DOCSLIB.ORG

6.2 the Work of Streams

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
6.2 the Work of Streams HSES_1eTE_C06.qxd 9/23/04 9:49 PM Page 164 Section 6.2 6.2 The Work of Streams 1 FOCUS Section Objectives 6.6 Explain how streams erode Key Concepts Vocabulary Reading Strategy their channels and transport How do streams erode ◆ bed load Monitoring Your Understanding Preview sediments. their channels and ◆ capacity the Key Concepts, topic headings, vocabulary, transport sediment? ◆ alluvium and figures in this section. List two things you 6.7 Explain how stream deposition expect to learn about each. After reading, state How does stream ◆ delta occurs. what you learned about each item you listed. deposition occur? ◆ natural levee 6.8 Identify the two general types What are the two types ◆ floodplain What I Expect to Learn What I Learned of stream valleys. of stream valleys? ◆ flood 6.9 Predict the causes of floods What causes floods, and ◆ drainage basin what are the major flood and describe major flood ◆ divide control measures? control measures. What is the relationship 6.10 Explain the relationship between a stream and between streams and drainage a drainage basin? basins. Reading Focus Streams are Earth’s most important agents of erosion. They can downcut or erode their channels. They can also transport enormous L2 Build Vocabulary amounts of sediment. Most of the sediment a stream carries comes Paraphrase Ask students to write the from weathering. Weathering produces huge amounts of material that vocabulary terms on a sheet of paper. are delivered to the stream by sheet flow, mass movements, and Instruct students to write a definition, in groundwater. Eventually, streams drop much of this material to create their own words, for each term as they many different depositional features. encounter the term while going through the chapter. After writing their own Erosion definition, encourage students to write Streams generally erode their channels lifting loose particles by the term in a complete sentence. abrasion, grinding, and by dissolving soluble material. When the L2 flow of water is turbulent enough, it can dislodge loose particles from Reading Strategy the channel and lift them into the moving water. In this manner, the Answers will vary. Sample answer: force of running water rapidly erodes some streambeds and banks. What I Expect to Learn—how erosion The stronger the current is, the more erosional power it has and the happens and what features it can form more effectively the water will pick up particles. What I Learned—streams erode by Sand and gravel carried in a stream can erode solid rock channels lifting loose particles and by abrasion like sandpaper grinds down wood. Moreover, pebbles caught in meanders swirling stream currents can act like cutting tools and bore circular “potholes” into the channel floor. 2 INSTRUCT What are three ways that streams erode their channels? Erosion Build Reading Literacy L1 Refer to p. 334D in Chapter 12, which 164 Chapter 6 provides guidelines for outlining. Outline Have students outline the section, leaving room for notes. Then have students scan through each heading and find the main idea. Allow students to refer to their outlines when answering the questions in Section 6.2 Assessment. Logical, Verbal 164 Chapter 6 HSES_1eTE_C06.qxd 5/16/04 9:09 AM Page 165 Sediment Transport Sediment Transport Integrate Chemistry L2 Streams transport sediment in three ways. Solutions and Suspensions Streams 1. in solution (dissolved load) transport sediment in solution and in 2. in suspension (suspended load) suspension. In chemistry, a solution is 3. scooting or rolling along the bottom (bed load) a homogeneous mixture of dissolved substances. A suspension is a Dissolved Load Most of the dissolved load enters streams heterogeneous mixture that separates through groundwater. Some of this load also enters by dissolving rock into layers over time. Ask students to along the stream’s course. The amount of material the stream carries write a paragraph explaining how in solution changes depending on climate and the geologic setting. streams are both solutions and Usually the dissolved load is expressed as parts of dissolved material suspensions. (Streams are composed, per million parts of water (parts per million, or ppm). Some rivers may in part, of groundwater that contains have a dissolved load of 1000 ppm or more. However, the average dissolved substances, and in this way figure for the world’s rivers is estimated at 115 to 120 ppm. Streams streams are solutions. Streams also supply almost 4 billion metric tons of dissolved substances to the transport fine sand, silt, and clay that are oceans each year. not dissolved, but rather suspended in moving water. In this way, streams are Suspended Load Most streams carry suspensions.) the