Sample records for lowland river banks
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Phosphorus load to surface water from bank erosion in a Danish lowland river basin.
Kronvang, Brian; Audet, Joachim; Baattrup-Pedersen, Annette; Jensen, Henning S; Larsen, Søren E
2012-01-01
Phosphorus loss from bank erosion was studied in the catchment of River Odense, a lowland Danish river basin, with the aim of testing the hypothesis of whether stream banks act as major diffuse phosphorus (P) sources at catchment scale. Furthermore, the study aimed at analyzing the impact of different factors influencing bank erosion and P loss such as stream order, anthropogenic disturbances, width of uncultivated buffer strips, and the vegetation of buffer strips. A random stratified procedure in geographical information system (GIS) was used to select two replicate stream reaches covering different stream orders, channelized vs. naturally meandering channels, width of uncultivated buffer strips (≤ 2 m and ≥ 10 m), and buffer strips with different vegetation types. Thirty-six 100-m stream reaches with 180 bank plots and a total of 3000 erosion pins were established in autumn 2006, and readings were conducted during a 3-yr period (2006-2009). The results show that neither stream size nor stream disturbance measured as channelization of channel or the width of uncultivated buffer strip had any significant ( erosion and P losses during each of the 3 yr studied. In buffer strips with natural trees bank erosion was significantly ( erosion amounted to 13.8 to 16.5 and 2.4 to 6.3 t P, respectively, in the River Odense catchment during the three study years. The net P input from bank erosion equaled 17 to 29% of the annual total P export and 21 to 62% of the annual export of P from diffuse sources from the River Odense catchment. Most of the exported total P was found to be bioavailable (71.7%) based on a P speciation of monthly suspended sediment samples collected at the outlet of the river basin. The results found in this study have a great importance for managers working with P mitigation and modeling at catchment scale. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
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Lambeets, Kevin
2009-01-01
This Ph.D.-thesis aimed to address which environmental factors influence the assemblage structure of mobile, riparian arthropods along spatially structured river banks of a rain-fed, lowland gravel river, the Common Meuse. As riverine ecosystems are basically non-equilibrium, dynamic ecosystems, mainly flow regimes and flood pulse characteristics are expected to shape both the distribution and behaviour of its inhabitants. The river banks along the Common Meuse are (in)frequently disturbed by...
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Flow controls on lowland river macrophytes: a review.
Franklin, Paul; Dunbar, Michael; Whitehead, Paul
2008-08-01
We review the current status of knowledge regarding the role that flow parameters play in controlling the macrophyte communities of temperate lowland rivers. We consider both direct and indirect effects and the interaction with other factors known to control macrophyte communities. Knowledge gaps are identified and implications for the management of river systems considered. The main factors and processes controlling the status of macrophytes in lowland rivers are velocity (hence also discharge), light, substrate, competition, nutrient status and river management practices. We suggest that whilst the characteristics of any particular macrophyte community reflect the integral effects of a combination of the factors, fundamental importance can be attributed to the role of discharge and velocity in controlling instream macrophyte colonisation, establishment and persistence. Velocity and discharge also appear to control the relative influence of some of the other controlling factors. Despite the apparent importance of velocity in determining the status of macrophyte communities in lowland rivers, relatively little is understood about the nature of the processes controlling this relationship. Quantitative knowledge is particularly lacking. Consequently, the ability to predict macrophyte abundance and distribution in rivers is still limited. This is further complicated by the likely existence of feedback effects between the growth of macrophytes and velocity. Demand for water resources increases the pressure on lowland aquatic ecosystems. Despite growing recognition of the need to allocate water for the needs of instream biota, the inability to assess the flow requirements of macrophyte communities limits the scope to achieve this. This increases the likelihood of overexploitation of the water resource as other users, whose demands are quantifiable, are prioritised.
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Gilfedder, Benjamin; Hofmann, Harald; Cartwrighta, Ian
2014-05-01
Groundwater-surface water interactions are often conceptually and numerically modeled as a two component system: a groundwater system connected to a stream, river or lake. However, transient storage zones such as hyporheic exchange, bank storage, parafluvial flow and flood plain storage complicate the two component model by delaying the release of flood water from the catchment. Bank storage occurs when high river levels associated with flood water reverses the hydraulic gradient between surface water and groundwater. River water flows into the riparian zone, where it is stored until the flood water recede. The water held in the banks then drains back into the river over time scales ranging from days to months as the hydraulic gradient returns to pre-flood levels. If the frequency and amplitude of flood events is high enough, water held in bank storage can potentially perpetually remain between the regional groundwater system and the river. In this work we focus on the role of bank storage in buffering river salinity levels against saline regional groundwater on lowland sections of the Avon River, Victoria, Australia. We hypothesize that the frequency and magnitude of floods will strongly influence the salinity of the stream water as banks fill and drain. A bore transect (5 bores) was installed perpendicular to the river and were instrumented with head and electrical conductivity loggers measuring for two years. We also installed a continuous 222Rn system in one bore. This data was augmented with long-term monthly EC from the river. During high rainfall events very fresh flood waters from the headwaters infiltrated into the gravel river banks leading to a dilution in EC and 222Rn in the bores. Following the events the fresh water drained back into the river as head gradients reversed. However the bank water salinities remained ~10x lower than regional groundwater levels during most of the time series, and only slightly above river water. During 2012 SE Australia
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Bączyk, Anna; Wagner, Maciej; Okruszko, Tomasz; Grygoruk, Mateusz
2018-06-15
Intensification of agriculture and ongoing urban sprawl exacerbate pressures on rivers. Small rivers in agricultural landscapes are especially exposed to excessive technical actions implemented in order to allow for harvesting river water for irrigation, draining agricultural water and receiving sewage. Regular dredging and macrophyte removal strongly interfere with the global need for preserving river biodiversity that allows agricultural lowland rivers to remain refuges for a variety of species, and-accordingly-to keep water bodies resilient for the benefit of society. In order to provide a comprehensive look at the influence of agricultural lowland river management on the ecological status of these water bodies, we conducted a literature review and a meta-analysis. For the structured literature review we selected 203 papers reflecting on the response of aquatic ecosystems to dredging and macrophyte management actions. The database of scientific contributions developed for our study consists of papers written by the authors from 33 countries (first authorship) addressing dredging, macrophyte removal, status of fish and macroinvertebrates as well as the general ecological status of lowland agricultural rivers. We revealed that 96% of the analyzed papers indicated unilateral, negative responses of aquatic ecosystems, particularly macroinvertebrates, ichthyofauna and macrophyte composition, to maintenance measures. We revealed that studies conducted in the European Union on the ecological status of rivers appeared to significantly increase in quantity after the implementation of the Water Framework Directive. Finally, we concluded that day-to-day management of lowland agricultural rivers requires revision in terms of compliance with environmental conservation requirements and the recurrent implementation of technical measures for river maintenance. Copyright © 2018 Elsevier B.V. All rights reserved.
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Habitats of 0+ fry in an English lowland river
Czech Academy of Sciences Publication Activity Database
Duncan, A.; Kubečka, Jan; Kett, S.; Hanna, N.; Skeldon, J.
2001-01-01
Roč. 12, 2-4 (2001), s. 153-171 ISSN 0945-3784 Institutional research plan: CEZ:AV0Z6017912 Keywords : 0+ fish communities * lowland river * connected backwater Subject RIV: DA - Hydrology ; Limnology
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Marcinkowski, Paweł; Grabowski, Robert C; Okruszko, Tomasz
2017-12-31
Anastomosing rivers were historically common around the world before extensive agricultural and industrial development in river valleys. Few lowland anastomosing rivers remain in temperate zones, and the protection of these river-floodplain systems is an international conservation priority. However, the mechanisms that drive the creation and maintenance of multiple channels, i.e. anabranches, are not well understood, particularly for lowland rivers, making it challenging to identify effective management strategies. This study uses a novel multi-scale, process-based hydro-geomorphological approach to investigate the natural and anthropogenic controls on anastomosis in lowland river reaches. Using a wide range of data (hydrologic, cartographic, remote-sensing, historical), the study (i) quantifies changes in the planform of the River Narew, Poland over the last 100years, (ii) documents changes in the natural and anthropogenic factors that could be driving the geomorphic change, and (iii) develops a conceptual model of the controls of anastomosis. The results show that 110km of anabranches have been lost from the Narew National Park (6810ha), a 42% reduction in total anabranch length since 1900. The rates of anabranch loss have increased as the number of pressures inhibiting anabranch creation and maintenance has multiplied. The cessation of localized water level and channel management (fishing dams, water mills and timber rafting), the loss of traditional floodplain activities (seasonal mowing) and infrastructure construction (embanked roads and an upstream dam) are contributing to low water levels and flows, the deposition of sediment at anabranch inlets, the encroachment of common reed (Phragmites australis), and the eventual loss of anabranches. By identifying the processes driving the loss of anabranches, this study provides transferable insights into the controls of anastomosis in lowland rivers and the management solutions needed to preserve the unique
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An analysis of river bank slope and unsaturated flow effects on bank storage.
Doble, Rebecca; Brunner, Philip; McCallum, James; Cook, Peter G
2012-01-01
Recognizing the underlying mechanisms of bank storage and return flow is important for understanding streamflow hydrographs. Analytical models have been widely used to estimate the impacts of bank storage, but are often based on assumptions of conditions that are rarely found in the field, such as vertical river banks and saturated flow. Numerical simulations of bank storage and return flow in river-aquifer cross sections with vertical and sloping banks were undertaken using a fully-coupled, surface-subsurface flow model. Sloping river banks were found to increase the bank infiltration rates by 98% and storage volume by 40% for a bank slope of 3.4° from horizontal, and for a slope of 8.5°, delay bank return flow by more than four times compared with vertical river banks and saturated flow. The results suggested that conventional analytical approximations cannot adequately be used to quantify bank storage when bank slope is less than 60° from horizontal. Additionally, in the unconfined aquifers modeled, the analytical solutions did not accurately model bank storage and return flow even in rivers with vertical banks due to a violation of the dupuit assumption. Bank storage and return flow were also modeled for more realistic cross sections and river hydrograph from the Fitzroy River, Western Australia, to indicate the importance of accurately modeling sloping river banks at a field scale. Following a single wet season flood event of 12 m, results showed that it may take over 3.5 years for 50% of the bank storage volume to return to the river. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.
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Methane emissions from a human-dominated lowland coastal river network (Shanghai, China)
Wang, D.; Yu, Z.
2017-12-01
Evasion of methane (CH4) in streams and rivers play a critical role in global carbon (C) cycle, offsetting the C uptake by terrestrial ecosystems. However, little is known about CH4 emissions from lowland coastal rivers profoundly modified by anthropogenic perturbations. Here, we report results from a long-term, large-scale study of CH4 partial pressures (pCH4) and evasion rates in the Shanghai river network. The spatiotemporal variability of pCH4 was examined along a land-use gradient and the annual CH4 evasion were estimated to assess its role in regional C budget. During the study period, the median pCH4 from 87 surveyed rivers was 241 μatm. CH4 was oversaturated throughout the river network, CH4 hotpots were concentrated in the small urban rivers and highly discharge-dependent. The annual median fCH4 for each site ranged from 3.1 mg C•m-2•d-1 to 296.6 mg C•m-2•d-1. The annual CH4 evasion were 105 Gg CO2-eq•yr-1 and 96 Gg CO2-eq•yr-1 for the entire river network and the mainland rivers, respectively. Given the rapid urbanization in global coastal areas, more research is needed to quantify the role of lowland coastal rivers as a major landscape C source in global C budget.
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Rhodes, Kimberly A.; Proffitt, Tiffany; Rowley, Taylor; Knappett, Peter S. K.; Montiel, Daniel; Dimova, Natasha; Tebo, Daniel; Miller, Gretchen R.
2017-12-01
As water grows scarcer in semiarid and arid regions around the world, new tools are needed to quantify fluxes of water and chemicals between aquifers and rivers. In this study, we quantify the volumetric flux of subsurface water to a 24 km reach of the Brazos River, a lowland river that meanders through the Brazos River Alluvium Aquifer (BRAA), with 8 months of high-frequency differential gaging measurements using fixed gaging stations. Subsurface discharge sources were determined using natural tracers and End-Member Mixing Analysis (EMMA). During a 4 month river stage recession following a high stage event, subsurface discharge decreased from 50 m3/s to 0, releasing a total of 1.0 × 108 m3 of water. Subsurface discharge dried up even as the groundwater table at two locations in the BRAA located 300-500 m from the river remained ˜4 m higher than the river stage. Less than 4% of the water discharged from the subsurface during the prolonged recession period resembled the chemical fingerprint of the alluvial aquifer. Instead, the chemistry of this discharged water closely resembled high stage "event" river water. Together, these findings suggest that the river is well connected to rechargeable bank storage reservoirs but disconnected from the broader alluvial aquifer. The average width of discrete bank storage zones on each side of the river, identified with Electrical Resistivity Tomography (ERT), was approximately 1.5 km. In such highly compartmentalized aquifers, groundwater pumping is unlikely to impact the exchange between the river and the alluvium.
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Lowland riparian herpetofaunas: the San Pedro River in southeastern Arizona
Philip C. Rosen
2005-01-01
Previous work has shown that southeastern Arizona has a characteristic, high diversity lowland riparian herpetofauna with 62-68 or more species along major stream corridors, and 46-54 species in shorter reaches within single biomes, based on intensive fieldwork and museum record surveys. The San Pedro River supports this characteristic herpetofauna, at least some of...
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Rogers, H.R.; Hartemink, A.E.
2000-01-01
Secondary fallow vegetation in parts of the Papua New Guinea lowlands is dominated by the shrub Piper aduncum L. that originates from South America. Here we report on its seed bank, growth rate and biomass accumulation. P. aduncum accounted for 69 % (408 m[minus sign]2) of the seed bank in the
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Role of vegetation on river bank accretion
Vargas Luna, A.
2016-01-01
There is rising awareness of the need to include the effects of vegetation in studies dealing with the morphological response of rivers. Vegetation growth on river banks and floodplains alters the river bed topography, reduces the bank erosion rates and enhances the development of new floodplains
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Rowland, J. C.; Dietrich, W. E.; Day, G.
2005-05-01
Along lowland river systems across the globe the exchange of water, sediment, carbon, nutrients and biota between main stem rivers and off-river water bodies (ORWB) is facilitated by the presence of stable secondary channels referred to here as tie channels. Sixty five percent of the ORWB along the middle Fly River in Papua New Guinea connect to the river through such channels. A similar percentage of the 37 ORWB located between Baton Rouge and Memphis on the lower Mississippi River at one time were linked to the river by tie or batture (as they are locally known) channels. Levee construction and other alterations aimed at flood control or navigation on the Mississippi have left only a handful of lakes connected to the river, of these, most are heavily altered by dredging or other modifications. Tie channels were also once common along major tributaries to the Mississippi, such as the Red River. In the much less disturbed Alaskan environment, tie channels are still common, especially along Birch Creek and the Koyukuk and Black rivers. Our studies on the Mississippi River, in Alaska and in Papua New Guinea indicate that tie channels possess a common channel form that is stable and self-maintaining for hundreds to possibly a thousand years. Tie channels exhibit narrow width to depth ratios (~ 5.5) and consistently scale in cross-sectional dimensions to the size of the lake into which they flow. Variations in river and lake stage drive flow bi-directionally through tie channels. A local high or sill in the bed of tie channels controls the degree and duration of connection between the river and ORWB, with many lakes becoming isolated during periods of low stage. The life-span of a tie channel depends on the rate of sediment loading to the ORWB. Our research indicates that this rate directly corresponds to the sediment loading in the main stem river. Along the Fly River, for example, a 5 to 7 fold increase in the river sediment load has resulted increases of 6 to 17
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Channel Bank Cohesion and the Maintenance of Suspension Rivers
Dunne, K. B. J.; Jerolmack, D. J.
2017-12-01
Gravel-bedded rivers organize their channel geometry and grain size such that transport is close to the threshold of motion at bankfull. Sand-bedded rivers, however, typically maintain bankfull fluid shear (or Shields) stresses far in excess of threshold; there is no widely accepted explanation for these "suspension rivers". We propose that all alluvial rivers are at the threshold of motion for their erosion-limiting material, i.e., the structural component of the river cross-section that is most difficult to mobilize. The entrainment threshold of gravel is large enough that bank cohesion has little influence on gravel-bed rivers. Sand, however, is the most easily entrained material; silt and clay can raise the entrainment threshold of sand by orders of magnitude. We examine a global dataset of river channel geometry and show that the shear stress range for sand-bedded channels is entirely within the range of entrainment thresholds for sand-mud mixtures - suggesting that rivers that suspend their sandy bed material are still threshold rivers in terms of bank material. We then present new findings from a New Jersey coastal-plain river examining if and how river-bank toe composition controls hydraulic geometry. We consider the toe because it is the foundation of the river bank, and its erosion leads to channel widening. Along a 20-km profile of the river we measure cross-section geometry, bed slope, and bed and bank composition, and we explore multiple methods of measuring the threshold shear stress of the the river-bank toe in-situ. As the composition of the river bed transitions from gravel to sand, we see preliminary evidence of a shift from bed-threshold to bank-threshold control on hydraulic geometry. We also observe that sub-bankfull flows are insufficient to erode (cohesive) bank materials, even though transport of sand is active at nearly all flows. Our findings highlight the importance of focusing on river-bank toe material, which in the studied stream is
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Yang, Jing; Zammit, Christian; Dudley, Bruce
2017-04-01
The phenomenon of losing and gaining in rivers normally takes place in lowland where often there are various, sometimes conflicting uses for water resources, e.g., agriculture, industry, recreation, and maintenance of ecosystem function. To better support water allocation decisions, it is crucial to understand the location and seasonal dynamics of these losses and gains. We present a statistical methodology to predict losing and gaining river reaches in New Zealand based on 1) information surveys with surface water and groundwater experts from regional government, 2) A collection of river/watershed characteristics, including climate, soil and hydrogeologic information, and 3) the random forests technique. The surveys on losing and gaining reaches were conducted face-to-face at 16 New Zealand regional government authorities, and climate, soil, river geometry, and hydrogeologic data from various sources were collected and compiled to represent river/watershed characteristics. The random forests technique was used to build up the statistical relationship between river reach status (gain and loss) and river/watershed characteristics, and then to predict for river reaches at Strahler order one without prior losing and gaining information. Results show that the model has a classification error of around 10% for "gain" and "loss". The results will assist further research, and water allocation decisions in lowland New Zealand.
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Czech Academy of Sciences Publication Activity Database
Adámek, Z.; Jurajda, Pavel; Prášek, Václav; Sukop, I.
2010-01-01
Roč. 397, 02 (2010), s. 1-12 ISSN 1961-9502 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Gobiidae * food * lowland reservoir * rip-rap bank * the Dyje River Subject RIV: EG - Zoology Impact factor: 0.304, year: 2010
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Turbidity and plant growth in large slow-flowing lowland rivers: progress report March 1989
Marker, A.F.H.
1989-01-01
The River Great Ouse is a highly managed large lowland river in eastern England. It drains rich arable land in the Midlands and Eastern England and over the years nutrient concentrations have increased and there is a general perception that the clarity of the water has decreased. The main river channels have been dredged a number of times partly for flood control reasons but also for recreational boating and navigation activities. The period covered by this first report has been used to devel...
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Sediment size of surface floodplain sediments along a large lowland river
Swanson, K. M.; Day, G.; Dietrich, W. E.
2007-12-01
Data on size distribution of surface sediment across a floodplain should place important constraints of modeling of floodplain deposition. Diffusive or advective models would predict that, generally, grain size should decrease away from channel banks. Variations in grain size downstream along floodplains may depend on downstream fining of river bed material, exchange rate with river banks and net deposition onto the floodplain. Here we report detailed grain size analyses taken from 17 floodplain transects along 450 km (along channel distance) reach of the middle Fly River, Papua New Guinea. Field studies have documented a systematic change in floodplain characteristics downstream from forested, more topographically elevated and topography bounded by an actively shifting mainstem channel to a downstream swamp grass, low elevation topography along which the river meanders are currently stagnant. Frequency and duration of flooding increase downstream. Flooding occurs both by overbank flows and by injections of floodwaters up tributary and tie channels connected to the mainstem. Previous studies show that about 40% of the total discharge of water passes across the floodplain, and, correspondingly, about 40% of the total load is deposited on the plain - decreasing exponentially from channel bank. We find that floodplain sediment is most sandy at the channel bank. Grain size rapidly declines away from the bank, but surprisingly two trends were also observed. A relatively short distance from the bank the surface material is finest, but with further distance from the bank (out to greater than 1 km from the 250 m wide channel) clay content decreases and silt content increases. The changes are small but repeated at most of the transects. The second trend is that bank material fines downstream, corresponding to a downstream finding bed material, but once away from the bank, there is a weak tendency for a given distance away from the bank the floodplain surface deposits to
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Directory of Open Access Journals (Sweden)
Daru Setyo Rini
2017-10-01
Full Text Available Ecohydraulic river bank protection design was developed as ECO-RIPRAP model and has been applied along 100 meter length to restore accelerated erosion sites in Surabaya River at Wringinanom and Klubuk. The model combined re-profiled and re-vegetated bank with rock toe reinforcement and addition of log groynes at 10 meter length interval. Various native plant species were planted on bank slopes, including water plants Ipomoea aquatica and Pistia stratiotes, grasses and shrubs Ipomoea carnea, Pluchea indica, Saccharum spontaneum, Arundo donax, and native tree species Ficus glomerata, Bambusa arundinacea, Dendrocalamus asper, Bambusa vulgaris, Ficus benjamina, Dillenia indica, Psidium guajava, Arthocarpus camansi, Arthocarpus elasticus, Hibiscus mutabilis, Nauclea sp., Inocarpus edulis, and Syzygium polyanthum. The river bank morphology after ECO-RIPRAP application showed alteration from erosion to sedimentation due to rock toe enforcement, log groynes protection, and increase of plant cover on littoral banks that decreased near bank velocity. The macro-invertebrate community shown increase of taxa richness, EPT richness, %EPT and %Atyidae, but decrease of %Chironomidae at restored sites. The fish community shown increase of taxa richness, increase of abundance by 54.2%, increase of Pangasius micronemus abundance by 25.6%, and increase of Hemibragus nemurus abundance by 6.3 % at restored reach. Rare fish species thrive back at restored area, namely Oxyeleotris marmorata, Mastacembelus unicolor and Hampala macrolepidota.
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Directory of Open Access Journals (Sweden)
Daru Setyo Rini
2018-01-01
Full Text Available There were 18 accelerated erosion sites identified along 7 km of Surabaya River Fishery Sanctuary Area. A model of ecohydraulic bank stabilization was applied to reduce bank erosion in Surabaya River at Gresik Regency Indonesia. The model is combination of reprofiled and revegetated bank with rock toe reinforcement and addition of log groynes. Various native plant species were planted and naturally grown to establish multi-strata littoral vegetation structure. This study assessed effects of ecohydraulic bank stabilization on bank morphology, near bank velocity and littoral macroinvertebrate community during September 2014 to August 2016. The study found that rock toe enforcement, log groynes and reprofiled bank slope could stabilized the eroded bank, and littoral vegetation formation reduced near bank velocity at restored sites. There were 31 families of macroinvertebrate found in Surabaya River with high abundance of moderately pollution sensitive taxa Atyidae and pollution tolerant taxa Corixidae, Chironomidae and Tubificidae. The taxa richness, diversity index and abundance of sensitive and moderately sensitive macroinvertebrate group were increased after application of ecohydraulic bank stabilization at restored area. The results shown that ecohydraulic bank stabilization structure provides multi-benefits in improving bank stabilization against erosion and providing new micro-habitats for biotic community. Keywords: ecohydraulic bank stabilization, macroinvertebrates, riparian restoration
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Sutrisno; Subrata, A.; Surahmanto; Christiyanto, M.; Surono; Achmadi, J.; Wahyono, F.; Pangestu, E.
2018-02-01
The study was aimed to obtain information regarding feed given and mineralstatus (Ca, P) in fodder and beef cattle in Jratunseluna river basin. Feed and drinking water given by farmers identified for 14 days and extracted sampling for mineralanalysis, t-test was used to compare mineral status in upland and lowland. Results of the research showed that feed given by farmers were varying. The ratio of forage/concentrates in lowland and upland areas was different, i.e. 67: 33 and 30: 70, respectivelly. Ca content on forage given in upland areas ranged from 0.17 to 0.74%, and concentrates from 0.002 to 0.49%, while Ca content on forage given in lowland areas ranged from 0.33 to 0.52%, and concentrates ranged from 0.38 to 0.49%. P content on forage in upland areas ranged from 0.02 to 0.04%, concentrates ranged from 0.018 to 0.09%,while P content on forage in lowland areas ranged from 0.03 to 0.07%, and concentrates ranged from 0.04 to 0.07% . Ca and P consumption in upland areas were 301.06 and 54.73 g, and 391.92 and 65.70 g in lowland.Caand P content of beef cattle’s hair in upland were 0.14 and 0.01%, while in lowland areas were 0.11 and 0.03%.It can be concluded that Ca and P intakeof beef cattle in Jratunseluna river basin were less and mineral status of Ca and P in marginal condition.
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Shorth-Term Impacts of Weed Cutting on the Physical Habitats in Lowland Rivers
DEFF Research Database (Denmark)
Pedersen, Morten Lauge; Baattrup-Pedersen, Annette; Rørth, Frederikke Rahbek
2011-01-01
We studied the effects of weed cutting at 3 reaches in two Danish lowland rivers with the objectives of examining the response to cutting in rivers with contrasting physical conditions, macrophyte diversity, and assemblage patterns. Physical characteristics and abundance of macrophyte species were...... registered 3 or 4 times throughout the study period on all reaches. Weed cutting did not affect the total coverage of stone, gravel and sand and substratum homogeneity, and no common response was found among the reaches. This result is likely to reflect both initial differences in the physical environment...
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Macfall, Janet; Robinette, Paul; Welch, David
2014-01-01
The Haw River, a high order river in the southeastern United States, is characterized by severe bank erosion and geomorphic change from historical conditions of clear waters and connected floodplains. In 2014 it was named one of the 10 most threatened rivers in the United States by American Rivers. Like many developed areas, the region has a history of disturbance including extensive upland soil loss from agriculture, dams, and upstream urbanization. The primary objective of this study was to identify the mechanisms controlling channel form and erosion of the Haw River. Field measurements including bank height, bankfull height, bank angle, root depth and density, riparian land cover and slope, surface protection, river width, and bank retreat were collected at 87 sites along 43.5 km of river. A Bank Erosion Hazard Index (BEHI) was calculated for each study site. Mean bank height was 11.8 m, mean width was 84.3 m, and bank retreat for 2005/2007-2011/2013 was 2.3 m. The greatest bank heights, BEHI values, and bank retreat were adjacent to riparian areas with low slope (<2). This is in contrast to previous studies which identify high slope as a risk factor for erosion. Most of the soils in low slope riparian areas were alluvial, suggesting sediment deposition from upland row crop agriculture and/or flooding. Bank retreat was not correlated to bank heights or BEHI values. Historical dams (1.2-3 m height) were not a significant factor. Erosion of the Haw River in the study section of the river (25% of the river length) contributed 205,320 m3 of sediment and 3759 kg of P annually. Concentration of suspended solids in the river increased with discharge. In conclusion, the Haw River is an unstable system, with river bank erosion and geomodification potential influenced by riparian slope and varied flows.
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Water quality and treatment of river bank filtrate
Directory of Open Access Journals (Sweden)
W. W. J. M. de Vet
2010-06-01
Full Text Available In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the river bank infiltrate but also by water percolating through covering layers. In the polder areas, these top layers consist of peat and deposits from river sediments and sea intrusions.
This paper discusses the origin and fate of macro components in river bank filtrate, based on extensive full-scale measurements in well fields and treatment systems of the Drinking Water Company Oasen in the Netherlands. First, it clarifies and illustrates redox reactions and the mixing of river bank filtrate and PW as the dominant processes determining the raw water quality for drinking water production. Next, full-scale results are elaborated on to evaluate trickling filtration as an efficient and proven one-step process to remove methane, iron, ammonium and manganese. The interaction of methane and manganese removal with nitrification in these systems is further analyzed. Methane is mostly stripped during trickling filtration and its removal hardly interferes with nitrification. Under specific conditions, microbial manganese removal may play a dominant role. -
Topographic Signatures of Meandering Rivers with Differences in Outer Bank Cohesion
Kelly, S. A.; Belmont, P.
2014-12-01
Within a given valley setting, interactions between river hydraulics, sediment, topography, and vegetation determine attributes of channel morphology, including planform, width and depth, slope, and bed and bank properties. These feedbacks also govern river behavior, including migration and avulsion. Bank cohesion, from the addition of fine sediment and/or vegetation has been recognized in flume experiments as a necessary component to create and maintain a meandering channel planform. Greater bank cohesion slows bank erosion, limiting the rate at which a river can adjust laterally and preventing so-called "runaway widening" to a braided state. Feedbacks of bank cohesion on channel hydraulics and sediment transport may thus produce distinct topographic signatures, or patterns in channel width, depth, and point bar transverse slope. We expect that in bends of greater outer bank cohesion the channel will be narrower, deeper, and bars will have greater transverse slopes. Only recently have we recognized that biotic processes may imprint distinct topographic signatures on the landscape. This study explores topographic signatures of three US rivers: the lower Minnesota River, near Mankato, MN, the Le Sueur River, south central MN, and the Fall River, Rocky Mountain National Park, CO. Each of these rivers has variability in outer bank cohesion, quantified based on geotechnical and vegetation properties, and in-channel topography, which was derived from rtkGPS and acoustic bathymetry surveys. We present methods for incorporating biophysical feedbacks into geomorphic transport laws so that models can better simulate the spatial patterns and variability of topographic signatures.
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Cascading effects of flow reduction on the benthic invertebrate community in a lowland river
DEFF Research Database (Denmark)
Graeber, Daniel; Pusch, Martin T.; Lorenz, Stefan
2013-01-01
on dissolved oxygen concentrations (DO) have not yet received much attention. We compared the macroinvertebrate composition between reference conditions and a situation after several years of discharge reduction in the Spree River (Brandenburg, Germany). Community composition shifted from rheophilic species...... concentration minima of less than 5 mg l−1 which prevailed 74% of the days in summer. This depletion of DO after flow reduction presumably caused the observed species turnover. Hence, flow reduction in lowland rivers may not only directly impair the ecological functions provided by benthic macroinvertebrates...
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Bank erosion along the dam-regulated lower Roanoke River, North Carolina
Hupp, C.R.; Schenk, E.R.; Richter, J.M.; Peet, Robert K.; Townsend, Phil A.
2009-01-01
Dam construction and its impact on downstream fluvial processes may substantially alter ambient bank stability and erosion. Three high dams (completed between 1953 and 1963) were built along the Piedmont portion of the Roanoke River, North Carolina; just downstream the lower part of the river flows across largely unconsolidated Coastal Plain deposits. To document bank erosion rates along the lower Roanoke River, >700 bank-erosion pins were installed along 66 bank transects. Additionally, discrete measurements of channel bathymetry, turbidity, and presence or absence of mass wasting were documented along the entire study reach (153 km). A bank-erosion- floodplain-deposition sediment budget was estimated for the lower river. Bank toe erosion related to consistently high low-flow stages may play a large role in increased mid- and upper-bank erosion. Present bank-erosion rates are relatively high and are greatest along the middle reaches (mean 63 mm/yr) and on lower parts of the bank on all reaches. Erosion rates were likely higher along upstream reaches than present erosion rates, such that erosion-rate maxima have since migrated downstream. Mass wasting and turbidity also peak along the middle reaches; floodplain sedimentation systematically increases downstream in the study reach. The lower Roanoke River isnet depositional (on floodplain) with a surplus of ??2,800,000 m3yr. Results suggest that unmeasured erosion, particularly mass wasting, may partly explain this surplus and should be part of sediment budgets downstream of dams. ?? 2009 The Geological Society of America.
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Bank retreat of a meandering river reach case study : River Irwell
Duran, R.; Beevers, L.; Crosato, A.; Wright, N.G.
2009-01-01
Lack of data is often considered a limitation when undertaking morphological studies. This research deals with the morphological study of a small river experiencing bank erosion for which only limited data are available. A reach of the meandering gravel-bed river Irwell (United Kingdom) is taken as
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Savannah River Laboratory data banks for risk assessment
International Nuclear Information System (INIS)
Durant, W.S.
1984-01-01
The Savannah River Laboratory maintains a series of computerized data banks primarily as an aid in probabilistic risk assessment studies for the Savannah River Plant (SRP) facilities. These include component failure rates, generic incidents, and reports of specific deviations from normal operating conditions. In addition to providing data for probability studies, these banks have served as a valuable aid in trend analyses, equipment histories, process hazards analyses, consequence assessments, incident audits, process problem solving, and training
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Suitability Evaluation of River Bank Filtration along the Second Songhua River, China
Directory of Open Access Journals (Sweden)
Lixue Wang
2016-04-01
Full Text Available The Second Songhua River is the biggest river system in Jilin Province, China. In recent years, the rapid economic development in this area has increased the prominence of water resources and water-related environmental problems; these include surface water pollution and the overexploitation of groundwater resources. Bank infiltration on the floodplains of the Second Songhua River is an important process of groundwater-surface water exchange under exploitation conditions. Understanding this process can help in the development of water resource management plans and strategies for the region. In this research, a multi-criteria evaluation index system was developed with which to evaluate the suitability of bank filtration along the Second Songhua River. The system was comprised of main suitability indexes for water quantity, water quality, the interaction intensity between surface water and groundwater, and the exploitation condition of groundwater resources. The index system was integrated into GIS (Geographic Information System to complete the evaluation of the various indicators. According to the weighted sum of each index, the suitability of river bank filtration (RBF in the study area was divided into five grades. Although the evaluation index system and evaluation method are applicable only to the Second Songhua River basin, the underlying principle and techniques it embodies can be applied elsewhere. For future generalization of the evaluation index system, the specific evaluation index and its scoring criteria should be modified appropriately based on local conditions.
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Emile S. Gardiner; Daniel C. Dey; John A. Stanturf; Brian Roy. Lockhart
2010-01-01
The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More...
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Geological setting control of flood dynamics in lowland rivers (Poland).
Wierzbicki, Grzegorz; Ostrowski, Piotr; Falkowski, Tomasz; Mazgajski, Michał
2018-04-27
We aim to answer a question: how does the geological setting affect flood dynamics in lowland alluvial rivers? The study area covers three river reaches: not trained, relatively large on the European scale, flowing in broad valleys cut in the landscape of old glacial plains. We focus on the locations where levees [both: a) natural or b) artificial] were breached during flood. In these locations we identify (1) the erosional traces of flood (crevasse channels) on the floodplain displayed on DEM derived from ALS LIDAR. In the main river channel, we perform drillings in order to measure the depth of the suballuvial surface and to locate (2) the protrusions of bedrock resistant to erosion. We juxtapose on one map: (1) the floodplain geomorphology with (2) the geological data from the river channel. The results from each of the three study reaches are presented on maps prepared in the same manner in order to enable a comparison of the regularities of fluvial processes written in (1) the landscape and driven by (2) the geological setting. These processes act in different river reaches: (a) not embanked and dominated by ice jam floods, (b) embanked and dominated by rainfall and ice jam floods. We also analyse hydrological data to present hydrodynamic descriptions of the flood. Our principal results indicate similarity of (1) distinctive erosional patterns and (2) specific geological features in all three study reaches. We draw the conclusion: protrusions of suballuvial bedrock control the flood dynamics in alluvial rivers. It happens in both types of rivers. In areas where the floodplain remains natural, the river inundates freely during every flood. In other areas the floodplain has been reclaimed by humans who constructed an artificial levee system, which protects the flood-prone area from inundation, until levee breach occurs. Copyright © 2018 Elsevier B.V. All rights reserved.
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Bank retreat study of a meandering river reach case study : River Irwell
Duran, R.; Beevers, L.; Crosato, A.; Wright, N.
2010-01-01
Lack of data is often considered a limitation when undertaking morphological studies. This research deals with morphological studies of small rivers experiencing bank erosion processes when only limited data are available. A reach of the meandering gravel-bed river Irwell (United Kingdom) is taken
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Theoretical investigation on discharge-induced river-bank erosion
Mosselman, E.
1989-01-01
Bank erosion is incorporated in one-dimensional and two-dimensional horizontal models for river morphology. The banks are assumed to consist of a fraction of cohesive material, which becomes washload after being eroded, and a fraction of granular material, with the same properties as the material of
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Desmet, N. J. S.; Van Belleghem, S.; Seuntjens, P.; Bouma, T. J.; Buis, K.; Meire, P.
When macrophytes are growing in the river, the vegetation induces substantial changes to the water quality. Some effects are the result of direct interactions, such as photosynthetic activity or nutrient uptake, whereas others may be attributed to indirect effects of the water plants on hydrodynamics and river processes. This research focused on the direct effect of macrophytes on oxygen dynamics and nutrient cycling. Discharge, macrophyte biomass density, basic water quality, dissolved oxygen and nutrient concentrations were in situ monitored throughout the year in a lowland river (Nete catchment, Belgium). In addition, various processes were investigated in more detail in multiple ex situ experiments. The field and aquaria measurement results clearly demonstrated that aquatic plants can exert considerable impact on dissolved oxygen dynamics in a lowland river. When the river was dominated by macrophytes, dissolved oxygen concentrations varied from 5 to 10 mg l -1. Considering nutrient retention, it was shown that the investigated in-stream macrophytes could take up dissolved inorganic nitrogen (DIN) from the water column at rates of 33-50 mg N kgdry matter-1 h. And DIN fluxes towards the vegetation were found to vary from 0.03 to 0.19 g N ha -1 h -1 in spring and summer. Compared to the measured changes in DIN load over the river stretch, it means that about 3-13% of the DIN retention could be attributed to direct nitrogen uptake from the water by macrophytes. Yet, the role of macrophytes in rivers should not be underrated as aquatic vegetation also exerts considerable indirect effects that may have a greater impact than the direct fixation of nutrients into the plant biomass.
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Volumetric measurement of river bank erosion from sequential historical aerial photography
Spiekermann, Raphael; Betts, Harley; Dymond, John; Basher, Les
2017-11-01
Understanding of the relative contribution of bank erosion to sediment budgets in New Zealand is limited. Few measurements of bank erosion rates exist, and this is a major limitation to the development of a locally calibrated model of bank erosion. The New Zealand sediment budget model, SedNetNZ, predicts bank erosion based on preliminary data, and this study aims to underpin the development of an improved model for bank erosion. Photogrammetric techniques and LiDAR were used to collect data on bank erosion rates for five different river reaches, ranging from 3 to 14 km in length, in the Kaipara Catchment, Northland, New Zealand. Changing river channel planform between the 1950s and 2015 was assessed using four to five well-spaced dates of historical aerial photographs. Changes in planform were combined with bank height, to calculate erosion and accretion volumes which were compared with SedNetNZ modelled estimates. Erosion and accretion is relatively evenly balanced in the study sites. The largest difference in terms of relative proportions of erosion and accretion are found along the Tangowahine River (13.4 km reach length), where 492,000 m3 of sediment eroded between 1956 and 2015 compared to 364,000 m3 of accretion. Lateral migration rates (erosion) for the five river reaches range between 0.14 m yr- 1 and 0.21 m yr- 1 and are comparable with those measured by previous assessments in New Zealand. The migration rates in channel widths per year for the three larger rivers (stream order 5-6) range between 0.4% and 0.8% of channel width per year. In contrast, the smaller streams (stream order 3-4) are retreating more rapidly, with width-averaged rates of 1.7% and 3.0%. Current SedNetNZ modelling tends to underestimate the bank height and greatly overestimates the migration rate.
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Deformation analysis and prediction of bank protection structure with river level fluctuations
Hu, Rui; Xing, Yixuan
2017-04-01
Bank structure is an important barrier to maintain the safety of the embankment. The deformation of bank protection structure is not only affected by soil pressure caused by the excavation of the riverway, but also by the water pressure caused river water level fluctuations. Thus, it is necessary to establish a coupled soil-water model to analyze the deformation of bank structure. Based on Druck-Prager failure criteria and groundwater seepage theory, a numerical model of bank protection structure with consideration of the pore water pressure of soil mass is established. According to the measured river level data with seasonal fluctuating, numerical analysis of the deformation of bank protection structure is implemented. The simulation results show that the river water level fluctuation has clear influence on the maximum lateral displacement of the pile. Meanwhile, the distribution of plastic zone is related to the depth of groundwater level. Finally, according to the river water level data of the recent ten years, we analyze the deformation of the bank structure under extreme river level. The result shows that, compared with the scenario of extreme high river level, the horizontal displacement of bank protection structure is larger (up to 65mm) under extreme low river level, which is a potential risk to the embankment. Reference Schweiger H F. On the use of drucker-prager failure criteria for earth pressure problems[J]. Computers and Geotechnics, 1994, 16(3): 223-246. DING Yong-chun，CHENG Ze-kun. Numerical study on performance of waterfront excavation[J]. Chinese Journal of Geotechnical Engineering，2013，35(2):515-521. Wu L M, Wang Z Q. Three gorges reservoir water level fluctuation influents on the stability of the slope[J]. Advanced Materials Research. Trans Tech Publications, 2013, 739: 283-286.
