Grade 12 Geography Geomorphology Revised Learner Notes
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Seasonal Flooding Affects Habitat and Landscape Dynamics of a Gravel
Seasonal flooding affects habitat and landscape dynamics of a gravel-bed river floodplain Katelyn P. Driscoll1,2,5 and F. Richard Hauer1,3,4,6 1Systems Ecology Graduate Program, University of Montana, Missoula, Montana 59812 USA 2Rocky Mountain Research Station, Albuquerque, New Mexico 87102 USA 3Flathead Lake Biological Station, University of Montana, Polson, Montana 59806 USA 4Montana Institute on Ecosystems, University of Montana, Missoula, Montana 59812 USA Abstract: Floodplains are comprised of aquatic and terrestrial habitats that are reshaped frequently by hydrologic processes that operate at multiple spatial and temporal scales. It is well established that hydrologic and geomorphic dynamics are the primary drivers of habitat change in river floodplains over extended time periods. However, the effect of fluctuating discharge on floodplain habitat structure during seasonal flooding is less well understood. We collected ultra-high resolution digital multispectral imagery of a gravel-bed river floodplain in western Montana on 6 dates during a typical seasonal flood pulse and used it to quantify changes in habitat abundance and diversity as- sociated with annual flooding. We observed significant changes in areal abundance of many habitat types, such as riffles, runs, shallow shorelines, and overbank flow. However, the relative abundance of some habitats, such as back- waters, springbrooks, pools, and ponds, changed very little. We also examined habitat transition patterns through- out the flood pulse. Few habitat transitions occurred in the main channel, which was dominated by riffle and run habitat. In contrast, in the near-channel, scoured habitats of the floodplain were dominated by cobble bars at low flows but transitioned to isolated flood channels at moderate discharge. -
The Upper James River
Waterproof The Upper James River The James River originates at the only class I or II rapids making it ideal will need to plan a river trip. This guide A Paddle Guide to the Upper confluence of the Jackson and Cowpasture for canoe or kayak trips at normal water includes locations of boat landings, rivers in Botetourt County and forms levels. The white water section below campsites, major rapids, and unique Virginia’s longest and most famous river. Glasgow includes a class III section for historic points of interests along the way. The upper section of the James River those interested in more technical water. This is a great resource for planning day is very scenic with stunning Blue Ridge trips as well as multi-day canoe camping mountain views. Dam releases on the This paddle guide covers the upper 64 expeditions. Jackson River flow releases ensure the miles section from the start of the James upper James River is typically run able river to the Cushaw Dam, just below all season. The first 60 miles contain Snowden. It includes everything a paddler Using This Map George Washington and Rapids (See River Safety panel for class system) Jefferson National Forrest* 30 Mile markers— numbered from start of the James Park* River counting down stream Landmark These maps have been orientated so that the river always flows from the bottom of the map to the top of the map. This allows paddlers to easily orient themselves in the river in terms of river right and left while paddling downstream. Bridge 1km Distance gauge 0 1mi North indicator Canal Boat launch Small boat launch Commercial campground River flow River Informal camping Appalachian Trail Hiking Trail *All land along river bank is private property unless noted otherwise. -
Abandonment of Unaweep Canyon (1.4–0.8 Ma), Western Colorado: Effects of Stream Capture and Anomalously Rapid Pleistocene River Incision
CRevolution 2: Origin and Evolution of the Colorado River System II themed issue Abandonment of Unaweep Canyon (1.4–0.8 Ma), western Colorado: Effects of stream capture and anomalously rapid Pleistocene river incision Andres Aslan1,*, William C. Hood2,*, Karl E. Karlstrom3,*, Eric Kirby4, Darryl E. Granger5,*, Shari Kelley6, Ryan Crow3,*, Magdalena S. Donahue3,*, Victor Polyak3,*, and Yemane Asmerom3,* 1Department of Physical and Environmental Sciences, Colorado Mesa University, Grand Junction, Colorado 81501, USA 2Grand Junction Geological Society, 515 Dove Court, Grand Junction, Colorado 81501, USA 3Department of Earth and Planetary Sciences, University of New Mexico, Northrop Hall 141, Albuquerque, New