largest part of their load in suspension. Verbal The visible cloud of sediment suspended in the water is the most obvious portion of a Build Science Skills L2 stream’s load. Streams usually carry only sand, silt, and clay this way. However, streams Using Models Some students will have also transport larger particles during a flood difficulty comprehending the tiny scale because water velocity increases. The total of one part per million. To help build amount of material a stream carries in sus- number sense and awareness of how pension increases dramatically during floods, small a part per million is, ask students as shown in Figure 8. to imagine they have a budget of one million dollars, and have them think of Bed Load Bed load is that part of a the cost of their lunch in terms of parts stream’s load of solid material that is made up per million. A four-dollar lunch would be of sediment too large to be carried in suspen- equal to 4 ppm. This represents only a sion. These larger, coarser particles move along the bottom, or bed, of Figure 8 During this 1997 flood, tiny fraction of their total budget. the suspended load in the muddy Logical the stream channel. The suspended and dissolved loads are always Ohio River is clearly visible. The moving. But the bed load moves only when the force of the water is greatest erosion and sediment great enough to move the larger particles. The grinding action of the transport occur during floods. Applying Concepts What other bed load is very important in eroding the stream channel. types of load might account for the muddiness of the river? Competence and Capacity The ability of streams to carry a load is determined by two factors: the stream’s competence and its capacity. Competence of a stream measures the largest particles it can transport. A stream’s competence increases with its velocity. In fact, the competence of a stream increases four times when the velocity doubles. The capacity of a stream is the maximum load it can carry. Capacity is directly related to a stream’s discharge. The greater the volume of water in a stream is, the greater its capacity is for carrying sediment. Running Water and Groundwater 165 Customize for English Language Learners Students who are learning English can benefit news. Have them discuss the type of damage from real-life examples that relate to science done by the flood and some of the amazing content. Encourage students to think of actual pictures of rescues and houses floating flooding events that may have occurred in downstream. Encourage students to share Answer to . your area or that they have heard about on the their knowledge and examples with the class. Figure 8 Dissolved load might account for the muddiness of the river. Streams erode their channels lifting loose particles by abrasion, grinding, and by dissolving soluble material. Running Water and Groundwater 165 HSES_1eTE_C06.qxd 9/23/04 11:04 PM Page 166 Section 6.2 (continued) Mississippi Delta Region A t Deposition c Figure 9 h a Baton Rouge fa la M Movement This map y a is shows the growth of the R s i is v s Mississippi River delta over e ippi Riv r er the past 5,000 to 6,000 years. New Orleans Alluvium L2 As you can see, the river has 2 built a series of sub-deltas, Purpose Students learn how one after the other. The deposition occurs in a stream. numbers indicate the order in 4 Materials mixed sediment (pebbles, which they were deposited. 6 Locating In which overall sand, silt, and clay-sized particles), clear direction has the Mississippi 1 3 glass jar with lid, water River built its delta over the 5 7 past few thousand years? Procedure Fill the jar about one-third Gulf of Mexico full with the mixed sediment. Pour water Locating How has the growth of the delta changed into the jar and tightly close the lid. the location of the mouth of Shake the jar and allow sediment to the Mississippi River in settle out. relation to New Orleans? Expected Outcome Sediment should settle out in layers, with pebbles on the bottom and clay-sized particles at the Deposition top. The water sorts the material as the energy from the shaking dissipates, the Whenever a stream slows down, the situation reverses. As a stream’s heavier material drops out sequentially. velocity decreases, its competence decreases and sediment begins to drop If this is not illustrated, try using a larger out, largest particles first. Each particle size has a critical settling veloc- jar, which will allow more room for the ity. Deposition occurs as streamflow drops below the critical materials to settle out. settling velocity of a certain particle size. The sediment in that cate- gory begins to settle out. Stream transport separates solid particles of various sizes, large to small. This process is called sorting. It explains why particles of similar size are deposited together.
