Running Water Lecture Notes PDF

11,.-'!'_.. ,, -- ,, I, ~ ,, l f l ,, I' ' '• "'Ir ' • □ Hydro/ogic Cycle ■ Unending circulation of water. Evaporation ✓ The process of a substance liquid changing gaseous In a Precipi 96,000 km3 Precipitation 284,000 km3 state to a state ration/Transpiration 60,000 km3 due to...

11,.-'!'_.. ,, -- ,, I, ~ ,, l f l ,, I' ' '• "'Ir ' • □ Hydro/ogic Cycle ■ Unending circulation of water. Evaporation ✓ The process of a substance liquid changing gaseous In a Precipi 96,000 km3 Precipitation 284,000 km3 state to a state ration/Transpiration 60,000 km3 due to an increase in temperature and/or pressure ~ 2015 Ptii:lloUI I EUUl,;i:ltiUII, Im;. HDA. Reyes I Principles of Geology • Hydro/ogic Cycle ■ Unending circulation of water. □ Precipitation Hydrologic Cycle ----------- ✓ Water released from clouds in the form of ra1 n, freezing rain, sleet, snow, or hail. ✓ It is the primary connection in the water cycle that provides for the delivery of atmospheric water to the Earth. Precipi 96,000 km Precipitation 284,000 km3 ~ 2015 Ptii:lloUI I EUUl,;i:ltiUII, Im;. HDA. Reyes I Principles of Geology • □ Hydro/ogic Cycle ■ Unending circulation of water. Runoff Hydrologic Cycle ✓ The draining away of water from the surface of an area of land. Precipitation 284,000 km3 Precipi 96,000 km3 Evaporation/Transpiration 60,000 km3 ~ 2015 Ptii:lloUI I EUUl,;i:ltiUII, Im;. HDA. Reyes I Principles of Geology • Hydro/ogic Cycle ■ Unending circulation of water. □ Infiltration Hydrologic Cycle ✓ When precipitation falls on land, it soaks into the ground. Precipitation 284,000 km3 Precipi 96,000 km3 Evaporation/Transpiration 60,000 km3 Infiltration ~ 2015 Ptii:lloUI I EUUl,;i:ltiUII, Im;. HDA. Reyes I Principles of Geology • Hydro/ogic Cycle ■ Unending circulation of water. □ Transpiration Hydrologic Cycle ✓ The process where plants absorb water through the roots and then give off water vapor through pores in their leaves. vaporation/Tran 60,000 k ~ 2015 Ptii:lloUI I EUUl,;i:ltiUII, Im;. HDA. Reyes I Principles of Geology • Hydro/ogic Cycle ■ Unending circulation of water. □ Evapotranspiration ✓ Combination Evaporation Transpiration. Hydrologic Cycle of and Precipitation 284,000 km3 Precipi 96,000 km3 Evaporation/Transpiration 60,000 km3 ✓ The transfer of water from the surface directly to the atmosphere. ~ 2015 Ptii:lloUI I EUUl,;i:ltiUII, Im;. HDA. Reyes I Principles of Geology • Hydrosphere Freshwater lakes 0.009% Saline !lakes and inland seas 0.008% Soil moisture 0.005% Atmosphere 0.001% Stream channels 0.0001% L Glaciers 2.15% Hydrosphere• Nonocean Component {% of total hydrosphere) HDA. Reyes I Principles of Geology ■ Although runoff makes up a small percentage of the total, running water is, nevertheless, the single most important erosional agent sculpting Earth's land surface. • Running Water ■ The amount of water that runs off rather than soaking into the ground depends on several factors: 1. 2. 3. 4. 5. Intensity and duration of rainfall; Amount of water already in the soil; Nature of the surface material; Slope of the land; The extent and type of vegetation. HDA. Reyes I Principles of Geology • Running Water ■ When water becomes runoff □ SheetF/ow ► An overland flow or downslope movement of water taking the form of a thin, continuous film over relatively smooth soil or rock surfaces and not concentrated into channels larger than rills. Source: https://en. wikipedia.org/wiki/Surface_ runoff HDA. Reyes I Principles of Geology • Running Water ■ When water becomes runoff □ Rills ► Threads of current that form tiny channels due to sheer flow. Source: :.....