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The role of multigelation in the development of river banks
Directory of Open Access Journals (Sweden)
Karol AUGUSTOWSKI
2013-03-01
Full Text Available The development of river banks is conditioned by a few factors: fluvial erosion, mass movements and subaerial processes. Many researchers believe that the subaerial phenomena are more preparatory processes to actual erosion than the erosion itself. Among the subaerial phenomena, freezing and thawing play a key role. Multigelation affects the stability and sustainability of river banks, not only in the northern reaches of Eurasia andNorth Americabut also in temperate latitudes. Susceptibility to change in bank morphology, however, is extremely selective. Within the same layer, at a distance of 1 metre the intensity of frost erosion can be very different. This is the result of many factors determining the rate of bank retreat. These include: the height of the bank, its structure and texture, physical and chemical properties of the material from which it is built, environmental conditions, soil moisture, water pressure in the pore spaces, porosity and density of the soil, organic matter content in the soil, temperature, vegetation, as well as thickness and duriation of snow cover. An important objective is therefore to show the differences in the rate of retreat of the river banks, and above all characterized by varying degrees of density and grain size of the material it is build of.
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Design Procedure Enhanced with Numerical Modeling to Mitigate River-Bank Erosion
Directory of Open Access Journals (Sweden)
Elhakeem Mohamed
2016-01-01
Full Text Available In this study, the 2D Finite Element Surface Water Modeling System (FESWMS is used to design barb structures to mitigate river bank erosion in a stream reach located on the Raccoon River near Adel, Iowa, USA just upstream of the US Highway Bridge 169. FESWMS is used also to access the barbs effect on the study reach. The model results showed that the proposed barb structures successfully reduced the flow velocity along the outside bank and increased the velocity in the center of the stream, thereby successfully increased the conveyance towards the core of the river. The estimated velocities values along the river-banks where the barbs exist were within the recommended values for channel stability design. Thus, the barb structures were able to reduce the erosion along the bankline.
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Directory of Open Access Journals (Sweden)
Ostrowski Piotr
2017-06-01
Full Text Available The paper presents examples of using low-altitude aerial images of a modern river channel, acquired from an ultralight aircraft. The images have been taken for two sections of the Vistula river: in the Małopolska Gorge and near Dęblin and Gołąb. Alongside with research flights, there were also terrestrial investigations, such as echo sounding of the riverbed and geological mapping, carried out in the river channel zone. A comparison of the results of aerial and terrestrial research revealed high clarity of the images, allowing for precise identification of the evidence that indicates the specific course of river channel processes. Aerial images taken from ultralight aircrafts can significantly increase the accuracy of geological surveys of river channel zones in the Polish Lowlands due to low logistic requirements.
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Directory of Open Access Journals (Sweden)
Sarah J. Halliday
2014-01-01
Full Text Available This paper reports the results of a 2-year study of water quality in the River Enborne, a rural river in lowland England. Concentrations of nitrogen and phosphorus species and other chemical determinands were monitored both at high-frequency (hourly, using automated in situ instrumentation, and by manual weekly sampling and laboratory analysis. The catchment land use is largely agricultural, with a population density of 123 persons km−2. The river water is largely derived from calcareous groundwater, and there are high nitrogen and phosphorus concentrations. Agricultural fertiliser is the dominant source of annual loads of both nitrogen and phosphorus. However, the data show that sewage effluent discharges have a disproportionate effect on the river nitrogen and phosphorus dynamics. At least 38% of the catchment population use septic tank systems, but the effects are hard to quantify as only 6% are officially registered, and the characteristics of the others are unknown. Only 4% of the phosphorus input and 9% of the nitrogen input is exported from the catchment by the river, highlighting the importance of catchment process understanding in predicting nutrient concentrations. High-frequency monitoring will be a key to developing this vital process understanding.
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van Dinter, M.; Cohen, K.M.; Hoek, W.Z.; Stouthamer, E.; Jansma, E.; Middelkoop, H.
2017-01-01
Fluvial lowlands have become attractive human settling areas all around the world over the last few millennia. Because rivers kept changing their course and networks due to avulsion, the sedimentary sequences in these areas are archives of both fluvial geomorphological and archaeological
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Does reintroducing large wood influence the hydraulic landscape of a lowland river system?
Matheson, Adrian; Thoms, Martin; Reid, Michael
2017-09-01
Our understanding of the effectiveness of reintroduced large wood for restoration is largely based on studies from high energy river systems. By contrast, few studies of the effectiveness of reintroducing large wood have been undertaken on large, low energy, lowland river systems: river systems where large wood is a significant physical feature on the in-channel environment. This study investigated the effect of reintroduced large wood on the hydraulic landscape of the Barwon-Darling River, Australia, at low flows. To achieve this, the study compared three hydraulic landscapes of replicated reference (naturally wooded), control (unwooded,) and managed (wood reintroduced) treatments on three low flow periods. These time periods were prior to the reintroduction of large wood to managed reaches; several months after the reintroduction of large wood into the managed reaches; and then more than four years after wood reintroduction following several large flood events. Hydraulic landscapes of reaches were characterised using a range of spatial measures calculated from velocity measurements taken with a boat-mounted Acoustic Doppler Profiler. We hypothesised that reintroduced large wood would increase the diversity of the hydraulic landscape at low flows and that managed reaches would be more similar to the reference reaches. Our results suggest that the reintroduction of large wood did not significantly change the character of the hydraulic landscape at the reach scale after several months (p = 0.16) or several years (p = 0.29). Overall, the character of the hydraulic landscape in the managed reaches was more similar to the hydraulic landscape of the control reaches than the hydraulic landscape of the reference reaches, at low flows. Some variability in the hydraulic landscapes was detected over time, and this may reflect reworking of riverbed sediments and sensitivity to variation in discharge. The lack of a response in the low flow hydraulic landscape to the
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Mobile Bank Conditions for Laminar Micro-Rivers
Devauchelle, Olivier; Josserand, Christophe; Lagrée, Pierre-Yves; Zaleski, Stéphane
2008-01-01
International audience; The present study aims to establish a simple mechanistic model for river bank erosion. Recent experiments demonstrate that small-scale laminar flumes can develop erosion structures similar to those encountered in Nature. From Saint-Venant's Equations, a classical sediment transport law and a simple avalanche model, it is shown that bank failure caused by flow erosion can be represented through simple boundary conditions. These conditions are able to deal with the water...
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Management of data banks at Westinghouse Savannah River Company
International Nuclear Information System (INIS)
Baughman, D.F.
1992-01-01
The Risk Assessment Methodology Group (RAM) of the Nuclear Processes Safety Research Section (NPSR) maintains the compilation of incidents that have occurred at the Savannah River Site. The data banks have gained national recognition for their value in risk-related studies. The information provided by these data banks is widely used at SRS and across the DOE Complex. This report discusses these data banks
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Lowland forest butterflies of the Sankosh River catchment, Bhutan
Directory of Open Access Journals (Sweden)
A.P. Singh
2012-10-01
Full Text Available This paper provides information on butterflies of the lowland forests of Bhutan for the first time. As a part of the biodiversity impact assessment for the proposed Sankosh hydroelectric power project, a survey was carried out along the Sankosh River catchment to study the butterfly diversity. The aim of the study was to identify species of conservation priority, their seasonality and to know the butterfly diversity potential of the area. Surveys were carried out during five different seasons (winter, spring, pre-monsoon, monsoon, post-monsoon lasting 18 days from January 2009 to March 2010. Pollard walk method was used to assess the diversity on four-line transects within 10-12 km radius of the proposed dam site. Two hundred and thirteen species, including 22 papilionids, were thus sampled. Eleven species amongst these are listed in Schedules I and II of the Indian Wildlife (Protection Act, 1972, of which 10 taxa (Pareronia avatar avatar, Nacaduba pactolus continentalis, Porostas aluta coelestis, Elymnias vasudeva vasudeva, Mycalesis mestra retus, Melanitis zitenius zitenius, Charaxes marmax, Athyma ranga ranga, Neptis manasa manasa and Neptis soma soma are of conservation priority as they are ‘rare’ in occurrence across their distribution range in the region. The maximum number of species (128 were recorded during the spring season (March and lowest (66 during July (monsoon. The seasonal pattern of variation in diversity was very typical of the pattern found in other areas of the lower foothills and adjoining plains of the Himalaya. Relative abundances of butterflies during spring varied significantly (p<0.05 as compared to winter, pre-monsoon and post-monsoon seasons. However, species composition changed with every season as Sorensen’s similarity index varied between 0.3076 to 0.5656. All these findings suggest that the lowland forests of Bhutan hold a rich and unique diversity of butterflies during every season of the year thus having
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Czech Academy of Sciences Publication Activity Database
Potopová, V.; Zahradníček, Pavel; Türkot, L.; Štěpánek, Petr; Soukup, J.
2015-01-01
Roč. 2015, č. 546920 (2015), s. 546920 ISSN 1687-9309 R&D Projects: GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : Central Europe * extremes * climate change * growing seasons * Elbe River Lowland Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.107, year: 2015
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The Impact of Human Encroachment and River Bank Agricultural ...
African Journals Online (AJOL)
The impact of human encroachment and river bank Agricultural activities on the habitat of the manatee (Trichechus Senegalensis) was investigated. The method of data collection involved the use of a structured questionnaire administered to farmers and fishermen. Vegetation survey in three selected sites along the river ...
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Unland, N. P.; Cartwright, I.; Cendón, D. I.; Chisari, R.
2014-12-01
Bank exchange processes within 50 m of the Tambo River, southeast Australia, have been investigated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River, which suggests the absence of significant bank storage. Major ion concentrations and δ2H and δ18O values of bank water also indicate that bank infiltration does not significantly impact groundwater chemistry under baseflow and post-flood conditions, suggesting that the gaining nature of the river may be driving the return of bank storage water back into the Tambo River within days of peak flood conditions. The covariance between 3H and 14C indicates the leakage and mixing between old (~17 200 years) groundwater from a semi-confined aquifer and younger groundwater (bank infiltration. Furthermore, the more saline deeper groundwater likely controls the geochemistry of water in the river bank, minimising the chemical impact that bank infiltration has in this setting. These processes, coupled with the strongly gaining nature of the Tambo River are likely to be the factors reducing the chemical impact of bank storage in this setting. This study illustrates the complex nature of river groundwater interactions and the potential downfall in assuming simple or idealised conditions when conducting hydrogeological studies.
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Yu, Matthew; Cartwright, Ian
2014-05-01
Defining the relationship between the river and its river bank is important in constraining baseflow to a river and enhancing our ability in protecting water resources and riparian ecology. Hydraulic heads, geochemistry and 3H were measured in river banks along the Ovens River, southeast Australia. The Ovens River is characterised by the transition from a single channel river residing within a mountain valley to a multi-channel meandering river on broad alluvial plains in the lower catchment. The 3H concentrations of most near-river groundwater (less than 10 m from river channel) and bank water (10 - 30 m from the river channel) in the valley range between 1.93 and 2.52 TU. They are similar to those of the river, which are between 2.37 and 2.24 TU. These groundwater also have a Na/Cl ratio of 2.7 - 4.7 and are close to the river Na/Cl ratios. These similarities suggest that most river banks in the valley are recharged by the river. The hydraulic heads and EC values indicate that some of these river banks are recharged throughout the year, while others are only recharged during high flow events. Some near-river groundwater and bank water in the valley have a much lower 3H concentration, ranging from 0.97 to 1.27 TU. They also have a lower Na/Cl ratio of 1.6 - 3.1. These differences imply that some of the river banks in the valley are rarely recharged by the river. The lack of infiltration is supported by the constant head gradient toward the river and the constant EC values in these river banks. The river banks with bank infiltration are located in the first few hundred kilometres in the valley and in the middle catchment where the valley is broaden. In the first few hundred kilometres in the valley, it has a relatively flat landscape and does not allow a high regional water table to form. The river thus is always above the water table and recharges the river banks and the valley aquifers. In the broader valley, the relatively low lateral hydraulic gradient is
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Numerical simulation of hydrodynamics and bank erosion in a river bend
Rinaldi, M.; Mengoni, B.; Luppi, L.; Darby, S.E.; Mosselman, E.
2008-01-01
We present an integrated analysis of bank erosion in a high-curvature bend of the gravel bed Cecina River (central Italy). Our analysis combines a model of fluvial bank erosion with groundwater flow and bank stability analyses to account for the influence of hydraulic erosion on mass failure
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Organic micropollutant removal during river bank filtration
Bertelkamp, C.
2015-01-01
This study investigated the factors influencing the main removal mechanisms (adsorption and biodegradation) for organic micropollutant (OMP) removal during river bank filtration (RBF) and the possibility of developing a predictive model of this process for OMP removal during RBF. Chapter 2 analysed
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Plant communities in relation to flooding and soil contamination in a lowland Rhine River floodplain
International Nuclear Information System (INIS)
Schipper, Aafke M.; Lotterman, Kim; Leuven, Rob S.E.W.; Ragas, Ad M.J.; Kroon, Hans de; Hendriks, A. Jan
2011-01-01
Using canonical correspondence analysis (CCA), relationships were investigated between plant species composition and flooding characteristics, heavy metal contamination and soil properties in a lowland floodplain of the Rhine River. Floodplain elevation and yearly average flooding duration turned out to be more important for explaining variation in plant species composition than soil heavy metal contamination. Nevertheless, plant species richness and diversity showed a significant decrease with the level of contamination. As single heavy metal concentrations seemed mostly too low for causing phytotoxic effects in plants, this trend is possibly explained by additive effects of multiple contaminants or by the concomitant influences of contamination and non-chemical stressors like flooding. These results suggest that impacts of soil contamination on plants in floodplains could be larger than expected from mere soil concentrations. In general, these findings emphasize the relevance of analyzing effects of toxic substances in concert with the effects of other relevant stressors. - Multiple contaminants and periodic flooding may pose cumulative stress to plants in lowland floodplains.
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Unland, N. P.; Cartwright, I.; Cendón, D. I.; Chisari, R.
2014-02-01
The residence time of groundwater within 50 m of the Tambo River, South East Australia, has been estimated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River which implies a gaining river system and not increasing bank storage with proximity to the Tambo River. Major ion concentrations and δ2H and δ18O values of bank water also indicate that bank infiltration does not significantly impact groundwater chemistry under baseflow and post-flood conditions, suggesting that the gaining nature of the river may be driving the return of bank storage water back into the Tambo River within days of peak flood conditions. The covariance between 3H and 14C indicates the leakage and mixing between old (~17 200 yr) groundwater from a semi-confined aquifer and younger groundwater (bank storage, as rapid pressure propagation into the semi-confined aquifer during flooding will minimise bank infiltration. This study illustrates the complex nature of river groundwater interactions and the potential downfall in assuming simple or idealised conditions when conducting hydrogeological studies.
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Numerical Estimation of the Outer Bank Resistance Characteristics in AN Evolving Meandering River
Wang, D.; Konsoer, K. M.; Rhoads, B. L.; Garcia, M. H.; Best, J.
2017-12-01
Few studies have examined the three-dimensional flow structure and its interaction with bed morphology within elongate loops of large meandering rivers. The present study uses a numerical model to simulate the flow pattern and sediment transport, especially the flow close to the outer-bank, at two elongate meandering loops in Wabash River, USA. The numerical grid for the model is based on a combination of airborne LIDAR data on floodplains and the multibeam data within the river channel. A Finite Element Method (FEM) is used to solve the non-hydrostatic RANS equation using a K-epsilon turbulence closure scheme. High-resolution topographic data allows detailed numerical simulation of flow patterns along the outer bank and model calibration involves comparing simulated velocities to ADCP measurements at 41 cross sections near this bank. Results indicate that flow along the outer bank is strongly influenced by large resistance elements, including woody debris, large erosional scallops within the bank face, and outcropping bedrock. In general, patterns of bank migration conform with zones of high near-bank velocity and shear stress. Using the existing model, different virtual events can be simulated to explore the impacts of different resistance characteristics on patterns of flow, sediment transport, and bank erosion.
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Water quality and treatment of river bank filtrate
De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.
2010-01-01
In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the
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Water quality and treatment of river bank filtrate
De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.
2009-01-01
In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the
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River banks and channel axis curvature: Effects on the longitudinal dispersion in alluvial rivers
Lanzoni, Stefano; Ferdousi, Amena; Tambroni, Nicoletta
2018-03-01
The fate and transport of soluble contaminants released in natural streams are strongly dependent on the spatial variations of the flow field and of the bed topography. These variations are essentially related to the presence of the channel banks and to the planform configuration of the channel. Large velocity gradients arise near to the channel banks, where the flow depth decreases to zero. Moreover, single thread alluvial rivers are seldom straight, and usually exhibit meandering planforms and a bed topography that deviates from the plane configuration. Channel axis curvature and movable bed deformations drive secondary helical currents which enhance both cross sectional velocity gradients and transverse mixing, thus crucially influencing longitudinal dispersion. The present contribution sets up a rational framework which, assuming mild sloping banks and taking advantage of the weakly meandering character often exhibited by natural streams, leads to an analytical estimate of the contribution to longitudinal dispersion associated with spatial non-uniformities of the flow field. The resulting relationship stems from a physics-based modeling of the flow in natural rivers, and expresses the bend averaged longitudinal dispersion coefficient as a function of the relevant hydraulic and morphologic parameters. The treatment of the problem is river specific, since it relies on an explicit spatial description, although linearized, of the flow field that establishes in the investigated river. Comparison with field data available from tracer tests supports the robustness of the proposed framework, given also the complexity of the processes that affect dispersion dynamics in real streams.
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O'Donnell, Jessica; Fryirs, Kirstie A; Leishman, Michelle R
2016-01-15
Anthropogenic disturbance has contributed to widespread geomorphic adjustment and the degradation of many rivers. This research compares for river reaches of varying condition, the potential for seed banks to support geomorphic river recovery through vegetation regeneration. Seven river reaches in the lower Hunter catchment of south-eastern Australia were assessed as being in poor, moderate, or good condition, based on geomorphic and ecological indicators. Seed bank composition within the channel and floodplain (determined in a seedling emergence study) was compared to standing vegetation. Seed bank potential for supporting geomorphic recovery was assessed by measuring native species richness, and the abundance of different plant growth forms, with consideration of the roles played by different growth forms in geomorphic adjustment. The exotic seed bank was considered a limiting factor for achieving ecological restoration goals, and similarly analysed. Seed bank native species richness was comparable between the reaches, and regardless of condition, early successional and pioneer herbs, sedges, grasses and rushes dominated the seed bank. The capacity for these growth forms to colonise and stabilise non-cohesive sediments and initiate biogeomorphic succession, indicates high potential for the seed banks of even highly degraded reaches to contribute to geomorphic river recovery. However, exotic propagules increasingly dominated the seed banks of moderate and poor condition reaches and reflected increasing encroachment by terrestrial exotic vegetation associated with riparian degradation. As the degree of riparian degradation increases, the resources required to control the regeneration of exotic species will similarly increase, if seed bank-based regeneration is to contribute to both geomorphic and ecological restoration goals. Copyright © 2015 Elsevier B.V. All rights reserved.
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Risk assessment data banks at the Savannah River Site
International Nuclear Information System (INIS)
Townsend, C.S.; Durant, W.S.; Baughman, D.F.
1993-01-01
In the risk assessment business, it is a well known fact that past mistakes will not be remembered if nothing is done to record them and make them available for future reference and review. The Savannah River Site maintains a computer database system for nonreactor facilities that contains a compilation of the incidents that have occurred since the start up of the Site in 1953. The nationally recognized data banks are highly valued across the US Department of Energy (DOE) complex for their use in risk-related analyses. They provide data for uses such as failure rate analyses, equipment reliability and breakdown studies, project justification, incident investigations, design studies, Safety Analysis Reports, Process Hazards Reviews, consequence analyses, quality assurance studies, trend analyses, management decision, administrative control effectiveness studies, and process problem solving. Five risk assessment data banks exist in the areas of reprocessing, fuel fabrication, waste management, tritium, and the Savannah River Technology Center. The data banks are comprised of approximately one-third million entries collectively and continue to grow at a rate of about two hundred entries per day
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Hydrochemical processes in lowland rivers: insights from in situ, high-resolution monitoring
Directory of Open Access Journals (Sweden)
A. J. Wade
2012-11-01
Full Text Available This paper introduces new insights into the hydrochemical functioning of lowland river systems using field-based spectrophotometric and electrode technologies. The streamwater concentrations of nitrogen species and phosphorus fractions were measured at hourly intervals on a continuous basis at two contrasting sites on tributaries of the River Thames – one draining a rural catchment, the River Enborne, and one draining a more urban system, The Cut. The measurements complement those from an existing network of multi-parameter water quality sondes maintained across the Thames catchment and weekly monitoring based on grab samples. The results of the sub-daily monitoring show that streamwater phosphorus concentrations display highly complex dynamics under storm conditions dependent on the antecedent catchment wetness, and that diurnal phosphorus and nitrogen cycles occur under low flow conditions. The diurnal patterns highlight the dominance of sewage inputs in controlling the streamwater phosphorus and nitrogen concentrations at low flows, even at a distance of 7 km from the nearest sewage treatment works in the rural River Enborne. The time of sample collection is important when judging water quality against ecological thresholds or standards. An exhaustion of the supply of phosphorus from diffuse and multiple septic tank sources during storm events was evident and load estimation was not improved by sub-daily monitoring beyond that achieved by daily sampling because of the eventual reduction in the phosphorus mass entering the stream during events. The results highlight the utility of sub-daily water quality measurements and the discussion considers the practicalities and challenges of in situ, sub-daily monitoring.
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Directory of Open Access Journals (Sweden)
Kade Small
Full Text Available Hypoxia represents a growing threat to biodiversity in freshwater ecosystems. Here, aquatic surface respiration (ASR and oxygen thresholds required for survival in freshwater and simulated blackwater are evaluated for four lowland river fishes native to the Murray-Darling Basin (MDB, Australia. Juvenile stages of predatory species including golden perch Macquaria ambigua, silver perch Bidyanus bidyanus, Murray cod Maccullochella peelii, and eel-tailed catfish Tandanus tandanus were exposed to experimental conditions of nitrogen-induced hypoxia in freshwater and hypoxic blackwater simulations using dried river red gum Eucalyptus camaldulensis leaf litter. Australia's largest freshwater fish, M. peelii, was the most sensitive to hypoxia but given that we evaluated tolerances of juveniles (0.99 ± 0.04 g; mean mass ±SE, the low tolerance of this species could not be attributed to its large maximum attainable body mass (>100,000 g. Concentrations of dissolved oxygen causing 50% mortality (LC50 in freshwater ranged from 0.25 ± 0.06 mg l(-1 in T. tandanus to 1.58 ± 0.01 mg l(-1 in M. peelii over 48 h at 25-26 °C. Logistic models predicted that first mortalities may start at oxygen concentrations ranging from 2.4 mg l(-1 to 3.1 mg l(-1 in T. tandanus and M. peelii respectively within blackwater simulations. Aquatic surface respiration preceded mortality and this behaviour is documented here for the first time in juveniles of all four species. Despite the natural occurrence of hypoxia and blackwater events in lowland rivers of the MDB, juvenile stages of these large-bodied predators are vulnerable to mortality induced by low oxygen concentration and water chemistry changes associated with the decomposition of organic material. Given the extent of natural flow regime alteration and climate change predictions of rising temperatures and more severe drought and flooding, acute episodes of hypoxia may represent an underappreciated risk to riverine fish
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Measuring techniques for the characterisation of 137Cs contaminated river banks, Slovakia
International Nuclear Information System (INIS)
Slavik, O.; Moravek, J.
2000-01-01
In 1990, 137 Cs contaminated areas were discovered along 19 km of the banks of the rivers receiving discharged waste waters from the Bohunice NPP. The contamination was the result of uncontrolled releases of drainage water from the radioactive waste treatment unit and two accidents on the CO 2 cooled and heavy water moderated NPP-A1 unit in 1976 and 1977. In total, more than 67.000 m 2 of bank surfaces (the lower and middle parts of their slopes) have been found to be contaminated with 137 Cs at levels exceeding 1 kBq/kg of soil. This paper describes the planning for restoration of these river banks with emphasis on site characterization techniques used for these purposes. The general strategy and application of monitoring techniques for the purposes of characterisation of contaminated river banks is the main topic of the work performed in the context of the IAEA CRP on 'Site Characterisation Techniques for Environmental Restoration'. First results in developing new and more sophisticated measuring techniques, needed for the characterization of discontinuous and spot-contamination found on parts of the banks are given. The technique described is based on a dose rate measurement approach, using ratio of two detector readings at two different distances above ground and Monte-Carlo simulations of the plastic scintillation detector responses. The method will also be useful, for the final, post-remediation survey of residual spots of 137 Cs contamination. (author)
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Braid-plain dynamics and bank erosion along the Matanuska River, Alaska
Curran, J. H.
2009-12-01
Braid-plain activity and geomorphic features in the Matanuska River in southcentral Alaska between 1949 and 2006 were examined to support a bank erosion hazard assessment. The glacial Matanuska River drains 6,500 km2 and is braided for 85 percent of its 150 km course, which parallels a major highway and flows through the towns of Sutton and Palmer, Alaska. The historical braid plain was defined as the envelope of areas with active channels, unvegetated bars, or vegetated bars with evidence of channels since 1949 and delineated in a GIS from 1949, 1962, and 2006 aerial orthoimagery. We created a strip map of bank height and composition (primarily bedrock and unconsolidated sediment) at braid-plain margins and outlined valley bottom features (terraces and tributary fans) adjacent to the braid plain to assess erodibility. Braid-plain dynamism has created a mosaic of extensive lightly vegetated bars interspersed with forested bars in strips along the banks and in small mid-channel positions. Abandoned channels filled with groundwater or tributary streamflow have created clearwater side channels within these bars that serve as the primary spawning location for chum, sockeye, and coho salmon in the Matanuska River basin. Erosion magnitudes for the periods 1949-1962 and 1962-2006 were computed as braid-plain expansion at transects across the historical braid-plain boundaries. Episodic, spatially distributed erosion and the antiquity of some eroded surfaces suggests that average annual erosion rates at a location are not adequate for assessing future erosion at that location in a braid plain. Lateral expansion caused bank erosion of 100 -275 m at 20 locations over the full period, about half at tributary fans and most occurring in a single time period. Minor growth of tributary fans constricted the braid plain, and emerging terraces have the potential to shrink the braid plain. Eroded banks included undated but pre-historic fluvial terraces and tributary fans. Where
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Directory of Open Access Journals (Sweden)
Przybyłek Jan
2017-12-01
Full Text Available River bank filtration (RBF is a system that enriches groundwater resources by induced infiltration of river water to an aquifer. Problematic during operation of RBF systems is the deterioration of infiltration effectiveness caused by river bed clogging. This situation was observed in the Krajkowo well field which supplies fresh water to the city of Poznań (Poland during and after the long hydrological drought between the years 1989 and 1992. The present note discusses results of specific hydrogeological research which included drilling of a net of boreholes to a depth of 10 m below river bottom (for sediment sampling as well as for hydrogeological measurements, analyses of grain size distribution and relative density studies. The results obtained have allowed the recognition of the origin of the clogging processes, as well as the documentation of the clogged parts of the river bottom designated for unclogging activities.
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Flow Regime Changes: From Impounding a Temperate Lowland River to Small Hydropower Operations
Directory of Open Access Journals (Sweden)
Petras Punys
2015-07-01
Full Text Available This article discusses the environmental issues facing small hydropower plants (SHPs operating in temperate lowland rivers of Lithuania. The research subjects are two medium head reservoir type hydro schemes considered within a context of the global fleet of SHPs in the country. This research considers general abiotic indicators (flow, level, water retention time in the reservoirs of the stream that may affect the aquatic systems. The main idea was to test whether the hydrologic regime has been altered by small hydropower dams. The analysis of changes in abiotic indicators is a complex process, including both pre- and post-reservoir construction and post commissioning of the SHPs under operation. Downstream hydrograph (flow and stage ramping is also an issue for operating SHPs that can result in temporary rapid changes in flow and consequently negatively impact aquatic resources. This ramping has been quantitatively evaluated. To avoid the risk of excessive flow ramping, the types of turbines available were evaluated and the most suitable types for the natural river flow regime were identified. The results of this study are to allow for new hydro schemes or upgrades to use water resources in a more sustainable way.
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Bray, E. N.; Dunne, T.; Dozier, J.
2011-12-01
Systematic downstream variation of channel characteristics, scaled by flow affects the transport and distribution of heat throughout a large river. As water moves through a river channel, streamflow and velocity may fluctuate by orders of magnitude primarily due to channel geometry, slope and resistance to flow, and the time scales of those fluctuations range from days to decades (Constantz et al., 1994; Lundquist and Cayan, 2002; McKerchar and Henderson, 2003). It is well understood that the heat budget of a river is primarily governed by surface exchanges, with the most significant surface flux coming from net shortwave radiation. The absorption of radiation at a given point in a river is determined by the wavelength-dependent index of refraction, expressed by the angle of refraction and the optical depth as a function of physical depth and the absorption coefficient (Dozier, 1980). Few studies consider the influence of hydrologic alteration to the optical properties governing net radiative heat transfer in a large lowland river, yet it is the most significant component of the heat budget and definitive to a river's thermal regime. We seek a physically based model without calibration to incorporate scale-dependent physical processes governing heat and flow dynamics in large rivers, how they change across the longitudinal profile, and how they change under different flow regimes. Longitudinal flow and heat flux analyses require synoptic flow time series from multiple sites along rivers, and few hydrometric networks meet this requirement (Larned et al, 2011). We model the energy budget in a regulated 240-km mainstem reach of the San Joaquin River California, USA equipped with multiple gaging stations from Friant Dam to its confluence with the Merced River during a large-scale flow experiment. We use detailed hydroclimatic observations distributed across the longitudinal gradient creating a non-replicable field experiment of heat fluxes across a range of flow regime
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Effects of Bank Revetment on Sacramento River, California
Michael D. Harvey; Chester C. Watson
1989-01-01
Twelve low radius of curvature bends, half of which were rivetted, were studied in the Butte Basin reach of Sacramento River, California, to determine whether bank revetment deleteriously affected salmonid habitat. At low discharge (128.6 cubic meters/s) it was demonstrated that revetment does not cause channel narrowing or deepening, nor does it prevent re-entrainment...
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Schenk, Edward R.; Hupp, Cliff R.; Richter, Jean M.; Kroes, Daniel E.
2010-01-01
Dam construction and its impact on downstream fluvial processes may substantially alter ambient bank stability, floodplain inundation patterns, and channel morphology. Most of the world's largest rivers have been dammed, which has prompted management efforts to mitigate dam effects. Three high dams (completed between 1953 and 1963) occur along the Piedmont portion of the Roanoke River, North Carolina; just downstream, the lower part of the river flows across largely unconsolidated Coastal Plain deposits. To document bank erosion rates along the lower Roanoke River, more than 700 bank erosion pins were installed along 124 bank transects. Additionally, discrete measurements of channel bathymetry, water clarity, and presence or absence of mass wasting were documented along the entire 153-kilometer-long study reach. Amounts of bank erosion in combination with prior estimates of floodplain deposition were used to develop a bank erosion and floodplain deposition sediment budget for the lower river. Present bank erosion rates are relatively high [mean 42 milimeters per year (mm/yr)] and are greatest along the middle reaches (mean 60 mm/yr) and on lower parts of the bank on all reaches. Erosion rates were likely higher along upstream reaches than present erosion rates such that erosion rate maxima have migrated downstream. Mass wasting and water clarity also peak along the middle reaches.
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Pupim, Fabiano do Nascimento; Bierman, Paul R.; Assine, Mario Luis; Rood, Dylan H.; Silva, Aguinaldo; Merino, Eder Renato
2015-04-01
The importance of Earth's low sloping areas in regard to global erosion and sediment fluxes has been widely and vigorously debated. It is a crucial area of research to elucidate geologically meaningful rates of land-surface change and thus the speed of element cycling on Earth. However, there are large portions of Earth where erosion rates have not been well or extensively measured, for example, the tropical lowlands. The Cuiabana lowlands are an extensive low-altitude and low-relief dissected metamorphic terrain situated in the Upper Paraguay river basin, central-west Brazil. Besides exposures of highly variable dissected metamorphic rocks, flat residual lateritic caps related to a Late Cenozoic planation surface dominate interfluves of the Cuiabana lowlands. The timescale over which the lowlands evolved and the planation surface developed, and the rate at which they have been modified by erosion, are poorly known. Here, we present measurements of in situ produced cosmogenic 10Be in outcropping metamorphic bedrock and clastic-lateritic caps to quantify rates of erosion of the surface and associated landforms in order to better understand the Quaternary landscape evolution of these lowlands. Overall, slow erosion rates (mean 10 m/Ma) suggest a stable tectonic environment in these lowlands. Erosion rates vary widely between different lithologies (range 0.57 to 28.3 m/Ma) consistent with differential erosion driving regional landform evolution. The lowest erosion rates are associated with the low-relief area (irregular plains), where clastic-laterite (mean 0.67 m/Ma) and quartzite (mean 2.6 m/Ma) crop out, whereas the highest erosion rates are associated with dissection of residual hills, dominated by metasandstone (mean 11.6 m/Ma) and phyllite (mean 27.6 m/Ma). These data imply that the Cuiabana lowland is comprised of two dominant landform sets with distinct and different dynamics. Because the planation surface (mostly lowlands) is lowering and losing mass more
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Possible Location of Gaspar Dias Fort in Relation to the Present River Bank
Digital Repository Service at National Institute of Oceanography (India)
Mascarenhas, A.; Tripati, S.; ManiMurali, R.
, it would be worthwhile to delineate the past river bank with respect to the present one, and to check whether any morphological changes occurred since then. Although the fort is marked by the river side in historical maps, the exact position of the shore...
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The science and practice of river restoration
Wohl, Ellen; Lane, Stuart N.; Wilcox, Andrew C.
2015-08-01
River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration as a social process. We also examine challenges for scientific understanding in river restoration. These include: how physical complexity supports biogeochemical function, stream metabolism, and stream ecosystem productivity; characterizing response curves of different river components; understanding sediment dynamics; and increasing appreciation of the importance of incorporating climate change considerations and resiliency into restoration planning. Finally, we examine changes in river restoration within the past decade, such as increasing use of stream mitigation banking; development of new tools and technologies; different types of process-based restoration; growing recognition of the importance of biological-physical feedbacks in rivers; increasing expectations of water quality improvements from restoration; and more effective communication between practitioners and river scientists.
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Energy Technology Data Exchange (ETDEWEB)
Jarvie, H.P., E-mail: hpj@ceh.ac.uk [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, OX10 8BB (United Kingdom); Neal, C. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, OX10 8BB (United Kingdom); Rowland, A.P. [Centre for Ecology and Hydrology, Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Neal, M.; Morris, P.N. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, OX10 8BB (United Kingdom); Lead, J.R. [School of Geography, Earth and Environmental Science, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Lawlor, A.J.; Woods, C.; Vincent, C.; Guyatt, H.; Hockenhull, K. [Centre for Ecology and Hydrology, Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)
2012-09-15
An assessment is made of the role of riverine colloids in macronutrient (nitrogen, phosphorus and carbon), metal and trace element partitioning and transport, for five rivers in the Ribble and Wyre catchments in north-western England, under baseflow/near-baseflow conditions. Cross-flow ultrafiltration was used to separate colloidal (< 0.45 Micro-Sign m > 1 kDa) and truly dissolved (< 1 kDa) fractions from river water. Clear patterns were observed, along the upland-lowland land use continuum, in the partitioning and transport of macronutrients and metals between the colloidal, truly dissolved and acid-available particulate (> 0.45 {mu}m, suspended) fractions. Of these operationally-defined fractions measured, colloids were generally more important for both macronutrient and metal transport in the upland than in the lowland rivers. The results suggest that organic moieties in truly dissolved form from sewage effluent may have a greater capacity to chelate metals. Organic-rich colloids in the upland moorlands and metal oxide colloidal precipitates in the industrial rivers had a higher capacity for binding metals than the colloidal fractions in the urban and agricultural lowland rivers. Aggregation of these colloids may provide an important mechanism for formation of larger suspended particulates, accounting for a higher degree of metal enrichment in the acid-available particulate fractions of the upland moorland and lowland industrial rivers, than in the lowland agricultural and urban rivers. This mechanism of transfer of contaminants to larger aggregates via colloidal intermediates, known as 'colloidal pumping' may also provide a mechanism for particulate P formation and the high proportion of P being transported in the particulate fraction in the uplands. The cross-flow ultrafiltration data also allowed refinement of partition coefficients, by accounting for colloids within the solids phase and replacing the filtered (< 0.45 {mu}m) fraction with the truly
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Assessment and classification of hydromorphological state of the Breń River
Directory of Open Access Journals (Sweden)
Borek Łukasz
2016-09-01
Full Text Available The paper presents the classification of the hydromorphological condition of the Breń River according to the River Habitat Survey (RHS. The research of the hydromorphological assessment of the Breń River, which is a right-bank tributary of the Vistula River and almost entirely flows through the area of the Dąbrowa Tarnowska district was conducted in June 2015. The research sites were situated on the border of the Tarnów Plateau and the Vistula Lowland. The Breń River in these sections flows through rural areas used for agricultural purposes with low-density housing. The analysis of qualitative parameters describing the morphological characteristics were based on two synthetic indices of stream quality: Habitat Quality Assesment (HQA and Habitat Modification Score (HMS. The calculated numerical values of the two indices proved that the sections of the Breń River correspond with the third and fifth class, which means a moderate (III and very bad (V hydromorphological condition.
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River Bank Erosion and the Influence of Environmental Flow Management
Vietz, Geoff J.; Lintern, Anna; Webb, J. Angus; Straccione, David
2018-03-01
Environmental flows aim to influence river hydrology to provide appropriate physical conditions for ecological functioning within the restrictions of flow regulation. The hydrologic characteristics of flow events, however, may also lead to unintended morphologic effects in rivers, such as increases in riverbank erosion beyond natural rates. This may negatively impact habitat for biota, riparian infrastructure, and land use. Strategic environmental flow delivery linked to monitoring and adaptive management can help mitigate risks. We monitor riverbank condition (erosion and deposition) relative to environmental flows on the Goulburn River, Victoria, Australia. We describe the process of adaptive management aimed at reducing potential impacts of flow management on bank condition. Field measurements (erosion pins) quantify the hydrogeomorphic response of banks to the delivery of planned and natural flow events. Managed flows provide opportunities for monitoring riverbank response to flows, which in turn informs planning. The results demonstrate that environmental flows have little influence on bank erosion and visual perceptions in the absence of monitoring are an unreliable guide. This monitoring project represents a mutually beneficial, science-practice partnership demonstrating that a traditional `know then do' approach can be foreshortened by close collaboration between researchers and managers. To do so requires transparent, often informal lines of communication. The benefits for researchers-a more strategic and targeted approach to monitoring activities; and benefits for the practitioners-reduced time between actions and understanding response; mean that a learn by doing approach is likely to have better outcomes for researchers, stakeholders, the public, and the environment.
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River Bank Erosion and the Influence of Environmental Flow Management.
Vietz, Geoff J; Lintern, Anna; Webb, J Angus; Straccione, David
2018-03-01
Environmental flows aim to influence river hydrology to provide appropriate physical conditions for ecological functioning within the restrictions of flow regulation. The hydrologic characteristics of flow events, however, may also lead to unintended morphologic effects in rivers, such as increases in riverbank erosion beyond natural rates. This may negatively impact habitat for biota, riparian infrastructure, and land use. Strategic environmental flow delivery linked to monitoring and adaptive management can help mitigate risks. We monitor riverbank condition (erosion and deposition) relative to environmental flows on the Goulburn River, Victoria, Australia. We describe the process of adaptive management aimed at reducing potential impacts of flow management on bank condition. Field measurements (erosion pins) quantify the hydrogeomorphic response of banks to the delivery of planned and natural flow events. Managed flows provide opportunities for monitoring riverbank response to flows, which in turn informs planning. The results demonstrate that environmental flows have little influence on bank erosion and visual perceptions in the absence of monitoring are an unreliable guide. This monitoring project represents a mutually beneficial, science-practice partnership demonstrating that a traditional 'know then do' approach can be foreshortened by close collaboration between researchers and managers. To do so requires transparent, often informal lines of communication. The benefits for researchers-a more strategic and targeted approach to monitoring activities; and benefits for the practitioners-reduced time between actions and understanding response; mean that a learn by doing approach is likely to have better outcomes for researchers, stakeholders, the public, and the environment.
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International Nuclear Information System (INIS)
Jarvie, H.P.; Neal, C.; Rowland, A.P.; Neal, M.; Morris, P.N.; Lead, J.R.; Lawlor, A.J.; Woods, C.; Vincent, C.; Guyatt, H.; Hockenhull, K.
