CEE 1030 1nd Edition Lecture 16: Running WaterOutline of Last Lecture I. Mass wastinga. Role of particle size and shapeb. Role of waterc. Role of underlying surfaceII. Other factors of mass wastingIII. ReviewIV. Mass wasting processesOutline of Current Lecture I. Hydrolic cycleII. Running waterIII. Divides and drainage networksIV. Vocab termsV. Stream erosion, transport, and depositionCurrent LectureI. Hydrolic cyclea. Hydrolic cycle: the continuous circulation of Earth’s water among oceans, atmosphere, and continentsb. Hydrolic processesi. Evaporation : the process of water turning from a liquid to a vaporii. Transpiration: the release of water vapor to the atmosphere by plantsiii. Precipitation: water that falls to the ground from the atmosphere to the hydrosphereiv. Infiltration: surface water draining into the ground through cracks and pore spaces in the regolithv. Runoff: water flowing over land rather than infiltrating the groundII. Running watera. One of the most important erosional agents on Earth’s land surfaceb. Infiltration vs. runoffi. Infiltration capacity: max amount of water soil can absorbii. Runoff begins as sheet flow: water draining in shallow, unconfined sheets across the ground1. Sheet flow erodes in narrow, shallow channels called rillsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.2. Runoff may widen and deepen rills to become gullies, ravines, etc.iii. Water flowing in channels are called streams, creeks, etc.1. Erosion of channels2. Transport of sediments3. Deposition of sedimentiv. Streamflow types1. Laminar flow: water particles move in straight-line paths downstream2. Turbulent flow: water flows erraticallyv. Factors of streamflow velocity1. Gradient of channel2. Channel morphology3. Dischargea. Measure discharge by calculating width x depth x velocity of channelvi. Drainage basin: the area where runoff drains downhill into water way or body of waterIII. Divides and drainage networksa. Drainage networks: interconnected system of tributaries, creeks, streams, and rivers in a drainage basin that feed into the main waterwayb. Divide: each drainage basin separated topographically from adjacent basinsc. Continental Divide: mountainous line that forms the border between two major watersheds of North AmericaIV. Vocab termsa. Stream profile: a cross-section of a stream that shows the gradient, channel morphology, and dischargeb. Base level: the lowest point to which a stream can erode (sea level: the ultimate base level)c. Stream valleys: young (V-shaped) or mature (U-shaped)d. Alluvial fans: depositions of sediments on land and in a fan shapee. Delta: like an alluvial fan, but deposited in a larger body of waterV. Stream erosion, transport, and depositiona. Stream erosioni. Streams cause erosion by:1. Lifting loosely consolidated particles2. Abrasion (mechanical weathering)3. Dissolution (chemical weathering)ii. Evidence of stream erosion: potholes, gorgesb. Sediment transporti. Stream’s load: the transported materialii. Dissolved load, suspended load, bed loadiii. Sediment load1. Capacity: maximum load a stream can transport2. Competence: largest particle a stream can transport3. Capacity and competence determined by velocityc. Sediment depositioni. When streamflow velocity decreases, competence is reduced and sediments are depositedii. Alluvium: sediments deposited by streamsiii. Channel deposits: sediment accumulation within a channel1. Bar: sand and gravel deposit2. Braided stream: stream consisting of numerous intertwining channelsiv. Floodplain deposits1. Natural levee: elevated landform composed of alluvium2. Backswamp: poorly drained area of floodplain3. Yazoo tributary: tributary flowing parallel to the main