-;;:-1.;:__..,::-::~•-:1 https://imaggeo. egu. eu/view/2 7 37/ HDA. Reyes I Principles of Geology • Running Water ■ When runoff water becomes □ Gullies ► Formed ril Is together. when meet Source: https;//www. dailyma ii. co. uk/news/article-2551912/5evere-soil-erosion-causes5ft-gullies-field-with out-crops-prio r-h eavy-winter-rain.html HDA. Reyes I Principles of Geology • Running Water ■ When water becomes runoff □ Brook, Creek, or Stream ► Formed when gullies combined. Source: https;//www. kestreltrus t. org/p /aces/scarb oroug h-brook-conservationarea/ HDA. Reyes I Principles of Geology • Running Water ■ When water becomes runoff □ River ► Formed when streams reached as undefined size. Source: https://elt ecenglish.com /2018/01/12/ielts-cuecard-january-2018-amajor-river-in-yourcount ry/ HDA. Reyes I Principles of Geology • Drainage Basin ■ The catchment area where all rivers drained. DraLna ge basin □ Divide - Imaginary line that bounds each drainage basin. Drainage drvide / '\ ~ ~slopes \ ( □ Continental Divide - splits an entire continent into enormous drainage basins ~ 1/ /"' Tri bu I ) / I. ~ V . .-Trunk stream Outlet HDA. Reyes I Principles of Geology . / _., • River Systems ■ Involve not only a network of stream channels, but also the entire drainage basin. ■ River systems can be divided into three zones 1. Sediment production-where erosion dominates, Zone of sediment 2. Sediment transport, 3. Sediment deposition production (erosion) -- --- ---FIGURE 9.6 Zone of transportation Trunkstream A river system can be divided into three zones based Zone or deposition the zones of sediment p roduction (erosion), sediment transport, and sediment deposition. (Adapted from Shumm) on the dominant processes operating w ithin eac h zone. These are HDA. Reyes I Principles of Geology • Stream Flow ■ Laminar Flow □ water moves in roughly straight-line paths parallel to the stream channel. ■ Turbulent Flow □ water moves in an erratic fashion characterized by a series of horizontal and vertical swirling motions. HDA. Reyes laminar flow turbulent flow Source: https;//www.cfdsupport.com/OpenFOAM-Training-by-CFDSupport/node2 75. html I Principles of Geology • Flow Velocity Channel A ■ Factors velocity 1. 2. 3. 4. affecting flow Maximum velocity / Channel slope or gradient; Channel size and cross-sectional shape; Channel roughness; The amount of water flowing in the channel. Depthl 1 unit A.Wide, shallow ohannel Cross-sectional area= 10 square units Wetted perimeter= 12 units Ratio = = 0.83 ~ B I Depth 2 units_ B. Narrow, deep channel HDA. Reyes * I Principles of Geology Width 5 urats _ -i _ __.._.._._.- Cross-sectional area= 10 square untts Wetted perimeter = 9 units Ratio = i= 1.11 • Discharge ■ The volume of water flowing past a certain point in a given unit of time. World's Largest Rivers Ranked by Discharge Drainage Area Average Discharge Square miles Cubic meters ,per second Cubic feet per second 5,778,000 2,231,000 212,400 7,500,000 Rep. of Congo 4,014,500 1,550,000 39,650 1,400,000 Yangtze China 1,942,500 750,000 2 1,800 770,000 4 Brahmaputra Bangladesh 935,000 361,000 19,800 5 Ganges India 1,059,300 409,000 18,700 700,000 660,000 6 Yenisei Russia 2,590,000 1,000,000 17,400 614,000 7 Mississippi Un1ted States 3,222,000 1,244,000 17,300 61 1,000 8 Orinoco Venezuela 880,600 340,000 17,000 600,000 9 Lena Russia 2,424,000 936,000 15,500 547,000 Parana Argentina 2,305,000 890,000 14,900 526,000 Rank River Coun.try 1 Amazon Brazil 2 Congo 3 10 ■ Square kilometers The Amazon River is responsible for about 20 percent of all the water . . reaching the ocean Via r,vers. Its nearest rival, Africa's Congo River, delivers about 4 percent of the total. HDA. Reyes I Principles of Geology • Changes Downstream ■ ■ ■ Longitudinal profile - Cross-sectional view of stream from its source area. Head or Headwaters - Source of the water Mouth -The outlet point Head C: 0 ·cu > Q) w Gentler gradient 1!::::::aaa=.