Mexico 87131, USA 4College of Earth, Ocean and Atmospheric Sciences, Oregon State University, 202D Wilkinson Hall, Corvallis, Oregon 97330, USA 5Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, USA 6New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, New Mexico 87801, USA ABSTRACT opment of signifi cant relief between adjacent through resistant Precambrian bedrock (Fig. 2). stream segments, which led to stream piracy. It has no major river at its base, and is currently Cosmogenic-burial and U-series dating, The response of rivers to the abandonment drained by two underfi t streams, East and West identifi cation of fl uvial terraces and lacus- of Unaweep Canyon illustrates how the Creeks, which drain the northeast and southwest trine deposits, and river profi le reconstruc- mode and tempo of long-term fl uvial incision ends of the canyon, respectively. Starting with tions show that capture of the Gunnison are punctuated by short-term geomorphic the Hayden Survey (Peale, 1877), geologists River by the Colorado River and abandon- events such as stream piracy. -
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. -
New Developments in River Valley Floodplain Mapping Using Dems
New Developments in River Valley Floodplain Mapping Using DEMs: A Survey of FLDPLN Model Applications Jude Kastens | Kevin Dobbs | Steve Egbert Kansas Biological Survey ASWM/NFFA Webinar | January 13, 2014 Kansas Applied Remote Sensing Kansas River Valley between Manhattan and Topeka Email: [email protected] Terrain Processing: DEM (Digital Elevation Model) This DEM was created using LiDAR data. Shown is a portion of the river valley for Mud Creek in Jefferson County, Kansas. Unfilled DEM (shown in shaded relief) 2 Terrain Processing: Filled (depressionless) DEM This DEM was created using LiDAR data. Shown is a portion of the river valley for Mud Creek in Jefferson County, Kansas. Filled DEM (shown in shaded relief) 3 Terrain Processing: Flow Direction Each pixel is colored based on its flow direction. Navigating by flow direction, every pixel has a single exit path out of the image. Flow direction map (gradient direction approximation) 4 Terrain Processing: Flow Direction Each pixel is colored based on its flow direction. Navigating by flow direction, every pixel has a single exit path out of the image. Flow direction map (gradient direction approximation) 5 Terrain Processing: Flow Accumulation The flow direction map is used to compute flow accumulation. flow accumulation = catchment size = the number of exit paths that a pixel belongs to Flow accumulation map (streamline identification) 6 Terrain Processing: Stream Delineation Using pixels with a flow accumulation value >106 pixels, the Mud Creek streamline is identified (shown in blue). “Synthetic Stream Network” 7 Terrain Processing: Floodplain Mapping The 10-m floodplain was computed for Mud Creek using the FLDPLN model. -
Topographic Controls on Divide Migration, Stream Capture, and Diversification in Riverine Life
Earth Surf. Dynam., 8, 893–912, 2020 https://doi.org/10.5194/esurf-8-893-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Topographic controls on divide migration, stream capture, and diversification in riverine life Nathan J. Lyons1, Pedro Val2, James S. Albert3, Jane K. Willenbring4, and Nicole M. Gasparini1 1Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA, USA 2Department of Geology, Federal University of Ouro Preto, Ouro Preto, Brazil 3Department of Biology, University of Louisiana at Lafayette, Lafayette, CA, USA 4Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA Correspondence: Nathan J. Lyons ([email protected]) Received: 16 October 2019 – Discussion started: 24 October 2019 Revised: 9 August 2020 – Accepted: 2 September 2020 – Published: 26 October 2020 Abstract. Drainages reorganise in landscapes under diverse conditions and process dynamics that impact biotic distributions and evolution. We first investigated the relative control that Earth surface process parameters have on divide migration and stream capture in scenarios of base-level fall and heterogeneous uplift. A model built with the Landlab toolkit was run 51 200 times in sensitivity analyses that used globally observed values. Large- scale drainage reorganisation occurred only in the model runs within a limited combination of parameters and conditions. Uplift rate, rock erodibility, and the magnitude of perturbation (base-level fall or fault displacement) had the greatest influence on drainage reorganisation. The relative magnitudes of perturbation and topographic relief limited landscape susceptibility to reorganisation. Stream captures occurred more often when the channel head distance to divide was low. -