Load more

Recommended publications
  • 1948 MACKIN Gradedriver G
    BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 69. PP. 463-512, 1 FIG. MAY 1948 CONCEPT OF THE GRADED RIVER BY J. HOOVER MACKIN CONTENTS Page Abstract 464 Introduction 465 Acknowledgments 466 Velocity and load 466 General statement 466 Energy and velocity 466 Competence 468 Capacity 468 The total load 469 The concept of grade 470 Examples of streams at grade 472 The graded stream as a system in equilibrium 475 The shifting equilibrium 477 Factors controlling the slope of the graded profile 479 General statement 479 Downvalley increase in discharge 479 Downvalley increase in ratio of load to discharge 480 Downvalley decrease in ratio of load to discharge 480 Downvalley decrease in caliber of load 481 Relationship between channel characteristics and slope 483 The concept of adjustment in section 484 Adjustment in section in the straight channel 485 Adjustment in section in the shifting channel 486 Effect of variation in channel characteristics on the graded profile 487 Local variation from mean slope 490 Backwater and draw-down effects 490 Effects of differences in rock resistance 491 Summary 491 Response of the graded stream to changes in control .. 492 General statement 492 Increase in load 493 Decrease in load 494 Changes in discharge 494 Rise of base level 496 Lowering of base level 498 Classification of changes in control 499 Regrading with progress of the erosion cycle 499 Short-term changes 501 Deposits of graded and aggrading streams 502 Secondary effects of aggradation 503 Decrease in supplied load 503 Decrease in discharge
    [Show full text]
  • River Dynamics 101 - Fact Sheet River Management Program Vermont Agency of Natural Resources
    River Dynamics 101 - Fact Sheet River Management Program Vermont Agency of Natural Resources Overview In the discussion of river, or fluvial systems, and the strategies that may be used in the management of fluvial systems, it is important to have a basic understanding of the fundamental principals of how river systems work. This fact sheet will illustrate how sediment moves in the river, and the general response of the fluvial system when changes are imposed on or occur in the watershed, river channel, and the sediment supply. The Working River The complex river network that is an integral component of Vermont’s landscape is created as water flows from higher to lower elevations. There is an inherent supply of potential energy in the river systems created by the change in elevation between the beginning and ending points of the river or within any discrete stream reach. This potential energy is expressed in a variety of ways as the river moves through and shapes the landscape, developing a complex fluvial network, with a variety of channel and valley forms and associated aquatic and riparian habitats. Excess energy is dissipated in many ways: contact with vegetation along the banks, in turbulence at steps and riffles in the river profiles, in erosion at meander bends, in irregularities, or roughness of the channel bed and banks, and in sediment, ice and debris transport (Kondolf, 2002). Sediment Production, Transport, and Storage in the Working River Sediment production is influenced by many factors, including soil type, vegetation type and coverage, land use, climate, and weathering/erosion rates.
    [Show full text]
  • Geothermal Hydrology of Valles Caldera and the Southwestern Jemez Mountains, New Mexico
    GEOTHERMAL HYDROLOGY OF VALLES CALDERA AND THE SOUTHWESTERN JEMEZ MOUNTAINS, NEW MEXICO U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 00-4067 Prepared in cooperation with the OFFICE OF THE STATE ENGINEER GEOTHERMAL HYDROLOGY OF VALLES CALDERA AND THE SOUTHWESTERN JEMEZ MOUNTAINS, NEW MEXICO By Frank W. Trainer, Robert J. Rogers, and Michael L. Sorey U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 00-4067 Prepared in cooperation with the OFFICE OF THE STATE ENGINEER Albuquerque, New Mexico 2000 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. For additional information write to: Copies of this report can be purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Information Services Water Resources Division Box 25286 5338 Montgomery NE, Suite 400 Denver, CO 80225-0286 Albuquerque, NM 87109-1311 Information regarding research and data-collection programs of the U.S. Geological Survey is available on the Internet via the World Wide Web. You may connect to the Home Page for the New Mexico District Office using the URL: http://nm.water.usgs.gov CONTENTS Page Abstract............................................................. 1 Introduction ........................................ 2 Purpose and scope........................................................................................................................
    [Show full text]
  • Classifying Rivers - Three Stages of River Development
    Classifying Rivers - Three Stages of River Development River Characteristics - Sediment Transport - River Velocity - Terminology The illustrations below represent the 3 general classifications into which rivers are placed according to specific characteristics. These categories are: Youthful, Mature and Old Age. A Rejuvenated River, one with a gradient that is raised by the earth's movement, can be an old age river that returns to a Youthful State, and which repeats the cycle of stages once again. A brief overview of each stage of river development begins after the images. A list of pertinent vocabulary appears at the bottom of this document. You may wish to consult it so that you will be aware of terminology used in the descriptive text that follows. Characteristics found in the 3 Stages of River Development: L. Immoor 2006 Geoteach.com 1 Youthful River: Perhaps the most dynamic of all rivers is a Youthful River. Rafters seeking an exciting ride will surely gravitate towards a young river for their recreational thrills. Characteristically youthful rivers are found at higher elevations, in mountainous areas, where the slope of the land is steeper. Water that flows over such a landscape will flow very fast. Youthful rivers can be a tributary of a larger and older river, hundreds of miles away and, in fact, they may be close to the headwaters (the beginning) of that larger river. Upon observation of a Youthful River, here is what one might see: 1. The river flowing down a steep gradient (slope). 2. The channel is deeper than it is wide and V-shaped due to downcutting rather than lateral (side-to-side) erosion.