----::::.===-------=---------------------..1. Mouth River length Copyright © 2006 Pearson Prentice Hall, Inc. HDA. Reyes I Principles of Geology • Stream Erosion ■ ■ Quarrying involves the removal of blocks from the bed of the channel Abrasion - the process by which the bed and banks of a bedrock channel are ceaselessly bombarded by particles carried into the flow. □ Potholes circular depressions created by the abrasive action of particles swirling 1n fast-moving eddies HDA. Reyes Source: http://www.kruger-national-park.de/ pages/english/imagegal/ery/blyde-river-canyon/bourkes-/uck-potho/es.php I Principles of Geology • Stream Erosion □ Potholes How Potholes are created / River water is swirled around in irregularities in the river bed creating vertical eddies , __ Rocks get swept into the small depressions and abrade the hollow. These rocks are called GRINDERS Source: http://www. geocoops. com/landforms. html HDA. Reyes I Principles of Geology // _ _ __ _____,,. The process continues deepening and enlarging the Pothole Ry Roh GF!mP.c;hy • Stream Sediment Transport □ Sediment Loads ► Dissolved Load Materials that are dissolved in the water. ► Suspended Load Materials that have silt and clay sizes. ► Bed Load - Coarse material, including coarse sands, gravels, and even boulders typically move along the bed of the channel HDA. Reyes Dissolved load (invisible) l Suspended load (silt, clay) I t Bedload (sand, gravel, boulders) c ~i Rolling FIGURE 9.12 Streams transport their load o f sediment in three ways. The dissolved and suspended loads are carried in the general flow. T he bed load includes coarse sand, gravel, and boulders that move by roll ing, sliding, and saltation. I Principles of Geology • Stream Sediment Transport □ Sediment Loads ► Solution - Carries the ► l dissolved load Suspended load Suspension - Carries Dissolved load (silt, clay) (invisible) the suspended sediments t Bedload Rolling - Rolling of (sand, gravel, boulders) c ~i suspended sediments Rolling Sliding or Traction Dragging of bed load FIGURE 9.12 Streams transport their load o f sediment in three ways. The dissolved and suspended loads are carried in the sediments. general flow. T he bed load includes coarse sand, gravel, and Saltation Series of boulders that move by roll ing, sliding, and saltation. jumps or bouncing of sediments along transport. HDA. Reyes I Principles of Geology I ► ► ► • Capacity vs. Competence □ Capacity ► The maximum load of solid particles a stream can transport per unit time. □ Competence ► Is a measure of a stream's ability to transport particles based on size rather than quantity. HDA. Reyes I Principles of Geology • Alluvium □ The general term for sediment deposited by streams. Source: https://geo graphyeducation. org/2017/12/21/alluvia/-fans-2/ HDA. Reyes Source:http://co/oradogeo/ogica/survey.org/co/orado-geo/ogy/igneousroc ks/volcan ic-ro cks/lava-f/o ws/cinder-con ej/o ws/ I Principles of Geology • Stream Channels □ Bedrock Channels ■ Cut into the underlying strata and typically form in the headwaters of river systems where streams have steep slopes ■ Steep bedrock channels . often develop a sequence of • /\ ~ pools and steps, relatively flat segments (pools) where alluvium tends to acc um uIate' and steep Source: https://fishbio.com/fie/d-notes/inside-fishbio/ bedrock-canyon segments (steps) where