Alluvial Valley Floor Research Articles

Topography and climate of Mount Karanfil (Pozantı/Adana)

The goal of this study is to investigate the impact of the topographic features of Mount Karanfil and its surroundings on the local climate. Mount Karanfil, located in the Mediterranean Basin, has a unique ecological position due to its topography. This study analyzed temperature, precipitation, and wind conditions at Mount Karanfil from 1980 to 2018 using data from the General Directorate of Meteorology (MGM). The temperature indices were calculated using the Clima data and the ArcGIS v10.5 software package. The temperature indices series was analyzed using cluster analysis in ArcGIS v10.5 before being used to calculate the maximum and minimum temperature and precipitation values for each month. The spatial estimation method IDW interpolation was then applied to these data. The initial analysis showed significant differences in temperature, precipitation, and wind conditions between this location and others. This may be due to the southern aspect of the landscape, which receives more precipitation than other slopes and is affected by south-oriented sectoral winds that bring abundant precipitation to the southern slopes. The results of the temperature indices analysis showed that evaporation tends to increase on hot days with high maximum temperatures compared to days with low minimum temperatures. The Emberger bioclimatic index also confirmed the typical Mediterranean climate of mild, rainy winters and hot, dry summers. In addition to the regional climate and geology, the geomorphologic conditions of the mountainous mass and the specific valley profiles of the Ecemis stream and Cakıt stream (such as the strait valley) were found to influence the local climate. These valley profiles, which are composed of narrow and deep dolomitic and limestone layers, showed differences in climate due to their slope, elevation, and aspect, as analyzed using digital elevation models with a resolution of 10–20 m. These topographic analyses revealed that elevation decreases and humidity increases in alluvial valley floors.

Assessment of sediment sources throughout the proglacial area of a small Arctic catchment based on high-resolution digital elevation models

The article presents calculations of quantitative modifications of the morphology of selected subsystems of a glacial valley through: (i) identification of the spatial distribution of important sources of sediment, (ii) assessment of the spatiotemporal variety of sediment volume and landform morphology, and (iii) assessment of the role of particular subsystems in sediment distribution. The study involved a comparison of the results of field measurements from 2010 to 2013 performed in the Scott Glacier catchment (10.1km2) in NW Wedel Jarlsberg Land (Spitsbergen). The assessment of the landform surface changes was performed by means of a precise Terrestrial Laser Scanning (TLS) survey. The applied field and post-processing techniques for oblique laser scanning permitted the acquisition of digital elevation data at a resolution 0.01m and density>500ptm−2. This allowed the development of a detailed terrain model, and balancing spatial quantitative changes in six research test areas (10,000m2) located within two subsystems of the catchment in a cascade arrangement. In the alluvial valley-floor subsystem, the survey covered: 1) the glacier terminus, 2) the intramarginal outwash plain, 3) the extramarginal braid-plain and 4) the alluvial fan, and in the slope subsystem: 5) the erosional-depositional slope in the gorge through terminal moraines, and 6) the solifluction slope. Three zones differing in terms of the spatiotemporal dynamics of geomorphic processes were distinguished within the two analysed valley subsystems. In the valley floor subsystem, these are: (i) the zone of basic supply (distribution throughout the melting season) and (ii) the redeposition zone (distribution particularly during floods), and in the slope subsystem: (iii) zone of periodical supply (distributed mainly in periods of increased precipitation and rapid increases in temperature in summer and during snow avalanches in winter). The glacier and the landforms of the channel and valley floor, as well as slope sediments transported as a result of mass wasting processes and activity of the active permafrost layer, constitute important sources of sediment supply over a short/3-year timescale. Evidence of major changes of the surface morphology (slopes, floodplain and channel platform) resulted in varied sediment budgets. The subtraction of consecutive DEMs of the test areas located in the alluvial valley subsystem revealed downstream spatial and volumetric differentiation, from the predominance of erosion (79% of volume; 43% of area) to the dominance of deposition (90/91%, respectively) in upper part of the valley floor to erosion predominance in the central (88/95%) and lower (87/82%) part of valley floor. The test areas located on the slope subsystem showed the opposite relationship: deposition dominance (88% of volume; 80% of area) in the upper gorge and erosion dominance (99/99%, respectively) in the lower part (solifluction slopes). The analysis of short-time repeated surveys (3-week survey) where volumes were calculated following DEM subtraction showed increased deposition (82% of volume; 79% of area) for the alluvial fan, and for solifluction slopes (70/57%, respectively).