    [Show full text]
  • FACT SHEET No
    FACT SHEET No. 7 Rangeland Watershed Program U.C. Cooperative Extension and USDA Natural Resources Conservation Service Riparian Terms Chew, Matthew K. 1991. Bank Balance: Managing Colorado's Riparian Areas. Bulletin 553A. Coop. Ext. Service, Colorado State University, Ft. Collins, CO. Pg. 41-44. Acre-foot. An amount of water that covers one Braided stream. A stream or river having flat acre to a depth of one foot. Equal to about multiple, dynamic, diverging, and converging 326,700 gallons or 43,560 cubic feet. channels, operating within a single, usually sandy streambed. Characteristic of intermittent or highly Aggradation. The process of building up a variable flows. streambank through sediment deposition. Capacity (sediment). The total amount of Alluvial. Refers to a feature that results from sediments a stream can move, including bed, sediments deposited by flowing water. The suspended, and dissolved loads. material itself is called alluvium. CFS. Cubic feet per second; a standard Anaerobic. Biological activity in the absence of measurement of stream discharge. Harder to free oxygen. The oily-looking black mud found in measure than it sounds. Always an estimate based swampy situations forms due to anaerobic on multiple measurements. decomposition of algae and plants. Cliff and slope. A terrain type made up of Aquifer. A body of groundwater. (This is not a multiple rock terraces that more or less stair-step lake in a cave; see “groundwater.”) down to a stream. Formed because some rock layers (strata) are more erosion-resistant than AUM. Animal Unit Month. The amount of forage others. consumed monthly by one cow with one calf.
    [Show full text]
  • The Origins and Dynamics of Phosphorus in Maine's Lake
    The Origins and Dynamics of Phosphorus in Maine’s Lake Auburn Watershed An Honors Thesis Presented to The Faculty of the Environmental Studies Program Bates College In partial fulfillment of the requirements for the Degree of Bachelor of Arts By Lars Gundersen Lewiston, Maine March 31st, 2020 ACKNOWLEDGEMENTS When I came to Bates, I did not expect to write a scientific thesis. I had enjoyed natural and field science throughout high school, but found it intimidating. Then, as a second semester first- year, I took Scientific Approaches to Environmental Issues with my future advisor, Holly Ewing. This was the class that, far more so than any other class I took at Bates, changed the trajectory of my academic, intellectual, and career interests. Holly thinks and talks about the natural sciences in a way that makes sense to me and has consistently gone out of her way to help me and my learning. Throughout our three classes together, a summer research job (when the groundwork for this thesis was laid), and the process of researching, writing and revising this thesis, she has approached my position as a relative newcomer to science with humor, generosity, and mentorship and pushed me to the edge of my intellectual abilities. Thank you, Holly. Thanks also to Ellen Labbe, my high school biology teacher, who introduced me to the natural and field sciences and piqued my interest in learning more in college. Thank you to Dan Fortin, Chris Curtis, and everyone at the AWD/LWD for providing me with data, teaching me the basics of watershed sampling (both as a summer research assistant with Holly and this year), and answering all my questions.