2012-01-01
An assessment is made of the role of riverine colloids in macronutrient (nitrogen, phosphorus and carbon), metal and trace element partitioning and transport, for five rivers in the Ribble and Wyre catchments in north-western England, under baseflow/near-baseflow conditions. Cross-flow ultrafiltration was used to separate colloidal ( 1 kDa) and truly dissolved ( 0.45 μm, suspended) fractions. Of these operationally-defined fractions measured, colloids were generally more important for both macronutrient and metal transport in the upland than in the lowland rivers. The results suggest that organic moieties in truly dissolved form from sewage effluent may have a greater capacity to chelate metals. Organic-rich colloids in the upland moorlands and metal oxide colloidal precipitates in the industrial rivers had a higher capacity for binding metals than the colloidal fractions in the urban and agricultural lowland rivers. Aggregation of these colloids may provide an important mechanism for formation of larger suspended particulates, accounting for a higher degree of metal enrichment in the acid-available particulate fractions of the upland moorland and lowland industrial rivers, than in the lowland agricultural and urban rivers. This mechanism of transfer of contaminants to larger aggregates via colloidal intermediates, known as ‘colloidal pumping’ may also provide a mechanism for particulate P formation and the high proportion of P being transported in the particulate fraction in the uplands. The cross-flow ultrafiltration data also allowed refinement of partition coefficients, by accounting for colloids within the solids phase and replacing the filtered (< 0.45 μm) fraction with the truly dissolved (< 1 kDa) concentrations. These provided a clearer description of the controls on metal and P partitioning along the upland-lowland continuum. -- Highlights: ► Using cross-flow ultrafiltration, we assess the role of colloids in macronutrient and metal partitioning
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Predicting the Rate of River Bank Erosion Caused by Large Wood Log
Zhang, N.; Rutherfurd, I.; Ghisalberti, M.
2016-12-01
When a single tree falls into a river channel, flow is deflected and accelerated between the tree roots and the bank face, increasing shear stress and scouring the bank. The scallop shaped erosion increases the diversity of the channel morphology, but also causes concern for adjacent landholders. Concern about increased bank erosion is one of the main reasons for large wood to still be removed from channels in SE Australia. Further, the hydraulic effect of many logs in the channel can reduce overall bank erosion rates. Although both phenomena have been described before, this research develops a hydraulic model that estimates their magnitude, and tests and calibrates this model with flume and field measurements, with logs with various configurations and sizes. Specifically, the model estimates the change in excess shear stress on the bank associated . The model addresses the effect of the log angle, distance from bank, and log size and flow condition by solving the mass continuity and energy conservation between the cross section at the approaching flow and contracted flow. Then, we evaluate our model against flume experiment preformed with semi-realistic log models to represent logs in different sizes and decay stages by comparing the measured and simulated velocity increase in the gap between the log and the bank. The log angle, distance from bank, and flow condition are systemically varied for each log model during the experiment. Final, the calibrated model is compared with the field data collected in anabranching channels of Murray River in SE Australia where there are abundant instream logs and regulated and consistent high flow for irrigation. Preliminary results suggest that a log can significantly increase the shear stress on the bank, especially when it positions perpendicular to the flow. The shear stress increases with the log angle in a rising curve (The log angle is the angle between log trunk and flow direction. 0o means log is parallel to flow with
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Radium contamination of the Laak river banks as a consequence of phosphate industry in Belgium
International Nuclear Information System (INIS)
Paridaens, J.; Vanmarcke, H.
2002-01-01
For over half a century, phosphate ores of marine origin, containing 226 Ra have been processed in Belgium to produce calcium phosphate for use in cattle food. As a result, the wastewaters contained 226 Ra, which was discharged into two little rivers, one of which is the Laak. The purpose of this study was to chart the radium contamination of the river banks, and of some areas that are regularly flooded by the river. It was seen that enhanced concentration of 226 Ra do occur along the river banks, but that the contaminated area is mostly confined to a 10 m strip on both sides of the river, even in the flooding zones. At present, no dwellings are present on top of the contamination, and no crops for direct human consumption are grown there, so there is no immediate threat to the population. (author)
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Keshavarzi, Alireza; Noori, Lila Khaje
2010-12-01
River bed scourings are a major environmental problem for fish and aquatic habitat resources. In this study, to prevent river bed and banks from scouring, different types of bed sills including convex, concave and linear patterns were installed in a movable channel bed in a laboratory flume. The bed sills were tested with nine different arrangements and under different flow conditions. To find the most effective bed sill pattern, the scouring depth was measured downstream of the bed sill for a long experimental duration. The scour depth was measured at the middle and at the end of each experimental test for different ratios of the arch radius to the channel width [r/w]. The experimental results indicated that the convex pattern with r/w=0.35 produced minimum bed scouring depth at the center line whereas the concave pattern with r/w=0.23 produced the minimum scour depth at the wall banks. Therefore, the convex pattern was the most effective configuration for prevention of scouring at the center line of the river while the concave pattern was very effective to prevent scouring at the river banks. These findings can be suggested to be used in practical applications.
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Savannah River Laboratory data banks for risk assessment of fuel reprocessing plants
International Nuclear Information System (INIS)
Durant, W.S.
1981-10-01
The Savannah River Laboratory maintains a series of computerized data banks primarily as an aid in probabilistic risk assessment studies in the fuel reprocessing facilities. These include component failure rates, generic incidents, and reports of specific deviations from normal operating conditions. In addition to providing data for probability studies, these banks, have served as a valuable aid in trend analysis, equipment histories, process hazards analysis, consequence assessments, incident audit, process problem solving, and training
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Spatio-temporal changes in river bank mass failures in the Lockyer Valley, Queensland, Australia
Thompson, Chris; Croke, Jacky; Grove, James; Khanal, Giri
2013-06-01
Wet-flow river bank failure processes are poorly understood relative to the more commonly studied processes of fluvial entrainment and gravity-induced mass failures. Using high resolution topographic data (LiDAR) and near coincident aerial photography, this study documents the downstream distribution of river bank mass failures which occurred as a result of a catastrophic flood in the Lockyer Valley in January 2011. In addition, this distribution is compared with wet flow mass failure features from previous large floods. The downstream analysis of these two temporal data sets indicated that they occur across a range of river lengths, catchment areas, bank heights and angles and do not appear to be scale-dependent or spatially restricted to certain downstream zones. The downstream trends of each bank failure distribution show limited spatial overlap with only 17% of wet flows common to both distributions. The modification of these features during the catastrophic flood of January 2011 also indicated that such features tend to form at some 'optimum' shape and show limited evidence of subsequent enlargement even when flow and energy conditions within the banks and channel were high. Elevation changes indicate that such features show evidence for infilling during subsequent floods. The preservation of these features in the landscape for a period of at least 150 years suggests that the seepage processes dominant in their initial formation appear to have limited role in their continuing enlargement over time. No evidence of gully extension or headwall retreat is evident. It is estimated that at least 12 inundation events would be required to fill these failures based on the average net elevation change recorded for the 2011 event. Existing conceptual models of downstream bank erosion process zones may need to consider a wider array of mass failure processes to accommodate for wet flow failures.
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Konsoer, K. M.; Rhoads, B. L.; Langendoen, E. J.; Johnson, K.; Ursic, M.
2012-12-01
Rates of meander migration are dependent upon dynamic interactions between planform geometry, three-dimensional flow structure, sediment transport, and the erodibility and geotechnical properties of the channel banks and floodplains. Riparian vegetation can greatly reduce the rate of migration through root-reinforcement and increased flow resistance near the bank. In particular, forested riverbanks can also provide large woody debris (LWD) to the channel, and if located near the outer bank, can act to amour the bank by disrupting three-dimensional flow patterns and redirecting flow away from the bank-toe, the locus of erosion in meandering rivers. In this paper, three-dimensional flow patterns and migration rates are compared for two meander bends, one forested and one non-forested, on the Wabash River, near Grayville, Illinois. Flow data were obtained using acoustic Doppler current profilers (ADCP) for two large flow events in May and June 2011. LWD was mapped using a terrestrial LiDAR survey, and residence times for the LWD were estimated by comparing the survey data to time-series aerial photography. Rates of migration and planform evolution were determined through time-series analysis of aerial photography from 1938-2011. Results from this study show that near-bank LWD can have a significant influence on flow patterns through a meander bend and can disrupt helical flow near the outer bank, thereby reducing the effect of the high velocity core on the toe of the bank. Additionally, these effects influence migration rates and the planform evolution of meandering rivers.
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Directory of Open Access Journals (Sweden)
Laks Ireneusz
2017-12-01
Full Text Available The analysis of in situ measurements of velocity distribution in the floodplain of the lowland river has been carried out. The survey area was located on a bypass channel of the Warta River (West of Poland which is filled with water only in case of flood waves. The floodplain is covered by grassland and reed marsh habitats. The velocity measurements were performed with an acoustic Doppler current profiler (ADCP in a cross-section with a bed reinforced with concrete slabs. The measured velocities have reflected the differentiated impact of various vegetation types on the loss of water flow energy. The statistical analyses have proven a relationship between the local velocities and the type of plant communities.
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Directory of Open Access Journals (Sweden)
Andrzej Zawal
2018-05-01
Full Text Available This paper examines the impact of disturbance factors—flooding and intermittency—on the distribution of water mites in the riparian springs situated in the valley of a small lowland river, the Krąpiel. The landscape factors and physicochemical parameters of the water were analysed in order to gain an understanding of the pattern of water mite assemblages in the riparian springs. Three limnological types of springs were examined (helocrenes, limnocrenes and rheocrenes along the whole course of the river and a total of 35 water mite species were found. Our study shows that flooding influences spring assemblages, causing a decrease in crenobiontic water mites in flooded springs. The impact of intermittency resulted in a high percentage of species typical of temporary water bodies. Surprisingly, the study revealed the positive impact of the anthropogenic transformation of the river valley: preventing the riparian springs from flooding enhances the diversity of crenobiontic species in non-flooded springs. In the conclusion, our study revealed that further conservation strategies for the protection of the riparian springs along large rivers would take into account ongoing climatic changes and possible the positive impact of the anthropogenic transformation of river valleys.
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Contraction rate, flow modification and bed layering impact on scour at the elliptical guide banks
Gjunsburgs, B.; Jaudzems, G.; Bizane, M.; Bulankina, V.
2017-10-01
Flow contraction by the bridge crossing structures, intakes, embankments, piers, abutments and guide banks leads to general scour and the local scour in the vicinity of the structures. Local scour is depending on flow, river bed and structures parameters and correct understanding of the impact of each parameter can reduce failure possibility of the structures. The paper explores hydraulic contraction, the discharge redistribution between channel and floodplain during the flood, local flow modification and river bed layering on depth, width and volume of scour hole near the elliptical guide banks on low-land rivers. Experiments in a flume, our method for scour calculation and computer modelling results confirm a considerable impact of the contraction rate of the flow, the discharge redistribution between channel and floodplain, the local velocity, backwater and river bed layering on the depth, width, and volume of scour hole in steady and unsteady flow, under clear water condition. With increase of the contraction rate of the flow, the discharge redistribution between channel and floodplain, the local velocity, backwater values, the scour depth increases. At the same contraction rate, but at a different Fr number, the scour depth is different: with increase in the Fr number, the local velocity, backwater, scour depth, width, and volume is increasing. Acceptance of the geometrical contraction of the flow, approach velocity and top sand layer of the river bed for scour depth calculation as accepted now, may be the reason of the structures failure and human life losses.
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Directory of Open Access Journals (Sweden)
M. Schletterer
2017-01-01
Full Text Available Within the joint Russian-Austrian monitoring programme “REFCOND_VOLGA (2006 – 20XX”, monitoring sites were established in the headwaters of the Volga (Tver Region. River Tudovka, a right tributary to the Volga River, was included within this monitoring programme as its catchment is partly protected and has only few anthropogenic activities. The monitoring activities include physico-chemical and hydraulic parameters as well as biota with a focus is on benthic organisms (diatoms and macrozoobenthos. In this work, the longitudinal patterns in community structure are classified in the lowland river Tudovka using a novel feature-based approach taken from signal processing theory. The method first clusters field sampling data into longitudinal classes (upper, middle, lower course. Community features based on the relative frequency of individual species occurring per class are then generated. We apply both generative and discriminative classification methods. The application of generative methods provides data models which predict the probability of a new sample to belong to an existing class. In contrast, discriminative approaches search for differences between classes and allocate new data accordingly. Leveraging both methods allows for the creation of stable classifications. On this basis we show how the community features can be used to predict the longitudinal class. The community features approach also allows for a robust cross-comparison of investigation reaches over time. In cases where suitable long-term data set are available, predictive models using this approach can also be developed.
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Sarma, J. N.; Acharjee, S.
2012-09-01
The Kaziranga National Park is a forest-edged riverine grassland inhabited by the world's largest population of one-horned rhinoceroses, as well as a wide diversity of animals. The park is situated on the southern bank of the Brahmaputra River at the foot of the Mikir Hills. National Highway 37 forms the southern boundary and the northern boundary is the river Brahmaputra and covers an area of about 430 km2. The Brahmaputra River flows by Kaziranga National Park in a braided course for about 53 km. Sequential changes in the position of banklines of the river due to consistent bank erosion have been studied from Survey of India topographic maps of 1912-1916 and 1972, satellite IRS LISS III images from 1998 to 2008 using GIS. Study of bank line shift due to the bank erosion around Kaziranga has been carried out for the periods 1912-1916 to 1972, 1972 to 1998 and 1998 to 2008. The amounts of the bank area lost due to erosion and gained due to sediment deposition are estimated separately. The total area eroded during 1912-1916 to 1972 was more (84.87 km2) as compared to accretion due to sediment deposition (24.49 km2), the total area eroded was also more in 1972-1998 (44.769 km2) as compared to accretion (29.47 km2) and the total area eroded was again more in 1998-2008 (20.41 km2) as compared to accretion (7.89 km2). The rates of erosion during 1912-1916 to 1970, 1970 to 1998, and 1998 to 2008 were 1.46, 1.59 and 1.021 km2 per year, respectively. During the entire period (1912-1916 to 2008) of study the erosion on the whole was 150.04 km2 and overall accretion was 61.86 km2 resulting in a loss of 88.188 km2 area of the park. The maximum amounts of shift of the bankline during 1912-1916 to 1970, 1970 to 1998, and 1998 to 2008 were 4.58 km, 3.36 km, and 1.92 km, respectively, which amount to the rates of shift as 0.078, 0.12 and 0.096 km per year, respectively. A lineament and a few faults have controlled the trend of the course of the Brahmaputra around Kaziranga area
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Bertelkamp, C.; Reungoat, J.; Botton, S.; Cornelissen, E.; Ghadiri, E.; De Jonge, M.; Singhal, N.; Van der Hoek, J.P.; Verliefde, A.R.D.
2012-01-01
This paper investigates the degradation behavior of 14 organic micropoliutants (OMPs), selected for their different physico-chemical properties (e.g., molecular weight, hydrophobicity and charge). In soil columns simulating the conditions prevailing in the first meter of river bank filtration (RBF)
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Zhang, Zhao-yong; Abuduwaili, Jilili; Jiang, Feng-qing
2015-07-01
This paper focuses on the sources, pollution status and potential ecology risks of heavy metals (Cr, Cu, Hg, As, Cd, Pb, and Zn) in the surface water, top sediment of river bed and soil along banks of Bortala River, which locates in the oasis region of Xinjiang, northwest China. Results showed that: (1) As a whole, contents of 7 tested heavy metals of Bortala River were low, while the maximum values of Hg, Cd, Pb, and Cr in the river water were significantly higher than those of Secondary Category of the Surface Water Quality Standards of People's Republic of China (GB 3838-2002) and Drinking Water Guideline from WHO. Analysis showed that the heavy metals contents of top sediment on river bed and soils along river banks were significantly higher than those of the river water. (Correlation analysis and enrichment factor (EF) calculation showed that in the river water, top sediment on river bed and soils along river banks, Hg, Cd, Pb, and Cr mainly originated from industrial emissions, urban and rural anthropogenic activities, transportation and agricultural production activities; While Cu, Zn, and As mainly originated from natural geological background and soil parent materials. (3) Pollution assessment showed that in three matrices, the single factor pollution index(Pi) and the integrated pollution index (Pz) of 7 heavy metals were all lower than 1, and they all belonged to safe and clean levels. (4) Potential ecology risk evaluation showed that as a whole the single factor potential ecological risk (Eir) and the integrated potential ecology risks (RI) of 7 heavy metals were relatively low, and would not cause threats to the health of water and soil environment of river basin, while the potential ecology risks of Cd, Hg, Pb, and Cr were significantly higher than those of other heavy metals.
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Lowland river systems - processes, form and function
DEFF Research Database (Denmark)
Pedersen, M. L.; Kronvang, B.; Sand-Jensen, K.
2006-01-01
Present day river valleys and rivers are not as dynamic and variable as they used to be. We will here describe the development and characteristics of rivers and their valleys and explain the background to the physical changes in river networks and channel forms from spring to the sea. We seek...... to answer two fundamental questions: How has anthropogenic disturbance of rivers changed the fundamental form and physical processes in river valleys? Can we use our understanding of fl uvial patterns to restore the dynamic nature of channelised rivers and drained fl oodplains in river valleys?...
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Fazel, Nasim; Torabi Haghighi, Ali; Kløve, Bjørn
2017-11-01
The natural flow regime of rivers has been strongly altered world-wide, resulting in ecosystem degradation and lakes drying up, especially in arid and semi-arid regions. Determining whether this is due mainly to climate change or to water withdrawal for direct human use (e.g. irrigation) is difficult, particularly for saline lake basins where hydrology data are scarce. In this study, we developed an approach for assessing climate and land use change impacts based on river flow records for headwater and lowland reaches of rivers, using the case of Lake Urmia basin, in north-westen Iran. Flow regimes at upstream and downstream stations were studied before and after major dam construction and irrigation projects. Data from 57 stations were used to establish five different time intervals representing 10 different land use development periods (scenarios) for upstream (not impacted) and downstream (impacted) systems. An existing river impact (RI) index was used to assess changes in three main characteristics of flow (magnitude, timing and, intra-annual variability). The results showed that irrigation was by far the main driving force for river flow regime changes in the lake basin. All stations close to the lake and on adjacent plains showed significantly higher impacts of land use change than headwaters. As headwaters are relatively unaffected by agriculture, the non-significant changes observed in headwater flow regimes indicate a minor effect of climate change on river flows in the region. The benefit of the method developed is clear interpretation of results based on river flow records, which is useful in communicating land use and climate change information to decision makers and lake restoration planners.
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Darby, Stephen E; Leyland, Julian; Kummu, Matti; Räsänen, Timo A; Lauri, Hannu
2013-04-01
We evaluate links between climate and simulated river bank erosion for one of the world's largest rivers, the Mekong. We employ a process-based model to reconstruct multidecadal time series of bank erosion at study sites within the Mekong's two main hydrological response zones, defining a new parameter, accumulated excess runoff (AER), pertinent to bank erosion. We employ a hydrological model to isolate how snowmelt, tropical storms and monsoon precipitation each contribute to AER and thus modeled bank erosion. Our results show that melt (23.9% at the upstream study site, declining to 11.1% downstream) and tropical cyclones (17.5% and 26.4% at the upstream and downstream sites, respectively) both force significant fractions of bank erosion on the Mekong. We also show (i) small, but significant, declines in AER and hence assumed bank erosion during the 20th century, and; (ii) that significant correlations exist between AER and the Indian Ocean Dipole (IOD) and El Niño Southern Oscillation (ENSO). Of these modes of climate variability, we find that IOD events exert a greater control on simulated bank erosion than ENSO events; but the influences of both ENSO and IOD when averaged over several decades are found to be relatively weak. However, importantly, relationships between ENSO, IOD, and AER and hence inferred river bank erosion are not time invariant. Specifically, we show that there is an intense and prolonged epoch of strong coherence between ENSO and AER from the early 1980s to present, such that in recent decades derived Mekong River bank erosion has been more strongly affected by ENSO.
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Soil microbial diversity patterns of a lowland spring environment
Vasileiadis, S.; Puglisi, E.; Arena, M.; Cappa, F.; Van Veen, J.A.; Cocconcelli, P.S.; Trevisan, M.
2013-01-01
The Po river plain lowland springs represent unique paradigms of managed environments. Their current locations used to be swamps that were drained 6–7 centuries ago, and they have been in constant use ever since. Our aims were to identify the effects of land use on the microbial communities of these
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Ecohydrology of an Embanked Lowland UK River Meadow and the Effects of Embankment Removal
Clilverd, H.; Thompson, J.; Sayer, C.; Heppell, K.; Axmacher, J.
2012-12-01
Pristine riparian and floodplain ecosystems are in a state of dynamic balance due to the regular floods that continuously reshape river channels and their banks, and transport water, sediment and nutrients onto the floodplain. However, the natural flow regime of many rivers has been altered by channelization and artificial embankments designed to protect agricultural and urban developments from flooding. This has had a lasting impact on the hydrological characteristics of floodplain ecosystems and the biological communities that inhabit them. Floodplain restoration, through embankment removal and the reconfiguration of river channels, is now being increasingly employed to re-establish river-floodplain connections and assist the recovery of lost or declining species. In order to manage a river restoration site for plant biodiversity, it is necessary to understand the physical and nutritional status of the root environment. We conducted fine scale (10 × 10 m) botanical and chemical sampling on a 3 ha embanked grassland meadow in Norfolk (Eastern England) and assessed the spatial pattern of plant communities in relation to soil physicochemical conditions. Continuous measurements of groundwater depth and river stage were collectively used to determine changes in the hydrological regime following embankment-removal. Prior to the restoration the meadow plant community was dominated by Holcus lanatus, Ranunculus repens and Agrostis stolonifera. Species richness was fairly low (mean: 8 spp. per m2), and indices of alpha-diversity suggest low heterogeneity of the plant assemblages (mean values for Shannon's Diversity and 1/Simpson's Diversity = 1.4 and 3.4, respectively). Top soils were moderately fertile, with mean respective Olsen P and plant available potassium concentrations of 9.1 mg P kg-1and 1.6 mg K+g-1. Plant available ammonium and nitrate concentrations were on average 31.7 mg NH4+-N kg-1 and 2.8 mg NO3--N kg-1, respectively. River water was enriched in nitrate
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Energy Technology Data Exchange (ETDEWEB)
Schipper, Aafke M. [Department of Environmental Science, Institute for Wetland and Water Research, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands)], E-mail: a.schipper@science.ru.nl; Wijnhoven, Sander [Centre for Sustainable Management of Resources, Institute for Science, Innovation and Society, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Netherlands Institute of Ecology, Centre for Estuarine and Marine Ecology, Monitor Taskforce, P.O. Box 140, 4400 AC Yerseke (Netherlands); Leuven, Rob S.E.W.; Ragas, Ad M.J.; Jan Hendriks, A. [Department of Environmental Science, Institute for Wetland and Water Research, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands)
2008-01-15
Soil metal concentrations, inundation characteristics and abundances of 14 arthropod taxa were investigated in a moderately contaminated lowland floodplain along the Rhine River and compared to the hinterland. Internal metal concentrations were determined for the orders of Coleoptera (beetles) and Araneida (spiders) and were related to soil concentrations. The floodplain was characterized by larger arthropod abundance than the hinterland, in spite of recurrent inundations and higher soil metal concentrations. Most arthropod taxa showed increasing abundance with decreasing distance to the river channel and increasing average inundation duration. For Cd, Cu, Pb and Zn, significant relations were found between arthropod concentrations and concentrations in soil. Significant relations were few but positive, indicating that increasing soil concentrations result in increasing body burdens in arthropods. For arthropod-eating vertebrates, these results might imply that larger prey availability in the floodplain coincides with higher metal concentrations in prey, possibly leading to increased exposure to metal contamination. - Recurrent floodplain inundations affect terrestrial arthropod numbers and metal contamination levels.
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International Nuclear Information System (INIS)
Schipper, Aafke M.; Wijnhoven, Sander; Leuven, Rob S.E.W.; Ragas, Ad M.J.; Jan Hendriks, A.
2008-01-01
Soil metal concentrations, inundation characteristics and abundances of 14 arthropod taxa were investigated in a moderately contaminated lowland floodplain along the Rhine River and compared to the hinterland. Internal metal concentrations were determined for the orders of Coleoptera (beetles) and Araneida (spiders) and were related to soil concentrations. The floodplain was characterized by larger arthropod abundance than the hinterland, in spite of recurrent inundations and higher soil metal concentrations. Most arthropod taxa showed increasing abundance with decreasing distance to the river channel and increasing average inundation duration. For Cd, Cu, Pb and Zn, significant relations were found between arthropod concentrations and concentrations in soil. Significant relations were few but positive, indicating that increasing soil concentrations result in increasing body burdens in arthropods. For arthropod-eating vertebrates, these results might imply that larger prey availability in the floodplain coincides with higher metal concentrations in prey, possibly leading to increased exposure to metal contamination. - Recurrent floodplain inundations affect terrestrial arthropod numbers and metal contamination levels
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Design principles of water sensitive in settlement area on the river banks
Ryanti, E.; Hasriyanti, N.; Utami, W. D.
2018-03-01
This research will formulate the principle of designing settlement area of Kapuas River Pontianak with the approach of water sensitive concept of urban design (WSUD) the densely populated settlement area. By using a case study the approach that is a dense settlement area located on the banks of the river with literature study techniques to formulate the aspects considered and components that are set in the design, descriptive analysis with the rationalistic paradigm for identification characteristics of the settlement in the river banks areas with consideration of WSUD elements and formulate the principles of designing water-sensitive settlement areas. This research is important to do because the problems related to the water management system in the existing riverside settlement in Pontianak has not been maximal to do. So the primary of this research contains several objectives that will be achieved that is identifying the characteristics of riverside settlement area based on consideration of design aspects of the area that are sensitive to water and the principle of designing the area so that the existing problem structure will be formulated in relation to the community’s need for infrastructure in settlement environment and formulate and develop appropriate technology guidelines for integrated water management systems in riverside settlement areas and design techniques for water-sensitive settlements (WSUD).
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Nowak, Arkadiusz; Rola, Kaja
2018-01-01
Riparian zones are very rich in species but subjected to strong anthropogenic changes and extremely prone to alien plant invasions, which are considered to be a serious threat to biodiversity. Our aim was to determine the spatial distribution of Chenopodium ficifolium, a species demonstrating strong confinement to large river valleys in Central Europe and an indicator of annual pioneer nitrophilous vegetation developing on river banks, which are considered to be of importance to the European Community. Additionally, the habitat preferences of the species were analysed. Differences in the richness and abundance of species diagnostic for riverside habitats, as well as the contribution of resident and invasive alien species in vegetation plots along three rivers differing in terms of size and anthropogenic impact were also examined. Finally, the effect of invaders on the phytocoenoses typical for C. ficifolium was assessed. The frequency of C. ficifolium clearly decreased with an increasing distance from the river. Among natural habitats, the species mostly preferred the banks of large rivers. The vegetation plots developing on the banks of the three studied rivers differed in total species richness, the number and cover of resident, diagnostic and invasive alien species, as well as in species composition. Our research indicates that abiotic and anthropogenic factors are the most significant drivers of species richness and plant cover of riverbank vegetation, and invasive alien plants affect this type of vegetation to a small extent. PMID:29543919
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Nobis, Agnieszka; Nowak, Arkadiusz; Rola, Kaja
2018-01-01
Riparian zones are very rich in species but subjected to strong anthropogenic changes and extremely prone to alien plant invasions, which are considered to be a serious threat to biodiversity. Our aim was to determine the spatial distribution of Chenopodium ficifolium, a species demonstrating strong confinement to large river valleys in Central Europe and an indicator of annual pioneer nitrophilous vegetation developing on river banks, which are considered to be of importance to the European Community. Additionally, the habitat preferences of the species were analysed. Differences in the richness and abundance of species diagnostic for riverside habitats, as well as the contribution of resident and invasive alien species in vegetation plots along three rivers differing in terms of size and anthropogenic impact were also examined. Finally, the effect of invaders on the phytocoenoses typical for C. ficifolium was assessed. The frequency of C. ficifolium clearly decreased with an increasing distance from the river. Among natural habitats, the species mostly preferred the banks of large rivers. The vegetation plots developing on the banks of the three studied rivers differed in total species richness, the number and cover of resident, diagnostic and invasive alien species, as well as in species composition. Our research indicates that abiotic and anthropogenic factors are the most significant drivers of species richness and plant cover of riverbank vegetation, and invasive alien plants affect this type of vegetation to a small extent.
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Walvoord, M. A.; Jepsen, S. M.; Rover, J.; Voss, C. I.; Briggs, M. A.
2015-12-01
Permafrost influence on the hydrologic connectivity of surface water bodies in high-latitude lowlands is complicated by subsurface heterogeneity and the propensity of the system to change over time. In general, permafrost limits the subsurface exchange of water, solute, and nutrients between lakes and rivers. It follows that permafrost thaw could enhance subsurface hydrologic connectivity among surface water bodies, but the impact of this process on lake distribution is not well known. Changes in the extent of lakes in interior Alaska have important ecological and societal impacts since lakes provide (1) critical habitat for migratory arctic shorebirds and waterfowl, fish, and wildlife, and (2) provisional, recreational, and cultural resources for local communities. We utilize electromagnetic imaging of the shallow subsurface and remote sensing of lake level dynamics in the Yukon Flats of interior Alaska, USA, together with water balance modeling, to gain insight into the influence of discontinuous permafrost on lowland lake systems. In the study region with relatively low precipitation, observations suggest that lakes that are hydrologically isolated during normal conditions are sustained by periodic river flooding events, including ice-jam floods that occur during river ice break-up. Climatically-influenced alterations in flooding frequency and intensity, as well as depth to permafrost, are quantitatively assessed in the context of lake maintenance. Scenario modeling is used to evaluate lake level evolution under plausible changing conditions. Model results demonstrate how permafrost degradation can reduce the dependence of typical lowland lakes on flooding events. Study results also suggest that river flooding may recharge a more spatially widespread zone of lakes and wetlands under future scenarios of permafrost table deepening and enhanced subsurface hydrologic connectivity.
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Directory of Open Access Journals (Sweden)
C. Buendía
2018-01-01
Full Text Available Phosphorus (P availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.
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Buendía, Corina; Kleidon, Axel; Manzoni, Stefano; Reu, Björn; Porporato, Amilcare
2018-01-01
Phosphorus (P) availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland) ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.
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Two case studies in river naturalization: planform migration and bank erosion control
Abad, J. D.; Guneralp, I.; Rhoads, B. L.; Garcia, M. H.
2005-05-01
A sound understanding of river planform evolution and bank erosion control, along with integration of expertise from several disciplines is required for the development of predictive models for river naturalization. Over the last few years, several methodologies have been presented for naturalization projects, from purely heuristic to more advanced methods. Since the time and space scales of concern in naturalization vary widely, there is a need for appropriate tools at a variety of time and space scales. This study presents two case studies at different scales. The first case study describes the prediction of river planform evolution for a remeandering project based on a simplified two-dimensional hydrodynamic model. The second case study describes the applicability of a Computational Fluid Dynamics (CFD) model for evaluating the effectiveness of bank-erosion control structures in individual meander bends. Understanding the hydrodynamic influence of control structures on flow through bends allows accurate prediction of depositional and erosional distribution patterns, resulting in better assessment on river planform stability, especially for the case of natural complex systems. The first case study introduces a mathematical model for evolution of meandering rivers that can be used in remeandering projects. In United States in particular, several rivers have been channelized in the past causing environmental and ecological problems. Following Newton's third law, "for every action, there is a reaction", naturalization techniques evolve as natural reactive solutions to channelization. This model (herein referred as RVR Meander) can be used as a stand-alone Windows application or as module in a Geographic Information System. The model was applied to the Poplar Creek re-meanderization project and used to evaluate re-meandering alternatives for an approximately 800-meter long reach of Poplar Creek that was straightened in 1938. The second case study describes a
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Land use changes caused by bank erosion along the lower part of the Bosna river from 2001 to 2013
Directory of Open Access Journals (Sweden)
Tošić Radislav
2014-01-01
Full Text Available The river channel dynamics are result of the complex interaction between natural and human impact. In the presented study, we assessed spatial and temporal dynamics of Bosna river channel migration during 2001-2013 period using orthophoto images and GIS. We have identified that the total area of bank erosion during given period equaled 2.8695 km2, of which 1.2178 km2 were on the left bank and 1.6516 km2 on the right bank. The total area of bank accretion from 2001 to 2013 equaled 2.6841 km2, of which 1.2864 km2 was on the left bank and 1.3977 km2 on the right bank. The Bosna riverbed average movement in the period 2001-2013 was established in the amount of 60.7 m. During this period, the average lateral channel migration was 5.05 m per year. Lateral migration of the Bosna River has caused serious problems: disappearance of arable land, forests, pastures and meadows, economic loss due to the reduction of agricultural. Using statistical analysis of a land use structure changes along the lower part of Bosna River, we obtained the results which show significant lost in arable land. According to results, 42.3 ha of arable land, 171.9 ha forests and 31.8 ha pastures and meadows were lost during 2001-2013 period. The data presented here are significant for practical issues such as predicting channel migration rates for engineering and planning purposes, soil and water management. [Projekat Ministarstva nauke Republike Srbije, br. 43007: The Research on Climate Change Influences on Environment: Influence Monitoring, Adaptation and Mitigation, subproject No. 9: Torrential Floods Frequency, Soil and Water Degradation as the Consequence of Global Changes
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Foster, Gez; Turner, Jonathan
2010-05-01
This paper reports the preliminary findings of an Irish Heritage Council INSTAR funded research project on the geoarchaeology and fluvial geomorphology of the lower River Boyne valley, eastern Ireland. The nature and evolution of the contemporary Boyne floodplain at Dunmoe, Co. Meath (53° 40' 22.8" N, 6° 37' 54.7" W) has been investigated using a multi-technique approach combining field and terrestrial LiDAR-based geomorphological mapping, radiocarbon dating of channel migration activity, electrical resistivity tomography surveys of sub-surface topography and high-resolution X-ray and XRF geochemical characterisation of fine-grained sediment fill sequences. All of these lines of evidence support a tripartite sub-division of the floodplain. Valley marginal floodplain Zone 1 is characterised by a colluvial sediment fill which has buried an irregular ditch-basin-platform surface containing recent archaeological material. Subtle variations in mapped elevation suggest that the buried surface may represent the site of an abandoned river-side complex, possibly a small docking area or port. Geomorphological field relationships suggest that the possible archaeological site was connected to a former bank line position of the main River Boyne (floodplain Zone 2) via a small canal. Radiocarbon dating of Zone 2 channel gravels suggests that the channel associated with this bank position was abandoned some time before 1490-1610 AD. Subsequent vertical and lateral channel migration, the onset of which has been radiocarbon dated to the 17th or 18th century AD, led to the development of the lowest and most recent floodplain surface (Zone 3). The sedimentology and geochemistry of the Zone 2 and 3 fluvial sediment sequences suggests that recent centuries have involved an increase in fluvial flood risk, evidenced by the burial of alluvial soils by bedded, shell-rich sands. A more complete understanding of the timing and environmental drivers of increasing flood risk is anticipated
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Rousseau, Yannick Y.; Van de Wiel, Marco J.; Biron, Pascale M.
2017-10-01
Meandering river channels are often associated with cohesive banks. Yet only a few river modelling packages include geotechnical and plant effects. Existing packages are solely compatible with single-threaded channels, require a specific mesh structure, derive lateral migration rates from hydraulic properties, determine stability based on friction angle, rely on nonphysical assumptions to describe cutoffs, or exclude floodplain processes and vegetation. In this paper, we evaluate the accuracy of a new geotechnical module that was developed and coupled with Telemac-Mascaret to address these limitations. Innovatively, the newly developed module relies on a fully configurable, universal genetic algorithm with tournament selection that permits it (1) to assess geotechnical stability along potentially unstable slope profiles intersecting liquid-solid boundaries, and (2) to predict the shape and extent of slump blocks while considering mechanical plant effects, bank hydrology, and the hydrostatic pressure caused by flow. The profiles of unstable banks are altered while ensuring mass conservation. Importantly, the new stability module is independent of mesh structure and can operate efficiently along multithreaded channels, cutoffs, and islands. Data collected along a 1.5-km-long reach of the semialluvial Medway Creek, Canada, over a period of 3.5 years are used to evaluate the capacity of the coupled model to accurately predict bank retreat in meandering river channels and to evaluate the extent to which the new model can be applied to a natural river reach located in a complex environment. Our results indicate that key geotechnical parameters can indeed be adjusted to fit observations, even with a minimal calibration effort, and that the model correctly identifies the location of the most severely eroded bank regions. The combined use of genetic and spatial analysis algorithms, in particular for the evaluation of geotechnical stability independently of the hydrodynamic
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Directory of Open Access Journals (Sweden)
Johannes Radinger
Full Text Available Habitat suitability and the distinct mobility of species depict fundamental keys for explaining and understanding the distribution of river fishes. In recent years, comprehensive data on river hydromorphology has been mapped at spatial scales down to 100 m, potentially serving high resolution species-habitat models, e.g., for fish. However, the relative importance of specific hydromorphological and in-stream habitat variables and their spatial scales of influence is poorly understood. Applying boosted regression trees, we developed species-habitat models for 13 fish species in a sand-bed lowland river based on river morphological and in-stream habitat data. First, we calculated mean values for the predictor variables in five distance classes (from the sampling site up to 4000 m up- and downstream to identify the spatial scale that best predicts the presence of fish species. Second, we compared the suitability of measured variables and assessment scores related to natural reference conditions. Third, we identified variables which best explained the presence of fish species. The mean model quality (AUC = 0.78, area under the receiver operating characteristic curve significantly increased when information on the habitat conditions up- and downstream of a sampling site (maximum AUC at 2500 m distance class, +0.049 and topological variables (e.g., stream order were included (AUC = +0.014. Both measured and assessed variables were similarly well suited to predict species' presence. Stream order variables and measured cross section features (e.g., width, depth, velocity were best-suited predictors. In addition, measured channel-bed characteristics (e.g., substrate types and assessed longitudinal channel features (e.g., naturalness of river planform were also good predictors. These findings demonstrate (i the applicability of high resolution river morphological and instream-habitat data (measured and assessed variables to predict fish presence, (ii the
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DEFF Research Database (Denmark)
Birnie-Gauvin, Kim; Aarestrup, Kim; Riis, Torsten M. O.
2017-01-01
modified by agriculture and other human activities for centuries, leaving management practitioners wondering how much change is acceptable to maintain sustainable fish populations and fisheries practices. 4. With examples from Denmark, this paper attempts to conceptualize the loss in habitat as a result...... of barriers in lowland streams and rivers, and the repercussions that such alterations may have on rheophilic fish populations. Furthermore, the need for management to address habitat loss and its related consequences concurrently with the improvement of fish passage is emphasized...
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Curran, Christopher A.; Konrad, Christopher P.; Dinehart, Randal L.; Moran, Edward H.
2008-01-01
The removal of two dams from the mainstem of the Elwha River is expected to cause a broad range of changes to the river and nearby coastal ecosystem. The U.S. Geological Survey has documented aspects of the condition of the river to allow analysis of ecological responses to dam removal. This report documents the bank topography, river bathymetry, and current velocity data collected along the lower 0.5 kilometer of the Elwha River, May 15-17, 2006. This information supplements nearshore and beach surveys done in 2006 as part of the U.S. Geological Survey Coastal Habitats in Puget Sound program near the Elwha River delta in the Strait of Juan de Fuca, Washington.
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Risk assessment data bank design at the Savannah River Site
International Nuclear Information System (INIS)
Townsend, C.S.; Johnson, K.B.
1992-01-01
The Savannah River Site has designed and implemented a database system containing a series of compilations of incidents used primarily for risk assessment. Four databases have been designed and implemented using advanced database management system computer software. These databases exist for reprocessing, fuel fabrication, waste management, and the Savannah River Technology Center. They are combined into one system caged the Risk Assessment Methodology (RAM) Fault Tree Data Banks. This paper will discuss the logical design of the data, the menus, and the operating platform. Built-in updating features, such as batch and on-line data entry; data validation methods; automatic update features; and expert system programs, will also be discussed. User functions, such as on-line search/view/report and statistical functions, will be presented. Security features and backup and recovery methods will also be covered
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Data banks for risk assessment at the Savannah River Site
International Nuclear Information System (INIS)
Durant, W.S.; Townsend, C.S.; Baughman, D.F.; Hang, P.
1992-01-01
One of the lessons learned from many years of risk assessment experience is that mistakes of the past are soon forgotten if no method is available to retrieve and review these events. Savannah River Site has maintained a computerized data bank system for recording, retrieving and reviewing its incident history. The system is based on a series of compilations developed primarily for risk assessment but has been found to be invaluable for many other uses such as equipment reliability, project justification, and incident investigations
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Directory of Open Access Journals (Sweden)
VERA POTOP
2012-11-01
Full Text Available A GIS tool to evaluate the spatial evolution of hydro-thermic features during growing season of vegetable crops in Elbe River lowland (Polabi. This article presents the results of the first study on combined mezoclimatological, microclimatological and topographical tools for evaluating precision farming in the growth of vegetable crops in the Elbe River lowland (Polabi region from the Czech Republic. We assess the variability of basically climatological characteristics in relation to topographic characteristics at the regional (Polabi and local (agricultural farm scales. At regional scale, interpolation approach is based on local linear regression and universal kriging interpolation. At local scale, two conventional interpolation methods, spline and local ordinary kriging with a Gaussian model variance across the fields, were applied. The local spline interpolators have been used in developing digital elevation models (DEMs and to determine the slope angle inclination of vegetable fields. The DEMs of the vegetable crops fields was developed at a 10 m x 10 m resolution based on elevation data collected in the field by a hand-held RTK- Global Positioning System receiver. This tool allowed the distinction of microclimatic conditions that produce altitude-slope-related patterns of the spatial-temporal distribution of the basic meteorological elements during growing season of vegetable crops. The effect of slope on diurnal extreme temperatures in the vegetable cropped field conditions was more pronounced than that of elevation. Accordingly to developed maps, the warmest and longest duration of sunshine, and the least precipitation totals during growing season occurred in the middle part of Polabi.