Developing a Form-Process Framework to Describe the Functioning of Semi-Arid Alluvial Fans in the Baviaanskloof Valley, South Africa
DEVELOPING A FORM-PROCESS FRAMEWORK TO DESCRIBE THE FUNCTIONING OF SEMI-ARID ALLUVIAL FANS IN THE BAVIAANSKLOOF VALLEY, SOUTH AFRICA A thesis submitted in the fulfilment of the requirements of the degree of MASTERS OF SCIENCE of RHODES UNIVERSITY By KERRY LEIGH BOBBINS December 2011 i Abstract The Baviaanskloof catchment is a semi - arid catchment located in the Cape Fold Mountains of South Africa. Little is known about the functioning of the complicated Baviaanskloof fluvial system, in particular the role of alluvial fans. This thesis will contribute to field of geomorphology and, more specifically, the field of fan morphometry, by producing a standalone fan framework outlining methods to investigate the influence of fan external and internal control variables. In this thesis, the framework is applied in the Baviaanskloof Valley alongside a case study and used to develop fan restoration guidelines. The framework incorporates external and internal fan control variables at a valley-wide and local fan scale. External control variables include accommodation space, base-level change, and drainage basin inputs. Internal control variables include fan style, morphometry and fan channels. The application of the framework required the creation of a spatial plan of fans and basins in the valley to measure morphometry data. Outcomes of the applied framework include; an understanding of base-level change on fans, relationships between fan basin characteristics and the fan surface and insight into fan channel processes. Results of the applied framework are investigated further using bivariate (correlation matrix) and multivariate (principle component analysis and regression analysis) analysis techniques. Significant relationships identified are: drainage basin area versus fan area, fan area and fan slope and drainage basin ruggedness and basin size. -
Floodplain Geomorphic Processes and Environmental Impacts of Human Alteration Along Coastal Plain Rivers, Usa
WETLANDS, Vol. 29, No. 2, June 2009, pp. 413–429 ’ 2009, The Society of Wetland Scientists FLOODPLAIN GEOMORPHIC PROCESSES AND ENVIRONMENTAL IMPACTS OF HUMAN ALTERATION ALONG COASTAL PLAIN RIVERS, USA Cliff R. Hupp1, Aaron R. Pierce2, and Gregory B. Noe1 1U.S. Geological Survey 430 National Center, Reston, Virginia, USA 20192 E-mail: [email protected] 2Department of Biological Sciences, Nicholls State University Thibodaux, Louisiana, USA 70310 Abstract: Human alterations along stream channels and within catchments have affected fluvial geomorphic processes worldwide. Typically these alterations reduce the ecosystem services that functioning floodplains provide; in this paper we are concerned with the sediment and associated material trapping service. Similarly, these alterations may negatively impact the natural ecology of floodplains through reductions in suitable habitats, biodiversity, and nutrient cycling. Dams, stream channelization, and levee/canal construction are common human alterations along Coastal Plain fluvial systems. We use three case studies to illustrate these alterations and their impacts on floodplain geomorphic and ecological processes. They include: 1) dams along the lower Roanoke River, North Carolina, 2) stream channelization in west Tennessee, and 3) multiple impacts including canal and artificial levee construction in the central Atchafalaya Basin, Louisiana. Human alterations typically shift affected streams away from natural dynamic equilibrium where net sediment deposition is, approximately, in balance with net -
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. -
An On-Line River Categorisation Tool
UNDERSTAND YOUR RIVER – AN ON-LINE RIVER ATEGORISATION OOL C T Figure 2. The successful River Restoration workshop that JBA ran in May 2012 brought to sharp relief that there is a vast gap in data, information and material availability relating to our understanding of River types natural processes in rivers and on floodplains. This means that many attempts at river restoration and naturalisation remain based around a limited overall understanding utilising a narrow set of Step-pool Description approaches developed largely for un-reactive low gradient heavily modified river channels. Step-pool river reaches are often composed of large boulder groups, forming steps separated by pools. The pools contain