    [Show full text]
  • Streams and Running Water Streams Are Part of the Hydrologic Cycle (Figure 10.1)
    Streams and Running Water Streams are part of the hydrologic cycle (Figure 10.1) Stream: body of running water that is confined in a channel and moves downhill under the influence of gravity. Cross-section of a typical stream (Figure 10.2) 1) Channel Flow 2) Sheet Flow Drainage Basin: area of a stream and its’ tributaries. Tributary: small stream flowing into a large one. Divide: ridge seperating drainage basins. Drainage Patterns 1) Dendritic: resembles tree branches > occurs on uniformly resistant rock 2) Radial: streams diverge outward from a central point > occurs on conic shapes, like volcanoes 3) Rectangular: steams have sharp bends ¾ due to presence of faulting, river follows the fault 4) Trellis: Parallel main streams with right angle tributaries > occurs on valley and ridge geomorphologies Factors Affecting Stream Erosion and Deposition 1) Velocity = distance/time Fast = 5km/hr or 3mi/hr Flood = 25 km/hr or 15 mi/hr Figure 10.6: Fastest in the middle of the channel a) Gradient: downhill slope of the bed of the stream ¾ very high near the mountains ¾ 50-200 feet/ mile in highlands, 0.5 ft/mile in floodplain b) Channel Shape and Roughness (Friction) > Figure 10.9 ¾ Lots of fine particles – low roughness, faster river ¾ Lots of big particles – high roughness, slower river (more friction) High Velocity = erosion (upstream) Low Velocity = deposition (downstream) Figure 10.7 > Hjulstrom Diagram What do these lines represent? Salt and clay are hard to erode, and typically stay suspended 2) Discharge: amount of flow Q = width x depth
    [Show full text]
  • The Water' Cycle
    'I ." Name'~~_~__-,,__....,......,....,......, ~ Class --,-_......,...._------,__ Date ....,......,-.:-_ ..: .•..'-' .. M.ODERN EARTH SCIENCE Section 1s.i The Water' Cycle • Read each statement below. If the statement .ls true, write T in the space provided. If the statement is false, write Fin tbe space provided. -'- 1. The hydrologic cycle is also called the water cycle. 2. Most water evaporating from the earth's surface evaporates from rivers and lakes. 3. When water vapor rises in the atmosphere, it expands and cools. 4. Evapotranspiration increases with increasing temperature. 5. Most water used by industry is recycled. 6. Irrigation is often necessary in areas having high evapotranspiration. Cboose the one best response. Write tbe letter of tbat cboice in tbe space provided. 7. Which of the following is an artificial means of producing fresh water from ocean water? .--i a. desalination b. saltation • c. evapotranspiration d. condensation 8. Which of the following is represented by this diagram? a. the earth's water budget b. local water budget . c. groundwater movement -·d. surface runoff 9. The arrow labeled X represents: a. absorption. b. evaporation.. c. rejuvenation. d. transpiration. _ 10. Approximately what percentage of the earth's precipitation falls-on the ocean? a. 5% b. 25% c. 750/0 d. 99% t • Chapter 13 47 l H_R_w_..._"_ter"_:_al_....._p_yrighted undernotice appearing earlier in thisworic. .'. Name _ Class _ Date -­ MODERN EARTH SCIENCE .... '''; ... .secti~n'· if2 River Systems Choose the one best response. Write the letter of that choice in the space provided. 1. What is the term for the main stream and tributaries of a river? a.
    [Show full text]
  • Riverine Dissolved Lithium Isotopic Signatures in Low-Relief Central
    Riverine dissolved lithium isotopic signatures in low-relief central Africa and their link to weathering regimes Soufian Henchiri, Jérôme Gaillardet, Mathieu Dellinger, Julien Bouchez, Robert Spencer To cite this version: Soufian Henchiri, Jérôme Gaillardet, Mathieu Dellinger, Julien Bouchez, Robert Spencer. River- ine dissolved lithium isotopic signatures in low-relief central Africa and their link to weathering regimes. Geophysical Research Letters, American Geophysical Union, 2016, 43 (9), pp.4391-4399. 10.1002/2016GL067711. hal-02133282 HAL Id: hal-02133282 https://hal.archives-ouvertes.fr/hal-02133282 Submitted on 21 Aug 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. PUBLICATIONS Geophysical Research Letters RESEARCH LETTER Riverine dissolved lithium isotopic signatures in low-relief 10.1002/2016GL067711 central Africa and their link to weathering regimes Key Points: Soufian Henchiri1, Jérôme Gaillardet1, Mathieu Dellinger1,2,JulienBouchez1, and Robert G. M. Spencer3 • Dissolved Li isotope composition at mouth of the Congo River is 1Institut
    [Show full text]
  • Influence of Hydrologic Alteration on Sediment, Dissolved Load
    resources Article Influence of Hydrologic Alteration on Sediment, Dissolved Load and Nutrient Downstream Transfer Continuity in a River: Example Lower Brda River Cascade Dams (Poland) Dawid Szatten * , Michał Habel and Zygmunt Babi ´nski Institute of Geography, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland; [email protected] (M.H.); [email protected] (Z.B.) * Correspondence: [email protected]; Tel.: +48-52-349-62-50 Abstract: Hydrologic alternation of river systems is an essential factor of human activity. Cascade- dammed waters are characterized by the disturbed outflow of material from the catchment. Changes in sediment, dissolved load and nutrient balance are among the base indicators of water resource monitoring. This research was based on the use of hydrological and water quality data (1984–2017) and the Indicators of Hydrologic Alteration (IHA) method to determine the influence of river regime changes on downstream transfer continuity of sediments and nutrients in the example of the Lower Brda river cascade dams (Poland). Two types of regimes were used: hydropeaking (1984–2000) and run–of–river (2001–2017). Using the IHA method and water quality data, a qualitative and quantitative relationship were demonstrated between changes of regime operation and sediment and nutrient balance. The use of sites above and below the cascade made it possible to determine Citation: Szatten, D.; Habel, M.; sediment, dissolved load, and nutrient trapping and removing processes. Studies have shown that Babi´nski,Z. Influence of Hydrologic Alteration on Sediment, Dissolved changes in operation regime influenced the supply chain and continuity of sediment and nutrient Load and Nutrient Downstream transport in cascade-dammed rivers.