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Directory of Open Access Journals (Sweden)
Philip B. Williams
2009-09-01
Full Text Available We describe a process and methodology for quantifying the extent of a type of historically prevalent, but now relatively rare, ecologically-valuable floodplains in the Sacramento lowland river system: frequently-activated floodplains. We define a specific metric the “Floodplain Activation Flow” (FAF, which is the smallest flood pulse event that initiates substantial beneficial ecological processes when associated with floodplain inundation. The “Activated Floodplain” connected to the river is then determined by comparison of FAF stage with floodplain topography. This provides a simple definition of floodplain that can be used as a planning, goal setting, monitoring, and design tool by resource managers since the FAF event is the smallest flood and corresponding floodplain area with ecological functionality—and is necessarily also inundated in larger flood events, providing additional ecological functions. For the Sacramento River we selected a FAF definition to be the river stage that occurs in two out of three years for at least seven days in the mid-March to mid-May period and "Activated Floodplains" to be those lands inundated at that stage. We analyzed Activated Floodplain area for four representative reaches along the lower Sacramento River and the Yolo Bypass using stream gauge data. Three of the most significant conclusions are described: (1 The area of active functional floodplain is likely to be less than commonly assumed based on extent of riparian vegetation; (2 Levee setbacks may not increase the extent of this type of ecologically-productive floodplain without either hydrologic or topographic changes; (3 Within the Yolo Bypass, controlled releases through the Fremont Weir could maximize the benefits associated with Activated Floodplain without major reservoir re-operation or grading. This approach identifies a significant opportunity to integrate floodplain restoration with flood management by establishing a FAF stage
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International Nuclear Information System (INIS)
Uunila, L.S.
1997-01-01
The effects of river ice and related flooding on the bank morphology and riparian vegetation along 655 km of the Peace River from Clayhurst, British Columbia to Fort Vermilion, Alberta were studied. The river has been regulated for hydroelectric power generation since 1968 and has experienced changes in the hydrologic and ice regimes. The rate of channel adjustments under the new hydrologic regime vary longitudinally, and depend greatly on the succession of riparian vegetation. This study was conducted to determine how much of the variation in both channel adjustment and rate of riparian succession is a result of allogenic effects of ice jams. The direct physical effects of ice and the indirect effects of ice jam flooding on the channel margin were investigated. Long term ice jam severity was found to generally peak well downstream of the principal observation point. The morphology of the channel at the severe ice jam locations fit the classical ice jam criteria of confined tight meanders with several mid-channel islands and shoals. Vegetation damage was the most visible impact to the riparian environment along the Peace River. 27 refs., 1 tab., 8 figs
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The Prognosis of Influence of The Oder River Waters Dammed by Malczyce Barrage on Left Bank Areas
Directory of Open Access Journals (Sweden)
Chalfen Mieczysław
2014-07-01
Full Text Available The finalisation of the construction of the Malczyce barrage is planned for 2015. Damming of the river will cause a change in the water and ground conditions in the adjoining areas. The paper analyses the influence of the water level in the Oder River dammed by the barrage on groundwater table level in the left bank valley.
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Ala-aho, P.; Soulsby, C.; Pokrovsky, O. S.; Kirpotin, S. N.; Karlsson, J.; Serikova, S.; Manasypov, R.; Lim, A.; Krickov, I.; Kolesnichenko, L. G.; Laudon, H.; Tetzlaff, D.
2018-03-01
The Western Siberian Lowlands (WSL) store large quantities of organic carbon that will be exposed and mobilized by the thawing of permafrost. The fate of mobilized carbon, however, is not well understood, partly because of inadequate knowledge of hydrological controls in the region which has a vast low-relief surface area, extensive lake and wetland coverage and gradually increasing permafrost influence. We used stable water isotopes to improve our understanding of dominant landscape controls on the hydrology of the WSL. We sampled rivers along a 1700 km South-North transect from permafrost-free to continuous permafrost repeatedly over three years, and derived isotope proxies for catchment hydrological responsiveness and connectivity. We found correlations between the isotope proxies and catchment characteristics, suggesting that lakes and wetlands are intimately connected to rivers, and that permafrost increases the responsiveness of the catchment to rainfall and snowmelt events, reducing catchment mean transit times. Our work provides rare isotope-based field evidence that permafrost and lakes/wetlands influence hydrological pathways across a wide range of spatial scales (10-105 km2) and permafrost coverage (0%-70%). This has important implications, because both permafrost extent and lake/wetland coverage are affected by permafrost thaw in the changing climate. Changes in these hydrological landscape controls are likely to alter carbon export and emission via inland waters, which may be of global significance.
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Energy Technology Data Exchange (ETDEWEB)
Le Gall, Marion; Evrard, Olivier [Laboratoire des Sciences et de l' Environnement, UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France); Foucher, Anthony [E.A 6293, Laboratoire GéoHydrosystèmes Continentaux (GéHCO), Université F. Rabelais de Tours, Faculté des Sciences et Techniques, Parc de Grandmont, 37200 Tours (France); Laceby, J. Patrick [Laboratoire des Sciences et de l' Environnement, UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France); Salvador-Blanes, Sébastien [E.A 6293, Laboratoire GéoHydrosystèmes Continentaux (GéHCO), Université F. Rabelais de Tours, Faculté des Sciences et Techniques, Parc de Grandmont, 37200 Tours (France); Thil, François; Dapoigny, Arnaud; Lefèvre, Irène [Laboratoire des Sciences et de l' Environnement, UMR 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Domaine du CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France); Cerdan, Olivier [Département Risques et Prévention, Bureau de Recherches Géologiques et Minières, 3 avenue Claude Guillemin, 45060 Orléans (France); and others
2016-10-01
Soil erosion often supplies high sediment loads to rivers, degrading water quality and contributing to the siltation of reservoirs and lowland river channels. These impacts are exacerbated in agricultural catchments where modifications in land management and agricultural practices were shown to accelerate sediment supply. In this study, sediment sources were identified with a novel tracing approach combining cesium ({sup 137}Cs) and strontium isotopes ({sup 87}Sr/{sup 86}Sr) in the Louroux pond, at the outlet of a lowland cultivated catchment (24 km{sup 2}, Loire River basin, France) representative of drained agricultural areas of Northwestern Europe. Surface soil (n = 36) and subsurface channel bank (n = 17) samples were collected to characterize potential sources. Deposited sediment (n = 41) was sampled across the entire surface of the pond to examine spatial variation in sediment deposits. In addition, a 1.10 m sediment core was sampled in the middle of the pond to reconstruct source variations throughout time. {sup 137}Cs was used to discriminate between surface and subsurface sources, whereas {sup 87}Sr/{sup 86}Sr ratios discriminated between lithological sources. A distribution modeling approach quantified the relative contribution of these sources to the sampled sediment. Results indicate that surface sources contributed to the majority of pond (μ 82%, σ 1%) and core (μ 88%, σ 2%) sediment with elevated subsurface contributions modeled near specific sites close to the banks of the Louroux pond. Contributions of the lithological sources were well mixed in surface sediment across the pond (i.e., carbonate sediment contribution, μ 48%, σ 1% and non-carbonate sediment contribution, μ 52%, σ 3%) although there were significant variations of these source contributions modeled for the sediment core between 1955 and 2013. These fluctuations reflect both the progressive implementation of land consolidation schemes in the catchment and the eutrophication of
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Hackney, C. R.; Darby, S. E.; Leyland, J.; Aalto, R. E.; Best, J.; Parsons, D. R.; Nicholas, A. P.
2016-12-01
Knowledge of bank erosion processes and rates along the world's largest rivers remains incomplete, primarily due to the difficulties of obtaining data pertaining to the key driving processes (i.e., during the floods that drive most bank retreat). Recently, larger scale bank roughness elements (slump blocks and embayments) have been shown to impact upon rates and locations of bank erosion. However, a complete understanding of the way such features affect rates of bank erosion is currently hindered by the lack of detailed concurrent observations of slump block geometry, embayment geometry and flow at formative discharges in natural environments. Here, we report on high spatial resolution topographic (Terrestrial Laser Scanner and Multibeam Echo Souder) and flow (Acoustic Doppler Current Profiler) surveys undertaken on the Mekong River, Cambodia, from which we extract the geometric properties of roughness elements across a range of scales. We combine this data with sub-bottom profile data, revealing the composition of the surrounding floodplain, to link, for the first time, scales of bank roughness to bank material composition. Through the categorisation of a series of cut river banks by roughness geometry, we show how rates and locations of bank erosion are dependent on that roughness and associated bank material changes. We test how observed patterns of bank erosion conform to previously detailed models of embayment development, and provide new insight into processes affecting the retreat of large river banks.
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Modelling tools for managing Induced RiverBank Filtration MAR schemes
De Filippis, Giovanna; Barbagli, Alessio; Marchina, Chiara; Borsi, Iacopo; Mazzanti, Giorgio; Nardi, Marco; Vienken, Thomas; Bonari, Enrico; Rossetto, Rudy
2017-04-01
Induced RiverBank Filtration (IRBF) is a widely used technique in Managed Aquifer Recharge (MAR) schemes, when aquifers are hydraulically connected with surface water bodies, with proven positive effects on quality and quantity of groundwater. IRBF allows abstraction of a large volume of water, avoiding large decrease in groundwater heads. Moreover, thanks to the filtration process through the soil, the concentration of chemical species in surface water can be reduced, thus becoming an excellent resource for the production of drinking water. Within the FP7 MARSOL project (demonstrating Managed Aquifer Recharge as a SOLution to water scarcity and drought; http://www.marsol.eu/), the Sant'Alessio IRBF (Lucca, Italy) was used to demonstrate the feasibility and technical and economic benefits of managing IRBF schemes (Rossetto et al., 2015a). The Sant'Alessio IRBF along the Serchio river allows to abstract an overall amount of about 0.5 m3/s providing drinking water for 300000 people of the coastal Tuscany (mainly to the town of Lucca, Pisa and Livorno). The supplied water is made available by enhancing river bank infiltration into a high yield (10-2 m2/s transmissivity) sandy-gravelly aquifer by rising the river head and using ten vertical wells along the river embankment. A Decision Support System, consisting in connected measurements from an advanced monitoring network and modelling tools was set up to manage the IRBF. The modelling system is based on spatially distributed and physically based coupled ground-/surface-water flow and solute transport models integrated in the FREEWAT platform (developed within the H2020 FREEWAT project - FREE and Open Source Software Tools for WATer Resource Management; Rossetto et al., 2015b), an open source and public domain GIS-integrated modelling environment for the simulation of the hydrological cycle. The platform aims at improving water resource management by simplifying the application of EU water-related Directives and at
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Mateusz Grygoruk; Magdalena Frąk; Aron Chmielewski
2015-01-01
Ecosystem deterioration in small lowland agricultural rivers that results from river dredging entails a significant threat to the appropriate ecohydrological conditions of these water bodies, expressed as homogenization of habitats and loss of biodiversity. Our study was aimed at a comparison of abundance and taxonomic structure of bottom-dwelling macroinvertebrates in dredged and non-dredged stretches of small lowland rivers and tributaries of the middle Narew River, namely: Czaplinianka, Tu...
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Liu, D.
2017-12-01
Plants, especially trees, in the riparian zone may have a significant impact on the flow rate, temperature and chemical properties of groundwater. A field study was conducted in the downstream bank of the Xin'an River dam, Zhejiang, China. In the field, two areas of about 20 meters apart were chosen, of which one was a open place and the other was covered with many orange trees. Comparison of hyporheic flow and water quality in the open and tree-covered banks were made by monitoring the water level, water temperature, water chemistry (March, 2015) along the cross sections perpendicular to the river. The analyses indicated that water level around the trees was relatively low in the day and high in the evening, thus changed the direction and magnitude of the natural groundwater flow velocity, totally strengthened the hyporheic exchange between the groundwater and river. The trees also changed the temperature distribution of the natural river bank, and induced the wider infiltration range of the low-temperature water. The temperature around the trees was relatively low in the day, yet it was high in the evening. Dissolved oxygen (DO) and electricity conductivity (EC) around the trees were significantly increased, yet the pH was almost unaffected.
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Restoration strategies for river floodplains along large lowland rivers in Europe
Buijse, A.D.; Coops, H.; Staras, M.; Jans, L.H.; Van Geest, G.J.; Grift, R.E.; Ibelings, B.W.; Oosterberg, W.; Roozen, F.C.J.M.
2002-01-01
1. Most temperate rivers are heavily regulated and characterised by incised channels, aggradated floodplains and modified hydroperiods. As a consequence, former extensive aquatic /terrestrial transition zones lack most of their basic ecological functions. 2. Along large rivers in Europe and North
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Restoration strategies for river floodplains along large lowland rivers in Europe
Buijse, A.D.; Coops, H.; Staras, M.; Jans, L.H.; Geest, van G.; Grift, R.E.; Ibelings, B.W.; Oosterberg, W.; Roozen, F.C.J.M.
2002-01-01
1. Most temperate rivers are heavily regulated and characterised by incised channels, aggradated floodplains and modified hydroperiods. As a consequence, former extensive aquatic/terrestrial transition zones lack most of their basic ecological functions. 2. Along large rivers in Europe and North
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Adaptations of lowland jungle mosses to anthropogenic environments in Guyana
Kuc, Marian
2000-01-01
Sixteen lowland jungle mosses growing in anthropogenic habitats at Santa and The Bell - Ituni localities on the Demerara River in Guyana were examined in detail with the aim of detecting any features which would indicate their adaptations to new habitats. Amounts of chlorophyll in leaf cells, protective coloration, alterations in leaf morphology, characteristics of old stems, rhizoid tomentum and fertility are considered as the most pronounced adaptive features of these species to new localit...
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Kemp, G. Paul; Day, John W.; Rogers, J. David; Giosan, Liviu; Peyronnin, Natalie
2016-12-01
Sand transport to the Mississippi River Delta (MRD) remains sufficient to build wetlands in shallow, sheltered coastal bays fed by engineered diversions on the Mississippi River (MR) and its Atchafalaya River (AR) distributary. But suspended mud (silt & clay) flux to the coast has dropped from a mean of 390 Mt y-1 in the early 1950s, to 100 Mt y-1 since 1970. This fine-grained sediment travels deeper into receiving estuarine basins and plays a critical role in sustaining existing marshes. Virtually all of the 300 Mt y-1 of missing mud once flowed from the Missouri River (MOR) Basin before nearly 100 dams were built as part of the Pick-Sloan water development project. About 100 Mt y-1 is now intercepted by main-stem Upper MOR dams closed in 1953. But the remaining 200 Mt y-1 is trapped by impoundments built on tributaries to the Lower MOR in the 1950s and 1960s. Sediment flux during the post-dam high MOR discharge years of 1973, 1993 and 2011 approached pre-dam levels when tributaries to the Lower MOR, including the Platte and Kansas Rivers, contributed to flood flows. West bank tributaries drain a vast, arid part of the Great Plains, while those entering from the east bank traverse the lowlands of the MOR floodplain. Both provinces are dominated by highly erodible loess soils. Staunching the continued decline in MR fine-grained sediment flux has assumed greater importance now that engineered diversions are being built to reconnect the Lowermost MR to the MRD. Tributary dam bypassing in the Lower MOR basin could increase mud supply to the MRD by 100-200 Mt y-1 within 1-2 decades. Such emergency measures to save the MRD are compatible with objectives of the Missouri River Restoration and Platte River Recovery Programs to restore MOR riparian habitat for endangered species. Rapid mobilization to shunt fine-grained sediments past as many as 50 Lower MOR tributary dams in several U.S. states will undoubtedly require as much regional coordination and funding in the 21st
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Directory of Open Access Journals (Sweden)
de Thoisy Benoit
2010-09-01
Full Text Available Abstract Background Understanding the forces that shaped Neotropical diversity is central issue to explain tropical biodiversity and inform conservation action; yet few studies have examined large, widespread species. Lowland tapir (Tapirus terrrestris, Perissodactyla, Tapiridae is the largest Neotropical herbivore whose ancestors arrived in South America during the Great American Biotic Interchange. A Pleistocene diversification is inferred for the genus Tapirus from the fossil record, but only two species survived the Pleistocene megafauna extinction. Here, we investigate the history of lowland tapir as revealed by variation at the mitochondrial gene Cytochrome b, compare it to the fossil data, and explore mechanisms that could have shaped the observed structure of current populations. Results Separate methodological approaches found mutually exclusive divergence times for lowland tapir, either in the late or in the early Pleistocene, although a late Pleistocene divergence is more in tune with the fossil record. Bayesian analysis favored mountain tapir (T. pinchaque paraphyly in relation to lowland tapir over reciprocal monophyly, corroborating the inferences from the fossil data these species are sister taxa. A coalescent-based analysis rejected a null hypothesis of allopatric divergence, suggesting a complex history. Based on the geographic distribution of haplotypes we propose (i a central role for western Amazonia in tapir diversification, with a key role of the ecological gradient along the transition between Andean subcloud forests and Amazon lowland forest, and (ii that the Amazon river acted as an barrier to gene flow. Finally, the branching patterns and estimates based on nucleotide diversity indicate a population expansion after the Last Glacial Maximum. Conclusions This study is the first examining lowland tapir phylogeography. Climatic events at the end of the Pleistocene, parapatric speciation, divergence along the Andean foothill
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de Thoisy, Benoit; da Silva, Anders Gonçalves; Ruiz-García, Manuel; Tapia, Andrés; Ramirez, Oswaldo; Arana, Margarita; Quse, Viviana; Paz-y-Miño, César; Tobler, Mathias; Pedraza, Carlos; Lavergne, Anne
2010-09-14
Understanding the forces that shaped Neotropical diversity is central issue to explain tropical biodiversity and inform conservation action; yet few studies have examined large, widespread species. Lowland tapir (Tapirus terrrestris, Perissodactyla, Tapiridae) is the largest Neotropical herbivore whose ancestors arrived in South America during the Great American Biotic Interchange. A Pleistocene diversification is inferred for the genus Tapirus from the fossil record, but only two species survived the Pleistocene megafauna extinction. Here, we investigate the history of lowland tapir as revealed by variation at the mitochondrial gene Cytochrome b, compare it to the fossil data, and explore mechanisms that could have shaped the observed structure of current populations. Separate methodological approaches found mutually exclusive divergence times for lowland tapir, either in the late or in the early Pleistocene, although a late Pleistocene divergence is more in tune with the fossil record. Bayesian analysis favored mountain tapir (T. pinchaque) paraphyly in relation to lowland tapir over reciprocal monophyly, corroborating the inferences from the fossil data these species are sister taxa. A coalescent-based analysis rejected a null hypothesis of allopatric divergence, suggesting a complex history. Based on the geographic distribution of haplotypes we propose (i) a central role for western Amazonia in tapir diversification, with a key role of the ecological gradient along the transition between Andean subcloud forests and Amazon lowland forest, and (ii) that the Amazon river acted as an barrier to gene flow. Finally, the branching patterns and estimates based on nucleotide diversity indicate a population expansion after the Last Glacial Maximum. This study is the first examining lowland tapir phylogeography. Climatic events at the end of the Pleistocene, parapatric speciation, divergence along the Andean foothill, and role of the Amazon river, have similarly shaped
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Tracing oxidative weathering from the Andes to the lowland Amazon Basin using dissoved rhenium
Dellinger, M.; Hilton, R. G.; West, A. J.; Torres, M.; Burton, K. W.; Clark, K. E.; Baronas, J. J.
2016-12-01
Over long timescales (>105 yrs), the abundance of carbon dioxide (CO2) in the atmosphere is determined by the balance of the major carbon sources and sinks. Among the major carbon sources, the oxidation of organic carbon contained within sedimentary rocks ("petrogenic" carbon, or OCpetro) is thought to result in CO2 emission of similar magnitude to that released by volcanism. Rhenium (Re) has been proposed as a proxy for tracing OCpetro oxidation. Here we investigate the source, behavior and flux of dissolved and particulate rhenium (Re) in the Madre de Dios watershed (a major Andean tributary of the Amazon River) and the lowlands, aiming to characterize the behavior of Re in river water and quantify the flux of CO2 released by OCpetro oxidation. Measured Re concentrations in Andean rivers range from 0.07 to 1.55 ppt. In the Andes, Re concentration do not change significantly with water discharge, whereas in the lowlands, Re concentration decrease at high water discharge. Mass balance calculation show that more than 70% of the dissolved Re is sourced from the oxidation of OCpetro the Andes-floodplain system. We calculate dissolved Re flux over a hydrological year to estimate the rates of oxidative weathering, and the associated CO2 release from OCpetro. Rates are high in the Andean headwaters, consistent with estimates from other mountain rivers with similar rates of physical erosion. We find evidence that a significant amount of additional oxidation (Re flux) happens during floodplain transport. These results have important implications for improving our understanding of the source and processes controlling Re in rivers, and allowing us to quantify long-term OCpetro cycling in large river basins.
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Palaeoflood evidence on the River Nore, South East Ireland
Fleming, Ciara; Turner, Jonathan; Bourke, Mary
2017-04-01
Past geomorphic changes can be detected in sediment sinks, through the investigation of natural sediment archives. Since the advent of palaeoflood hydrology in the 1980s, numerous authors have demonstrated that such sediment deposits record valuable evidence of past flooding events. Many of these studies have focussed on fluvial systems in arid environments, with bedrock channels proving to be particularly successful field sites. In some districts, the collected datasets are now routinely employed to augment analyses of flood frequency and magnitude, which have traditionally relied on extrapolation of short hydrometric datasets. This study targets river reaches in a temperate humid environment, with a predominantly alluvial channel. The River Nore is one of the largest catchments draining South East Ireland. It is situated in a valley with an inherited glacial legacy and is principally a lowland river catchment. Specific morphological zones have been targeted which are optimal for flood deposit preservation, including palaeochannels, tributary junctions and floodplain overbank settings.There are a variety of anthropogenic pressures evident in this landscape. Among them are channelisation of select tributaries, a legacy of coal mining in the upland Carboniferous limestones, and the installation of man-made obstacles or modifications along the length of the river channel such as sluices and weirs. Regarding land-use, the majority of the catchment is dominated by agriculture, mainly pasture with some tillage. This study investigates palaeoflood evidence in the River Nore catchment and examines the development of the river floodplain using a variety of complementary field and desk-based methods. The sub-surface and micro-topography of river reaches are investigated using Ground Penetrating Radar (GPR) and Unmanned Aerial Vehicle (UAV) technology. Flood deposits have been characterised by examination of bank exposures and sediment cores. Installation of sediment traps
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Bank filtered water quality characteristics in Okgog-Ri area of Youngsan-River, Korea
Energy Technology Data Exchange (ETDEWEB)
Park, Hee-Youl; Kim, Hyoung-Soo [Korea Water Resources Corp., Taejeon(Korea)
2001-02-28
Preliminary artificial recharge groundwater intake method using bank filtering had been conducted in Okgog-Ri of Youngsan-River to evaluate the possibility of substitution of surface water intake method in the area. In order to investigate the characteristics of bank filtered groundwater, we examined the hydrogeological properties of alluvium and water quality of stream and groundwater. It is observed that nitrate in stream water from synthetic fertilizer and poultry manure is almost consumed during bank filtering in this area. This implies that denitrification of organic carbon and the oxidation of pyrite present in the alluvium aquifer. Groundwater samples from bank filtering show high Mn concentration. This high Mn concentration may be resulted from decreasing redox potential due to denitrification and increasing mobility due to redox reaction of Mn-oxide. In the study area, there is a typical tendency that Al concentrations of water samples decrease according to increasing pH. This tendency is interpreted as forming of amorphous Al(OH){sub 3} precipitates by reducing the Al{sup 3+} solubilities. It is revealed that the bank filtered groundwater in the area is not edible because color, turbidity, heterotrophic bacteria, coliform and Mn of the groundwater exceed the guideline of drinking water. Even though the bank filtered groundwater without treatment does not satisfy the guideline of drinking water, the groundwater shows a good water quality compared with stream water. So, the water treatment method using bank filtered groundwater can be more economical and efficient than the treatment using direct intake of stream water in the aspect of water quality. (author). 15 refs., 2 tabs., 7 figs.
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Directory of Open Access Journals (Sweden)
Regiane Campos Magalhães
2013-12-01
Full Text Available The study about the mineralogical and chemical lowland soils generate information to compose a current survey about the susceptibility of lowland soil to process Fallen Lands. With this purpose we studied five profiles the banks of the Solimões River, located in the municipality of Iranduba (AM. The information obtained allowed to determine the Neosoil Fluvic the study area has favorable conditions for cultivation with an average pH of 6.2, with high levels of Ca, Mg, K, P, micronutrients and zero Al content, with high levels of C and M. O. in the first layer and a decrease in depth. Thus, Neosoil Fluvic was characterized as Tb eutrophic, with base saturation above 50%, with good CTC. The mineralogy was homogeneous in all profiles, with a predominance of primary minerals: Quartz, Albite and rutile, with low proportions of clay minerals Muscovite, Kaolinite, Muscovite-Illite interstratified and Illite.
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Ground water flow velocity in the bank of the Columbia River, Hanford, Washington
International Nuclear Information System (INIS)
Ballard, S.
1995-12-01
To properly characterize the transport of contaminants from the sediments beneath the Hanford Site into the Columbia River, a suite of In Situ Permeable Flow Sensors was deployed to accurately characterize the hydrologic regime in the banks of the river. The three dimensional flow velocity was recorded on an hourly basis from mid May to mid July, 1994 and for one week in September. The first data collection interval coincided with the seasonal high water level in the river while the second interval reflected conditions during relatively low seasonal river stage. Two flow sensors located approximately 50 feet from the river recorded flow directions which correlated very well with river stage, both on seasonal and diurnal time scales. During time intervals characterized by falling river stage, the flow sensors recorded flow toward the river while flow away from the river was recorded during times of rising river stage. The flow sensor near the river in the Hanford Formation recorded a component of flow oriented vertically downward, probably reflecting the details of the hydrostratigraphy in close proximity to the probe. The flow sensor near the river in the Ringold Formation recorded an upward component of flow which dominated the horizontal components most of the time. The upward flow in the Ringold probably reflects regional groundwater flow into the river. The magnitudes of the flow velocities recorded by the flow sensors were lower than expected, probably as a result of drilling induced disturbance of the hydraulic properties of the sediments around the probes. The probes were installed with resonant sonic drilling which may have compacted the sediments immediately surrounding the probes, thereby reducing the hydraulic conductivity adjacent to the probes and diverting the groundwater flow away from the sensors
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Ahmed, J.; Constantine, J. A.; Hales, T. C.
2017-12-01
Meandering channels provide a conduit through which sediment and water is routed from the uplands to the sea. Alluvial material is periodically stored and transported through the channel network as permitted by the prevailing hydrologic conditions. The lowlands are typically characterised by accumulations of sediment attached to the inner banks of meander bends (point bars). These bedforms have been identified as important for facilitating a link between in-stream sediment supplies and channel dynamism. A 2D curvilinear hydrodynamic model (MIKE 21C) was used to perform a number of experiments in which the sediment load was adjusted to investigate how changes in alluvial material fluxes affect the development of point bars and the resultant patterns of bank erosion. A doubling of the sediment load caused a longitudinal increase in the bar in the upstream direction and caused a coeval doubling of the transverse channel slope at the meander apex. The upstream growth of the point bar was accompanied by an increase in length over which lateral migration took place at the outer bank. The magnitude of outer bank erosion was 9-times greater for the high-sediment simulation. These results suggest that enhanced sediment loads (potentially the result of changes in land use or climate) can trigger greater rates of bank erosion and channel change through the sequestration of alluvial material on point bars, which encourage high-velocity fluid deflection towards the outer bank of the meander. This controls riparian habitat development and exchanges of sediment and nutrients across the channel-floodplain interface.
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Wallace, Robert; Ayala, Guido; Viscarra, Maria
2012-12-01
Lowland tapir distribution is described in northwestern Bolivia and southeastern Peru within the Greater Madidi-Tambopata Landscape, a priority Tapir Conservation Unit, using 1255 distribution points derived from camera trapping efforts, field research and interviews with park guards from 5 national protected areas and hunters from 19 local communities. A total of 392 independent camera trapping events from 14 camera trap surveys at 11 sites demonstrated the nocturnal and crepuscular activity patterns (86%) of the lowland tapir and provide 3 indices of relative abundance for spatial and temporal comparison. Capture rates for lowland tapirs were not significantly different between camera trapping stations placed on river beaches versus those placed in the forest. Lowland tapir capture rates were significantly higher in the national protected areas of the region versus indigenous territories and unprotected portions of the landscape. Capture rates through time suggested that lowland tapir populations are recovering within the Tuichi Valley, an area currently dedicated towards ecotourism activities, following the creation (1995) and subsequent implementation (1997) of the Madidi National Park in Bolivia. Based on our distributional data and published conservative estimates of population density, we calculated that this transboundary landscape holds an overall lowland tapir population of between 14 540 and 36 351 individuals, of which at least 24.3% are under protection from national and municipal parks. As such, the Greater Madidi-Tambopata Landscape should be considered a lowland tapir population stronghold and priority conservation efforts are discussed in order to maintain this population. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.
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Directory of Open Access Journals (Sweden)
Craig A Boys
Full Text Available Fish screens can help prevent the entrainment or injury of fish at irrigation diversions, but only when designed appropriately. Design criteria cannot simply be transferred between sites or pump systems and need to be developed using an evidence-based approach with the needs of local species in mind. Laboratory testing is typically used to quantify fish responses at intake screens, but often limits the number of species that can studied and creates artificial conditions not directly applicable to screens in the wild. In this study a field-based approach was used to assess the appropriateness of different screen design attributes for the protection of a lowland river fish assemblage at an experimental irrigation pump. Direct netting of entrained fish was used along with sonar technology to quantify the probability of screen contact for a Murray-Darling Basin (Australia fish species. Two approach velocities (0.1 and 0.5 m.sec(-1 and different sizes of woven mesh (5, 10 and 20 mm were evaluated. Smaller fish (<150 mm in the assemblage were significantly more susceptible to entrainment and screen contact, especially at higher approach velocities. Mesh size appeared to have little impact on screen contact and entrainment, suggesting that approach velocity rather than mesh size is likely to be the primary consideration when developing screens. Until the effects of screen contacts on injury and survival of these species are better understood, it is recommended that approach velocities not exceed 0.1 m.sec(-1 when the desire is to protect the largest range of species and size classes for lowland river fish assemblages in the Murray-Darling Basin. The field method tested proved to be a useful approach that could compliment laboratory studies to refine fish screen design and facilitate field validation.
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Boets, Pieter; Gobeyn, Sacha; Dillen, Alain; Poelman, Eddy; Goethals, Peter L M
2018-05-01
Huge efforts have been made during the past decades to improve the water quality and to restore the physical habitat of rivers and streams in western Europe. This has led to an improvement in biological water quality and an increase in fish stocks in many countries. However, several rheophilic fish species such as brown trout are still categorized as vulnerable in lowland streams in Flanders (Belgium). In order to support cost-efficient restoration programs, habitat suitability modeling can be used. In this study, we developed an ensemble of habitat suitability models using metaheuristic algorithms to explore the importance of a large number of environmental variables, including chemical, physical, and hydromorphological characteristics to determine the suitable habitat for reintroduction of brown trout in the Zwalm River basin (Flanders, Belgium), which is included in the Habitats Directive. Mean stream velocity, water temperature, hiding opportunities, and presence of pools or riffles were identified as the most important variables determining the habitat suitability. Brown trout mainly preferred streams with a relatively high mean reach stream velocity (0.2-1 m/s), a low water temperature (7-15°C), and the presence of pools. The ensemble of models indicated that most of the tributaries and headwaters were suitable for the species. Synthesis and applications . Our results indicate that this modeling approach can be used to support river management, not only for brown trout but also for other species in similar geographical regions. Specifically for the Zwalm River basin, future restoration of the physical habitat, removal of the remaining migration barriers and the development of suitable spawning grounds could promote the successful restoration of brown trout.
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Interaction between opposite river bank dynamics
Bonilla Porras, J.A.; Crosato, A.; Uijttewaal, W.S.J.
2017-01-01
Although many studies regarding bank erosion and accretion can be found in the literature, it is not common to find works studying the interaction between opposite banks. Some existing morphodynamic models describe bank erosion as an event that depends on
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Directory of Open Access Journals (Sweden)
G.J. Bredenkamp
1995-08-01
Full Text Available As part of a vegetation survey programme for nature conservation areas in South Africa, surveys of the plant communities of the rocky outcrops and river banks in the Manyeleti Game Reserve were undertaken. The Cardiospermo corindii-Acacietalia nigricentis are restricted to quartz and gabbro hills, mainly on shallow, soils, whereas the Spirostachyo africanae-Diospyretalia mespiliformis occur on the banks of small dry rivers. From a Braun-Blanquet analysis of the vegetation of the rocky outcrops and the riparian vegetation, two new orders, two new alliances and six new associations were identified and described. Additionally a quantitative assessment of the woody component of each association is presented. Ordinations based on floristic data revealed the position of the syntaxa on an environmental gradient.
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Lowland-upland migration of sauropod dinosaurs during the Late Jurassic epoch.
Fricke, Henry C; Hencecroth, Justin; Hoerner, Marie E
2011-10-26
Sauropod dinosaurs were the largest vertebrates ever to walk the Earth, and as mega-herbivores they were important parts of terrestrial ecosystems. In the Late Jurassic-aged Morrison depositional basin of western North America, these animals occupied lowland river-floodplain settings characterized by a seasonally dry climate. Massive herbivores with high nutritional and water needs could periodically experience nutritional and water stress under these conditions, and thus the common occurrence of sauropods in this basin has remained a paradox. Energetic arguments and mammalian analogues have been used to suggest that migration allowed sauropods access to food and water resources over a wide region or during times of drought or both, but there has been no direct support for these hypotheses. Here we compare oxygen isotope ratios (δ(18)O) of tooth-enamel carbonate from the sauropod Camarasaurus with those of ancient soil, lake and wetland (that is, 'authigenic') carbonates that formed in lowland settings. We demonstrate that certain populations of these animals did in fact undertake seasonal migrations of several hundred kilometres from lowland to upland environments. This ability to describe patterns of sauropod movement will help to elucidate the role that migration played in the ecology and evolution of gigantism of these and associated dinosaurs.
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E.S. Gardiner; D.C. Dey; John Stanturf; B.R. Lockhart
2010-01-01
The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More recently, declines in...
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Quantifying landscape change in an arctic coastal lowland using repeat airborne LiDAR
Jones, Benjamin M.; Stoker, Jason M.; Gibbs, Ann E.; Grosse, Guido; Romanovsky, Vladimir E.; Douglas, Thomas A.; Kinsman, Nichole E.M.; Richmond, Bruce M.
2013-01-01
Increases in air, permafrost, and sea surface temperature, loss of sea ice, the potential for increased wave energy, and higher river discharge may all be interacting to escalate erosion of arctic coastal lowland landscapes. Here we use airborne light detection and ranging (LiDAR) data acquired in 2006 and 2010 to detect landscape change in a 100 km2 study area on the Beaufort Sea coastal plain of northern Alaska. We detected statistically significant change (99% confidence interval), defined as contiguous areas (>10 m2) that had changed in height by at least 0.55 m, in 0.3% of the study region. Erosional features indicative of ice-rich permafrost degradation were associated with ice-bonded coastal, river, and lake bluffs, frost mounds, ice wedges, and thermo-erosional gullies. These features accounted for about half of the area where vertical change was detected. Inferred thermo-denudation and thermo-abrasion of coastal and river bluffs likely accounted for the dominant permafrost-related degradational processes with respect to area (42%) and volume (51%). More than 300 thermokarst pits significantly subsided during the study period, likely as a result of storm surge flooding of low-lying tundra (impact of warm summers in the late-1980s and mid-1990s. Our results indicate that repeat airborne LiDAR can be used to detect landscape change in arctic coastal lowland regions at large spatial scales over sub-decadal time periods.
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Su, Xiaoru; Shu, Longcang; Chen, Xunhong; Lu, Chengpeng; Wen, Zhonghui
2016-12-01
Interactions between surface waters and groundwater are of great significance for evaluating water resources and protecting ecosystem health. Heat as a tracer method is widely used in determination of the interactive exchange with high precision, low cost and great convenience. The flow in a river-bank cross-section occurs in vertical and lateral directions. In order to depict the flow path and its spatial distribution in bank areas, a genetic algorithm (GA) two-dimensional (2-D) heat-transport nested-loop method for variably saturated sediments, GA-VS2DH, was developed based on Microsoft Visual Basic 6.0. VS2DH was applied to model a 2-D bank-water flow field and GA was used to calibrate the model automatically by minimizing the difference between observed and simulated temperatures in bank areas. A hypothetical model was developed to assess the reliability of GA-VS2DH in inverse modeling in a river-bank system. Some benchmark tests were conducted to recognize the capability of GA-VS2DH. The results indicated that the simulated seepage velocity and parameters associated with GA-VS2DH were acceptable and reliable. Then GA-VS2DH was applied to two field sites in China with different sedimentary materials, to verify the reliability of the method. GA-VS2DH could be applied in interpreting the cross-sectional 2-D water flow field. The estimates of horizontal hydraulic conductivity at the Dawen River and Qinhuai River sites are 1.317 and 0.015 m/day, which correspond to sand and clay sediment in the two sites, respectively.
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Directory of Open Access Journals (Sweden)
Allison-Oguru, EA.
2000-01-01
Full Text Available This study focuses on assessment of the effect of government's economic liberalization policy on the flow of commercial banks credit to farmers in Rivers State. The empirical analyses are based on information obtained from a sample of 25 out of the over 30 commercial banks operating in the State. Results from the analyses indicate that despite the deregulation of interest rates associated with economic liberalization, commercial banks in the State are unable to meet one-half of the loan requests of farmers. The flow of loanable funds can therefore not be said to have been enhanced by interest rates deregulation. It is argued that simply re-moving restrictions on interest rates is not a sufficient condition for enhanced flow of commercial bank credit to farmers in the State. Such a policy must be complemented with programmes of sharing initial risks and administrative costs between government and the private sector.
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1984-07-01
influencing bank erosion along the Tanana River. Soils The regional soil association along both reaches is loamy, consisting of nearly level histic pergelic ...conspicuous. Most areas of this association are flooded occasionally. The histic pergelic cryaquepts occur in poorly drained, low areas such as meander...great depth; usually occupy natural levees. 6Histic pergelic cryaquepts: soils with texture ranging from gravelly sand to clay, color from gray to
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Lawalenna
2011-01-01
???Lowland??? denotes regions of low elevation, which are particularly vulnerable to climatic and environmental changes. For example, global warming, which appears to be causing a rise in sea level, must ultimately affect the safety of coastal dikes and other coastal infrastructures, as well as threaten the water and ecological systems in lowland areas. Lowland regions are also particularly susceptible to natural disasters. Action is now required for the development of new tech...
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Radiocarbon dating of floodplain and young terraces alluvial sediments of Latvia rivers
International Nuclear Information System (INIS)
Eberhards, G.; Saltupe, B.