bedrock is exposed. ~ ~ HDA. Reyes , ~( - .._ I Principles of Geology • Stream Channels □ Alluvial Channels ■ ■ Form in sediment that was previously deposited in the valley. When the valley floor reaches sufficient width, material deposited by the stream can form a floodplain that borders the channel. HDA. Reyes I Principles of Geology Source: https://ar. wikipedia. org/wiki/%D9%86% D9%87%D8%B1 %D9%85%D8%AC%D8%AF%D9%88%D9%84 • Stream Channels □ Alluvial Channels ■ Meandering Channels ✓ Streams that transport much of their load 1n suspension generally move in sweeping bends Mmtimum wfocity,, FIGURE 9.14 When o ~lJt::adll t tllt:"dltt.kl~, ib .lUtlt: of mnxim11m ~pP.Pd "ihiftc- rnw.:.rrl thP nllTPr h;mk ThP point bars sho.vn here are on the White River near Vcmol, Ut.ih. The block ,me whrte photo ~O'N.3 ero5ion ol a cut blink along the N~Wl'l\ 1~11111 RN..., U 1 Washingion Srate. By eroding its outer bank and dcpoottmq motcnol on the in, ide of the bend, a otreom i, oblc to ,hilt ou channel. troinl b.,r p/,oro hy M1 /Jrl..,j OJ/i,-.,, cul l,,.,A:. photo by P. A G!ancy, U.S. Gco/"11,c•/ 5'6Voy} HDA. Reyes I Principles of Geology Mioti:l11111nn v....__:itJ ...."-~ - • Stream Channels □ Alluvial Channels ■ Meandering Channels ✓ Cut bank - Zone of active erosion ✓ Point Bar - Zone of deposition Mmtimum wfocity,, FIGURE 9.14 When o ~lJt::adll t tllt:"dltt.kl~, ib .lUtlt: of mnxim11m ~pP.Pd "ihiftc- rnw.:.rrl thP nllTPr h;mk ThP point bars sho.vn here are on the White River near Vcmol, Ut.ih. The block ,me whrte photo ~O'N.3 ero5ion ol a cut blink along the N~Wl'l\1~11111 RN..., U 1 Washingion Srate. By eroding its outer bank and dcpoottmq motcnol on the in,ide of the bend, a otreom i, oblc to ,hilt ou channel. troinl b.,r p/,oro hy M1 /Jrl..,j OJ/i,-.,, cul l,,.,A:. photo by P. A G!ancy, U.S. Gco/"11,c•/ 5'6Voy} HDA. Reyes I Principles of Geology • Stream Channels □ Alluvial Channels ■ Fl GURE 9.15 Oxbow lakes occupy abandoned meanders. As they fill with sediment, oxbow lakes gradually become swampy meander scars. Aerial vrew of an oxbow lake created by the meandering Green River near Bronx, Wyoming. (Photo by Micha&/ Colll9r) Meandering Channels ✓ Cutoff ✓ OxbowLake Geologist's Sketch HDA. Reyes I Principles of Geology • Stream Channels □ Alluvial Channels ■ Braided Channels ✓ Form where a large portion of a stream's load consists of coarse material (sand and gravel) and the stream has a highly variable discharge. Source: http:/ If astwindtoaim. biogspot. com/2013/02/f/uvial-landform-0 7braided-channel. html HDA. Reyes I Principles of Geology • Base Level □ Fundamental concept in the study of stream activity, base level is defined as the lowest elevation to which a stream can erode its channel. □ Ultimate base level - refers to sea level. □ Local or Temporary base levels - include lakes, resistant layers of rock, and rivers that act as base levels for their tributaries FIGURE 9.17 When a dam ,s built and a reservoir forms, the stream's Ud~t! lt1vt1l i~ rdi~t!U. I Iii~ rt1tluw~ lht! ~lrtidr11', vt1lodly dllU lt1du, to depozition and a reduction ot the gradient upztream from th0. ms0.rvoir A. cGi-W ltfv~I Dam Rcoorvoir l '-'/ - ;:........... OriyimJ µrufile B. HDA. Reyes I Principles of Geology • Graded Stream □ Has the necessary slope and other channel characteristics to maintain the minimum velocity required to transport the material supplied to it. □ On average, a graded system is neither eroding nor depositing material but is simply transporting it. □ When a stream reaches equilibrium~ it becomes a self-regulating system in which a change in one characteristic causes a change in the