finer sediment. The channel is JBA are developing a website detailing the findings of the workshop and providing information and often stable and the channel gradient is steep. Typical features guidance on the character and functioning of rivers in the UK synthesised from academic research Typical features found in this river system include step-pools and rapids. Flow regime (Figure 1) and field experience (Figure 2). Common flow types include chutes and turbulent flow interspersed with pools. Figure 1. Braided Description Braided river reaches are rare in the UK. They occur in areas of high gradients with high bedload. The channel is characterised by a number of threads, which can be highly dynamic particularly during larger floods. Typical features Typical features found in this river system include rapids, riffles, pools and cut-off channels. Flow regime Common flow types include chutes. Rapid Wandering Description A wandering channel type has the characteristics of a braided and active single-thread system , with a smaller bed material size, a shallower slope and wider valley floor. -
A Groundwater Sapping in Stream Piracy
Darryll T. Pederson, Department of energy to the system as increased logic settings, such as in a delta, stream Geosciences, University of Nebraska, recharge causes groundwater levels to piracy is a cyclic event. The final act of Lincoln, NE 68588-0340, USA rise, accelerating stream piracy. stream piracy is likely a rapid event that should be reflected as such in the geo- INTRODUCTION logic record. Understanding the mecha- The term stream piracy brings to mind nisms for stream piracy can lead to bet- ABSTRACT an action of forcible taking, leaving the ter understanding of the geologic record. Stream piracy describes a water-diver- helpless and plundered river poorer for Recognition that stream piracy has sion event during which water from one the experience—a takeoff on stories of occurred in the past is commonly based stream is captured by another stream the pirates of old. In an ironic sense, on observations such as barbed tribu- with a lower base level. Its past occur- two schools of thought are claiming vil- taries, dry valleys, beheaded streams, rence is recognized by unusual patterns lain status. Lane (1899) thought the term and elbows of capture. A marked of drainage, changes in accumulating too violent and sudden, and he used change of composition of accumulating sediment, and cyclic patterns of sediment “stream capture” to describe a ground- sediment in deltas, sedimentary basins, deposition. Stream piracy has been re- water-sapping–driven event, which he terraces, and/or biotic distributions also ported on all time and size scales, but its envisioned to be less dramatic and to be may signify upstream piracy (Bishop, mechanisms are controversial. -
Formation Mechanism for Upland Low-Relief Surface Landscapes in the Three Gorges Region, China
remote sensing Article Formation Mechanism for Upland Low-Relief Surface Landscapes in the Three Gorges Region, China Lingyun Lv 1,2, Lunche Wang 1,2,* , Chang’an Li 1,2, Hui Li 1,2 , Xinsheng Wang 3 and Shaoqiang Wang 1,2,4 1 Key Laboratory of Regional Ecology and Environmental Change, School of Geography and Information Engineering, China University of Geosciences, Wuhan 430074, China; [email protected] (L.L.); [email protected] (C.L.); [email protected] (H.L.); [email protected] (S.W.) 2 Hubei Key Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan 430074, China 3 Hubei Key Laboratory of Regional Development and Environmental Response, Hubei University, Wuhan 430062, China; [email protected] 4 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China * Correspondence: [email protected] Received: 9 November 2020; Accepted: 26 November 2020; Published: 27 November 2020 Abstract: Extensive areas with low-relief surfaces that are almost flat surfaces high in the mountain ranges constitute the dominant geomorphic feature of the Three Gorges area. However, their origin remains a matter of debate, and has been interpreted previously as the result of fluvial erosion after peneplain uplift. Here, a new formation mechanism for these low-relief surface landscapes has been proposed, based on the analyses of low-relief surface distribution, swath profiles, χ mapping, river capture landform characteristics, and a numerical analytical model. The results showed that the low-relief surfaces in the Three Gorges area could be divided into higher elevation and lower elevation surfaces, distributed mainly in the highlands between the Yangtze River and Qingjiang River.