Geomorphology

Lake Formation graben- downfaulted trough; e.g. Lake Tahoe caldera- subsidence of magma chamber; e.g. Crater Lake, OR Landslides glacial activity- e.g. scour, morain dams, & ice melt solution- CaCO3 (limestone) Oxbow wind- playa lakes humans & beaver

Oxbow Lake

Fluvial Morphology determined by geology of the site: dendritic- deposits of uniform resistance rectangular- follow faults trellis- flow between parallel ridges

Stream Ordering System method of numbering streams as part of a drainage basin network; the smallest unbranched tributary is called 1st order, the stream receiving the tributary is 2nd order, and so on.

Stream Ordering

Stream Type ephemeral- channels not well defined; flow during and shortly after precipitation events intermittent- generally flow only during the wet season perennial- year round

spatial scale in lotic ecosystems World Continent Drainage Watershed Stream

Channel Patterns straight, meandering, & braided sinuosity- degree of curvature and meandering pool/riffle sequence; stream energy is lost at the head of the pool causing deposition

Braided Stream

Sedimentation & Channel Patterns erosion- chemical and mechanical processes by which stream channels are formed agrade- increase slope/gradient through deposition.

Deposition process where particles that have been entrained and transported are deposited.

factors effecting deposition stream gradient flow volume particle size impoundments

results of deposition delta- results when flowing water meets standing water alluvial fan- sediments are deposited on land after eroding from higher elevation alluvial flood plain-

Delta

Alluvial Fan

Alluvial Floodplain

Flow Classification

Sediment

Particulate Inorganic Matter (PIM) suspended sediments; primarily silt and clay

Dissolved Organic Matter (DOM) decomposed particulate organics (particles < 0.45 um); carbohydrates, humic acids, tannins, proteins, & alcohols

Particulate Organic Matter (POM) larger sized particles; leaves, woody debris, and dead animals important habitat & nutrients Fine Particulate Organic Matter (FPOM)- < 1mm- >0.45um Coarse Particulate Organic Matter (CPOM)- > 1mm