    [Show full text]
  • Studies of Longitudinal Stream Profiles in Virginia and Maryland
    Studies of Longitudinal Stream Profiles in Virginia and Maryland By JOHN T. HACK SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL. SURVEY PROFESSIONAL PAPER 294-B Preliminary results of a study of the form of small river valleys in relation to geology. Some factors controlling the longitudinal profiles of streams are described in q'uantitative terms UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1957 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 75 cents (paper cover) CONTENTS Page Peg* AbstractL 45 Relation of particle size of material on the bed to stream IntroductionL 47 lengthL 68 Methods of study and definitions of factors measuredL 47 Mathematical expression of the longitudinal profile and Description of areas studied L 49 its relation to particle size of material on the bedL 69 Middle River basinL 50 Mathematical expression in previous work on longitudinal North River basinL 50 profilesL 74 Alluvial terrace areasL 50 Origin and composition of stream-bed materialL 74 Calfpasture River basinL 50 Franks Mill reach of the Middle RiverL 76 Tye River basin L 52 Eidson CreekL 81 Gillis FallsL 52 East Dry BranchL 82 Coastal Plain streamsL 53 North RiverL 84 Factors determining the slope of the stream channelL 53 Calfpasture ValleyL 84 Discharge and drainage areaL 54 Gillis FallsL 85 Size of material on the stream bedL 54 Ephemeral streams in areas of residuumL 85 Channel cross sectionL 61 Some factors controlling variations in size: conclusions_ _ _ 86 Summary of factors controlling channel slopeL 61 The longitudinal profile and the cycle of erosionL 87 Factors determining the position of the channel in space: the References cited L 94 shape of the long profileL 63 IndexL 95 Relation of stream length to drainage area L 63 ILLUSTRATIONS Pag e Page PLATE99.
    [Show full text]
  • Settling Sediments Adapted From: SEDIMENTATOR Copyright 1996 Janeval Toys, Inc
    Sedimentation Settling Sediments Adapted from: SEDIMENTATOR Copyright 1996 Janeval Toys, Inc. ACADEMIC STANDARDS: ENVIRONMENT & ECOLOGY Grade Level: Basic/Intermediate 10th Grade Duration: 40 minutes 4.1 A Describe the changes that occur from a streams origin to its final outflow. 4.1 B Explain the relationships among landforms, vegetation, and the amount and Setting: classroom speed of water. Analyze a stream’s physical characteristics. Summary: Investigating sediment Explain how the speed of water and vegetation cover relates to erosion. deposition using a Sedimentator that 4.1 C Describe the physical characteristics of a stream and determine the types of students construct. organisms found in aquatic environments. Describe and explain the physical factors that affect a stream and the Objectives: Students will learn how organisms living there. sediments are deposited in different Identify the types of organisms that would live in a stream based on the stream’s physical characteristics. aquatic environments. Students will be able to distinguish among ACADEMIC STANDARDS: SCIENCE & TECHNOLOGY different sediment types and 7th Grade recognize the rocks produced from 3.5A Describe earth features and processes. sediments. Describe the processes involved in the creation of geologic features (e.g. folding, faulting, volcanism, sedimentation) and that these processes seen today (e.g. erosion, weathering, crustal plate movement) are similar to those Vocabulary: chemical weathering, seen in the past. mechanical weathering, sediment, Distinguish
    [Show full text]