates  Phosphates = excessive amounts can cause algal blooms in ponds/lakes  Chlorine = can combine with other compounds forming potentially carcinogenic compounds (cancer causing compounds)

Wetlands  Land area that is covered with water for a large part of the year  AKA: bogs, marshes, swamps

Bogs  Receive water from precipitation  Soils tend to be rich in SPHAGNUM = peat moss  Peat moss breaks down= acidic soil  Acidic soil supports unusual plants

Marshes  Form along mouths of streams and in areas with extensive deltas  Grasses, reeds, sedges, rushes, and abundant wildlife