2000-01-01
This paper include new information about alluvial sediments structure and radiocarbon data of some Latvia free-meandering rivers (Gauja, Ogre, Liela and Maza Jugla, Daugava) floodplains and first terraces. In this present study we examined Gauja river floodplains in the different geomorphological and geological areas. Radiocarbon dating add the fact that the high level floodplain (4-5 m) formation and sediment accumulation take place 3000-5000 years before present (BP) middle level floodplains formed 1500-2100 years BP. Investigations show that one river terraces and floodplains with same relative height have a several absolute age. The rivers crossed same hypsometrical regions (highlands, lowlands) downstream in lowlands alluvial terraces performed as floodplains or from from floodplains to terraces with same height. On the highest, middle and in the lower parts of the rivers with free - meandering channel to - day the dynamic balance of the channel processes exits 4000-5000 years. (author)
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Quantifying landscape change in an arctic coastal lowland using repeat airborne LiDAR
International Nuclear Information System (INIS)
Jones, Benjamin M; Stoker, Jason M; Gibbs, Ann E; Richmond, Bruce M; Grosse, Guido; Romanovsky, Vladimir E; Douglas, Thomas A; Kinsman, Nicole E M
2013-01-01
Increases in air, permafrost, and sea surface temperature, loss of sea ice, the potential for increased wave energy, and higher river discharge may all be interacting to escalate erosion of arctic coastal lowland landscapes. Here we use airborne light detection and ranging (LiDAR) data acquired in 2006 and 2010 to detect landscape change in a 100 km 2 study area on the Beaufort Sea coastal plain of northern Alaska. We detected statistically significant change (99% confidence interval), defined as contiguous areas (>10 m 2 ) that had changed in height by at least 0.55 m, in 0.3% of the study region. Erosional features indicative of ice-rich permafrost degradation were associated with ice-bonded coastal, river, and lake bluffs, frost mounds, ice wedges, and thermo-erosional gullies. These features accounted for about half of the area where vertical change was detected. Inferred thermo-denudation and thermo-abrasion of coastal and river bluffs likely accounted for the dominant permafrost-related degradational processes with respect to area (42%) and volume (51%). More than 300 thermokarst pits significantly subsided during the study period, likely as a result of storm surge flooding of low-lying tundra (<1.4 m asl) as well as the lasting impact of warm summers in the late-1980s and mid-1990s. Our results indicate that repeat airborne LiDAR can be used to detect landscape change in arctic coastal lowland regions at large spatial scales over sub-decadal time periods. (letter)
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Directory of Open Access Journals (Sweden)
Nizar Shamsuddin Mohd Khairul
2017-01-01
Full Text Available Groundwater tables forecasting during implemented river bank infiltration (RBI method is important to identify adequate storage of groundwater aquifer for water supply purposes. This study illustrates the development and application of artificial neural networks (ANNs to predict groundwater tables in two vertical wells located in confined aquifer adjacent to the Langat River. ANN model was used in this study is based on the long period forecasting of daily groundwater tables. ANN models were carried out to predict groundwater tables for 1 day ahead at two different geological materials. The input to the ANN models consider of daily rainfall, river stage, water level, stream flow rate, temperature and groundwater level. Two different type of ANNs structure were used to predict the fluctuation of groundwater tables and compared the best forecasting values. The performance of different models structure of the ANN is used to identify the fluctuation of the groundwater table and provide acceptable predictions. Dynamics prediction and time series of the system can be implemented in two possible ways of modelling. The coefficient correlation (R, Mean Square Error (MSE, Root Mean Square Error (RMSE and coefficient determination (R2 were chosen as the selection criteria of the best model. The statistical values for DW1 are 0.8649, 0.0356, 0.01, and 0.748 respectively. While for DW2 the statistical values are 0.7392, 0.0781, 0.0139, and 0.546 respectively. Based on these results, it clearly shows that accurate predictions can be achieved with time series 1-day ahead of forecasting groundwater table and the interaction between river and aquifer can be examine. The findings of the study can be used to assist policy marker to manage groundwater resources by using RBI method.
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Die Moran, Andres; El kadi Abderrezzak, Kamal; Tassi, Pablo; Herouvet, Jean-Michel
2014-05-01
Bank erosion is a key process that may cause a large number of economic and environmental problems (e.g. land loss, damage to structures and aquatic habitat). Stream bank erosion (toe erosion and mass failure) represents an important form of channel morphology changes and a significant source of sediment. With the advances made in computational techniques, two-dimensional (2-D) numerical models have become valuable tools for investigating flow and sediment transport in open channels at large temporal and spatial scales. However, the implementation of mass failure process in 2D numerical models is still a challenging task. In this paper, a simple, innovative algorithm is implemented in the Telemac-Mascaret modeling platform to handle bank failure: failure occurs whether the actual slope of one given bed element is higher than the internal friction angle. The unstable bed elements are rotated around an appropriate axis, ensuring mass conservation. Mass failure of a bank due to slope instability is applied at the end of each sediment transport evolution iteration, once the bed evolution due to bed load (and/or suspended load) has been computed, but before the global sediment mass balance is verified. This bank failure algorithm is successfully tested using two laboratory experimental cases. Then, bank failure in a 1:40 scale physical model of the Rhine River composed of non-uniform material is simulated. The main features of the bank erosion and failure are correctly reproduced in the numerical simulations, namely the mass wasting at the bank toe, followed by failure at the bank head, and subsequent transport of the mobilised material in an aggradation front. Volumes of eroded material obtained are of the same order of magnitude as the volumes measured during the laboratory tests.
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Directory of Open Access Journals (Sweden)
Simone Rodrigues Slusarski
2012-06-01
Full Text Available The vegetation from the upper Paraná river floodplain is a fragment of Seasonal Semideciduous Forest (SSF that presents fields, lowlands and extensive areas of pasture along with forest formations. Aiming to accomplish analyses of floristic similarity between riparian forests remnants in this floodplain, an analysis using nine surveys was performed, four on the right bank, two on the left bank and three at an island, including tree species. Sørensen’s (ISs and Jaccard’s (ISj similarity coefficients were calculated, and a Correspondence Analysis (CA was applied to a matrix of presence and absence of species. Thirty-seven families, 80 genera and 110 species were recorded. Among the species, 5.5% were generalist, while 29.1% were exclusive to one survey. The values of ISs and ISj ranged from 31 to 78.4%, and 31 to 64.5%, respectively. The CA grouped the surveys in the right and left banks and the island; the species with the highest positive correlation on axis 1 were the most common in the surveys on the left bank. The obtained results evidenced that floristic surveys constitute important indicatives for evaluations of the vegetation distribution in the floodplain.
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Hidayat, H.
2013-01-01
Tidal rivers and lowland wetlands present a transition region where the interests of hydrologists and physical oceanographers overlap. Physical oceanographers tend to simplify river hydrology, by often assuming a constant river discharge when studying estuarine dynamics. Hydrologists, in turn,
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Stability evaluation of modernized bank protections in a culvert construction
Cholewa, Mariusz; Plesiński, Karol; Kamińska, Katarzyna; Wójcik, Izabela
2018-02-01
The paper presents stability evaluation of the banks of the Wilga River on a chosen stretch in Koźmice Wielkie, Małopolska Province. The examined stretch included the river bed upstream from the culvert on a district road. The culvert construction, built over four decades ago, was disassembled in 2014. The former construction, two pipes that were 1.4 m in diameter, was entirely removed. The investor decided to build a new construction in the form of insitu poured reinforced concrete with a 4 x 2 m cross section. Change of geometry and different location in relation to the river current caused increase in the flow velocity and, as a consequence, erosion of both protected and natural banks. Groundwater conditions were determined based on the geotechnical tests that were carried out on soil samples taken from the banks and the river bed. Stability calculations of natural slopes of the Wilga River and the ones protected with riprap indicate mistakes in the design project concerning construction of the river banks. The purpose of the study was to determine the stability of the Wilga River banks on a selected section adjacent to the rebuilt culvert. Stability of a chosen cross section was analysed in the paper. Presented conclusions are based on the results of geotechnical tests and numerical calculations.
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Lidar quantification of bank erosion in Blue Earth County, Minnesota.
Kessler, A C; Gupta, S C; Dolliver, H A S; Thoma, D P
2012-01-01
Sediment and phosphorus (P) transport from the Minnesota River Basin to Lake Pepin on the upper Mississippi River has garnered much attention in recent years. However, there is lack of data on the extent of sediment and P contributions from riverbanks vis-à-vis uplands and ravines. Using two light detection and ranging (lidar) data sets taken in 2005 and 2009, a study was undertaken to quantify sediment and associated P losses from riverbanks in Blue Earth County, Minnesota. Volume change in river valleys as a result of bank erosion amounted to 1.71 million m over 4 yr. Volume change closely followed the trend: the Blue Earth River > the Minnesota River at the county's northern edge > the Le Sueur River > the Maple River > the Watonwan River > the Big Cobb River > Perch Creek > Little Cobb River. Using fine sediment content (silt + clay) and bulk density of 37 bank samples representing three parent materials, we estimate bank erosion contributions of 48 to 79% of the measured total suspended solids at the mouth of the Blue Earth and the Le Sueur rivers. Corresponding soluble P and total P contributions ranged from 0.13 to 0.20% and 40 to 49%, respectively. Although tall banks (>3 m high) accounted for 33% of the total length and 63% of the total area, they accounted for 75% of the volume change in river valleys. We conclude that multitemporal lidar data sets are useful in estimating bank erosion and associated P contributions over large scales, and for riverbanks that are not readily accessible for conventional surveying equipment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
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Directory of Open Access Journals (Sweden)
Marcelo Gomes Miguez
2015-08-01
Full Text Available The development of cities has always had a very close relation with water. However, cities directly impact land use patterns and greatly change natural landscapes, aggravating floods. Considering this situation, this paper intends to discuss lowland occupation and city sustainability in what regards urban stormwater management, fluvial space, and river restoration, aiming at minimizing flood risks and improving natural and built environment conditions. River plains tend to be attractive places for a city to grow. From ancient times, levees have been used to protect lowland areas along major watercourses to allow their occupation. However, urban rivers demand space for temporary flood storage. From a systemic point of view, levees along extensive river reaches act as canalization works, limiting river connectivity with flood plains, rising water levels, increasing overtopping risks and transferring floods downstream. Departing from this discussion, four case studies in the Iguaçu-Sarapuí River Basin, a lowland area of Rio de Janeiro State, Brazil, are used to compose a perspective in which the central point refers to the need of respecting watershed limits and giving space to rivers. Different aspects of low-lying city planning are discussed and analyzed concerning the integration of the built and natural environments.
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RiverCare: towards self-sustaining multifunctional rivers
Augustijn, Denie; Schielen, Ralph; Hulscher, Suzanne
2014-05-01
Rivers are inherently dynamic water systems involving complex interactions among hydrodynamics, morphology and ecology. In many deltas around the world lowland rivers are intensively managed to meet objectives like safety, navigation, hydropower and water supply. With the increasing pressure of growing population and climate change it will become even more challenging to reach or maintain these objectives and probably also more demanding from a management point of view. In the meantime there is a growing awareness that rivers are natural systems and that, rather than further regulation works, the dynamic natural processes should be better utilized (or restored) to reach the multifunctional objectives. Currently many integrated river management projects are initiated all over the world, in large rivers as well as streams. Examples of large scale projects in the Netherlands are 'Room for the River' (Rhine), the 'Maaswerken' (Meuse), the Deltaprogramme and projects originating from the European Water Framework Directive (WFD). These projects include innovative measures executed never before on this scale and include for example longitudinal training dams, side channels, removal of bank protection, remeandering of streams, dredging/nourishment and floodplain rehabilitation. Although estimates have been made on the effects of these measures for many of the individual projects, the overall effects on the various management objectives remains uncertain, especially if all projects are considered in connection. For all stakeholders with vested interests in the river system it is important to know how that system evolves at intermediate and longer time scales (10 to 100 years) and what the consequences will be for the various river functions. If the total, integrated response of the system can be predicted, the system may be managed in a more effective way, making optimum use of natural processes. In this way, maintenance costs may be reduced, the system remains more natural
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De Vries, M.
1993-01-01
One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.
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Werner, Petra; Köhler, Jan
2005-02-01
We studied chlorophyll a (chl. a), biovolume and species composition of benthic algae and phytoplankton in the eutrophic lower River Spree in 1996. The chl. a concentration was estimated as 3.5 (2.7-4.5) μg/cm2 for epipsammon, 9.4 (7.4-11.9) μg/cm2 for epipelon and 6.7 (5.7-7.8) μg/cm2 for the epilithon (median and 95% C. L.). The mean total biomass of benthic algae was significantly higher (6.0 μg chl. a/cm2) than the areal chl. a content of the pelagic zone (1.6 μg chl. a/cm2). Although certain phytoplankton taxa were abundant in the periphyton, benthic taxa generally dominated the assemblages. Seasonal dynamics of benthic algae were probably controlled by light and nitrate supply (sand), discharge fluctuations (sand, mud) and invertebrate grazing (stones). This paper shows the importance of benthic algae even in phytoplankton-rich lowland rivers with sandy or muddy sediments.
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Samadi, A.; Amiri-Tokaldany, E.; Davoudi, M. H.; Darby, S. E.
2011-11-01
Composite river banks consist of a basal layer of non-cohesive material overlain by a cohesive layer of fine-grained material. In such banks, fluvial erosion of the lower, non-cohesive, layer typically occurs at a much higher rate than erosion of the upper part of the bank. Consequently, such banks normally develop a cantilevered bank profile, with bank retreat of the upper part of the bank taking place predominantly by the failure of these cantilevers. To predict the undesirable impacts of this type of bank retreat, a number of bank stability models have been presented in the literature. These models typically express bank stability by defining a factor of safety as the ratio of resisting and driving forces acting on the incipient failure block. These forces are affected by a range of controlling factors that include such aspects as the overhanging block geometry, and the geotechnical properties of the bank materials. In this paper, we introduce a new bank stability relation (for shear-type cantilever failures) that considers the hydrological status of cantilevered riverbanks, while beam-type failures are analyzed using a previously proposed relation. We employ these stability models to evaluate the effects of parameter uncertainty on the reliability of riverbank stability modeling of overhanging banks. This is achieved by employing a simple model of overhanging failure with respect to shear and beam failure mechanisms in a series of sensitivity tests and Monte Carlo analyses to identify, for each model parameter, the range of values that induce significant changes in the simulated factor of safety. The results show that care is required in parameterising (i) the geometrical shape of the overhanging-block and (ii) the bank material cohesion and unit weight, as predictions of bank stability are sensitive to variations of these factors.
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Equilibrium depth of scour at straight guide banks
Gjunsburgs, B.; Bulankina, V.
2017-10-01
The equilibrium stage of scour at the head of straight guide banks with a uniform and stratified bed conditions have been studied. The contraction of the river by bridge crossing with straight guide banks considerably alters the flow pattern. The streamlines become curve and the concentration of streamlines, longitudinal and transverse slopes of the water surface, a local increase in velocity, vortex and eddy structures, and the origin of a flow separation zone between the extreme streamlines and the guide bank are observed and local scour is developing at the head of the straight guide banks. New formulae for calculation of equilibrium depth of scour at straight guide banks at uniform and stratified river bed is elaborated and confirmed by tests and computer modelling results.
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Wu, M. S.; Feakins, S. J.; Ponton, C.; West, A. J.; Galy, V.
2017-12-01
The carbon and hydrogen isotopic compositions (respectively δ13C and δD) of plant wax biomarkers have been widely used to reconstruct past climate and environment. To understand how leaf waxes are sourced within a river catchment, and how their isotopic signature is transferred from source to sink, we study δ13C and δD of C29 n-alkanes and C30 n-alkanoic acids in the Madre de Dios River catchment along the eastern flank of the Peruvian Andes. We sampled soils across a 3.5km elevation transect and find gradients in δ13Cwax (ca. +1.5‰/km) and δDwax (ca. -10 ‰/km) similar to gradients in tree canopy leaves (Feakins et al., 2016 GCA; Wu et al., 2017 GCA). We also collected river suspended sediment samples along the Madre de Dios River and its tributaries, which together drain an area of 75,400 km2 and 6 km of elevation. We utilize soil data and a digital elevation model to construct isoscapes, delineate catchments for each river sampling location, predict river values assuming spatial uniform integration, and compare our predictions with observed values. Although both compounds generally follow isotopic gradients defined by catchment elevations, the dual isotope and compound-class comparison reveals additional processes. For C30 n-alkanoic acid we find an up to 1km lower-than-expected catchment signal, indicating degradation of upland contributions in transit and replacement with lowland inputs. In contrast, mountain-front river locations are susceptible to upland-biases (up to 1km higher sourcing) in C29 n-alkane sourcing, likely due to enhanced erosion and higher leaf wax stock in Andean soil compared to the lowland, and greater persistence of n-alkanes than n-alkanoic acids. For both compounds, the bias is eliminated with several hundred km of river transit across the floodplain. In one location, we identify significant petrogenic contamination of n-alkanes but not n-alkanoic acids. These results indicate the power in combining dual compound classes and
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Neotropical lowland forests along environmental gradients
Toledo, M.
2010-01-01
Neotropical lowlands feature an extraordinary display of vegetation types. This is especially the case for Bolivia where three biogeographical regions, Amazonian, Brazilian-Paranaense and Gran Chaco meet in the lowland areas, providing thus an ideal setting to study vegetation-environment
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Petroleum possibilities of the James Bay Lowland area: Drilling in the James Bay Lowland
Energy Technology Data Exchange (ETDEWEB)
Martison, N W
1954-12-31
Interest in the possible occurrence of petroleum and natural gas in the James Bay lowland arises from the presence there of Palaeozoic sedimentary formations resembling those in south-western Ontario. The first part of this report reviews earlier geologic surveys conducted in the lowland and reports results of field work and drill core studies 1946-51. It describes the area`s topography, climate, stratigraphy and palaeontology (Ordovician to Lower Cretaceous, plus Pleistocene and recent glacial deposits), structural geology, and evidence of petroleum. Lists of fossils and correlations are included. The appendices include a list of fossil locations and drill logs. The second part details the drilling programs carried out in the lowland by the Ontario Dept. of Mines, including detailed logs, as well as drilling carried out by some other organisations.
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Flood occurrence mapping of the middle Mahakam lowland area using satellite radar
Directory of Open Access Journals (Sweden)
H. Hidayat
2012-07-01
Full Text Available Floodplain lakes and peatlands in the middle Mahakam lowland area are considered as ecologically important wetland in East Kalimantan, Indonesia. However, due to a lack of data, the hydrological functioning of the region is still poorly understood. Among remote sensing techniques that can increase data availability, radar is well-suitable for the identification, mapping, and measurement of tropical wetlands, for its cloud unimpeded sensing and night and day operation. Here we aim to extract flood extent and flood occurrence information from a series of radar images of the middle Mahakam lowland area. We explore the use of Phased Array L-band Synthetic Aperture Radar (PALSAR imagery for observing flood inundation dynamics by incorporating field water level measurements. Water level measurements were carried out along the river, in lakes and in peatlands, using pressure transducers. For validation of the open water flood occurrence map, bathymetry measurements were carried out in the main lakes. A series of PALSAR images covering the middle and lower Mahakam area in the years 2007 through 2010 were collected. A fully inundated region can be easily recognized on radar images from a dark signature. Open water flood occurrence was mapped using a threshold value taken from radar backscatter of the permanently inundated river and lakes areas. Radar backscatter intensity analysis of the vegetated floodplain area revealed consistently high backscatter values, indicating flood inundation under forest canopy. We used those values as the threshold for flood occurrence mapping in the vegetated area.
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Somchob Poo-Inna; Song-Koon Jantakajon; Terdthai Pantachai
2009-01-01
Problem statement: The fresh water fish in The Chi River was a major source of food of people living in this area. The objectives of this research were: (1) to study the historical background, current situation and problems of local fish conservation in front of The Chi River by community participation and (2) to find the opriate model for zoning the local fish conservation on the bank of The Chi River by sustainable community participation. Approach: The research area in Esan Reg...
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Hydrology and phosphorus transport simulation in a lowland polder by a coupled modeling system.
Yan, Renhua; Huang, Jiacong; Li, Lingling; Gao, Junfeng
2017-08-01
Modeling the rain-runoff processes and phosphorus transport processes in lowland polders is critical in finding reasonable measures to alleviate the eutrophication problem of downstream rivers and lakes. This study develops a lowland Polder Hydrology and Phosphorus modeling System (PHPS) by coupling the WALRUS-paddy model and an improved phosphorus module of a Phosphorus Dynamic model for lowland Polder systems (PDP). It considers some important hydrological characteristics, such as groundwater-unsaturated zone coupling, groundwater-surface water feedback, human-controlled irrigation and discharge, and detailed physical and biochemical cycles of phosphorus in surface water. The application of the model in the Jianwei polder shows that the simulated phosphorus matches well with the measured values. The high precision of this model combined with its low input data requirement and efficient computation make it practical and easy to the water resources management of Chinese polders. Parameter sensitivity analysis demonstrates that K uptake , c Q2 , c W1 , and c Q1 exert a significant effect on the modeled results, whereas K resuspensionMax , K settling , and K mineralization have little effect on the modeled total phosphorus. Among the three types of uncertainties (i.e., parameter, initial condition, and forcing uncertainties), forcing uncertainty produces the strongest effect on the simulated phosphorus. Based on the analysis result of annual phosphorus balance when considering the high import from irrigation and fertilization, lowland polder is capable of retaining phosphorus and reducing phosphorus export to surrounding aquatic ecosystems because of their special hydrological regulation regime. Copyright © 2016 Elsevier Ltd. All rights reserved.
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The susceptibility of large river basins to orogenic and climatic drivers
Haedke, Hanna; Wittmann, Hella; von Blanckenburg, Friedhelm
2017-04-01
Large rivers are known to buffer pulses in sediment production driven by changes in climate as sediment is transported through lowlands. Our new dataset of in situ cosmogenic nuclide concentration and chemical composition of 62 sandy bedload samples from the world largest rivers integrates over 25% of Earth's terrestrial surface, distributed over a variety of climatic zones across all continents, and represents the millennial-scale denudation rate of the sediment's source area. We can show that these denudation rates do not respond to climatic forcing, but faithfully record orogenic forcing, when analyzed with respective variables representing orogeny (strain rate, relief, bouguer anomaly, free-air anomaly), and climate (runoff, temperature, precipitation) and basin properties (floodplain response time, drainage area). In contrast to this orogenic forcing of denudation rates, elemental bedload chemistry from the fine-grained portion of the same samples correlates with climate-related variables (precipitation, runoff) and floodplain response times. It is also well-known from previous compilations of river-gauged sediment loads that the short-term basin-integrated sediment export is also climatically controlled. The chemical composition of detrital sediment shows a climate control that can originate in the rivers source area, but this signal is likely overprinted during transfer through the lowlands because we also find correlation with floodplain response times. At the same time, cosmogenic nuclides robustly preserve the orogenic forcing of the source area denudation signal through of the floodplain buffer. Conversely, previous global compilations of cosmogenic nuclides in small river basins show the preservation of climate drivers in their analysis, but these are buffered in large lowland rivers. Hence, we can confirm the assumption that cosmogenic nuclides in large rivers are poorly susceptible to climate changes, but are at the same time highly suited to detect
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Environmental Risk of Metal Mining Contaminated River Bank Sediment at Redox-Transitional Zones
Directory of Open Access Journals (Sweden)
Sarah F. L. Lynch
2014-01-01
Full Text Available Diffuse metal pollution from mining impacted sediment is widely recognised as a potential source of contamination to river systems and may significantly hinder the achievement of European Union Water Framework Directive objectives. Redox-transitional zones that form along metal contaminated river banks as a result of flood and drought cycles could cause biogeochemical changes that alter the behaviour of polyvalent metals iron and manganese and anions such as sulphur. Trace metals are often partitioned with iron, manganese and sulphur minerals in mining-contaminated sediment, therefore the dissolution and precipitation of these minerals may influence the mobility of potentially toxic trace metals. Research indicates that freshly precipitated metal oxides and sulphides may be more “reactive” (more adsorbent and prone to dissolution when conditions change than older crystalline forms. Fluctuations at the oxic-anoxic interface brought about through changes in the frequency and duration of flood and drought episodes may therefore influence the reactivity of secondary minerals that form in the sediment and the flux of dissolved trace metal release. UK climate change models predict longer dry periods for some regions, interspersed with higher magnitude flood events. If we are to fully comprehend the future environmental risk these climate change events pose to mining impacted river systems it is recommended that research efforts focus on identifying the primary controls on trace metal release at the oxic-anoxic interface for flood and drought cycles of different duration and frequency. This paper critically reviews the literature regarding biogeochemical processes that occur at different temporal scales during oxic, reducing and dry periods and focuses on how iron and sulphur based minerals may alter in form and reactivity and influence the mobility of trace metal contaminants. It is clear that changes in redox potential can alter the composition
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Discharge estimation in a backwater affected meandering river
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H. Hidayat
2011-08-01
Full Text Available Variable effects of backwaters complicate the development of rating curves at hydrometric measurement stations. In areas influenced by backwater, single-parameter rating curve techniques are often inapplicable. To overcome this, several authors have advocated the use of an additional downstream level gauge to estimate the longitudinal surface level gradient, but this is cumbersome in a lowland meandering river with considerable transverse surface level gradients. Recent developments allow river flow to be continuously monitored through velocity measurements with an acoustic Doppler current profiler (H-ADCP, deployed horizontally at a river bank. This approach was adopted to obtain continuous discharge estimates at a cross-section in the River Mahakam at a station located about 300 km upstream of the river mouth in the Mahakam delta. The discharge station represents an area influenced by variable backwater effects from lakes, tributaries and floodplain ponds, and by tides. We applied both the standard index velocity method and a recently developed methodology to obtain a continuous time-series of discharge from the H-ADCP data. Measurements with a boat-mounted ADCP were used for calibration and validation of the model to translate H-ADCP velocity to discharge. As a comparison with conventional discharge estimation techniques, a stage-discharge relation using Jones formula was developed. The discharge rate at the station exceeded 3250 m3 s−1. Discharge series from a traditional stage-discharge relation did not capture the overall discharge dynamics, as inferred from H-ADCP data. For a specific river stage, the discharge range could be as high as 2000 m3 s−1, which is far beyond what could be explained from kinematic wave dynamics. Backwater effects from lakes were shown to be significant, whereas interaction of the river flow with tides may impact discharge variation in the fortnightly frequency band
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Arliansyah, Joni; Hartono, Yusuf; Hastuti, Yulia; Astuti, Rinna
2017-11-01
Palembang City is one of the cities having the largest river in Indonesia and it should be able to take advantage of river transportation as an alternative choice. Inadequate availability of river transport facilities and infrastructures makes the people prefer other modes of land transportation rather than using river transportation. In addition, the development planning of river transportation such as the development of river taxi is less successful because it is not yet based on the movement pattern of the origin of the community travel destination. Based on the above matter, this study was conducted. The aim of the study was to find out the characteristics and factors affecting the mode choice of the community living along the bank of Musi River of Palembang City to be the basis of the development of river transportation system in Palembang City. The selected modes were motorcycles, cars, city transports, and ketek (motorized boats). Survey of home interviews was conducted to determine the origin of the destination and characteristics of travel was conducted in 30 villages located on the banks of Musi River. Field survey was conducted to determine the conditions and types of existing river transportation facilities and services. The results show that only 5.3 % of the occurrence movement used river transportation, the rest used motorcycles (69.1%), urban transport (15.9 %) and cars (9.7%), with the travel range less than10 minutes and 10 - 20 minutes as much as 43.2 % and 29 % of the total trips. From the socioeconomic profile of the community, it is found that most of the people living along the Musi River have low and middle incomes with the largest types of jobs as workers, students, shop owner, and housewives. The peak movement time for the movement of river transport occurs at 7:00 - 8:00, 10:00 - 11:00 and 16:00 - 17:00 with the movement of origin of the destination of river transportation is known to be 50% at the traditional market center of Dermaga of
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A Stochastic Water Balance Framework for Lowland Watersheds
Thompson, Sally; MacVean, Lissa; Sivapalan, Murugesu
2017-11-01
The water balance dynamics in lowland watersheds are influenced not only by local hydroclimatic controls on energy and water availability, but also by imports of water from the upstream watershed. These imports result in a stochastic extent of inundation in lowland watersheds that is determined by the local flood regime, watershed topography, and the rate of loss processes such as drainage and evaporation. Thus, lowland watershed water balances depend on two stochastic processes—rainfall and local inundation dynamics. Lowlands are high productivity environments that are disproportionately associated with urbanization, high productivity agriculture, biodiversity, and flood risk. Consequently, they are being rapidly altered by human development—generally with clear economic and social motivation—but also with significant trade-offs in ecosystem services provision, directly related to changes in the components and variability of the lowland water balance. We present a stochastic framework to assess the lowland water balance and its sensitivity to two common human interventions—replacement of native vegetation with alternative land uses, and construction of local flood protection levees. By providing analytical solutions for the mean and PDF of the water balance components, the proposed framework provides a mechanism to connect human interventions to hydrologic outcomes, and, in conjunction with ecosystem service production estimates, to evaluate trade-offs associated with lowland watershed development.
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Su, Xiaosi; Lu, Shuai; Yuan, Wenzhen; Woo, Nam Chil; Dai, Zhenxue; Dong, Weihong; Du, Shanghai; Zhang, Xinyue
2018-03-01
The spatial and temporal distribution of redox zones in an aquifer is important when designing groundwater supply systems. Redox zonation can have direct or indirect control of the biological and chemical reactions and mobility of pollutants. In this study, redox conditions are characterized by interpreting the hydrogeological conditions and water chemistry in groundwater during bank infiltration at a site in Shenyang, northeast China. The relevant redox processes and zonal differences in a shallow flow path and deeper flow path at the field scale were revealed by monitoring the redox parameters and chemistry of groundwater near the Liao River. The results show obvious horizontal and vertical components of redox zones during bank filtration. Variations in the horizontal extent of the redox zone were controlled by the different permeabilities of the riverbed sediments and aquifer with depth. Horizontally, the redox zone was situated within 17 m of the riverbank for the shallow flow path and within 200 m for the deep flow path. The vertical extent of the redox zone was affected by precipitation and seasonal river floods and extended to 10 m below the surface. During bank filtration, iron and manganese oxides or hydroxides were reductively dissolved, and arsenic that was adsorbed onto the medium surface or coprecipitated is released into the groundwater. This leads to increased arsenic content in groundwater, which poses a serious threat to water supply security.
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Rowland, J. C.; Dietrich, W. E.; Day, G.; Parker, G.
2009-06-01
Tie channels connect rivers to floodplain lakes on many lowland rivers and thereby play a central role in floodplain sedimentology and ecology; yet they are generally unrecognized and little studied. Here we report the results of field studies focused on tie channel origin and morphodynamics in the following three contrasting systems: the Middle Fly River (Papua New Guinea), the Lower Mississippi River, and Birch Creek in Alaska. Across these river systems, tie channels vary by an order of magnitude in size but exhibit the same characteristic morphology and appear to develop and evolve by a similar set of processes. In all three systems, the channels are characterized by a narrow, leveed, single-thread morphology with maximum width approximately one tenth the width of the mainstem river. The channels typically have a V-shaped cross section, unlike most fluvial channels. These channels develop as lakes become isolated from the river by sedimentation. Narrowing of the connection between river and lake causes a sediment-laden jet to develop. Levees develop along the margins of the jet leading to channel emergence and eventual levee aggradation to the height of the mainstem levees. Bidirectional flow in these channels is common. Outflows from the lake scour sediment and prevent channel blockage. We propose that channel geometry and size are then controlled by a dynamic balance between channel narrowing by suspended sediment deposition and incision and widening by mass failure of banks during outflows. Tie channels are laterally stable and may convey flow for hundreds to a few thousand of years.
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Paul E. Berry; Alex C. Wiedenhoeft
2004-01-01
Micrandra inundata is a distinctive new species adapted to seasonally flooded black-water river banks in southern Venezuela. Trees rarely exceed 10 m in height but have thick basal trunks composed of very lightweight wood. It has the smallest leaves and fruits of any known Micrandra species and appears to be most closely related to M. minor Benth. The botanical...
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On the issue of taxonomical status of steppe viper (Vipera renardi in Right-bank Ukraine
Directory of Open Access Journals (Sweden)
A. L. Baybuz
2011-07-01
Full Text Available Data on morphologic variability of the steppe viper in the Kirovograd region (Right-bank Ukraine are given firstly. Tentative estimation of the similaritylevel of the local population and the populations from the Left-bank Ukraine and the Crimea was carried out using methods of the multivariate statistics. Morphological data in line with the results of mitochondrial DNA analysis show that the population in the Kirovograd region belongs to widespread Eurasian species Vipera renardiand morphologically most close to the original populations of the lowland Crimea, Sivash and Forest-Steppe of the Left-bank Ukraine. This could indicate the complicated history of the Right-bank Ukraine colonization by the steppe viper and possible influence of environmental conditions on the vipers’ morphology
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Biodiversity of microcrustaceans (Cladocera, Copepoda in a lowland river ecosystem
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Maciej Karpowicz
2016-06-01
Full Text Available This study presents comprehensive research on microcrustacean diversity in different types of aquatic environments in the Upper Narew Valley over five years. A total of 559 samples were analyzed, and 74 species of crustacean zooplankton were identified. Metacyclops planus (Gurney, 1909 is a new species for the fauna of Poland and was found in oxbow lakes and tributary streams. The results of the study suggest that oxbow lakes, with more than 80% of all recorded species, may significantly contribute to the regional biodiversity of floodplain rivers. The highest crustacean community diversity was observed in the semi-lotic oxbow lakes, which emphasizes the role of intermediate disturbance in enhancing biodiversity of water bodies in river valleys. Generally, more “heterogeneous” habitats, such as small oxbow lakes and tributary streams, had higher crustacean species richness. However, a sampling station that was quite “homogeneous”, the Narew River upstream the Siemianówka Reservoir, had high crustacean species richness. The species accumulation curves revealed that approximately 50 - 100 zooplankton samples taken from different environments of river valley are required to establish crustacean species richness. These data could be important for river catchment management and could act as pilot survey data for monitoring plans.
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Randrianiaina, R.-D.; Strauß, A.; Glos, J.; Glaw, F.; Vences, M.
2011-01-01
We provide detailed morphological descriptions of the tadpoles of Malagasy river bank frogs of the subgenera Ochthomantis and Maitsomantis (genus Mantidactylus, family Mantellidae), and data on relative abundance and habitat preferences of Ochthomantis species from Ranomafana National Park in
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Energy Technology Data Exchange (ETDEWEB)
Rowland, Joel C [Los Alamos National Laboratory; Dietrich, William E [UC BERKELEY; Day, Geoff [NEWCREST MINING; Parker, Gary [UNIV OF ILLINOIS
2009-01-01
Tie channels connect rivers to floodplain lakes on many lowland rivers and thereby play a central role in floodplain sedimentology and ecology, yet they are generally unrecognized and little studied. here we report the results of field studies focused on tie channel origin and morphodynamics in three contrasting systems: the Middle Fly River, Papua New Guinea, the Lower Mississippi River, and Birch Creek in Alaska. Across these river systems, tie channels vary by an order of magnitude in size but exhibit the same characteristic morphology and appear to develop and evolve by a similar set of processes. In all three systems, the channels are characterized by a narrow, leveed single-thread morphology with maximum width approximately one tenth the width of the mainstem river. The channels typically have a V shaped cross-section, unlike most fluvial channels. These channels develop as lakes become isolated from the river by sedimentation. Narrowing of the connection between river and lake causes a sediment-laden jet to develop. Levees develop along the margins of the jet leading to channel emergence and eventual levee aggradation to the height of the mainstem levees. Bi-directional flow in these channels is common. Outflows from the lake scour sediment and prevent channel blockage. We propose that channel geometry and size are then controlled by a dynamic balance between channel narrowing by suspended sediment deposition and incision and widening by mass failure of banks during outflows. Tie channels are laterally stable and may convey flow for hundreds to a few thousand of years.
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A. Walega; A. Cupak; D.M. Amatya; E. Drozdzal
2017-01-01
The aim of the study is to compare direct outflow from storm events estimated using modifications of original SCS-CN procedure. The study was conducted in a mountainous catchment of Kamienica River and a highland catchment draining Stobnica River located in Upper Vistula water region, both in Poland, and a headwater lowland watershed WS80 located at the Santee...
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Seed bank composition in a secondary forest in the Lower Delta of the Paraná River (Argentina
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Fábio Kalesnik
2013-03-01
Full Text Available The native forests once occupying the coastal levees of the Lower Delta islands of the Paraná River (in Argentina have been replaced by commercial forests. Many of those forests have been abandoned, resulting in secondary forest formation that is subject to numerous invasive exotic species. A priori observations suggest that successional trends do not lead to recovery of the original forest. The aim of the present study was to analyze the role of invasive exotic species in these environments and the likelihood of recovery of the original forest cover. Therefore, we examined the composition of the seed bank and of the standing vegetation, as well as the population structure of tree species. Secondary forests are described as being in an intermediate successional stage, with few exotic species (mainly trees but with a high abundance of standing vegetation and seed banks. These exotic species will likely continue to successfully predominate in different forest strata over the next stages. Because of the low density of native tree species, it is difficult to predict their future persistence. In conclusion, ecological restoration strategies will be needed in order to increase native tree species richness and biodiversity of the forests in the Lower Delta of the Paraná River.
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What Should a Restored River Look Like? (Invited)
Florsheim, J. L.; Chin, A.
2010-12-01
Removal of infrastructure such as dams, levees, and erosion control structures is a promising approach toward restoring river system connectivity, processes, and ecology. Significant management challenges exist, however, related to removal of such structures that have already transformed riparian processes or societal perceptions. Here, we consider the effects of bank erosion infrastructure versus the benefits of allowing channel banks to erode in order to address the question: what should a restored river look like? The extent of channel bank infrastructure globally is unknown; nevertheless, it dominates rivers in most urban areas and is growing in rural areas as small projects merge and creeks and rivers are progressively channelized. Bank erosion control structures are usually installed to limit land loss and to reduce associated hazards. Structures are sometimes themselves considered restoration under the assumption that sediment erosion is bad for ecosystems. Geomorphic and ecological effects of bank erosion control structures are well understood, however, and include loss of sediment sources, bank substrate, dynamic geomorphic processes, and riparian habitat. Thus, a rationale for allowing eroding banks in restored rivers is as follows: 1) bank erosion processes are a component of system-scale channel adjustment needed to accommodate variable hydrology and sediment loads and to promote long-term stability; 2) bank erosion is a source of coarse and fine sediment to channels needed to maintain downstream bed elevations and topographic heterogeneity; and 3) bank erosion is a component of river migration, a process that promotes riparian vegetation succession and provides large woody material and morphologic diversity required to sustain habitat and riparian biodiversity. When structures that were originally intended to control or manage dynamic natural processes such as flooding and erosion are removed, not surprisingly, a return to dynamic processes may cause
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Flow and Residence Times of Dynamic River Bank Storage and Sinuosity-Driven Hyporheic Exchange
Gomez-Velez, J. D.; Wilson, J. L.; Cardenas, M. B.; Harvey, J. W.
2017-10-01
Hydrologic exchange fluxes (HEFs) vary significantly along river corridors due to spatiotemporal changes in discharge and geomorphology. This variability results in the emergence of biogeochemical hot-spots and hot-moments that ultimately control solute and energy transport and ecosystem services from the local to the watershed scales. In this work, we use a reduced-order model to gain mechanistic understanding of river bank storage and sinuosity-driven hyporheic exchange induced by transient river discharge. This is the first time that a systematic analysis of both processes is presented and serves as an initial step to propose parsimonious, physics-based models for better predictions of water quality at the large watershed scale. The effects of channel sinuosity, alluvial valley slope, hydraulic conductivity, and river stage forcing intensity and duration are encapsulated in dimensionless variables that can be easily estimated or constrained. We find that the importance of perturbations in the hyporheic zone's flux, residence times, and geometry is mainly explained by two-dimensionless variables representing the ratio of the hydraulic time constant of the aquifer and the duration of the event (Γd) and the importance of the ambient groundwater flow (Δh∗). Our model additionally shows that even systems with small sensitivity, resulting in small changes in the hyporheic zone extent, are characterized by highly variable exchange fluxes and residence times. These findings highlight the importance of including dynamic changes in hyporheic zones for typical HEF models such as the transient storage model.
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Rivers running deep : complex flow and morphology in the Mahakam River, Indonesia
Vermeulen, B.
2014-01-01
Rivers in tropical regions often challenge our geomorphological understanding of fluvial systems. Hairpin bends, natural scours, bifurcate meander bends, tie channels and embayments in the river bank are a few examples of features ubiquitous in tropical rivers. Existing observation techniques
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The social connectivity of urban rivers
Kondolf, G. Mathias; Pinto, Pedro J.
2017-01-01
By social connectivity we refer to the communication and movement of people, goods, ideas, and culture along and across rivers, recognizing longitudinal, lateral, and vertical connectivity, much as has been described for other rivers for hydrology and ecology. We focus on rivers as they pass through cities, and the relationships between these rivers and city dwellers. Historically, the most important longitudinal connectivity function of rivers was their role as major transport routes and the simplification of formerly complex, irregular banks and beds, into straight, uniform shipping channels has resulted in a loss of lateral and vertical connectivity, notably the quotidian uses such as fishing, washing clothes, water supply, swimming and other recreation. The scale of the river itself, and its scale in comparison to the scale of the city, largely determine the river's social function and the degree to which it influences city form. River width affects the perception of 'closeness' of the other bank, ease of bridging the river, influence of the river on the city's street pattern, and type of waterfront uses that occur. Up to 15 m wide, people can converse, whereas across rivers 50 to 200 m wide, people are not recognizable but still clearly visible, instilling the banks with a 'lively' atmosphere. At widths over 200 m, people blur, yet moving vehicles and trees branches shaking in wind may still provide some dynamic elements to an otherwise static landscape composed of building facades. In exceptionally wide rivers, the city on the opposite bank is little more than a skyline, which often becomes a signature and symbol of regional identity. In contemplating how people use rivers, we can define a range of human activities in relation to height above the water (i.e., instream to banktop), a vertical dimension of human connectivity with rivers. Many uses occur on the top of the bank, such as quiet contemplation, walking, or cycling along a riverside trail, while
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33 CFR 165.150 - New Haven Harbor, Quinnipiac River, Mill River.
2010-07-01
... River, Mill River. 165.150 Section 165.150 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... New Haven Harbor, Quinnipiac River, Mill River. (a) The following is a regulated navigation area: The... 303°T to point D at the west bank of the mouth of the Mill River 41°18′05″ N, 72°54′23″ W thence south...