others to counteract the effect. HDA. Reyes I Principles of Geology • Knickpoint □ Part of a river or channel where there 1s a sharp change 1n channel slope, such as a waterfall or lake. Source: https;//revisegeo.wordpress. com/alevel/rejuven ation/I HDA. Reyes I Principles of Geology • Knickpoint □ The world's highest uninterrupted waterfall is Venezuela's Angel Falls. The water plunges 979 meters (3212 feet). Source: https://voyagenation.co m/en/v/AngelFalls/GranSabana/Bolivar HDA. Reyes I Principles of Geology • Shaping of Stream Valleys □ Consists of a channel and the surrounding terrain that directs water to the stream. It includes the valley floor, which is the lower, flatter area that is partially or totally occupied by the stream channel, and the sloping valley walls that rise above the valley floor on both sides. Source: https://pixabay.com/en/photos/ stream %20valley/ HDA. Reyes I Principles of Geology • Shaping of Stream Valleys □ Valley Deepening ✓ When a stream's gradient is steep and the channel is well above base level, downcutting is the dominant activity. ✓ Abrasion caused by bed load sliding and rolling along the bottom and the hydraulic power of fast-moving water slowly lower the stream bed. ✓ The most prominent features of V-shaped valleys are rapids and waterfalls. ✓ Both occur where the stream's gradient increases significantly, a situation usually caused by variations in the erodability of the bedrock into which a stream channel is cutting. HDA. Reyes I Principles of Geology • Shaping of Stream Valleys □ Valley Widening ✓ As a stream approaches a graded condition, downcutting becomes less dominant. ✓ At this point the stream's channel takes on a meandering pattern, and more of its energy is directed from side to side. As a result, the valley widens as the river cuts away at one bank and then the other. ✓ The continuous lateral erosion caused by shifting meanders gradually produces a broad, flat valley floor covered with alluvium. ✓ Floodplain HDA. Reyes I Principles of Geology • Shaping of Stream Valleys Site of erosion Site of deposil iOn B. Floodplain - well developed_ _..J C. FIGURE 9.20 Development of an erosional floodplain. HDA. Reyes I Principles of Geology • Shaping of Stream Valleys □ Incised Meanders and Stream Terraces FIGURE 9.21 Incised meanders. Aerial view of incised meanders of the Colorado River on the Colorado Plateau. As the plateau gradually rose, these meanders downcut because of the steepening gradient. (Photo by Michael Collier) HDA. Reyes I Principles of Geology • Shaping of Stream Valleys □ Incised Meanders and Stream Terraces FIGURE 9.21 Incised meanders. Aerial view of incised meanders of the Colorado River on the Colorado Plateau. As the plateau gradually rose, these meanders downcut because of the steepening gradient. (Photo by Michael Collier) HDA. Reyes I Principles of Geology • Type of stream □ Tributaries - a river or stream flowing into a larger river or lake. □ Distributaries - main channel dividing into several smaller ones, Distri butary Tributary HDA. Reyes I Principles of Geology Source: https://www.quora.com/What/s-a-tributary-and-distributory • Depositional Landforms □ Bars - small-scale channel deposits. BS Diagonal B,u,; 81 Point 8s13 86 Mam Channel Branching with Numerous Mid-Bars and Islands B2 Point Bars with Few Mld,Channel Bars B7 Side Bars and Mid Channel Bars with length Exceeding 2·3 Channel Widths B3 Numerous Mid-Channel Bars 84 Side Bars 88 Delta Bars Illustrations of various depositional features as modified from Oaley et al. (1973) (Rosgen 1996) HDA. Reyes I Principles of Geology Source: http://www.fgmorph.com/fg_ B_ 12.php • Depositional Landforms □ Delta - form where sediment-charged streams enter the relatively still waters of a lake, an inland sea, or the ocean. ► Types of Delta 1. 