Morphologic Features of Kapıdağ Peninsula and its Coasts (NW-Turkey) using by Remote Sensing and DTM

Although it is an inland sea, the Sea of Marmara and
 its surroundings have rather complex morphology due to the active tectonics of
 the North Anatolian Fault (NAF) zone in this region. The Kapıdağ Peninsula
 which is located at its southern coasts also represents a complex morphology.
 Macro morphologic units of Kapıdağ Peninsula are N-S trending deep valley
 systems, mountain areas and Belkıs isthmus. The most coastal area of peninsula
 has terraces, coastal plains and alluvial valley floors. These unique
 morphologic features can explain some parameters of active tectonics of the Sea
 of Marmara region. In order to investigate these geomorphologic features of the
 Kapıdağ peninsula in detail, some land observations, satellite data, Digital
 Terrain Models (DTMs which have been evaluated from topographic maps with a
 vertical precision of ±3m and cell size of 8m), Geographic Information Systems
 (GIS), traditional methods and some integrated techniques such as image
 processing were used.

Fold and fault control on the drainage pattern of a double-karst-aquifer system, Winterstaude, Austrian Alps

Lithostratigraphy and geologic structures are major controls on groundwater flow in alpine karst systems. Understanding these factors is important for the delimitation of drinking water pro­tection zones. The Winterstaude mountain chain, western Aus­tria, belongs to the Helvetic nappes and consists of Cretaceous sedimentary rocks, including two karstifiable formations: Örfla and Schrattenkalk Limestone (lower and upper karst aquifer), separated by 60 m of marl. Strata are folded and cut by faults withdisplacements of 40–70 m. Folded carbonate rocks con­tinue below the alluvial valley floor so that the karst system can be subdivided in shallow and deep phreatic zones. This area is suitable for studying the combined influence of folds and faults on groundwater flow in a double-aquifer system. A multi-trac­er test withseven injections aimed at characterising hydraulic connections and linear flow velocities. Results show that (i) plunging synclines form the main drainage pathways in the up­per karst aquifer, withmaximum linear velocities of 91 m/h, while anticlines act as water divides; (ii) recharge into the lower aquifer, whichforms the central ridge of the mountain chain, contributes to springs discharging from the upper aquifer near the foot of the mountain (local flow systems); (iii) the two aq­uifers are hydraulically connected, presumably via faults, be­cause their displacements are in the same order of magnitude as the thickness of the intervening marl; (iv) flow in the upper aquifer continues below the valley floor toward the river, withmaximum velocities of 22 m/h(intermediate flow system).

Problems in naming and defining the swampy meadow—An Australian perspective

This paper explores the confusing terminology used in the description of a landform characterised by swampy, alluvial valley floors, generally known in Australia as ‘swampy meadows’. Swampy meadows were once common in the Australian landscape. Following the impacts of European settlement, such as clearing, grazing, swamp burning and draining, functionally intact systems have become rare in the contemporary landscape. Detrimental affects on swampy meadows are now increasingly being recognised, leading to a need for their restoration and conservation. Confusion over terminology and definitions, however, has hindered our capacity to understand the complex nature of these systems, and to develop appropriate management strategies and policies to protect and restore them. In particular, a multi-disciplinary understanding of their geomorphic processes, hydrology, and ecological form and function is not catered for in any single definition or characterisation that is useful to policy makers and land managers. The paper discusses the repercussions that unclear swampy meadow nomenclature has on ecological understanding, conservation policy, restoration, and land values. It concludes with the construction of a more precise taxonomic definition of the swampy meadow.