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International Nuclear Information System (INIS)
Jonge, Maarten de; Vijver, Bart van de; Blust, Ronny; Bervoets, Lieven
2008-01-01
sediment. This study indicated that to assess the effect of metal pollution in lowland rivers, the combined use of macroinvertebrates and diatoms is more appropriate than the use of both biota separately
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Energy Technology Data Exchange (ETDEWEB)
Jonge, Maarten de [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: maarten.dejonge@ua.ac.be; Vijver, Bart van de [Department of Bryophytes and Thallophytes, National Botanic Garden of Belgium, Domein van Bouchout, 1860 Meise (Belgium); Blust, Ronny; Bervoets, Lieven [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)
2008-12-15
sediment. This study indicated that to assess the effect of metal pollution in lowland rivers, the combined use of macroinvertebrates and diatoms is more appropriate than the use of both biota separately.
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Jäger, A.; Posselt, M.; Schaper, J. L.; Lewandowski, J.
2017-12-01
Not only transport, but especially transformation of polar organic micropollutants in urban streams is of increasing concern for urban water management. While concentrations of pharmaceuticals might decrease down the river, concentrations of their more persistent metabolites potentially increase due to microbial transformation. The river Erpe, an urban lowland stream located in Berlin, Germany, receives high loads of treated waste water. A Lagrangian sampling scheme was applied to follow water parcels 4.7 km down the river using the diurnal fluctuations of electrical conductivity as an intrinsic conservative tracer. Each experiment comprised of hourly sample collection for two days, accompanied by discharge measurements and continuous data logging of electrical conductivity. The fate of pharmaceuticals and their transformation products was compared between seasons (April and June) and before and after a stretch of the river has been cleared of macrophytes. The set of micropollutants was analysed by a newly developed direct injection-UHPLC-MS/MS method. The behaviour of individual micropollutants was compound-specific. Valsartan and metoprolol were attenuated by up to 18% of their original concentration. At the same time the transformation products valsartan acid and metoprolol acid increased in concentration by up to 24%. Their formation along the reach varied between seasons and was influenced by macrophyte removal. The findings indicate that the self-purification capacity of urban rivers is variable in time and sensitive to changes in the river's hydrological regime and emphasize the relevance of formation of transformation products in urban rivers.
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River meander modeling of the Wabash River near the Interstate 64 Bridge near Grayville, Illinois
Lant, Jeremiah G.; Boldt, Justin A.
2018-01-16
Natural river channels continually evolve and change shape over time. As a result, channel evolution or migration can cause problems for bridge structures that are fixed in the flood plain. A once-stable bridge structure that was uninfluenced by a river’s shape could be encroached upon by a migrating river channel. The potential effect of the actively meandering Wabash River on the Interstate 64 Bridge at the border with Indiana near Grayville, Illinois, was studied using a river migration model called RVR Meander. RVR Meander is a toolbox that can be used to model river channel meander migration with physically based bank erosion methods. This study assesses the Wabash River meandering processes through predictive modeling of natural meandering over the next 100 years, climate change effects through increased river flows, and bank protection measures near the Interstate 64 Bridge.
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Energy Technology Data Exchange (ETDEWEB)
Baattrup-Pedersen, Annette, E-mail: abp@bios.au.dk [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Göthe, Emma [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Riis, Tenna [Department of Bioscience, Aarhus University, Ole Worms Allé 1, Building 1135, Room 217, DK-8000 Aarhus C (Denmark); O' Hare, Matthew T. [Centre for Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom)
2016-02-01
Historically, close attention has been paid to negative impacts associated with nutrient loads to streams and rivers, but today hydromorphological alterations are considered increasingly implicated when lowland streams do not achieve good ecological status. Here, we explore if trait-abundance patterns of aquatic plants change along gradients in hydromorphological degradation and eutrophication in lowland stream sites located in Denmark. Specifically, we hypothesised that: i) changes in trait-abundance patterns occur along gradients in hydromorphological degradation and ii) trait-abundance patterns can serve to disentangle effects of eutrophication and hydromorphological degradation in lowland streams reflecting that the mechanisms behind changes differ. We used monitoring data from a total of 147 stream reaches with combined data on aquatic plant species abundance, catchment land use, hydromorphological alterations (i.e. planform, cross section, weed cutting) and water chemistry parameters. Traits related to life form, dispersal, reproduction and survival together with ecological preference values for nutrients and light (Ellenberg N and L) were allocated to 41 species representing 79% of the total species pool. We found clear evidence that habitat degradation (hydromorphological alterations and eutrophication) mediated selective changes in the trait-abundance patterns of the plant community. Specific traits could distinguish hydromorphological degradation (free-floating, surface; anchored floating leaves; anchored heterophylly) from eutrophication (free-floating, submerged; leaf area). We provide a conceptual framework for interpretation of how eutrophication and hydromorphological degradation interact and how this is reflected in trait-abundance patterns in aquatic plant communities in lowland streams. Our findings support the merit of trait-based approaches in biomonitoring as they shed light on mechanisms controlling structural changes under environmental
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International Nuclear Information System (INIS)
Baattrup-Pedersen, Annette; Göthe, Emma; Riis, Tenna; O'Hare, Matthew T.
2016-01-01
Historically, close attention has been paid to negative impacts associated with nutrient loads to streams and rivers, but today hydromorphological alterations are considered increasingly implicated when lowland streams do not achieve good ecological status. Here, we explore if trait-abundance patterns of aquatic plants change along gradients in hydromorphological degradation and eutrophication in lowland stream sites located in Denmark. Specifically, we hypothesised that: i) changes in trait-abundance patterns occur along gradients in hydromorphological degradation and ii) trait-abundance patterns can serve to disentangle effects of eutrophication and hydromorphological degradation in lowland streams reflecting that the mechanisms behind changes differ. We used monitoring data from a total of 147 stream reaches with combined data on aquatic plant species abundance, catchment land use, hydromorphological alterations (i.e. planform, cross section, weed cutting) and water chemistry parameters. Traits related to life form, dispersal, reproduction and survival together with ecological preference values for nutrients and light (Ellenberg N and L) were allocated to 41 species representing 79% of the total species pool. We found clear evidence that habitat degradation (hydromorphological alterations and eutrophication) mediated selective changes in the trait-abundance patterns of the plant community. Specific traits could distinguish hydromorphological degradation (free-floating, surface; anchored floating leaves; anchored heterophylly) from eutrophication (free-floating, submerged; leaf area). We provide a conceptual framework for interpretation of how eutrophication and hydromorphological degradation interact and how this is reflected in trait-abundance patterns in aquatic plant communities in lowland streams. Our findings support the merit of trait-based approaches in biomonitoring as they shed light on mechanisms controlling structural changes under environmental
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76 FR 35434 - Federal Home Loan Bank Members Selected for Community Support Review
2011-06-17
............ Massachusetts. Company. Danversbank Danvers........ Massachusetts. Mechanics' Co-operative Bank. Taunton.... OceanFirst Bank Tom Rivers..... New Jersey. Roma Bank Robbinsville... New Jersey. Glen Rock Savings Bank... Savings, FSB........ Munster........ Indiana. Farmers and Mechanics Federal Bloomfield..... Indiana...
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Ghysels, Gert; Benoit, Sien; Awol, Henock; Jensen, Evan Patrick; Debele Tolche, Abebe; Anibas, Christian; Huysmans, Marijke
2018-04-01
An improved general understanding of riverbed heterogeneity is of importance for all groundwater modeling studies that include river-aquifer interaction processes. Riverbed hydraulic conductivity (K) is one of the main factors controlling river-aquifer exchange fluxes. However, the meter-scale spatial variability of riverbed K has not been adequately mapped as of yet. This study aims to fill this void by combining an extensive field measurement campaign focusing on both horizontal and vertical riverbed K with a detailed geostatistical analysis of the meter-scale spatial variability of riverbed K . In total, 220 slug tests and 45 standpipe tests were performed at two test sites along the Belgian Aa River. Omnidirectional and directional variograms (along and across the river) were calculated. Both horizontal and vertical riverbed K vary over several orders of magnitude and show significant meter-scale spatial variation. Horizontal K shows a bimodal distribution. Elongated zones of high horizontal K along the river course are observed at both sections, indicating a link between riverbed structures, depositional environment and flow regime. Vertical K is lognormally distributed and its spatial variability is mainly governed by the presence and thickness of a low permeable organic layer at the top of the riverbed. The absence of this layer in the center of the river leads to high vertical K and is related to scouring of the riverbed by high discharge events. Variograms of both horizontal and vertical K show a clear directional anisotropy with ranges along the river being twice as large as those across the river.
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An appraisal of river erosion mitigation in the Niger Delta
International Nuclear Information System (INIS)
Aban, T. K. S.; Omuso, W. O.
1999-01-01
River erosion processes in the Niger Delta and the effectiveness of locally applied remedial measures is appraised, using information on channel geometry, flow velocity distribution, soil type, stratification, bank height and steepness, state of compaction, together with pool level variation in river channels. High flow velocity and bank height were identified as the major erosion causative factors. Local responses towards erosion mitigation have involved structural methods to varying degree of success. River training has been recommended as a long - term regional approach to mitigate river bank erosion. However, in the short -term revetments, concrete and sheets piles may be applied cautiously
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Bank Swallow - Monitoring [ds6
California Natural Resource Agency — The data set represents the annual count of bank swallow burrows at nesting colonies located along the Sacramento River. The data set contains two databases which...
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Yulianti, D.; Marwoto, P.; Fianti
2018-03-01
This research aims to determine the type, concentration, and distribution of heavy metals in vegetables on the banks river Kaligarang using Neutron Analysis Activation (NAA) Method. The result is then compared to its predefined threshold. Vegetable samples included papaya leaf, cassava leaf, spinach, and water spinach. This research was conducted by taking a snippet of sediment and vegetation from 4 locations of Kaligarang river. These snippets are then prepared for further irradiated in the reactor for radioactive samples emiting γ-ray. The level of γ-ray energy determines the contained elements of sample that would be matched to Neutron Activation Table. The results showed that vegetablesat Kaligarang are containing Cr-50, Co-59, Zn-64, Fe-58, and Mn-25, and well distributed at all research locations. Furthermore, the level of the detected metal elements is less than the predefined threshold.
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Tracking the movements of a post-nesting Southern River Terrapin (Batagur affinis edwardmolli)
Chen, Pelf-Nyok; Wong, Adrian
2015-09-01
A Southern River Terrapin (Batagur affinis edwardmolli) Conservation Project was initiated on one terrapin nesting bank in 2011, following the discovery of a River Terrapin population in the Kemaman River, Terengganu in 2010. Since this project was initiated, Turtle Conservation Society of Malaysia (TCS) was instrumental in the gazettement of three nesting banks along the Kemaman River, from which all River Terrapin eggs are collected for incubation. However, there are at least a dozen other "unprotected" nesting banks along the river, where all eggs were collected for human consumption. This project attempted to determine the movements of a post-nesting River Terrapin, with hopes that it would provide the preliminary baseline information on the utilization of adjacent nesting banks. The solution was a GPS tracking device that transmitted coordinates every hour over cellular networks. Location-based data was sent via Short Message Service (SMS) to our own SMS gateway running on a Raspberry Pi credit-card size computer, which was then logged in a database and presented graphically via Google Maps. It was a complete tracking and monitoring system. This solution enabled researchers to remotely track the movements of a River Terrapin, hence reducing the costs of research. The movements of a post-nesting River Terrapin were tracked for eight days before the battery was drained. On the third day, this River Terrapin ascended an adjacent riverbank and spent less than an hour on the bank, presumably to deposit her remaining eggs. This study confirmed that River Terrapins do utilize other suitable nesting banks if/whenever available. Results from such tracking studies will be used to leverage on the protection of adjacent nesting banks, thus providing greater protection for the critically endangered River Terrapins.
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Large woody debris (LWD) is an important component of ecosystem function in floodplain rivers. We examined the effects on LWD distribution of shoreline land use, bank stabilization, local channel geomorphology, and distance from the dam in the Garrison Reach, a regulated reach of...
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Wang, W.; Oswald, S. E.; Munz, M.; Strasser, D.
2017-12-01
Bank filtration is widely used either as main- or pre-treatment process for water supply. The colmation of the river bottom as interface to groundwater plays a key role for hydraulic control of flow paths and location of several beneficial attenuation processes, such as pathogen filtration, mixing, biodegradation and sorption. Along the flow path, mixing happens between the `young' infiltrated water and ambient `old' groundwater. To clarify the mechanisms and their interaction, modelling is often used for analysing spatial and temporal distribution of the travelling time, quantifying mixing ratios, and estimating the biochemical reaction rates. As the most comprehensive tool, 2-D or 3-D spatially-explicit modelling is used in several studies, and for area with geological heterogeneity, the adaptation of different natural tracers could constrain the model in respect to model non-uniqueness and improve the interpretation of the flow field. In our study, we have evaluated the influence of a river excavation and bank reconstruction project on the groundwater-surface water exchange at a bank filtration site. With data from years of field site monitoring, we could include besides heads and temperature also the analysis of stable isotope data and ions to differentiate between infiltrated water and groundwater. Thus, we have set up a 3-D transient heat and mass transport groundwater model, taking the strong local geological heterogeneity into consideration, especially between river and water work wells. By transferring the effect of the river excavation into a changing hydraulic conductivity of the riverbed, model could be calibrated against both water head and temperature time-series observed. Finally, electrical conductivity dominated by river input was included as quasi-conservative tracer. The `triple' calibrated, transient model was then used to i) understand the flow field and quantify the long term changes in infiltration rate and distribution brought by the
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Stabilization of the bank upstream on the north shore of the La Grande-1 installation
International Nuclear Information System (INIS)
Massiera, M.
1998-01-01
As part of the completion of the La Grande-1 project, construction of a 2,444 m long dyke was required on the north bank of the La Grande River. Sensitive marine clay, covered with deltaic and river sand and silt deposits was discovered which required special design features such as stabilization of the river bank, to avoid the possibility of disastrous retrogressive slides. This paper describes the geotechnical conditions of the northern terrace and the options available for stabilizing the river bank. Different phases of the construction of the stabilization dyke, including the excavated trench across the terrace, the instrumentation installed and the control measures taken, are also outlined. 8 refs., 1 tab., 3 figs
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Examining the physical meaning of the bank erosion coefficient used in meander migration modeling
Constantine, Candice R.; Dunne, Thomas; Hanson, Gregory J.
2009-05-01
Widely used models of meander evolution relate migration rate to vertically averaged near-bank velocity through the use of a coefficient of bank erosion ( E). In applications to floodplain management problems, E is typically determined through calibration to historical planform changes, and thus its physical meaning remains unclear. This study attempts to clarify the extent to which E depends on measurable physical characteristics of the channel boundary materials using data from the Sacramento River, California, USA. Bend-average values of E were calculated from measured long-term migration rates and computed near-bank velocities. In the field, unvegetated bank material resistance to fluvial shear ( k) was measured for four cohesive and noncohesive bank types using a jet-test device. At a small set of bends for which both E and k were obtained, we discovered that variability in k explains much of the variability in E. The form of this relationship suggests that when modeling long-term meander migration of large rivers, E depends largely on bank material properties. This finding opens up the possibility that E may be estimated directly from field data, enabling prediction of meander migration rates for systems where historical data are unavailable or controlling conditions have changed. Another implication is that vegetation plays a limited role in affecting long-term meander migration rates of large rivers like the Sacramento River. These hypotheses require further testing with data sets from other large rivers.
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Directory of Open Access Journals (Sweden)
2007-01-01
Full Text Available This paper reports on a major UK initiative to address deficiencies in understanding the hydro-ecological response of groundwater-dominated lowland catchments. The scope and objectives of this national programme are introduced and focus on one of three sets of research basins – the Pang/Lambourn Chalk catchments, tributaries of the river Thames in southern England. The motivation for the research is the need to support integrated management of river systems that have high ecological value and are subject to pressures that include groundwater abstraction for water supply, diffuse pollution, and land use and climate change. An overview of the research programme is provided together with highlights of some current research findings concerning the hydrological functioning of these catchments. Despite the importance of the Chalk as a major UK aquifer, knowledge of the subsurface movement of water and solutes is poor. Solute transport in the dual porosity unsaturated zone depends on fracture/matrix interactions that are difficult to observe; current experimental and modelling research supports the predominance of matrix flow and suggests that slow migration of a time-history of decades of nutrient loading is occurring. Groundwater flows are complex; catchments vary seasonally and are ill-defined and karst features are locally important. Groundwater flow pathways are being investigated using natural and artificial geochemical tracers based on experimental borehole arrays; stream-aquifer interaction research is using a combination of geophysics, borehole array geochemistry and longitudinal profiles of stream flow and solutes. A complex picture of localised subsurface inflows, linked to geological controls and karst features, and significant longitudinal groundwater flow below the river channel is emerging. Management implications are discussed. Strategies to control surface application of nutrients are expected to have little effect on groundwater
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Directory of Open Access Journals (Sweden)
N. Fohrer
2009-08-01
Full Text Available The aims of this study are to identify the capacities of applying an ecohydrological model for simulating flow and to assess the impact of point and non-point source pollution on nitrate loads in a complex lowland catchment, which has special hydrological characteristics in comparison with those of other catchments. The study area Kielstau catchment has a size of approximately 50 km2 and is located in the North German lowlands. The water quality is not only influenced by the predominating agricultural land use in the catchment as cropland and pasture, but also by six municipal wastewater treatment plants.
Ecohydrological models like the SWAT model (Soil and Water Assessment Tool are useful tools for simulating nutrient loads in river catchments. Diffuse entries from the agriculture resulting from fertilizers as well as punctual entries from the wastewater treatment plants are implemented in the model set-up.
The results of this study show good agreement between simulated and measured daily discharges with a Nash-Sutcliffe efficiency and a correlation coefficient of 0.76 and 0.88 for the calibration period (November 1998 to October 2004; 0.75 and 0.92 for the validation period (November 2004 to December 2007. The model efficiency for daily nitrate loads is 0.64 and 0.5 for the calibration period (June 2005 to May 2007 and the validation period (June 2007 to December 2007, respectively. The study revealed that SWAT performed satisfactorily in simulating daily flow and nitrate loads at the lowland catchment in Northern Germany. -
The contribution of bank and surface sediments to fluvial sediment ...
African Journals Online (AJOL)
The contribution of bank and surface sediments to fluvial sediment transport of the Pra River. ... the relative contribution of surface and bank sediments to the fluvial sediment transport. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT
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DENTAL LESIONS IN THE LOWLAND TAPIR (TAPIRUS TERRESTRIS).
Tjørnelund, Karen B; Jonsson, Lena M; Kortegaard, Hanne; Arnbjerg, Jens; Nielsen, Søren S; Bertelsen, Mads F
2015-06-01
Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs (Tapirus terrestris) in particular, is scarce. A recent study identified resorptive lesions of unknown etiology as a common problem in the Malayan tapir (Tapirus indicus). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually and radiographically examined. The specimens were divided into subpopulations according to age (juveniles, young adults, adults) and origin (free-range or captive). Dental lesions were identified in 24% (11/46) of the study population. The most common pathologic findings were complicated dental fractures with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions present frequent problems for lowland tapirs, occurring both in captive and in free-ranging individuals, and indicates that increasing age should be considered a risk factor for the development of these lesions. Notably, the predominant dental problems in lowland tapirs and Malayan tapirs are not the same.
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Denitrification in the Mississippi River network controlled by flow through river bedforms
Gomez-Velez, Jesus D.; Harvey, Judson W.; Cardenas, M. Bayani; Kiel, Brian
2015-01-01
Increasing nitrogen concentrations in the world’s major rivers have led to over-fertilization of sensitive downstream waters1, 2, 3, 4. Flow through channel bed and bank sediments acts to remove riverine nitrogen through microbe-mediated denitrification reactions5, 6, 7, 8, 9, 10. However, little is understood about where in the channel network this biophysical process is most efficient, why certain channels are more effective nitrogen reactors, and how management practices can enhance the removal of nitrogen in regions where water circulates through sediment and mixes with groundwater - hyporheic zones8, 11, 12. Here we present numerical simulations of hyporheic flow and denitrification throughout the Mississippi River network using a hydrogeomorphic model. We find that vertical exchange with sediments beneath the riverbed in hyporheic zones, driven by submerged bedforms, has denitrification potential that far exceeds lateral hyporheic exchange with sediments alongside river channels, driven by river bars and meandering banks. We propose that geomorphic differences along river corridors can explain why denitrification efficiency varies between basins in the Mississippi River network. Our findings suggest that promoting the development of permeable bedforms at the streambed - and thus vertical hyporheic exchange - would be more effective at enhancing river denitrification in large river basins than promoting lateral exchange through induced channel meandering.
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Integration of fluvial erosion factors for predicting landslides along meandering rivers
Chen, Yi-chin; Chang, Kang-tsung; Ho, Jui-yi
2015-04-01
River incision and lateral erosion are important geomorphologic processes in mountainous areas of Taiwan. During a typhoon or storm event, the increase of water discharge, flow velocity, and sediment discharge enhances the power of river erosion on channel bank. After the materials on toe of hillslope were removed by river erosion, landslides were triggered at outer meander bends. Although it has been long expected that river erosion can trigger landslide, studies quantifying the effects of river erosion on landslide and the application of river erosion index in landslide prediction are still overlooked. In this study, we investigated the effect of river erosion on landslide in a particular meanders landscape of the Jhoukou River, southern Taiwan. We developed a semi-automatic model to separate meandering lines into several reach segments based on the inflection points and to calculate river erosion indexes, e.g. sinuosity of meander, stream power, and stream order, for each reach segment. This model, then, built the spatial relationship between the reaches and its corresponding hillslopes, of which the toe was eroded by the reach. Based on the spatial relationship, we quantified the correlations between these indexes and landslides triggered by Typhoon Morakot in 2009 to examine the effects of river erosion on landslide. The correlated indexes were then used as landslide predictors in logistic regression model. Results of the study showed that there is no significant correlation between landslide density and meander sinuosity. This may be a result of wider channel dispersing the erosion at a meandering reach. On the other hand, landslide density at concave bank is significantly higher than that at convex bank in the downstream (stream order > 3), but that is almost the same in the upstream (stream order bank. In contrast, river sediment in the downstream is an erosion agent eroding the concave bank laterally, but also depositing on the concave side and protecting
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Analysis of Prognosis of Lowland River Bed Erosion Based on Geotechnical Parameters
Directory of Open Access Journals (Sweden)
Smaga Agnieszka
2015-12-01
Full Text Available The river erosion is a complex process, the dynamics of which is very difficult to predict. Its intensity largely depends on hydraulic conditions of the river channel. However, it is also thought that natural resistance of the subsoil has a great influence on the scale of the erosion process. Predicting the effects of this process is extremely important in the case of constructing a piling structure (for example, artificial reservoirs. The partition of the river channel causes significant lowering of the river channel bed downstream the dam which threatens the stability of hydro technical and engineering (bridges buildings. To stop this unwanted phenomenon, stabilizing thresholds are built. However, random location of thresholds significantly reduces their effectiveness. Therefore, taking under consideration natural geotechnical conditions of the subsoil appears to be extremely important.
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Directory of Open Access Journals (Sweden)
Alessandro Balestrieri
Full Text Available In recent years, the "forest-specialist" pine marten Martes martes has been reported to also occur also in largely fragmented, lowland landscapes of north-western Italy. The colonization of such an apparently unsuitable area provided the opportunity for investigating pine marten ecological requirements and predicting its potential south- and eastwards expansion. We collected available pine marten occurrence data in the flood plain of the River Po (N Italy and relate them to 11 environmental variables by developing nine Species Distribution Models. To account for inter-model variability we used average ensemble predictions (EP. EP predicted a total of 482 suitable patches (8.31% of the total study area for the pine marten. The main factors driving pine marten occurrence in the western River Po plain were the distance from watercourses and the distance from woods. EP suggested that the pine marten may further expand in the western lowland, whilst the negligible residual wood cover of large areas in the central and eastern plain makes the habitat unsuitable for the pine marten, except for some riparian corridors and the pine wood patches bordering the Adriatic coast. Based on our results, conservation strategies should seek to preserve remnant forest patches and enhance the functional connectivity provided by riparian corridors.
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Directory of Open Access Journals (Sweden)
Mateusz Grygoruk
2015-08-01
Full Text Available Ecosystem deterioration in small lowland agricultural rivers that results from river dredging entails a significant threat to the appropriate ecohydrological conditions of these water bodies, expressed as homogenization of habitats and loss of biodiversity. Our study was aimed at a comparison of abundance and taxonomic structure of bottom-dwelling macroinvertebrates in dredged and non-dredged stretches of small lowland rivers and tributaries of the middle Narew River, namely: Czaplinianka, Turośnianka, Dąb, and Ślina. The experimental setup was (1 to collect samples of the bottom material from the river stretches that either persisted in a non-modified state (dredging was not done there in the last few years or had been subjected to river dredging in the year of sampling; and (2 to analyze the abundance and taxonomic structure of macroinvertebrates in the collected samples. The study revealed that at the high level of statistical significance (from p = 0.025 to p = 0.001, the total abundance of riverbed macroinvertebrates in the dredged stretches of the rivers analyzed was approximately 70% lower than in non-dredged areas. We state that the dredging of small rivers in agricultural landscapes seriously affects their ecological status by negatively influencing the concentrations and species richness of benthic macroinvertebrates.
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Ecological studies on the freshwater fishes of the Alligator Rivers Region, Northern Territory
International Nuclear Information System (INIS)
Bishop, K.A.; Allen, S.A.; Pollard, D.A.; Cook, M.G.
1986-01-01
The tropical climate of the Alligator Rivers Region of the Northern Territory has a distinctive Wet-Dry cycle resulting in seasonal flows in the creeks and rivers of its catchments. The present study, begun during August 1978, aimed at developing an ecological monitoring system that would detect changes in freshwater fish communities brought about by recent uranium mining and processing in the lowlands of the region
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The tritium balance of the Ems river basin
International Nuclear Information System (INIS)
Krause, W.J.
1989-01-01
For the Ems river basin, as a fine example of a Central European lowland basin, an inventory of the tritium distribution is presented for the hydrologic years 1951 to 1983. On the basis of a balance model, the tritium contents in surface waters and groundwater of the Ems river basin are calculated, using known and extrapolated tritium input data and comparing them with the corresponding values measured since 1974. A survey of tritium flows occurring in this basin is presented, taking meteorologic and hydrologic facts into account. (orig.)
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Missouri River 1943 Compact Line
Iowa State University GIS Support and Research Facility — Flood Control, Bank Stabilization and development of a navigational channel on the Missouri River had a great impact on the river and adjacent lands. The new...
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33 CFR 165.709 - Security Zone; Charleston Harbor, Cooper River, South Carolina.
2010-07-01
..., Cooper River, South Carolina. 165.709 Section 165.709 Navigation and Navigable Waters COAST GUARD... § 165.709 Security Zone; Charleston Harbor, Cooper River, South Carolina. (a) Regulated area. The Coast Guard is establishing a fixed security zone on all waters of the Cooper River, bank-to-bank and surface...
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Effect of flood-induced chemical load on filtrate quality at bank filtration sites
Ray, C.; Soong, T.W.; Lian, Y.Q.; Roadcap, G.S.
2002-01-01
Riparian municipal wells, that are located on riverbanks, are specifically designed to capture a portion of the river water through induced infiltration. Runoff from agricultural watersheds is found to carry enormous amounts of pesticides and nitrate. While the risk of contamination for a vast majority of sites with small-capacity vertical wells is low, potential exists for medium to large capacity collector wells to capture a fraction of the surface water contaminants during flood. Prior monitoring and current modeling results indicate that a small-capacity (peak pumpage 0.0315 m3/s) vertical bank filtration well may not be affected by river water nitrate and atrazine even during flood periods. For a medium capacity (0.0875-0.175 m3/s) hypothetical collector well at the same site, potential exists for a portion of the river water nitrate and atrazine to enter the well during flood periods. Various combinations of hydraulic conductivity of the riverbed or bank material were used. For nitrate, it was assumed either no denitrification occurred during the period of simulation or a half-life of 2 years. Equilibrium controlled sorption (organic carbon partition coefficient of 52 ml/g) and a half-life of between 7.5 and 15 weeks were considered for atrazine. Combinations of these parameters were used in various simulations. Peak concentrations of atrazine or nitrate in pumped water could vary from less than 1% to as high as 90% of that in the river. It was found that a combination of river stage, pumping rates, hydraulic properties of the riverbed and bank, and soil/pesticide properties could affect contaminant entry from river water to any of these wells. If the hydraulic conductivity of the bed and bank material were low, atrazine would not reach the pumping well with or without sorption and degradation. However, for moderately low permeable bank and bed materials, some atrazine from river water could enter a hypothetical collector well while pumping at 0.0875 m3/s. It
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River restoration: separating myths from reality
Friberg, N.; Woodward, G.
2015-12-01
River restorations are a social construct where degraded systems are physically modified to obtain a pre-disturbance set of attributes. These can be purely esthetic but are often linked to some kind of biotic recovery or the provision of important ecosystem services such as flood control or self-purification. The social setting of restoration projects, with a range of potential conflicts, significantly reduces scale of most interventions to a size with little room, or wish, for natural processes. We show that projects sizes are still very small and that the restoration target is not to recover natural geomorphic processes but rather to fulfil human perception of what a nice stream looks like. One case from Danish lowland streams, using a space-for-time substitution approach, shows excess use of pebble and gravel when restoring channelized sandy bottom streams, de-coupling the link between energy and substrate characteristics that are found in natural lowland systems. This has implication for both the biological structure and functioning of these systems as a direct link between substrate heterogeneity and macroinvertebrate diversity was not found in restored streams, while the density of grazer increased indicating an increased use of periphyton as a basal resource. Another case of adding woody debris to UK lowland streams, using a BACI study design, showed very little effect on the macroinvertebrate community even after a 100-year flood, which indicate that added tree trunks did not provide additional flow refugia. We suggest that restoration schemes should aim at restoring the natural physical structural complexity in the streams and at the same time enhance the possibility of re-generating the natural geomorphological processes sustaining the habitats in streams and rivers.
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Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands
Douglas, Peter M. J.; Pagani, Mark; Canuto, Marcello A.; Brenner, Mark; Hodell, David A.; Eglinton, Timothy I.; Curtis, Jason H.
2015-01-01
Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800–950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period. PMID:25902508
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Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands.
Douglas, Peter M J; Pagani, Mark; Canuto, Marcello A; Brenner, Mark; Hodell, David A; Eglinton, Timothy I; Curtis, Jason H
2015-05-05
Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800-950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period.
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Mobile bank conditions for laminar microrivers
Devauchelle , Olivier; Josserand , Christophe; Lagrée , Pierre-Yves; Zaleski , Stéphane
2008-01-01
International audience; The present study aims to establish a simple mechanistic model for river bank erosion. Recent experiments demonstrate that small-scale laminar flumes can develop erosion structures similar to those encountered in Nature. From the Saint-Venant Equations, a classical sediment transport law and a simple avalanche model, it is shown that bank failure caused by flow erosion can be represented through simple boundary conditions. These conditions are able to deal with the wat...
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Phenomena and characteristics of barrier river reaches in the middle and lower Yangtze River, China
You, Xingying; Tang, Jinwu
2017-06-01
Alluvial river self-adjustment describes the mechanism whereby a river that was originally in an equilibrium state of sediment transport encounters some disturbance that destroys the balance and results in responses such as riverbed deformation. A systematic study of historical and recent aerial photographs and topographic maps in the Middle and Lower Reaches of the Yangtze River (MLYR) shows that river self-adjustment has the distinguishing feature of transferring from upstream to downstream, which may affect flood safety, waterway morphology, bank stability, and aquatic environmental safety over relatively long reaches downstream. As a result, it is necessary to take measures to control or block this transfer. Using the relationship of the occurrence time of channel adjustments between the upstream and downstream, 34 single-thread river reaches in the MLYR were classified into four types: corresponding, basically corresponding, basically not corresponding, not corresponding. The latter two types, because of their ability to prevent upstream channel adjustment from transferring downstream, are called barrier river reaches in this study. Statistics indicate that barrier river reaches are generally single thread and slightly curved, with a narrow and deep cross-sectional morphology, and without flow deflecting nodes in the upper and middle parts of reaches. Moreover, in the MLYR, barrier river reaches have a hydrogeometric coefficient of {}1.2‱, a silty clay content of the concave bank {>}{9.5}%, and a median diameter of the bed sediment {>}{0.158} mm. The barrier river reach mechanism lies in that can effectively centralise the planimetric position of the main stream from different upstream directions, meaning that no matter how the upper channel adjusts, the main stream shows little change, providing relatively stable inflow conditions for the lower reaches. Regarding river regulation, it is necessary to optimise the benefits of barrier river reaches; long river
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Venunathan, N; Kaliprasad, C S; Narayana, Y
2016-10-01
The paper presents the activity concentrations of 232 Th, 226 Ra and 40 K in the sediments and river bank soil samples collected from the Kallada river environs of coastal Kerala. The radiological risks associated with these radionuclides were calculated. The samples were processed following standard procedure, and activity was counted using a high-efficiency 5″ × 5″ NaI (Tl) detector coupled to GSPEC gamma spectroscopy system. The mean values of measured activities of 232 Th, 226 Ra and 40 K in soil samples were found to be 98.1 ± 0.4, 60.3 ± 1.1 and 343.4 ± 1.8 Bq kg -1 , respectively, which results in an average absorbed dose rate of 103 nGy h -1 The corresponding values for sediment samples were found to be 88.0 ± 0.4, 48.6 ± 0.9 and 423.2 ± 2.0 Bq kg -1 , respectively, with a resulting absorbed dose rate of 95 nGy h -1 Radium equivalent activity, annual effective dose equivalent, the external and internal hazard indices were determined and compared with recommended limits. The results of the work provide background data on natural radioactive isotopes, which are useful in the assessment of human radiation exposure from natural environment. The accumulation of information on natural radiation is of great value for radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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77 FR 3774 - Formations of, Acquisitions by, and Mergers of Bank Holding Companies
2012-01-25
..., Dupont, Indiana. River Valley Financial Bank, Madison, Indiana, the existing thrift subsidiary of... FEDERAL RESERVE SYSTEM Formations of, Acquisitions by, and Mergers of Bank Holding Companies The companies listed in this notice have applied to the Board for approval, pursuant to the Bank Holding Company...
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Dental lesions in the lowland tapir (Tapirus terrestris)
DEFF Research Database (Denmark)
Tjørnelund, Karen B.; Jonsson, Lena M.; Kortegaard, Hanne Ellen
2015-01-01
Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs ( Tapirus terrestris ) in particular, is scarce. A recent study identified resorptive lesions...... of unknown etiology as a common problem in the Malayan tapir ( Tapirus indicus ). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually...... with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions...
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Explanatory Factors of the Expansion of Recreation Function on the Bank of Danube River in Budapest
Directory of Open Access Journals (Sweden)
Pál Szabó
2015-10-01
Full Text Available In a city's development a river and riverbank played important role, however in recent decades the functions of them have changed, transformed, especially in major cities in the more developed countries, so the city administration was faced with a new phenomenon and geographical space: the changing riverbanks, and the utilization, development, revitalization of them has become a key issue. The various real processes showed the direction that these areas should be provided to the people, and the recreation service will be important for the local residents and tourists. Overall, the urban waterfront development is an increasingly important researched topic and policy. The question is: can we realize it in Budapest also nowadays? In recent years, those processes took place in Budapest, which resulted in an increasing utilization of the Danube and its banks for recreational functions. On the one hand, local social and economic processes have led to the waterfront sites released, on the other hand the needs of the residential population and tourists using the river and the riverside for recreational purposes have increased, and thirdly, the new city administration decided to renew the banks of the Danube, mainly to create new recreational areas. In this paper, we analyze these three factors, focusing on a past short period, because there is an exceptional cohesion between the processes, the needs and the new development goals. Two case studies are in the paper also: the Margaret Island as the oldest traditional recreational area in Budapest, and the Kopaszi-dam, as the newest and successful recreational area of Budapest. The analysis of the processes is based on data and literature, the analysis of the needs is based on a survey, and the analysis of the goals is based on the different development documents.
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Directory of Open Access Journals (Sweden)
Gemma Burgazzi
2017-04-01
Full Text Available Braided rivers are among the most variable and dynamic riverine systems. Changes in these environments are sudden and frequent, driven by the high hydrological variability. They host high levels of local heterogeneity, with many different habitats in close proximity establishing a mosaic of patches. This provides the conditions for high levels of biodiversity, with strong community variability in particular among the different habitats at the stream-reach level. Nevertheless, these systems are still poorly studied and their complexity is often not taken into account in biomonitoring protocols. We applied mixed effects modelling, spatial ordination techniques and beta-diversity partitioning (into nestedness and turnover components with the aim of improving the knowledge of braided rivers, investigating: i the organization of macroinvertebrate communities among the different habitats of a river reach, and ii the temporal variability of this organization (both among seasons and during summer. We predicted a differentiation of macroinvertebrate communities between distinct habitats within rivers, with this differentiation increasing during the low-flow period. We carried out our study in four braided rivers and streams of the Po River basin (Northern Italy sampling three different kinds of mesohabitats (main channel, secondary channel and pool in eight stations during seven campaigns from June 2015 to April 2016. We found a high variability of taxa richness, abundance and community structure among mesohabitats, with marginal ones accounting for the greater part of macroinvertebrate diversity. Secondary channels resulted as being the habitat hosting greater taxa diversity, with 10 exclusive taxa. Surprisingly the mesohabitat communities differed greatly during the seasonal phase, whereas their dissimilarity decreased during summer. This could be explained considering the summer flow reduction as a homogenizing force, leading to a general loss of the
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Piman, T.; Vasconcelos, V. V.; Apirumanekul, C.; Krittasudthacheewa, C.
2017-12-01
Bank erosion along the braided stretches of Ayeyarwady and Chindwin Rivers has been one of the main concerns at Sagaing region, in Myanmar, because it threatens villages, infrastructure and farmland, while the consequent sedimentation hampers boat transportation. This study assesses the changes on these two river channels and its sandbanks, in their confluence area. A special focus is given to infer the risk of villages to bank erosion. Landsat images from 1973, 1989, and annual series from 1998 to 2015 were used to evaluate frequency and rates of erosion, deposition and vegetation restabilization. Maps showed where the channels maintained stable and which areas faced bank erosion more frequently. From 1973 to 2015, 30% of the river valley in the studied area faced bank erosion. Although the summed area of the river channel remained relatively stable throughout the period, the rates of bank erosion vs. bank restabilization were higher after 2004. Most of the village area in the in the river valley within the bluffs (89% - 71km2) have not faced bank erosion since 1973, while 8.9% (7 km2) are in vulnerable areas that faced erosion before 2012, and bank erosion destroyed 1.3% (1 km2) of the villages from 2012 to 2015. The average rate of village land loss from bank erosion within the river valley from 1973 to 2012 was 0.18 km2/year, but increased to 0.33km2/year during 2012-2015. The villages located just downstream from the confluence of Chindwin and Ayeyarwady River faced higher problems with bank erosion. Approximately half of the village area (51.5% - 87km2) adjacent to the bluffs (outside the river valley) were facing stable land since 1973 (lowest risk), while 5.8% (10 km2) were facing stable river channel (low risk) and 42.7% (73 km2) were facing areas of unstable river channel (possible risk). As for the biggest urban sites, Monywa and Pakokku face areas of unstable river channel, while Sagaing and Myingyan are safer, facing areas of stable land. A detailed
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Analysis of VIA and EbA in a River Bank Erosion Prone Area of Bangladesh Applying DPSIR Framework
Directory of Open Access Journals (Sweden)
Syed Hafizur Rahman
2016-10-01
Full Text Available This study aims to set up a comprehensive approach to the Vulnerability and Impact Assessment (VIA of river erosion and to suggest Ecosystem-based Adaptation (EbA practices. Based on the analysis of vulnerability using the Driver-Pressure-State-Impact-Response (DPSIR framework, this paper discusses some of the significant climatic (rainfall pattern, temperature, seasonal drift, cold wave and heat wave and non-climatic (river erosion, repetitive death of field crops and agrochemicals forces in the Kazipur Upazila (Sirajganj District—a river erosion-prone area of Bangladesh. Both primary (Key Informants Interview, Household Survey, and Focus Group Discussion and secondary (climatic, literature review data have been used in revealing the scenario of climatic stress. The analysis revealed a slightly increasing trend of mean annual temperature, and a decreasing trend of total annual rainfall from 1981 to 2015, which have been supported by people’s perception. This study found that river erosion, the increase of temperature and the late arrival of monsoon rain, excessive monsoon rainfall, high use of agrochemicals, and flow alterations are major drivers in the riverine ecosystem. These drivers are creating pressures on agricultural land, soil fertility, water availability and livelihood patterns of affected communities. Hence, floating bed cultivation, integrated pest management, use of cover crops, reforestation, the introduction of an agro-weather forecasting system, and a new variety of flood tolerant species have been suggested as potential EbA to cope with river bank erosion and to increase the capacity of the affected ecosystem.
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Estimating the recreational carrying capacity of a lowland river section.
Lorenz, Stefan; Pusch, Martin T
2012-01-01
Recreational boating represents a major human use of inland waters in many regions. However, boating tourism may affect the ecological integrity of surface waters in multiple ways. In particular, surface waves produced by boating may disturb freshwater invertebrates, such as interrupting the filtration activity of benthic mussels. As mussels may significantly contribute to self-purification, disturbance may have crucial impacts on water quality, and thus on water tourism. In this paper we calculate the carrying capacity of a river section for sustainable boating tourism based on the preservation of water quality. This approach is complemented by spatial and social approaches for carrying capacity estimates. The ecological carrying capacity significantly decreases with lower water levels during summer. Hence, the analysis of variables that influence the river's carrying capacity allows the formation of recommendations for management measures that integrate social, touristic and ecological aspects.