2. 3. Cuspate Delta -Tooth-shaped delta. Arcuate Delta - Fan-shaped delta. Bird's Foot Delta- River dominated delta Source: http://www.cesbio. upstlse.fr/multitemp/?a uthor=3 https :/lwww.afrika online. cz/rservice.ph p ?akce=tisk&cis/ocla nku=2002101601 https://earthobserv atory.nasa.qov/ima qes/4526/mississipp i-river-de/ta HDA. Reyes I Principles of Geology • Depositional Landforms □ Natural Levees - deposit of sand or mud built up along, and sloping away from, either side of the flood plain of a river or stream. □ Back Swamp/ Marsh - The area behind the levee is characteristically poorly drained for the obvious reason that water cannot flow over the levee and into the river. □ Yazoo Tributaries - any tributary stream that runs parallel to, and within the floodplain of a larger river for considerable distance, before eventually joining it. HDA. Reyes I Principles of Geology • Depositional Landforms Ane sediments deposited Coarse sediments deposited Floodstage Developing, natural levee Coarse sediments Flne sediments Post flood Fine sediments Coarse sediments deposited depos1t ed Ffoodstage Natural levees --~ , Natural levee ~ _____ -~ L--- - - ,. - . - - - - .- Natural levee after numerous floods FIGURE 9.25 Natura l levee5 are gently 5loping 5truct\Jres that are created by repeated floods. The diagram s on the right show t he sequence of d evelo pment. Because the ground next to the strei!!m channel is higher than the adjacent floodplain, back swamps and yazoo tributaries may develop. HDA. Reyes I Principles of Geology • Depositional Landforms □ Alluvial Fan - fan-shaped deposits that accumulate along steep mountain fronts. Source: http://www.marlimillerph oto. com/alluvia/fans. html HDA. Reyes I Principles of Geology • Drainage Patterns □ Dendritic Drainage Pattern - characterized by irregular branching of tributary streams that resemble the branching pattern of a deciduous tree. Source: https://www.civilsdaily.co m/http-s3-ap-southeast1-amazonaws-com-wpcdup/oad4-3/ A. Dendritic HDA. Reyes I Principles of Geology • Drainage Patterns □ Radial Drainage Pattern - This pattern typically develops on isolated volcanic cones and domal uplifts. VoJcano ~ Source: https;//www.geoforcxc.c om/water/rivers/radial/ HDA. Reyes I Principles of Geology • Drainage Patterns □ Rectangular Drainage Pattern - This pattern typically develops where the bedrock is crisscrossed by a series of joints. Source: https;//www.pmfias.com lfluvia/-erosiona/landforms-drainagepatterns-river-valleyformation/ C.Aeotanglilar HDA. Reyes I Principles of Geology • Drainage Patterns □ Trellis Drainage Pattern - a rectangular pattern in which tributary streams are nearly parallel to one another and have the appearance of a garden trellis. This pattern forms in areas underlain by alternating bands of resistant and less resistant rock and is particularly well displayed 1n the folded areas. HDA. Reyes Valleys cut in less-resistant rock Trellis Source: https://www.geoforcxc.com/water/rivers/trellis/ I Principles of Geology Lutgens, F., Tarbuck, E. and Tasa, D. (2012). Essentials of Geology Eleventh Edition. Upper Saddle River, New Jersey: Pearson Prentice Hall. https ://water. u sgs.gov/ edu/watercyclep recip itat ion. htm I https ://study.com/a cad emy/lesso n/wh at-is-eva po ration-definition -examplesq u iz.ht ml www.yourdictionary.com/transpiration https ://en cyclopedia 2.thefreed iction ary.com/s heet+fl ow HDA. Reyes I Principles of Geology