Modern sediment yield compared to geologic rates of sediment production in a semi‐arid basin, New Mexico: assessing the human impact

Abstract An Erratum has been published for this article in Earth Surface Processes and Landforms 29(13) 2004, 1707.In the semi‐arid Arroyo Chavez basin of New Mexico, a 2·28 km2 sub‐basin of the Rio Puerco, we contrasted short‐term rates (3 years) of sediment yield measured with sediment traps and dams with long‐term, geologic rates (∼10 000 years) of sediment production measured using 10Be. Examination of erosion rates at different time‐scales provides the opportunity to contrast the human impact on erosion with background or geologic rates of sediment production. Arroyo Chavez is grazed and we were interested in whether differences in erosion rates observed at the two time‐scales are due to grazing.The geologic rate of sediment production, 0·27 kg m−2 a−1 is similar to the modern sediment yields measured for geomorphic surfaces including colluvial slopes, gently sloping hillslopes, and the mesa top which ranged from 0·12 to 1·03 kg m−2 a−1. The differences between modern sediment yield and geologic rates of sediment production were most noticeable for the alluvial valley floor, which had modern sediment yields as high as 3·35 kg m−2 a−1. The hydraulic state of the arroyo determines whether the alluvial valley floor is aggrading or degrading. Arroyo Chavez is incised and the alluvial valley floor is gullied and piped and is a source of sediment. The alluvial valley floor is also the portion of the basin most modified by human disturbance including grazing and gas pipeline activity, both of which serve to increase erosion rates. Copyright © 2004 John Wiley & Sons, Ltd.

Stochastic Theory of Particle Trajectories through Alluvial Valley Floors

Temporary storage of sediment within alluvial valley floors modulates the long‐term transport of sediment through landscapes. The fate of weathering minerals or sediment‐bound constituents in fluvial environments depends on the relative time scales of constituent degradation and particle residence time within valleys. Particles follow a set of trajectories through valley floors: some particles pass directly through the channel, reaching the basin outlet rapidly after being introduced to the fluvial system; others remain for long periods in deposits such as flood plains. Traditional sediment routing theory, based on the principle of sediment mass conservation along reaches of channel, does not account for exchanges of sediment with temporary sediment storage reservoirs outside the channel, such as flood plains, deltas, and alluvial fans. This article formalizes a theory that incorporates the role of such exchanges in the migration of sediment through river systems, by computing the probabilistic structure of particle trajectories through alluvial valley floors. Equations are developed for computing these trajectories from the sediment budget of a valley floor in steady state. Mathematical strategies for using such relationships to model transient storage conditions are proposed, and other potential model enhancements are discussed. The approach is illustrated using a hypothetical valley floor as an example. The theory can be used to examine rates of sediment overturn in valleys, map particle residence times, and account for the redistribution and decomposition of weathering minerals and particle‐bound constituents. The theory has numerous potential management applications, some of which are discussed herein. The hypothetical example demonstrates that the probability distribution of particle residence times in the valleys of most alluvial rivers should be strongly right skewed.

Recent Changes in the Geochemistry of the Reclaimed Porcupine Creek Alluvial Valley Floor, North Antelope/Rochelle Mine Campbell County, Wyoming

Two sections of the Porcupine Creek alluvial valley floor have been reconstructed at Powder River Coal Company's North Antelope Rochelle Mine using specialized reclamation methods. The lower section of Porcupine Creek (AVF Reach 1) was re-constructed in 1985, but flow was bypassed by a diversion until early-2001. In addition, the lower creek was reconstructed using old channel design criteria that utilized a guide channel and limited the amount of pooled water. The lower reclaimed Porcupine Creek was constructed from native alluvium as required by the Wyoming Department of Environmental Quality / Land Quality Division (WDEQ/LQD) at the time. TDS and selenium concentrations in the alluvial monitoring wells in the lower reclaimed channel have been higher than in premining alluvial waters. The water quality reflected the new mobility of the constituents after mixing and oxidation of the highly mineralized alluvial material occurred during mining and aquifer construction. The alluvial water quality slowly improved between 1985 and 2001, but the future postmining water quality remained a concern. Following construction of pools and counter-weirs on AVF Reach 1 in early 2002 as part of a wetland establishment project, alluvial water levels have risen significantly. Boron concentrations spiked upward in the alluvial waters as water flushed through the vadose zone, but are now lower. Selenium concentrations are now much lower and geochemical conditions appear to be more reducing. The results of recent monitoring highlight the important geochemical processes ongoing in the aquifer and show that the construction of the pools and wetlands has improved the alluvial water quality in the AVF Reach 1. Further study of AVF Reach 1 is warranted as water quality in the reclaimed alluvium stabilizes. An upstream section of Porcupine Creek (AVF Reach 2) was reclaimed in 1999 primarily using selected overburden material as alluvium. TDS and selenium concentrations are much lower in AVF Reach 2.