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Effects of an extreme flood on river morphology (case study: Karoon River, Iran)
Yousefi, Saleh; Mirzaee, Somayeh; Keesstra, Saskia; Surian, Nicola; Pourghasemi, Hamid Reza; Zakizadeh, Hamid Reza; Tabibian, Sahar
2018-03-01
An extreme flood occurred on 14 April 2016 in the Karoon River, Iran. The occurred flood discharge was the highest discharge recorded over the last 60 years in the Karoon River. Using the OLI Landsat images taken on 8 April 2016 (before the flood) and 24 April 2016 (after the flood) the geomorphic effects were detected in different land cover types within the 155-km-long study reach. The results show that the flood significantly affected the channel width and the main effect was high mobilization of channel sediments and severe bank erosion in the meandering reaches. According to field surveys, the flood occupied the channel corridor and even the floodplain parts. However, the channel pattern was not significantly altered, although the results show that the average channel width increased from 192 to 256 m. Statistical results indicate a significant change for active channel width and sinuosity index at 99% confidence level for both indexes. The flood-induced morphological changes varied significantly for different land cover types along the Karoon River. Specifically, the channel has widened less in residential areas than in other land cover types because of the occurrence of bank protection structures. However, the value of bank retreat in residential and protected sides of the Karoon River is more than what we expected during the study of extreme flood.
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The Role of Conjoining (Tie) Channels in Lowland Floodplain Development and Lake Infilling
Rowland, J. C.; Dietrich, W. E.; Day, G.; Lepper, K.; Wilson, C. J.
2003-12-01
In simple models of lowland river systems, water and sediment enter the main stem via tributary and secondary channels and are only redistributed to the floodplain during overbank and crevasse splay events. Along numerous river systems across the globe, however, water and sediment are regularly exchanged between the river and off river water bodies via stable, narrow channels. These channels, known as tie channels on the Fly River in Papua New Guinea and batture channels along the lower Mississippi, are largely overlooked but important components of floodplain sediment dispersal where they exist. These channels become pathways of sediment dispersal to the floodplain system when elevated river stages force sediment-laden flows into the off-river water bodies. On the Fly River, it is estimated that about 50% of the sediment delivery to the floodplain is via these channels, and along low gradient tributary channels during flood driven flow reversals. During low flow, tie channels serve to drain the floodplain. With the outgoing flows, large amounts sediment can be carried and lost to the floodplain; floodplain lakes progressively infill with sediment as the mouth of these channels steadily prograde lakeward. These lake deposits not only become significant stratigraphic components of floodplains (traditionally referred to as clay plugs), but are important local sinks recording hundreds to thousands of years of river history. As with all sinks, the proper interpretation of these stratigraphic records requires understanding the processes by which sediment is delivered to the sink and how these processes alter the paleohydraulic and climatic signals of interest. We have conducted field investigations of conjoining channels in Papua New Guinea (the Fly and Strickland Rivers), Louisiana (Raccourci Old River ~ 65 km upriver of Baton Rouge) and Alaska (Birch Creek). These field investigations include extensive surveys of both cross and along channel morphological trends
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78 FR 29091 - Safety Zone; Outer Banks Bluegrass Festival; Shallowbag Bay, Manteo, NC
2013-05-17
...-AA00 Safety Zone; Outer Banks Bluegrass Festival; Shallowbag Bay, Manteo, NC AGENCY: Coast Guard, DHS... the Outer Banks Bluegrass Festival. This action is necessary to protect the life and property of the... vessels from a portion of Shallowbag Bay River during the Outer Banks Bluegrass Festival Fireworks display...
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Wolfert, Hendrik Pieter
2001-01-01
Integrated spatial planning for river rehabilitation requires insight in the geomorphology of river systems. Procedures are elaborated to implement a functional-geographical approach in geomorphology, in which a view of rivers as four-dimensional systems and the use of a process-based hierarchy of
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Stabilization of the dyke on the north bank of the La Grande 1 hydroelectric complex
International Nuclear Information System (INIS)
Massiera, M.; Tournier, J-P.
2000-01-01
Special design features required in constructing a 2444 m long dyke on the north bank of the La Grade River at the site of the La Grande 1 hydroelectric power project are described. The special features involved construction of a downstream bank and upstream stabilization berms to avoid the occurrence of potentially dangerous retrogressive slides. These special features were deemed essential due to the presence of sensitive marine clay, covered with deltaic sand and silt and river sand deposits. The paper highlights the geotechnical and hydrogeological conditions of the northern terrace, and describes the different construction phases of stabilizing the river bank. Control of groundwater pressures in the lower aquifer with relief wells is emphasized. 9 refs., 1 tab., 17 figs
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Application of HEC-RAS for flood forecasting in perched river-A case study of hilly region, China
Sun, Pingping; Wang, Shuqian; Gan, Hong; Liu, Bin; Jia, Ling
2017-04-01
Flooding in small and medium rivers are seriously threatening the safety of human beings’ life and property. The simulation forecasting of the river flood and bank risk in hilly region has gradually become a hotspot. At present, there are few studies on the simulation of hilly perched river, especially in the case of lacking section flow data. And the method of how to determine the position of the levee breach along the river bank is not much enough. Based on the characteristics of the sections in hilly perched river, an attempt is applied in this paper which establishes the correlation between the flow profile computed by HEC-RAS model and the river bank. A hilly perched river in Lingshi County, Shanxi Province of China, is taken as the study object, the levee breach positions along the bank are simulated under four different design storm. The results show that the flood control standard of upper reach is high, which can withstand the design storm of 100 years. The current standard of lower reach is low, which is the flooding channel with high frequency. As the standard of current channel between the 2rd and the 11th section is low, levee along that channel of the river bank is considered to be heighten and reinforced. The study results can provide some technical support for flood proofing in hilly region and some reference for the reinforcement of river bank.
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International Nuclear Information System (INIS)
Venunathan, N.; Kaliprasad, C.S.; Narayana, Y.
2015-01-01
The paper presents the activity concentrations of 232 Th, 226 Ra and 40 K in the sediments and river bank soil samples collected from the Kallada river environs of coastal Kerala. The radiological risks associated with these radionuclides were calculated. The samples were processed following standard procedure and activity were counted using a high efficiency 5 inch x 5 inch NaI(Tl) detector coupled to GSPEC gamma spectroscopy system. The mean values of measured activities of 232 Th, 226 Ra and 40 K in soil samples were found to be 98.1±04, 60.3±1.1 and 343.4 ± 1.8 Bq.kg -1 respectively, which results in an average absorbed dose rate of 103 nGyh -1 . The corresponding values for sediment samples were found to be 88.0±04, 48.6±0.9 and 423.2±2.03 Bq.kg -1 respectively, with a resulting absorbed dose rate of 95 nGyh -1 . The mean value of radium equivalent activity in soil and sediments were found to be 227.1 Bq.kg -1 and 207.1 Bq.kg -1 respectively, which are within the recommended limit. External and internal hazard indices were also calculated and were found to be 0.61 and 0.78 respectively for soil, and 0.56 and 0.69 respectively for sediments. The Annual Effective Dose equivalents from the soil and sediment matrices in the Kallada river environment were estimated to be 0.13 mSv y -1 and 0.12 mSv y -1 respectively. The measured radioactivity, hazard indices and effective dose received by population were found to be within the recommended limits. The results of the work provide background data on natural radioactive isotopes which are useful in the assessment of human radiation exposure from natural environment. The accumulation of information on natural radiation is of great value for radiation protection. (author)
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Alpine hydropower schemes and their 'remote influence' on lakes and rivers downstream
International Nuclear Information System (INIS)
Wuest, A.
2003-01-01
This article discusses the effect that alpine dams and reservoirs have on lakes and rivers in the lowlands. Not only the contribution of Swiss alpine hydropower installations to Switzerland's electricity generation capacity is mentioned, but also the way they 'export' ecological deficits to lower-lying regions. Examples of this are quoted, including, for example, the filtering-out of around 50% of water-borne particles in the river Rhone by the dams in its catchment area. The consequences of such effects for the ecology of lakes and rivers are discussed. Further examples of how the alpine dams hold back nutrients and regulate the flow and temperature of rivers are given and the resulting ecological effects are commented on
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Gensac, Erwan; Martinez, Jean-Michel; Vantrepotte, Vincent; Anthony, Edward J.
2016-04-01
Fine-grained sediments supplied to the Ocean by the Amazon River and their transport under the influence of continental and oceanic forcing drives the geomorphic change along the 1500 km-long coast northward to the Orinoco River delta. The aim of this study is to give an encompassing view of the sediment dynamics in the shallow coastal waters from the Amazon River mouth to the Capes region (northern part of the Amapa region of Brazil and eastern part of French Guiana), where large mud banks are formed. Mud banks are the overarching features in the dynamics of the Amazon-Orinoco coast. They start migrating northward in the Capes region. Suspended Particulate Matter (SPM) concentrations were calculated from satellite products (MODIS Aqua and Terra) acquired over the period 2000-2013. The Census-X11 decomposition method used to discriminate short-term, seasonal and long-term time components of the SPM variability has rendered possible a robust analysis of the impact of continental and oceanic forcing. Continental forcing agents considered are the Amazon River water discharge, SPM concentration and sediment discharge. Oceanic forcing comprises modelled data of wind speed and direction, wave height and direction, and currents. A 150 km-long area of accretion is detected at Cabo Norte that may be linked with a reported increase in the river's sediment discharge concurrent with the satellite data study period. We also assess the rate of mud bank migration north of Cabo Norte, and highlight its variability. Although we confirm a 2 km y-1 migration rate, in agreement with other authors, we show that this velocity may be up to 5 km y-1 along the Cabo Orange region, and we highlight the effect of water discharge by major rivers debouching on this coastal mud belt in modulating such rates. Finally, we propose a refined sediment transport pattern map of the region based on our results and of previous studies in the area such as the AMASSEDS programme, and discuss the
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Re-Meandering of Lowland Streams
DEFF Research Database (Denmark)
Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai
2014-01-01
We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinver...
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Anibas, Christian; Tolche, Abebe Debele; Ghysels, Gert; Nossent, Jiri; Schneidewind, Uwe; Huysmans, Marijke; Batelaan, Okke
2017-12-01
Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached -90 mm d-1, while in spring and early summer fluxes were -42 mm d-1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.
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Anibas, Christian; Tolche, Abebe Debele; Ghysels, Gert; Nossent, Jiri; Schneidewind, Uwe; Huysmans, Marijke; Batelaan, Okke
2018-05-01
Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached -90 mm d-1, while in spring and early summer fluxes were -42 mm d-1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.
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Water resources in the Blackstone River basin, Massachusetts
Walker, Eugene H.; Krejmas, Bruce E.
1983-01-01
The Blackstone River heads in brooks 6 miles northwest of Worcester and drains about 330 square miles of central Massachusetts before crossing into Rhode Island at Woonsocket. The primary source of the Worcester water supply is reservoirs, but for the remaining 23 communities in the basin, the primary source is wells. Bedrock consists of granitic and metamorphic rocks. Till mantles the uplands and extends beneath stratified drift in the valleys. Stratified glacial drift, consisting of clay, silt, and fine sand deposited in lakes and coarse-textured sand and gravel deposited by streams, is found in lowlands and valleys. The bedrock aquifer is capable of sustaining rural domestic supplies throughout the Blackstone River basin. Bedrock wells yield an average of 10 gallons per minute, but some wells, especially those in lowlands where bedrock probably contains more fractures and receives more recharge than in the upland areas, yield as much as 100 gallons per minute. Glacial sand and gravel is the principal aquifer. It is capable of sustaining municipal supplies. Average daily pumpage from this aquifer in the Blackstone River basin was 10.4 million gallons per day in 1978. The median yield of large-diameter wells in the aquifer is 325 gallons per minute. The range of yields from these wells is 45 to 3,300 gallons per minute. The median specific capacity is about 30 gallons per minute per foot of drawdown.
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Aalto, R. E.; Lauer, J. W.; Darby, S. E.; Best, J.; Dietrich, W. E.
2015-12-01
During glacial-marine transgressions vast volumes of sediment are deposited due to the infilling of lowland fluvial systems and shallow shelves, material that is removed during ensuing regressions. Modelling these processes would illuminate system morphodynamics, fluxes, and 'complexity' in response to base level change, yet such problems are computationally formidable. Environmental systems are characterized by strong interconnectivity, yet traditional supercomputers have slow inter-node communication -- whereas rapidly advancing Graphics Processing Unit (GPU) technology offers vastly higher (>100x) bandwidths. GULLEM (GpU-accelerated Lowland Landscape Evolution Model) employs massively parallel code to simulate coupled fluvial-landscape evolution for complex lowland river systems over large temporal and spatial scales. GULLEM models the accommodation space carved/infilled by representing a range of geomorphic processes, including: river & tributary incision within a multi-directional flow regime, non-linear diffusion, glacial-isostatic flexure, hydraulic geometry, tectonic deformation, sediment production, transport & deposition, and full 3D tracking of all resulting stratigraphy. Model results concur with the Holocene dynamics of the Fly River, PNG -- as documented with dated cores, sonar imaging of floodbasin stratigraphy, and the observations of topographic remnants from LGM conditions. Other supporting research was conducted along the Mekong River, the largest fluvial system of the Sunda Shelf. These and other field data provide tantalizing empirical glimpses into the lowland landscapes of large rivers during glacial-interglacial transitions, observations that can be explored with this powerful numerical model. GULLEM affords estimates for the timing and flux budgets within the Fly and Sunda Systems, illustrating complex internal system responses to the external forcing of sea level and climate. Furthermore, GULLEM can be applied to most ANY fluvial system to
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The Physic-chemical and Bacteriological Contamination of Water in Sitnica, Iber and Lushta rivers
, Flora Zabërgja; , Mihone Kerolli; , Asllan Vitaku; , Afete Musliu
2016-01-01
The study on the physic-chemical and bacteriological contamination of water was carried out in three rivers of Mitrovica town, in Kosova. Water quality in the lowland rivers (like Sitnica which crosses central Kosova), Iber and Lushta is very poor owing to a lack of waste water treatment and waste disposal. According to the effluents received, six sampling station were selected. The results obtained shows that bacterial contamination is very frequent, particularly with the pressure of colifor...
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Hubble, Thomas; De Carli, Elyssa; Airey, David; Breakfree 2012-2013, Scientific Parties MV
2014-05-01
The peak of the recent prolonged 'Millennium Drought' (1997-2011) triggered an episode of widespread mass failure in the alluvial river-banks of the Lower Murray River in South Australia. Multi-beam surveying of the channel and submerged river-banks between Mannum and Murray Bridge and coring of the bank sediments has been undertaken in sections of the river where large bank failures threatened private housing or public infrastructure. This data demonstrates that the bank materials are soft, horizontally-layered muds and that translational, planar slab-slides have frequently occurred in permanently submerged portions of the Murray's river banks. Despite these riverine features being several orders of magnitude smaller than the translational submarine landslides of the continental margins, the submerged river-bank slides are strikingly similar in their morphology to their submarine equivalents. Intriguingly, the Murray River translational slide failure-surfaces are usually developed as river-floor-parallel features in a manner similar to many submarine landslides which present failure-surfaces that are developed on seafloor-parallel, bedding planes. In contrast however, the Murray's river-bank slides occur on steep slopes (>20o) and their failure surfaces must cut across the horizontal laminations and layering of the muds at a relative high angle which removes the possibility of a weak sediment layer being responsible for the occurrence of these failures. Modelling of the river-bank failures with classical soil mechanics methods and the measured physical properties of the river-bank materials indicates that the failures are probably a consequence of flood-flow scour removing the bank-slope toe in combination with pore-pressure effects related to river-level fluctuation (ie. drawdown). Nevertheless, the Murray's translational slab-slides provide a reliable example of slope-parallel planar failure in muds that does not require a stratigraphic weak layer to explain the
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River-corridor habitat dynamics, Lower Missouri River
Jacobson, Robert B.
2010-01-01
Intensive management of the Missouri River for navigation, flood control, and power generation has resulted in substantial physical changes to the river corridor. Historically, the Missouri River was characterized by a shifting, multithread channel and abundant unvegetated sandbars. The shifting channel provided a wide variety of hydraulic environments and large areas of connected and unconnected off-channel water bodies.Beginning in the early 1800s and continuing to the present, the channel of the Lower Missouri River (downstream from Sioux City, Iowa) has been trained into a fast, deep, single-thread channel to stabilize banks and maintain commercial navigation. Wing dikes now concentrate the flow, and revetments and levees keep the channel in place and disconnect it from the flood plain. In addition, reservoir regulation of the Missouri River upstream of Yankton, South Dakota, has substantially changed the annual hydrograph, sediment loads, temperature regime, and nutrient budgets.While changes to the Missouri River have resulted in broad social and economic benefits, they have also been associated with loss of river-corridor habitats and diminished populations of native fish and wildlife species. Today, Missouri River stakeholders are seeking ways to restore some natural ecosystem benefits of the Lower Missouri River without compromising traditional economic uses of the river and flood plain.
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Directory of Open Access Journals (Sweden)
P. Schneider
2011-08-01
Full Text Available River restoration projects have been launched over the last two decades to improve the ecological status and water quality of regulated rivers. As most restored rivers are not monitored at all, it is difficult to predict consequences of restoration projects or analyze why restorations fail or are successful. It is thus necessary to implement efficient field assessment strategies, for example by employing sensor networks that continuously measure physical parameters at high spatial and temporal resolution. This paper focuses on the design and implementation of an instrumentation strategy for monitoring changes in bank filtration, hydrological connectivity, groundwater travel time and quality due to river restoration. We specifically designed and instrumented a network of monitoring wells at the Thur River (NE Switzerland, which is partly restored and has been mainly channelized for more than 100 years. Our results show that bank filtration – especially in a restored section with alternating riverbed morphology – is variable in time and space. Consequently, our monitoring network has been adapted in response to that variability. Although not available at our test site, we consider long-term measurements – ideally initiated before and continued after restoration – as a fundamental step towards predicting consequences of river restoration for groundwater quality. As a result, process-based models could be adapted and evaluated using these types of high-resolution data sets.
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Directory of Open Access Journals (Sweden)
Maike Groeschke
2017-06-01
Full Text Available In the Indian metropolis of Delhi, the Yamuna River is highly influenced by sewage water, which has led to elevated ammonium (NH4+ concentrations up to 20 mg/L in the river water during 2012–2013. Large drinking water production wells located in the alluvial aquifer draw high shares of bank filtrate. Due to the infiltrating river water, the raw water NH4+ concentrations in some wells exceed the threshold value of 0.5 mg/L ammonia-N of the Indian drinking water specifications, making the water unfit for human consumption without prior treatment. However, to meet the city’s growing water demand, it might be advantageous to consider the long-term use of the well field. This requires the development of an adapted post-treatment unit in concert with an adjusted well field management. To better understand the groundwater dynamics and contamination and decontamination times at the well field, a theoretical modeling study has been conducted. The results of 2D numerical modeling reveal that the groundwater flux beneath the river is negligible because of the aquifer and river geometry, indicating that infiltrating river water is not diluted by the ambient groundwater. Increasing the water abstraction in the wells closest to the river would result in a larger share of bank filtrate and a decreasing groundwater table decline. Simplified 1D reactive transport models set up for a distance of 500 m (transect from the riverbank to the first production well showed that the NH4+ contamination will prevail for the coming decades. Different lithological units of the aquifer (sand and kankar—a sediment containing calcareous nodules have a strong influence on the respective contamination and decontamination periods, as the retardation of NH4+ is higher in the kankar than in the sand layer. Although this simplified approach does not allow for a quantification of processes, it can support decision-making about a possible future use of the well field and point to
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Murgulet, Dorina; Murgulet, Valeriu; Spalt, Nicholas; Douglas, Audrey; Hay, Richard G
2016-12-01
There is a lack of understanding and methods for assessing the effects of anthropogenic disruptions, (i.e. river fragmentation due to dam construction) on the extent and degree of groundwater-surface water interaction and geochemical processes affecting the quality of water in semi-arid, coastal catchments. This study applied a novel combination of electrical resistivity tomography (ERT) and elemental and isotope geochemistry in a coastal river disturbed by extended drought and periodic flooding due to the operation of multiple dams. Geochemical analyses show that the saltwater barrier causes an increase in salinity in surface water in the downstream river as a result of limited freshwater inflows, strong evaporation effects on shallow groundwater and mostly stagnant river water, and is not due to saltwater intrusion by tidal flooding. Discharge from bank storage is dominant (~84%) in the downstream fragment and its contribution could increase salinity levels within the hyporheic zone and surface water. When surface water levels go up due to upstream freshwater releases the river temporarily displaces high salinity water trapped in the hyporheic zone to the underlying aquifer. Geochemical modeling shows a higher contribution of distant and deeper groundwater (~40%) in the upstream river and lower discharge from bank storage (~13%) through the hyporheic zone. Recharge from bank storage is a source of high salt to both upstream and downstream portions of the river but its contribution is higher below the dam. Continuous ERT imaging of the river bed complements geochemistry findings and indicate that while lithologically similar, downstream of the dam, the shallow aquifer is affected by salinization while fresher water saturates the aquifer in the upstream fragment. The relative contribution of flows (i.e. surface water releases or groundwater discharge) as related to the river fragmentation control changes of streamwater chemistry and likely impact the interpretation
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2013-05-02
Bank erosion is endangering approximately 1,100 feet of a 42-inch concrete gravity sanitary main, two manholes, and a 30-inch iron sanitary sewer...stabilizing the bank. Kingfisher nests are excavated burrows with bare soil along stream banks (USACE, 2009). “Banks with a high content of clay , gravel, or...34’ g -- - -- - - ---- --- -------- 1 LEGEND ESTIMATED 42’’ GRAVITY SEWER LINE ESTIMATED 30’’ FORCE MAIN ® SANITARY SEWER MANHOLE • AUTO
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Magnitude and processes of bank erosion at a small stream in Denmark
DEFF Research Database (Denmark)
Veihe, Anita; Jensen, Niels H.; Schiøtz, Iris Gunia
2011-01-01
River banks are important sources of sediment and phosphorus to fluvial systems, and the erosion processes operating on the banks are complex and change over time. This study explores the magnitude of bank erosion on a cohesive streambank within a small channelized stream and studies the various...... (17Ð6–30Ð1 mm year-1) and total P content on the banks were relatively high, which makes the bank an important source of sediment and phosphorus to the stream, and it was estimated that 0Ð27 kg Ptot year-1 ha-1 may potentially be supplied to the stream from the banks. Yearly pin erosion rates...
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Bank stability as a risk factor for pipeline infrastructure: a Scottish example
Maniatis, Georgios; Williams, Richard; Hoey, Trevor
2017-04-01
Bank erosion is a spatially variable process controlled by a number of factors that are interrelated (e.g. grain size, moisture content, organic content, vegetation, bank gradient). As a risk factor, bank erosion has been strongly connected to the failure of infrastructure that crosses or is adjacent to morphologically dynamic rivers. To manage this risk, comprehensive infrastructure asset management programs should include risk assessment of all structures that cross or are near a river. In Scotland, a significant proportion of cross-river infrastructure is pipe bridges, for both clean and waste water. These river crossings are maintained and managed by Scottish Water, a supplier responsible for a 48,000 km long drinking water pipe network and a 52,000 km long wastewater pipe network. Recently, Scottish Water began a comprehensive pipe bridge asset inspection program, which incorporates the acquisition of data to assess riverbank stability. The first step in the development of this database is the use of a prototype software application (a tablet app) which simplifies the surveying process by framing specific geomorphological questions and surveying tasks. As a result, the surveys can be conducted by inspectors with no specialist training in bank stability assessment and then reviewed by those with more expertise. Here, results are presented of a review of survey data, enabling the identification of the assets that are most at risk from bank erosion. The assessment focuses on assets from catchments in two contrasting areas of Scotland; the Hebrides and Glasgow. The uncertainty analysis focuses on input data quality and the variability of information available for desk based risk assessments using Geographic Information Systems (GIS). In parallel, considerations regarding the extension of this framework towards a unified strategy for assessing bank erosion are discussed such as the selection of a statistical framework and the catchment classification process
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International Nuclear Information System (INIS)
Freyer, K.; Treutler, H.C.
1997-01-01
With a half life of 3.8 days, the 222 Rn found in all groundwater makes an excellent tracer for solving several problems in the field of environmental research and hydrology. In Germany alluvial aquifers connected to rivers are used for drinking water extraction. Consequently importance is attached to studying the exchange processes between surface water and groundwater in order to determine infiltration velocities and infiltrate retention times in the aquifer. However, such investigations require a reliable, reproducible method for determining radon activity concentrations in groundwater samples, as well as a suitable sampling technique. This paper reports on just such a method, containing detailed instructions for sampling, transportation and activity determination using liquid scintillation spectrometry following toluene extraction. Spectral analysis and α/β separation improve the accuracy of measurement. The detection limit is about 0.05 Bq/1; the total error is 222 Rn by employing the effect that surface water infiltrating an aquifer absorbs 222 Rn along the infiltration pathway. As the degree of uptake is a function of the retention time, flow paths and flow velocities can all be determined by measuring the radon activity concentrations at the various groundwater gauging stations along measuring profiles. Corresponding investigations were carried out into a pleistocene aquifer below the River Elbe near a waterworks extracting bank-filtered water. The findings are presented and the technique's possibilities and limitations are discussed
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A spatial and seasonal assessment of river water chemistry across North West England.
Rothwell, J J; Dise, N B; Taylor, K G; Allott, T E H; Scholefield, P; Davies, H; Neal, C
2010-01-15
This paper presents information on the spatial and seasonal patterns of river water chemistry at approximately 800 sites in North West England based on data from the Environment Agency regional monitoring programme. Within a GIS framework, the linkages between average water chemistry (pH, sulphate, base cations, nutrients and metals) catchment characteristics (topography, land cover, soil hydrology, base flow index and geology), rainfall, deposition chemistry and geo-spatial information on discharge consents (point sources) are examined. Water quality maps reveal that there is a clear distinction between the uplands and lowlands. Upland waters are acidic and have low concentrations of base cations, explained by background geological sources and land cover. Localised high concentrations of metals occur in areas of the Cumbrian Fells which are subjected to mining effluent inputs. Nutrient concentrations are low in the uplands with the exception sites receiving effluent inputs from rural point sources. In the lowlands, both past and present human activities have a major impact on river water chemistry, especially in the urban and industrial heartlands of Greater Manchester, south Lancashire and Merseyside. Over 40% of the sites have average orthophosphate concentrations >0.1mg-Pl(-1). Results suggest that the dominant control on orthophosphate concentrations is point source contributions from sewage effluent inputs. Diffuse agricultural sources are also important, although this influence is masked by the impact of point sources. Average nitrate concentrations are linked to the coverage of arable land, although sewage effluent inputs have a significant effect on nitrate concentrations. Metal concentrations in the lowlands are linked to diffuse and point sources. The study demonstrates that point sources, as well as diffuse sources, need to be considered when targeting measures for the effective reduction in river nutrient concentrations. This issue is clearly important
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Jaeger, Anna; Posselt, Malte; Schaper, Jonas; Lewandowski, Jörg
2017-04-01
Transport and fate of polar organic micropollutants in urban streams are of increasing concern for urban water management. Appropriate river management techniques may support a river's ability to self-purify. The river Erpe, an urban lowland stream located in Berlin, Germany, receives treated wastewater which increases its discharge up to 4-fold. Numerous micropollutants (e.g. pharmaceuticals, personal care products, performance chemicals) which survive the treatment process are released into the river and threaten ecosystems and aquatic groundwater quality. In the present work the transport of 57 substances was investigated along a 4.7 km stretch of the river with the aim of understanding the influence of varying seasonal and hydrological conditions on micropollutant fate. We hypothesized that particularly transient storage is a main driver of micropollutant attenuation. A Lagrangian sampling scheme was applied to follow water parcels down the river using the diurnal fluctuations of conservative solute concentrations as an intrinsic tracer. Water samples were collected at two (April) and three (June) stations along a 4.7 km reach downstream of the wastewater inflow. In June the experiment was conducted twice, before and after the first stretch was cleared of macrophytes. Each experiment comprised of hourly sample collection for 48 hours, accompanied by discharge measurements and continuous data logging of water-level, -temperature and electric conductivity. The set of micropollutants, which included both parent compounds and transformation products, was analysed by a newly developed direct injection-UHPLC-MS/MS method. The behaviour of individual micropollutants was compound-specific. Carbamazepine and benzotriazole were persistent along the river stretch while substances such as valsartan and metoprolol were attenuated by up to 15% of their original concentration. Interestingly, some transformation products, such as valsartan acid increased in concentration
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Directory of Open Access Journals (Sweden)
Tomasz Kałuża
2016-04-01
Full Text Available The work attempts to determine the impact of small hydrotechnical structures on channel hydromorphology as a measure of river restoration. The experiment was set up in Flinta River in Polish lowland where extensive hydromorphological survey was competed. At the first stage of restoration project containers filled with plant clumps working as sediment traps (plant basket hydraulic structures – PBHS were introduced. Those structures were relatively small but at the same time, large enough to change the river flow efficiently – working like low crested weirs. Two year monitoring program provided information about the impact of introducing such structures on river morphology and explained the PBHS impact on flow pattern of the river.
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River habitat assessment for ecological restoration of Wei River Basin, China.
Yang, Tao; Wang, Shuo; Li, Xiaoping; Wu, Ting; Li, Li; Chen, Jia
2018-04-11
As an important composition component of river ecosystems, river habitats must undergo quality assessment to potentially provide scientific basis for river ecological restoration. Substrate composition, habitat complexity, bank erosion degree, river meandering degree, human activity intensity, vegetation buffer width, water quality, and water condition were determined as indicators for river habitat assessment. The comprehensive habitat quality index (CHQI) was established for the Wei River Basin. In addition, the indicator values were determined on the basis of a field investigation at 12 national hydrological stations distributed across the Wei, Jing, and Beiluo Rivers. The analytic hierarchy process was used to determine the indicator weights and thus distinguish the relative importance of the assessment indicator system. Results indicated that the average CHQIs for the Wei, Jing, and Beiluo Rivers were 0.417, 0.508, and 0.304, respectively. The river habitat quality for the three rivers was well. As for the whole river basin, the river habitat quality for 25% of the cross section was very well, the other 25% was well, and the 50% remaining was in critical state. The river habitat quality of the Jing River was better than that of the Wei and Beiluo Rivers.
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H-ADCP discharge monitoring of a large tropical river
Hidayat, H.; Sassi, M.G.; Vermeulen, B.
2012-01-01
River flow can be continuously monitored through velocity measurements with an acoustic Doppler current profiler, deployed horizontally at a river bank (H-ADCP). This approach was adopted to obtain continuous discharge estimates at two cross-sections in the River Mahakam, i.e. at an upstream station
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Directory of Open Access Journals (Sweden)
Anna Sieczka
2018-03-01
Full Text Available This study presents the results of the influence of the specific geological landforms occurring in a lowland river floodplain on the recharge and drainage conditions in an agricultural area. Particular attention has been paid to the presence of the buried erosional channels of flood waters, which may constitute the preferential paths for migration of agricultural contaminants. Moreover, the changes of effective infiltration which affect the hydrogeological regime of the tested area were analyzed. Priority was also given to the use of laboratory techniques in order to determine the parameters influencing the contaminant migration in the soil-water environment for the purpose of hydrogeological modeling. Laboratory tests, based on a column experiment, were performed in a Trautwein apparatus with reference to the constant head procedure, using conservative and reactive markers. The parameters of advection, dispersion, and sorption, obtained in the laboratory experiment were then used as the input data for the hydrodynamic model of groundwater flow and contaminant migration in the research area. Based on the created digital model of groundwater flow, the multi-variant analysis of the effect of specific geological features on the conditions of contaminant transport in a valley was performed. The presented tools and methods contributed to a significant increase in the accuracy of recognizing zones susceptible to water pollution and should be adopted in other valley areas exposed to contamination.
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Energy Technology Data Exchange (ETDEWEB)
N/A
1999-04-28
The Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-1205) for the proposed implementation of a wetland mitigation bank program at the Savannah River Site (SRS), located near Aiken, South Carolina. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an environmental impact statement (EIS) is not required, and DOE is issuing this Finding of No Significant Impact (FONSI) and Floodplain Statement of Findings.
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Preliminary studies in rice-fish culture in a rainfed lowland ecology ...
African Journals Online (AJOL)
Mixed farms of rice and fish are yet to receive attention in Ghana, despite lowland rice being grown under inundation in most areas nationwide. In a preliminary study, Nile tilapia (Oreochromis niloticus) was successfully cultured in a rainfed lowland rice farm, although no additional care was provided for fishes. The highest ...
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Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya
Tamooh, F.; Van den Meersche, K.; Meysman, F.; Marwick, T.R.; Borges, A.V.; Merckx, R.; Dehairs, F.; Schmidt, S.; Nyunja, J.; Bouillon, S.
2012-01-01
We studied patterns in organic carbon pools and their origin in the Tana River Basin (Kenya), in February 2008 (dry season), September–November 2009 (wet season), and June–July 2010 (end of wet season), covering the full continuum from headwater streams to lowland mainstream sites. A consistent
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Rate estimates for lateral bedrock erosion based on radiocarbon ages, Duck River, Tennessee
International Nuclear Information System (INIS)
Brakenridge, G.R.
1985-01-01
Rates of bedrock erosion in ingrown meandering rivers can be inferred from the location of buried relict flood-plain and river-bank surfaces, associated paleosols, and radiocarbon dates. Two independent methods are used to evaluate the long-term rates of limestone bedrock erosion by the Duck River. Radiocarbon dates on samples retrieved from buried Holocene flood-plain and bank surfaces indicate lateral migration of the river bank at average rates of 0.6-1.9 m/100 yr. Such rates agree with lateral bedrock cliff erosion rates of 0.5-1.4 m/100 yr, as determined from a comparison of late Pleistocene and modern bedrock cliff and terrace scarp positions. These results show that lateral bedrock erosion by this river could have occurred coevally with flood-plain and terrace formation and that the resulting evolution of valley meander bends carved into bedrock is similar in many respects to that of channel meanders cut into alluvium. 11 references, 5 figures
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Directory of Open Access Journals (Sweden)
Renata Kędzior
2014-10-01
Full Text Available The aim of the investigation was to estimate factors responsible for sustaining riverine communities in stream sections with various bank regulation systems. The research were conducted on Porebianka stream in the Polish Western Carpathians, where 10 different types of river regulations were chosen for the analysis (strong incision without alluvial deposits, redeposition with sand and gravel banks, concrete revetment walls along the banks, channel with banks lined with rip-rap and reference unmanaged cross- section. We conclude that the carabid beetles assemblages of the studied river sections respond mainly to hydraulic parameters of the stream. Elimination of frequent natural bank inundation (due to the regulations of the banks is the main factor responsible for the impoverishment and extinction of riverine communities.
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Organism-substrate relationships in lowland streams
Tolkamp, H.H.
1980-01-01
A field and laboratory study on the microdistribution of bottom dwelling macroinvertebrates to investigate the role of the stream substrate In the development and preservation of the macroinvertebrate communities in natural, undisturbed lowland streams is described. Field data on bottom substrates
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International Nuclear Information System (INIS)
Rodriguez Estrella, T.; Lopez Bermudes, F.
1984-01-01
This neotectonic investigation concentrates on the southern area in the high fertile lowland of the Segura river (23 Km 2 ). Our methodology is various, pointing towards a better understanding of the recent tectonic activity which have taken place in this area. Our methods and techniques have been indirect and direct. Indirect techniques: aerial photography (at different scales and different periods of time), hydrochemistry (over 70 analyses) seismicity (from the end of last century) and vertical electric fathoming probings (64 S.E.V. of AB=1000). Direct techniques: geomorphology (alluvial terraces and loose meanders), mechanic fathoming probings (over 50) and structural cuttings in the ground. Archaeology has contributed to a great extent to clarify the existence of neotectonics in this alluvial terraces and its dating. Lastly, certain hydrogeologic criteria have been analysed concerning the recent deformations of the Spanish Southeast, as well as, some general considerations on the neotectonic of this area on the Iberian Peninsula. (author)
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Preliminary studies in rice-fish culture in a rainfed lowland ecology ...
African Journals Online (AJOL)
Preliminary studies in rice-fish culture in a rainfed lowland ecology in Ghana. PKA Dartey, RK Bam, J Ofori. Abstract. Mixed farms of rice and fish are yet to receive attention in Ghana, despite lowland rice being grown under inundation in most areas nationwide. In a preliminary study, Nile tilapia (Oreochromis niloticus) was ...
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Interlinking of Rivers in India: Issues & Challenges
MEHTA, Dharmendra; MEHTA, Naveen K.
2013-01-01
Abstract. The rivers in India are truly speaking not only life-line of masses but also for wild-life. The rivers play a vital role in the lives of the Indian people. The river systems help us in irrigation, potable water, cheap transportation, electricity as well as a source of livelihood for our ever increasing population. Some of the major cities of India are situated at the banks of holy rivers. Proper management of river water is the need of the hour. Indian agriculture largely d...
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Ecological Effects of Re-introduction of Salmonid Spawning Gravel in Lowland Danish Streams
DEFF Research Database (Denmark)
Pedersen, Morten Lauge; Kristensen, Esben Astrup; Kronvang, Brian
2009-01-01
recently been conducted in many streams and rivers. However, systematic monitoring of these spawning gravel restoration projects is limited. The overall aim of this paper was to evaluate gravel reintroduction as a long-term salmonid rehabilitation method in 32 lowland streams. Displacement of gravel......, including both restored reaches and upstream control reaches. Downstream displacement of gravel was most common at sites where gravel was reintroduced without further improvement, although these sites exhibited the highest density of YOY brown trout (Salmo trutta), evidencing that the remaining gravel...... is still functional. The intensive study of three streams showed that spawning was enhanced by the introduction of spawning gravel at the restored sites compared to control sites and that habitat quality generally were improved. Our results also suggest complex interactions exist between spawning activity...
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Gis Approach to Estimation of the Total Phosphorous Transfer in the Pilica River Lowland Catchment
Directory of Open Access Journals (Sweden)
Magnuszewski Artur
2014-09-01
Full Text Available In this paper, the Pilica River catchment (central Poland is analyzed with a focus on understanding the total phosphorous transfer along the river system which also contains the large artificial Sulejów Reservoir. The paper presents a GIS method for estimating the total phosphorous (TP load from proxy data representing sub-catchment land use and census data. The modelled load of TP is compared to the actual transfer of TP in the Pilica River system. The results shows that the metrics of connectivity between river system and dwelling areas as well as settlement density in the sub-catchments are useful predictors of the total phosphorous load. The presence of a large reservoir in the middle course of the river can disrupt nutrient transport along a river continuum by trapping and retaining suspended sediment and its associated TP load. Analysis of the indirect estimation of TP loads with the GIS analysis can be useful for identifying beneficial reservoir locations in a catchment. The study has shown that the Sulejów Reservoir has been located in a subcatchment with a largest load of the TP, and this feature helps determine the problem of reservoir eutrphication
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Schenk, Edward R.; McCargo, Jeremy W.; Moulin, Bertrand; Hupp, Cliff R.; Richter, Jean M.
2015-01-01
This study examines the relation between logjams and largemouth bass (Micropterus salmoides) on the alluvial sand-bed lower Roanoke River. Disparate data sets from previous bank erosion, fisheries, and large wood studies were used to compare the distribution of largemouth bass with logjam frequency. Logjams are related to the frequency of bank mass wasting increasing from near an upstream dam to the middle reach of the study segment and then decreasing as the river approaches sea level. The highest concentration of largemouth bass and logjams was in the middle reach (110 fish per hour and 21 jams per km). Another measure of largemouth bass distribution, fish biomass density (g h1 ), had a similar trend with logjams and was a better predictor of fish distribution versus logjams (R2= 0.6 and 0.8 and p = 0.08 and 0.02 for fish per hour and g h1 versus logjam, respectively). We theorize that the preference for adult bass to congregate near logjams indicates the use of the jams as feeding areas. The results of a principal component analysis indicate that fish biomass concentration is much more related to logjam frequency than channel geometry (width, depth, and bank height), bed grain size, bank erosion, or turbidity. The results of this research support recent studies on in-channel wood and fisheries: Logjams appear to be important for maintaining, or increasing, both largemouth bass numbers and total biomass of fish in large eastern North American rivers. Persistent logjams, important as habitat, exist where relatively undisturbed river reaches allow for bank erosion inputs of wood and available anchoring locations. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
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The mountain-lowland debate: deforestation and sediment transport in the upper Ganga catchment.