Predicting the fate of sediment and pollutants in river floodplains.

Geological processes such as erosion and sedimentation redistribute toxic pollutants introduced to the landscape by mining, agriculture, weapons development, and other human activities. A significant portion of these contaminants is insoluble, adsorbing to soils and sediments after being released. Geologists have long understood that much of this sediment is stored in river floodplains, which are increasingly recognized as important nonpoint sources of pollution in rivers. However, the fate of contaminated sediment has generally been analyzed using hydrodynamic models of in-channel processes, ignoring particle exchange with the floodplain. Here, we present a stochastic theory of sediment redistribution in alluvial valley floors that tracks particle-bound pollutants and explicitly considers sediment storage within floodplains. We use the theory to model the future redistribution and radioactive decay of 137Cs currently stored on sediment in floodplains at the Los Alamos National Laboratory (LANL) in New Mexico. Model results indicate that floodplain storage significantly reduces the rate of sediment delivery from upper Los Alamos Canyon, allowing 50% of the 137Cs currently residing in the valley floor to decay radioactively before leaving LANL. A sensitivity analysis shows that the rate of sediment overturn in the valley (and hence, the total amount of radioactive 137Cs predicted to leave LANL) is significantly controlled by the rate of sediment exchange with the floodplain. Our results emphasize that flood plain sedimentation and erosion processes can strongly influence the redistribution of anthropogenic pollutants in fluvial environments. We introduce a new theoretical framework for examining this interaction, which can provide a scientific basis for decision-making in a wide range of river basin management scenarios.

97/04380 Results of the first western coal availability study—Hilight Quadrangle, Powder River Basin, Wyoming: Molina, C. L. et al. Proc. Annu. Int. Pittsburgh. Coal Conf., 1996, 13, (2), 798–803

The US Geological Survey, in cooperation with the Bureau of Land Management, Geological Survey of Wyoming, and US Bureau of Mines, has produced an estimate of the amount of available coal in an area about 35 miles south of Gillette, Wyoming, where the Wyodak coal bed is, in places, more than 100 ft thick. Available coal is coal that actually is accessible for development under current regulatory, land-use, and technologic conditions. The first western coal availability study, in the Hilight quadrangle, has shown that approximately 60% (2.7 billion tons) of the total 4.4 billion tons of original coal resources in the quadrangle is available for development. Of this total 4.4 billion tons, 2.9 billion tons are contained in the Main Wyodak coal bed; 67% (1.9 billion tons) of this coal bed is considered available. Local coal-development considerations include dwellings, railroads, pipelines, power lines, wildlife habitat (eagles), alluvial valley floors, cemeteries, the Hilight oil and gas field, and the Hilight gas plant. Some of these considerations would be mitigated so that surface mining could proceed; others presently preclude mining in their vicinity.

Sediment transfer and transformation of an alluvial valley floor: The river South Tyne, Northumbria, U.K.

AbstractThe amounts of alluvial storage and the mechanisms responsible for the dispersal of sediment associated with historic metal mining are examined for a 115 year timespan on a 22 km reach of the River South Tyne, northern England. Analysis of lateral and vertical channel change over this period, the extent of actively reworked gravels, and identification of metals in alluvial units, show five ‘sedimentation zones’ separated by more stable reaches. Aggradation in the late nineteenth century was followed by a period of storage and local reworking, and then incision. Some reaches show short‐term storage of sediment injected from tributaries which may be dispersed by floods. There is some evidence of transfer of sediment bodies downvalley within sedimentation zones, and of a sediment ‘wave’ movement between zones in lower parts of the South Tyne investigated. Present‐day incision, the variation in the area of actively reworked gravel spreads, and the widespread dispersal of fine‐grained toxic metal mining wastes all have practical implications. The intricate response of the channel system to historic changes in sediment supply is not readily described by either a complex response model or a simple translatory wave.

Instability of Alluvial Valley Floors: A Method for its Assessment

ABSTRACTUSING previously collected data on the morphology of semiarid valleys, a technique is developed for discriminating between stable and unstable valley floors. Relations between drainage area, discharge, and flow depth are used to develop a shear-stress indicator that can be used to identify those reaches of a valley floor that are most likely to fail by gullying.