Wasson, R J; Juyal, N; Jaiswal, M; McCulloch, M; Sarin, M M; Jain, V; Srivastava, P; Singhvi, A K
2008-07-01
The Himalaya-Gangetic Plain region is the iconic example of the debate about the impact on lowlands of upland land-use change. Some of the scientific aspects of this debate are revisited by using new techniques to examine the role of deforestation in erosion and river sediment transport. The approach is whole-of-catchment, combining a history of deforestation with a history of sediment sources from well before deforestation. It is shown that deforestation had some effect on one very large erosional event in 1970, in the Alaknanda subcatchment of the Upper Ganga catchment, but that both deforestation and its effects on erosion and sediment transport are far from uniform in the Himalaya. Large magnitude erosional events occur for purely natural reasons. The impact on the Gangetic Plain of erosion caused by natural events and land cover change remains uncertain.
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Otter ( Lutra lutra ) predation on stocked brown trout ( Salmo trutta ) in two Danish lowland rivers
DEFF Research Database (Denmark)
Jacobsen, Lene
2005-01-01
This study aimed to evaluate otter predation on stocked trout. Large hatchery-reared trout (16-30 cm) were stocked into two Danish rivers with different fish populations. Otter diet before and after trout stocking was determined by analysing 685 spraints, collected regularly during the 35-day study...... period. Fish composition in the rivers before stocking was assessed by electrofishing. In River Trend, a typical trout river, the proportion of trout in the otter diet increased from 8% before stocking to 33% a few days after stocking. Moreover, trout lengths in the diet changed significantly towards...... the lengths of stocked trout, indicating that newly stocked trout were preferred to wild trout. In River Skals, dominated by cyprinids, there was no change in otter diet after stocking of hatchery trout, i.e., these were ignored by otter. Otter predation should be taken into account together with fish...
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78 FR 40394 - Safety Zone; Outer Banks Bluegrass Festival; Shallowbag Bay, Manteo, NC
2013-07-05
...-AA00 Safety Zone; Outer Banks Bluegrass Festival; Shallowbag Bay, Manteo, NC AGENCY: Coast Guard, DHS... Festival. This action is necessary to protect the life and property of the maritime public from the hazards... Shallowbag Bay River during the Outer Banks Bluegrass Festival Fireworks display. DATES: This rule is...
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Stream bank and sediment movement associated with 2008 flooding, South Fork Iowa River
Stream bank erosion can cause substantial damage to riparian systems and impact the use of water downstream. Risks of bank erosion increase during extreme flood events, and frequencies of extreme events may be increasing under changing climate. We assessed bank erosion within the South Fork Iowa Riv...
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Directory of Open Access Journals (Sweden)
Jan Dvořák
2013-01-01
Full Text Available This paper deals with the dietary behaviour and the tree species preference in the river bank stands in the diet of established population Eurasian Beaver (Castor fiber L., 1758 in the environment of Oderské vrchy; the objective is to assess the suitability of this environment for future development of the Eurasian Beaver and to asses the influence of the beaver’s dietary behaviour on the river bank stands. In the monitored area, the total of 5 tree species with the following preference were recorded: willow (Salix 42.2%, aspen (Populus 28%, dogwood (Comus 15.5%, birch (Betula 7.4% and alder (Alnus 6.9%. The most damaged diameter interval recorded within the all damaged tree species ranges from 2.6 to 6 cm, followed by the interval 6.1–12 cm. Over 61% of the trees felled by the beaver had a bigger diameter. The most sensitive reaction to beaver’s dietary behaviour was shown by aspen (reduction of numbers by 27.6% and by willow (reduction of numbers by 16.6% on the monitored area.
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Lynch Alfaro, Jessica W; Boubli, Jean P; Paim, Fernanda P; Ribas, Camila C; Silva, Maria Nazareth F da; Messias, Mariluce R; Röhe, Fabio; Mercês, Michelle P; Silva Júnior, José S; Silva, Claudia R; Pinho, Gabriela M; Koshkarian, Gohar; Nguyen, Mai T T; Harada, Maria L; Rabelo, Rafael M; Queiroz, Helder L; Alfaro, Michael E; Farias, Izeni P
2015-01-01
The squirrel monkey, Saimiri, is a pan-Amazonian Pleistocene radiation. We use statistical phylogeographic methods to create a mitochondrial DNA-based timetree for 118 squirrel monkey samples across 68 localities spanning all Amazonian centers of endemism, with the aim of better understanding (1) the effects of rivers as barriers to dispersal and distribution; (2) the area of origin for modern Saimiri; (3) whether ancestral Saimiri was a lowland lake-affiliated or an upland forest taxa; and (4) the effects of Pleistocene climate fluctuation on speciation. We also use our topology to help resolve current controversies in Saimiri taxonomy and species relationships. The Rondônia and Inambari centers in the southern Amazon were recovered as the most likely areas of origin for Saimiri. The Amazon River proved a strong barrier to dispersal, and squirrel monkey expansion and diversification was rapid, with all speciation events estimated to occur between 1.4 and 0.6Ma, predating the last three glacial maxima and eliminating climate extremes as the main driver of squirrel monkey speciation. Saimiri expansion was concentrated first in central and western Amazonia, which according to the "Young Amazon" hypothesis was just becoming available as floodplain habitat with the draining of the Amazon Lake. Squirrel monkeys also expanded and diversified east, both north and south of the Amazon, coincident with the formation of new rivers. This evolutionary history is most consistent with a Young Amazon Flooded Forest Taxa model, suggesting Saimiri has always maintained a lowland wetlands niche and was able to greatly expand its range with the transition from a lacustrine to a riverine system in Amazonia. Saimiri vanzolinii was recovered as the sister group to one clade of Saimiri ustus, discordant with the traditional Gothic vs. Roman morphological division of squirrel monkeys. We also found paraphyly within each of the currently recognized species: S. sciureus, S. ustus, and S
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Model of Ciliwung River Flood Diversion Tunnel Using HEC-RAS Software
Directory of Open Access Journals (Sweden)
Nugroho Joko
2018-01-01
Full Text Available As a coastal city which lies in lowland area, Jakarta is prone to flooding. One major river which flow through Jakarta is Ciliwung River. There are alternatives to reduce flood risk, such as: river capacity improvement, existing natural reservoir and polder system improvement, upstream reservoir construction, city drainage improvement, flood channel construction and flood diversion. This paper presents capacity analysis of a proposed flood diversion of Ciliwung River to Cipinang River. Cipinang River has its downstream end at Eastern Flood Canal (Kanal Banjir Timur, KBT. This diversion is based on the available capacity of KBT. A 1-D numerical hydraulic model using HEC-RAS based on a proposed design is used to assess the performance of the diversion system in any combination of upstream and downstream boundary condition. Simulations were done for steady condition. The results show that capacity of the system can be achieved for certain condition at upstream and downstream boundary. The effects at the downstream reach of Ciliwung and Cipinang River due to the diversion are also obtained.
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Riverbank Collapse on the lower Murray River: recent phenomenon or long-term geomorphic process?
De Carli, E.; Hubble, T.; Jaksa, M.; Clarke, S. L.; Airey, D.; O'Toole, J.; Carpenter, G.
2013-12-01
The lower Murray River connects the Murray-Darling River Basin to the Southern Ocean and drains 14% of Australia's landmass. During the Millennium Drought (1997-2011) record low inflows for the Basin were recorded and the lower Murray River received only 19% of its long-term average inflow for 2008-2009, causing the pool-level in the lowermost reaches near Goolwa to fall 1 m below sea level. This event triggered widespread mass failure in the alluvial river banks and ground subsidence in some river-adjacent floodplain deposits between Blanchetown and Lake Alexandrina. Multi-beam bathymetry, sediment core and geotechnical data are presented for a number of sites investigated between Mannum and White Sands. Interpretation of this data indicates three different bank-failure slide morphologies present in the banks and adjacent channel. Type 1, ';recent' (2009-2011) deep-seated rotational slumps characterised by distinct, sharply-defined failure scars and associated debris fields of angular blocks shed from the failure site. Type 2, ';relatively-recent' shallow planar-failures, with less well-defined smoother failure scars and associated debris fields of smoothed or rounded blocks and pinnacles. Type 3, ';relatively-old' shallow planar-failures characterised by subdued relief slump scars that do not present an associated debris field. It is suspected that successive floods or high-flow events progressively erode and redistribute material, smoothing the landslide scars and redistributing the slide-debris deposits. Bank-failure and the delivery of material from the slides into the channel is interpreted as an ongoing and long-term geomorphic characteristic of the lower Murray River, rather than a new phenomenon that occurred as a response to unusually low river levels during the Millennium Drought. The larger size and rotational style of the recent Type 1 failures is most likely to be a consequence of the drought and anthropogenic modifications of the river channel and
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Evaluating private land conservation in the Cape Lowlands, South Africa.
Von Hase, Amrei; Rouget, Mathieu; Cowling, Richard M
2010-10-01
Evaluation is important for judiciously allocating limited conservation resources and for improving conservation success through learning and strategy adjustment. We evaluated the application of systematic conservation planning goals and conservation gains from incentive-based stewardship interventions on private land in the Cape Lowlands and Cape Floristic Region, South Africa. We collected spatial and nonspatial data (2003-2007) to determine the number of hectares of vegetation protected through voluntary contractual and legally nonbinding (informal) agreements with landowners; resources spent on these interventions; contribution of the agreements to 5- and 20-year conservation goals for representation and persistence in the Cape Lowlands of species and ecosystems; and time and staff required to meet these goals. Conservation gains on private lands across the Cape Floristic Region were relatively high. In 5 years, 22,078 ha (27,800 ha of land) and 46,526 ha (90,000 ha of land) of native vegetation were protected through contracts and informal agreements, respectively. Informal agreements often were opportunity driven and cheaper and faster to execute than contracts. All contractual agreements in the Cape Lowlands were within areas of high conservation priority (identified through systematic conservation planning), which demonstrated the conservation plan's practical application and a high level of overlap between resource investment (approximately R1.14 million/year in the lowlands) and priority conservation areas. Nevertheless, conservation agreements met only 11% of 5-year and 9% of 20-year conservation goals for Cape Lowlands and have made only a moderate contribution to regional persistence of flora to date. Meeting the plan's conservation goals will take three to five times longer and many more staff members to maintain agreements than initially envisaged. © 2010 Society for Conservation Biology.
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Spatial and temporal (1963-2012 variability of ichthyofauna in the large lowland Warta River, Poland
Directory of Open Access Journals (Sweden)
Andrzej Kruk
2015-11-01
Full Text Available The Warta River is a tributary of the Odra (Oder River. It is 795.2 km long. In 1986 the large Jeziorsko dam reservoir was constructed in the 306th km of its course. In the late 1980s, the river pollution assumed its highest level and stopped increasing as the former political system collapsed and many industrial plants went bankrupt. Unified fish electrocatches have been performed along the Warta River since the 1960s. During the last sampling, in 2011-2012, fish fauna in the middle course of the river was in the poorest condition due to the destabilizing upstream impact of the Jeziorsko dam reservoir, large amounts of wastewater input to the river, and the lack of unpolluted tributaries that could serve as sources of recolonizers. The weakest human pressure was reported for the upper and lower courses, which resulted in higher numbers of species significantly preferring them, and the higher species richness. Species richness significantly increased in comparison with the previous sampling occasions (in 1963-66, 1986-88, and 1996-98. Significant increases in the stability of occurrence, abundance or biomass were recorded for many species including burbot, chub, dace, ide, gudgeon, bleak, bitterling, perch and spined loach. Significant declines in the above mentioned population parameters were rare and related mainly to European eel (a migratory species. The previously recorded strong negative trend (declines in rheophils, increase in the dominance of roach and perch has been reversed. However, regenerated fish assemblages were not recorded in 1996-98 (i.e. several years after the beginning of the improvement in water quality but in 2011-2012 (i.e. about one decade later. We have noticed a similar delay in ichthyofauna recovery also in the Pilica River (Vistula system. This is why we believe that about 15 years are necessary to observe a considerable improvement in fish fauna in larger degraded rivers.
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International Nuclear Information System (INIS)
Bonte, P.; Le Cloarec, M.F.; Dumoulin, J.P.; Sogon, S.; Tessier, L.; Mouchel, J.M.; Thomas, A.J.
2000-01-01
This study was undertaken to test the application of environmental radioactive tracers for estimating sediment mass and sediment residence time in rivers. A continuous sampling of the Seine river suspended matter (SM) using sediment traps was made during two months, between Paris and the estuary, along a 120 km long river section. The hydrological regime corresponded to the low water stage, where the SM transport is reduced. The measured tracers in the SM include short-lived natural ( 7 Be, 234 Th xs ) and artificial ( 131 I) radionuclides, as well as the longer-lived natural 210 Pb xs and its descendant the 210 Po. 137 Cs was used to check grain-size effects. A simple steady state model allowed us to estimate the total sediment mass, i.e. the SM, plus the resuspendable matter (RM), and the sediment residence time. Despite their different half-lives (8 to 53 days) and their different geochemical properties, consistent results were obtained with 131 I, 7 Be and 234 Th xs . The best estimate of the sediment mass present in the river is (24-41)·10 3 tons; it is essentially composed of the RM which is 10-17 times more abundant than the SM. In these hydrological conditions, the sediment residence time is quite long (1.6-2.8 months). (author) [es
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Impacts of the 2016 outburst flood on the Bhote Koshi River valley, central Nepal
Cook, Kristen; Andermann, Christoff; Gimbert, Florent; Hovius, Niels; Adhikari, Basanta
2017-04-01
The central Nepal Himalaya is a region of rapid erosion where fluvial processes are largely driven by the annual Indian Summer Monsoon, which delivers up to several meters of precipitation each year. However, the rivers in this region are also subject to rare catastrophic floods caused by the sudden failure of landslide or moraine dams. Because these floods happen rarely, it has been difficult to isolate their impact on the rivers and adjacent hillslopes, and their importance for the long-term evolution of Himalayan rivers is poorly constrained. On the 5th of July, 2016, the Bhote Koshi River in central Nepal was hit by a glacial lake outburst flood (GLOF). The flood passed through a seismic and hydrological observatory installed along the river in June 2015, and we have used the resulting data to constrain the timing, duration, and bedload transport properties of the outburst flood. The impact of the flood on the river can be further observed with hourly time-lapse photographs, daily measurements of suspended sediment load, repeat lidar surveys, and satellite imagery. Overall, our observatory data span two monsoon seasons, allowing us to evaluate the impacts of the outburst flood relative to the annual monsoon flood. The outburst flood affected the river on several timescales. In the short term, it transported large amounts of coarse sediment and restructured the river bed during the hours of the flood pulse itself. Over intermediate timescales it resulted in elevated bedload and suspended load transport for several weeks following the flood. Over longer timescales the flood undercut and destabilized the river banks and hillslopes in a number of locations, leading to bank collapses, slumps, and landslides. We map changes in the channel and associated mass wasting using rapidEye imagery from Oct. 2015 and Oct. 2016. We also use repeat terrestrial lidar scans to quantify the magnitude of change in multiple locations along the river channel and to measure bank
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the left bank of the Rimac river
International Development Research Centre (IDRC) Digital Library (Canada)
The Focus City Research Initiative (FCRI) is a series of eight action research ... Reducing physical vulnerability of residents ... physically (along the edge of the Rimac river, on the .... the topic of disaster risk management and vulnerability.
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International Nuclear Information System (INIS)
Owen, Eric J; Svenson, G
2000-01-01
The effects of deforestation of the banks of the Meta River was studied on a length of 25.7 km. between Puerto Lopez and the island of San Isidro using aerial photographs of the years 1939, 1950, 1974/1989 and 1997. The deforestation from 17.06% to 82.35% caused a reduction in length of 2.25 km. an increase in width (206%), area of the river (189%) and affected 482 hec. of the land adjacent to the river that is equivalent of 10.483.500 tons of soil for a mean of 3458.6 t/km/year. Regression equations were calculated using percent bank deforested vs. width, area of the river and area affected by the river. The correlation coefficients higher than 0.9720
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Schirmer, M.; Luster, J.; Linde, N.; Perona, P.; Mitchell, E. A. D.; Barry, D. A.; Hollender, J.; Cirpka, O. A.; Schneider, P.; Vogt, T.; Radny, D.; Durisch-Kaiser, E.
2014-06-01
River restoration can enhance river dynamics, environmental heterogeneity and biodiversity, but the underlying processes governing the dynamic changes need to be understood to ensure that restoration projects meet their goals, and adverse effects are prevented. In particular, we need to comprehend how hydromorphological variability quantitatively relates to ecosystem functioning and services, biodiversity as well as ground- and surface water quality in restored river corridors. This involves (i) physical processes and structural properties, determining erosion and sedimentation, as well as solute and heat transport behavior in surface water and within the subsurface; (ii) biogeochemical processes and characteristics, including the turnover of nutrients and natural water constituents; and (iii) ecological processes and indicators related to biodiversity and ecological functioning. All these aspects are interlinked, requiring an interdisciplinary investigation approach. Here, we present an overview of the recently completed RECORD (REstored CORridor Dynamics) project in which we combined physical, chemical, and biological observations with modeling at a restored river corridor of the perialpine Thur River in Switzerland. Our results show that river restoration, beyond inducing morphologic changes that reshape the river bed and banks, triggered complex spatial patterns of bank infiltration, and affected habitat type, biotic communities and biogeochemical processes. We adopted an interdisciplinary approach of monitoring the continuing changes due to restoration measures to address the following questions: How stable is the morphological variability established by restoration? Does morphological variability guarantee an improvement in biodiversity? How does morphological variability affect biogeochemical transformations in the river corridor? What are some potential adverse effects of river restoration? How is river restoration influenced by catchment-scale hydraulics
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Molecular profiling of interspecific lowland rice populations derived ...
African Journals Online (AJOL)
STORAGESEVER
2008-12-03
Dec 3, 2008 ... Molecular profiling of interspecific lowland rice populations ... Both cluster and principal component analyses revealed two major groups ...... simulations. Theor ... inheritance, chromosomal location, and population dynamics.
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Sensitivity of the hydrologic cycle in Tana river basin to climate change
International Nuclear Information System (INIS)
Mutua, F.M.
1998-01-01
The Tana River basin in Kenya has four distinct climates along it's gradient from cool humid in mount Kenya region through arid and semi arid in the lower plains to semi humid coastal climate. From the highlands of mount Kenya to the plateau on the lowlands, the river traverses some sections which have high potential for hydro-electric power generation. The government has constructed water reovirus to collect water for electricity generation. The influence of the reovirus have also caused climate modification. The aim of the study was to investigate the sensitivity of the river flows in the Tana river to climate change. The study indicates that, as long as temperature increment of up to 2 degrees centigrade are accompanied by positive changes (greater than 10%) in rainfall over the basin, then the hydrologic cycle adjust itself accordingly to give a positive response (increased runoff) in terms of the river at the outlet
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Water Banks: Using Managed Aquifer Recharge to Meet Water Policy Objectives
Directory of Open Access Journals (Sweden)
Sharon B. Megdal
2014-05-01
Full Text Available Innovation born of necessity to secure water for the U.S. state of Arizona has yielded a model of water banking that serves as an international prototype for effective use of aquifers for drought and emergency supplies. If understood and adapted to local hydrogeological and water supply and demand conditions, this could provide a highly effective solution for water security elsewhere. Arizona is a semi-arid state in the southwestern United States that has growing water demands, significant groundwater overdraft, and surface water supplies with diminishing reliability. In response, Arizona has developed an institutional and regulatory framework that has allowed large-scale implementation of managed aquifer recharge in the state’s deep alluvial groundwater basins. The most ambitious recharge activities involve the storage of Colorado River water that is delivered through the Central Arizona Project (CAP. The CAP system delivers more than 1850 million cubic meters (MCM per year to Arizona’s two largest metropolitan areas, Phoenix and Tucson, along with agricultural users and sovereign Native American Nations, but the CAP supply has junior priority and is subject to reduction during declared shortages on the Colorado River. In the mid-1980s the State of Arizona established a framework for water storage and recovery; and in 1996 the Arizona Water Banking Authority was created to mitigate the impacts of Colorado River shortages; to create water management benefits; and to allow interstate storage. The Banking Authority has stored more than 4718 MCM of CAP water; including more than 740 MCM for the neighboring state of Nevada. The Nevada storage was made possible through a series of interrelated agreements involving regional water agencies and the federal government. The stored water will be recovered within Arizona; allowing Nevada to divert an equal amount of Colorado River water from Lake Mead; which is upstream of CAP’s point of diversion
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Sewage-effluent phosphorus: A greater risk to river eutrophication than agricultural phosphorus?
International Nuclear Information System (INIS)
Jarvie, Helen P.; Neal, Colin; Withers, Paul J.A.
2006-01-01
Phosphorus (P) concentrations from water quality monitoring at 54 UK river sites across seven major lowland catchment systems are examined in relation to eutrophication risk and to the relative importance of point and diffuse sources. The over-riding evidence indicates that point (effluent) rather than diffuse (agricultural) sources of phosphorus provide the most significant risk for river eutrophication, even in rural areas with high agricultural phosphorus losses. Traditionally, the relative importance of point and diffuse sources has been assessed from annual P flux budgets, which are often dominated by diffuse inputs in storm runoff from intensively managed agricultural land. However, the ecological risk associated with nuisance algal growth in rivers is largely linked to soluble reactive phosphorus (SRP) concentrations during times of ecological sensitivity (spring/summer low-flow periods), when biological activity is at its highest. The relationships between SRP and total phosphorus (TP; total dissolved P + suspended particulate P) concentrations within UK rivers are evaluated in relation to flow and boron (B; a tracer of sewage effluent). SRP is the dominant P fraction (average 67% of TP) in all of the rivers monitored, with higher percentages at low flows. In most of the rivers the highest SRP concentrations occur under low-flow conditions and SRP concentrations are diluted as flows increase, which is indicative of point, rather than diffuse, sources. Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk. Particulate phosphorus (PP) may form a significant proportion of the phosphorus load to rivers, particularly during winter storm events, but this is of questionable relevance for river eutrophication
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International Nuclear Information System (INIS)
Vanmarcke, H.; Paridaens, J.
2000-01-01
A chemical plant in the north of Belgium processes since 1929 large quantities of marine phosphate ore, with a 226 Ra content of 1500 Bq/kg, into products suited for animal feeding, using hydrochloric acid (HCl) as dissolution agent instead of the more common sulphuric acid (H 2 SO 4 ). Until 1991, two thirds of the radium was released with the waste water into two small rivers with a concentration of about 20 Bq/l and a flow rate of 1500 m 3 /h. Adding barium salts has recently reduced the radium concentration of the waste water to 3 Bq/l. The purpose of this study was to map the historical radium contamination of one of the receiving rivers, the Laak, over a distance of 20 km. Enhanced dose rates are found everywhere along the Laak between the discharge points and the merging with the Grote Nete. The contamination is mostly confined to a narrow strip of 5 to 10 m wide on one or on both sides, caused by the periodic dredging of the sediment. The measured dose rates vary between the low natural background of the region, 50 to 80 nSv/h, and 1000 to 2000 nSv/h. The total surface area contaminated above 100 nSv/h amounts to 22 ha. The radiological impact on the surrounding population was estimated. Realistic scenarios for critical groups for the external exposure result in doses of a few hundreds of μSv/year. Pastures and maize for animal feeding are currently the only cultures along the contaminated banks of the Laak. This additional step in the food chain reduces the internal doses to a few tens of μSv/year. The inhalation of radon decay products in open air poses no problem. The construction of dwellings on the contaminated banks would undo this favorable situation as radon gas could accumulate in the dwellings resulting in doses that could exceed the limit for radiation workers. (author)
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Landuse Types within Channel Corridor and River Channel Morphology of River Ona, Ibadan, Nigeria
Directory of Open Access Journals (Sweden)
Olutoyin Fashae
2017-12-01
Full Text Available The importance of river a corridor warrants a well thought out and balanced management approach because it helps in improving or maintaining water quality, protecting wetlands, etc. Hence, this study seeks to identify major landuse types within the River Ona Corridor; examine the impact of these landuse types within the River Ona corridor on its channel morphology and understand the risk being posed by these landuse types. The study is designed by selecting two reaches of six times the average width from each of the four major landuse types that exist along the river corridor. This study revealed that along the downstream section of Eleyele Dam of River Ona, natural forest stabilizes river channel banks, thereby presenting a narrow and shallow width and depth respectively but the widest of all is found at the agricultural zones.
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Energy Technology Data Exchange (ETDEWEB)
Freyer, K.; Treutler, H.C. [Leipzig-Halle Ltd, Permoserstr, Leipzig (Germany). Centre for Environmental Research; Dehnert, J.; Nestler, W. [Hochschule fuer Technik und Wirtschaft Dresrden, Dresden (Germany)
1997-10-01
With a half life of 3.8 days, the {sup 222}Rn found in all groundwater makes an excellent tracer for solving several problems in the field of environmental research and hydrology. In Germany alluvial aquifers connected to rivers are used for drinking water extraction. Consequently importance is attached to studying the exchange processes between surface water and groundwater in order to determine infiltration velocities and infiltrate retention times in the aquifer. However, such investigations require a reliable, reproducible method for determining radon activity concentrations in groundwater samples, as well as a suitable sampling technique. This paper reports on just such a method, containing detailed instructions for sampling, transportation and activity determination using liquid scintillation spectrometry following toluene extraction. Spectral analysis and {alpha}/{beta} separation improve the accuracy of measurement. The detection limit is about 0.05 Bq/1; the total error is <{+-}10%. Infiltration processes are studied with {sup 222}Rn by employing the effect that surface water infiltrating an aquifer absorbs {sup 222}Rn along the infiltration pathway. As the degree of uptake is a function of the retention time, flow paths and flow velocities can all be determined by measuring the radon activity concentrations at the various groundwater gauging stations along measuring profiles. Corresponding investigations were carried out into a pleistocene aquifer below the River Elbe near a waterworks extracting bank-filtered water. The findings are presented and the technique`s possibilities and limitations are discussed 12 refs., 3 figs.
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Conveyance estimation in channels with emergent bank vegetation ...
African Journals Online (AJOL)
Emergent vegetation along the banks of a river channel influences its conveyance considerably. The total channel discharge can be estimated as the sum of the discharges of the vegetated and clear channel zones calculated separately. The vegetated zone discharge is often negligible, but can be estimated using ...
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Verstraeten, Ingrid M.; Thurman, E.M.; Lindsey, M.E.; Lee, E.C.; Smith, R.D.
2002-01-01
The changes in triazine and acetamide concentrations in water during natural and artificial treatment by bank filtration, ozonation, filtration, and chlorination were measured at the well field and drinking water treatment plant of Lincoln, Nebraska, USA. The city's groundwater supply is affected by induced infiltration and transport of triazines and acetamide herbicides from the Platte River in late spring and early summer. The objective of the study was to evaluate the effect of infiltration and treatment on the presence of triazines and acetamides in drinking water. Samples of river water, well water, and public supply water at various stages of water treatment were collected from 1997-1999 during spring-runoff when the presence of herbicides in the Platte River is largest. In 1999, parent compounds were reduced by 76% of the concentration present in river water (33% by bank filtration, 41% by ozonation, and 1.5% by chlorination). Metabolites of herbicides for which analytical techniques existed were reduced by 21% (plus 26% by bank filtration, minus 23% by ozonation, and minus 24% by chlorination). However, increases in concentrations of specific metabolite compounds were identified after bank filtration and ozonation. After bank filtration, increases in cyanazine amide, cyanazine acid, and deethylcyanazine acid were identified. After ozonation, concentrations of deisopropylatrazine, deethylatrazine, didealkylatrazine, atrazine amide-I, hydroxydeethylatrazine, hydroxydeisopopylatrazine, deethylcyanazine acid, and deethylcyanazine increased. Concentrations of cyanazine acid and ethanesulfonic and oxanilic acids of acetamides decreased during ozonation. Our findings suggest that bank filtration and ozonation of water in part can shift the assessment of risk to human health associated with the consumption of the water from the parent compounds to their degradation products.
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Geomorphic analysis of the river response to sedimentation downstream of Mount Rainier, Washington
Czuba, Jonathan A.; Magirl, Christopher S.; Czuba, Christiana R.; Curran, Christopher A.; Johnson, Kenneth H.; Olsen, Theresa D.; Kimball, Halley K.; Gish, Casey C.
2012-01-01
A study of the geomorphology of rivers draining Mount Rainier, Washington, was completed to identify sources of sediment to the river network; to identify important processes in the sediment delivery system; to assess current sediment loads in rivers draining Mount Rainier; to evaluate if there were trends in streamflow or sediment load since the early 20th century; and to assess how rates of sedimentation might continue into the future using published climate-change scenarios. Rivers draining Mount Rainier carry heavy sediment loads sourced primarily from the volcano that cause acute aggradation in deposition reaches as far away as the Puget Lowland. Calculated yields ranged from 2,000 tonnes per square kilometer per year [(tonnes/km2)/yr] on the upper Nisqually River to 350 (tonnes/km2)/yr on the lower Puyallup River, notably larger than sediment yields of 50–200 (tonnes/km2)/yr typical for other Cascade Range rivers. These rivers can be assumed to be in a general state of sediment surplus. As a result, future aggradation rates will be largely influenced by the underlying hydrology carrying sediment downstream. The active-channel width of rivers directly draining Mount Rainier in 2009, used as a proxy for sediment released from Mount Rainier, changed little between 1965 and 1994 reflecting a climatic period that was relatively quiet hydrogeomorphically. From 1994 to 2009, a marked increase in geomorphic disturbance caused the active channels in many river reaches to widen. Comparing active-channel widths of glacier-draining rivers in 2009 to the distance of glacier retreat between 1913 and 1994 showed no correlation, suggesting that geomorphic disturbance in river reaches directly downstream of glaciers is not strongly governed by the degree of glacial retreat. In contrast, there was a correlation between active-channel width and the percentage of superglacier debris mantling the glacier, as measured in 1971. A conceptual model of sediment delivery processes
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The potential for dams to impact lowland meandering river floodplain geomorphology.
Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J
2014-01-01
The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.
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The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology
Directory of Open Access Journals (Sweden)
Philip M. Marren
2014-01-01
Full Text Available The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection and active impacts (changes in geomorphological processes and functioning. These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows.
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Bedoya-Soto, Juan Mauricio; Poveda, Germán; Trenberth, Kevin E.; Vélez-Upegui, Jorge Julián
2018-03-01
During 2009-2011, Colombia experienced extreme hydroclimatic events associated with the extreme phases of El Niño-Southern Oscillation (ENSO). Here, we study the dynamics of diverse land-atmosphere phenomena involved in such anomalous events at continental, regional, and local scales. Standardized anomalies of precipitation, 2-m temperature, total column water (TCW), volumetric soil water (VSW), temperature at 925 hPa, surface sensible heat (SSH), latent heat (SLH), evaporation (EVP), and liquid water equivalent thickness (LWET) are analyzed to assess atmosphere-land controls and relationships over tropical South America (TropSA) during 1986-2013 (long term) and 2009-2011 (ENSO extreme phases). An assessment of the interannual covariability between precipitation and 2-m temperature is performed using singular value decomposition (SVD) to identify the dominant spatiotemporal modes of hydroclimatic variability over the region's largest river basins (Amazon, Orinoco, Tocantins, Magdalena-Cauca, and Essequibo). ENSO, its evolution in time, and strong and consistent spatial structures emerge as the dominant mode of variability. In situ anomalies during both extreme phases of ENSO 2009-2011 over the Magdalena-Cauca River basins are linked at the continental scale. The ENSO-driven hydroclimatic effects extend from the diurnal cycle to interannual timescales, as reflected in temperature data from tropical glaciers and the rain-snow boundary in the highest peaks of the Central Andes of Colombia to river levels along the Caribbean lowlands of the Magdalena-Cauca River basin.
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Directional layouts in central lowland Maya settlement
DEFF Research Database (Denmark)
Bevan, Andrew; Jobbová, Eva; Helmke, Christophe
2013-01-01
This paper suggests the existence of non-random, directional patterns in the location of housemounds across the Late Classic Maya settlement landscape at Baking Pot, Belize, and then explores the wider implications of this patterning in the central Maya lowlands. It introduces an anisotropic method...
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Plant basket hydraulic structures (PBHS) as a new river restoration measure.
Kałuża, Tomasz; Radecki-Pawlik, Artur; Szoszkiewicz, Krzysztof; Plesiński, Karol; Radecki-Pawlik, Bartosz; Laks, Ireneusz
2018-06-15
River restoration has become increasingly attractive worldwide as it provides considerable benefits to the environment as well as to the economy. This study focuses on changes of hydromorphological conditions in a small lowland river recorded during an experiment carried out in the Flinta River, central Poland. The proposed solution was a pilot project of the construction of vegetative sediment traps (plant basket hydraulic structures - PBHS). A set of three PBSH was installed in the riverbed in one row and a range of hydraulic parameters were recorded over a period of three years (six measurement sessions). Changes of sediment grain size were analysed, and the amount and size of plant debris in the plant barriers were recorded. Plant debris accumulation influencing flow hydrodynamics was detected as a result of the installation of vegetative sediment traps. Moreover, various hydromorphological processes in the river were initiated. Additional simulations based on the detected processes showed that the proposed plant basket hydraulic structures can improve the hydromorphological status of the river. Copyright © 2018 Elsevier B.V. All rights reserved.
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Masi, Shelly; Cipolletta, Chloé; Robbins, Martha M
2009-02-01
The most important environmental factor explaining interspecies variation in ecology and sociality of the great apes is likely to be variation in resource availability. Relatively little is known about the activity patterns of western lowland gorillas (Gorilla gorilla gorilla), which inhabit a dramatically different environment from the well-studied mountain gorillas (G. beringei beringei). This study aims to provide a detailed quantification of western lowland gorillas' activity budgets using direct observations on one habituated group in Bai Hokou, Central African Republic. We examined how activity patterns of both sexes are shaped by seasonal frugivory. Activity was recorded with 5-min instantaneous sampling between December 2004 and December 2005. During the high-frugivory period the gorillas spent less time feeding and more time traveling than during the low-frugivory period. The silverback spent less time feeding but more time resting than both females and immatures, which likely results from a combination of social and physiological factors. When compared with mountain gorillas, western lowland gorillas spend more time feeding (67 vs. 55%) and traveling (12 vs. 6.5%), but less time resting (21 vs. 34%) and engaging in social/other activities (0.5 vs. 3.6%). This disparity in activity budgets of western lowland gorillas and mountain gorillas may be explained by the more frugivorous diet and the greater dispersion of food resources experienced by western lowland gorillas. Like other apes, western lowland gorillas change their activity patterns in response to changes in the diet. (c) 2008 Wiley-Liss, Inc.
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Missouri River Flood 2011 Vulnerabilities Assessment Report. Volume 2 - Technical Report
2012-10-01
Michels at Dakota Dunes , South Dakota. ............................................................................................................... 2...91 Figure 28. Upper Hamburg Bend Levee Toe Scour...Bend Project at Dakota Dunes along Left Bank River Mile 737 ........................... 109 Figure 37. Stage Trends on the Missouri River at St
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Directory of Open Access Journals (Sweden)
J. R. Santillan
2016-09-01
Full Text Available In this paper, we investigated how survey configuration and the type of interpolation method can affect the accuracy of river flow simulations that utilize LIDAR DTM integrated with interpolated river bed as its main source of topographic information. Aside from determining the accuracy of the individually-generated river bed topographies, we also assessed the overall accuracy of the river flow simulations in terms of maximum flood depth and extent. Four survey configurations consisting of river bed elevation data points arranged as cross-section (XS, zig-zag (ZZ, river banks-centerline (RBCL, and river banks-centerline-zig-zag (RBCLZZ, and two interpolation methods (Inverse Distance-Weighted and Ordinary Kriging were considered. Major results show that the choice of survey configuration, rather than the interpolation method, has significant effect on the accuracy of interpolated river bed surfaces, and subsequently on the accuracy of river flow simulations. The RMSEs of the interpolated surfaces and the model results vary from one configuration to another, and depends on how each configuration evenly collects river bed elevation data points. The large RMSEs for the RBCL configuration and the low RMSEs for the XS configuration confirm that as the data points become evenly spaced and cover more portions of the river, the resulting interpolated surface and the river flow simulation where it was used also become more accurate. The XS configuration with Ordinary Kriging (OK as interpolation method provided the best river bed interpolation and river flow simulation results. The RBCL configuration, regardless of the interpolation algorithm used, resulted to least accurate river bed surfaces and simulation results. Based on the accuracy analysis, the use of XS configuration to collect river bed data points and applying the OK method to interpolate the river bed topography are the best methods to use to produce satisfactory river flow simulation outputs
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Dispersal and colonisation of plants in lowland streams: success rates and bottlenecks
DEFF Research Database (Denmark)
Riis, Tenna
2008-01-01
-rich lowland streams. Rather, I conclude that primary colonisation is the main constraint to regaining vegetation in lowland streams in general and in vegetation-free rehabilitated streams in particular. Therefore, if plant colonisation is a target for stream rehabilitation, it is important to enhance......Plant dispersal and colonisation, including rates of dispersal, retention, colonisation and survival of dispersed propagules (shoots and seeds), were studied in a 300-m stream reach in a macrophyte-rich lowland stream during one growing season. Relationships between colonisation processes...... and simple flow parameters were tested. Each fortnight during a growing season, the number of dispersed plant propagules and the number of new and lost plant colonisations since the last sampling day were recorded. The retention of dispersing shoots was tested on two occasions during the growing season...
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Tocantins river as an effective barrier to gene flow in Saguinus niger populations
Directory of Open Access Journals (Sweden)
Marcelo Vallinoto
2006-01-01
Full Text Available The Saguinus represent the basal genus of the Callitrichinae subfamily. Traditionally this genus is divided into three groups: Hairy, Mottled and Bare-face, however, molecular data failed to validate these groups as monophyletic units, as well as raised some subspecies to the species status. This is the case of the former subspecies Saguinus midas midas and S. midas niger, which are now considered as different species. In the present study, we sequenced a portion of the D-loop mtDNA region in populations from the East bank of the Xingu and from both banks of the Tocantins river, in order to test the effectiveness of large rivers as barriers to the gene flow in Saguinus. According to our results, the populations from the East and West banks of the Tocantins river are more divergent than true species like S. mystax and S. imperator. The Tocantins river may be acting as a barrier to gene flow, and consequently these very divergent populations may represent distinct taxonomic entities (species?.
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Stability of River Bifurcations from Bedload to Suspended Load Dominated Conditions
de Haas, T.; Kleinhans, M. G.
2010-12-01
Bifurcations (also called diffluences) are as common as confluences in braided and anabranched rivers, and more common than confluences on alluvial fans and deltas where the network is essentially distributary. River bifurcations control the partitioning of both water and sediment through these systems with consequences for immediate river and coastal management and long-term evolution. Their stability is poorly understood and seems to differ between braided rivers, meandering river plains and deltas. In particular, it is the question to what extent the division of flow is asymmetrical in stable condition, where highly asymmetrical refers to channel closure and avulsion. Recent work showed that bifurcations in gravel bed braided rivers become more symmetrical with increasing sediment mobility, whereas bifurcations in a lowland sand delta become more asymmetrical with increasing sediment mobility. This difference is not understood and our objective is to resolve this issue. We use a one-dimensional network model with Y-shaped bifurcations to explore the parameter space from low to high sediment mobility. The model solves gradually varied flow, bedload transport and morphological change in a straightforward manner. Sediment is divided at the bifurcation including the transverse slope effect and the spiral flow effect caused by bends at the bifurcation. Width is evolved whilst conserving mass of eroded or built banks with the bed balance. The bifurcations are perturbed from perfect symmetry either by a subtle gradient advantage for one branch or a gentle bend at the bifurcation. Sediment transport was calculated with and without a critical threshold for sediment motion. Sediment mobility, determined in the upstream channel, was varied in three different ways to isolate the causal factor: by increasing discharge, increasing channel gradient and decreasing particle size. In reality the sediment mobility is mostly determined by particle size: gravel bed rivers are near
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Characteristics and value of the Thukela Banks crustacean and ...
African Journals Online (AJOL)
This study describes the Thukela Banks crustacean and linefish fisheries and investigates the potential impacts of reduced flow from the Thukela River on the value of these fisheries. Data were obtained from published and unpublished material, key informants and government records. The crustacean fishery employs ...
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Sarin, M. M.; Krishnaswami, S.; somayajulu, B. L. K.; Moore, W. S.
1990-05-01
The most comprehensive data set on uranium, thorium, and radium isotopes in the Ganga-Brahmaputra, one of the major river systems of the world, is reported here. The dissolved 238U concentration in these river waters ranges between 0.44 and 8.32 μ/1, and it exhibits a positive correlation with major cations (Na + K + Mg + Ca). The 238U /∑Cations ratio in waters is very similar to that measured in the suspended sediments, indicating congruent weathering of uranium and major cations. The regional variations observed in the [ 234U /238U ] activity ratio are consistent with the lithology of the drainage basins. The lowland tributaries (Chambal, Betwa, Ken, and Son), draining through the igneous and metamorphic rocks of the Deccan Traps and the Vindhyan-Bundelkhand Plateau, have [ 234U /238U ] ratio in the range 1.16 to 1.84. This range is significantly higher than the near equilibrium ratio (~1.05) observed in the highland rivers which drain through sedimentary terrains. The dissolved 226Ra concentration ranges between 0.03 and 0.22 dpm/1. The striking feature of the radium isotopes data is the distinct difference in the 228Ra and 226Ra abundances between the highland and lowland rivers. The lowland waters are enriched in 228Ra while the highland waters contain more 226Ra. This difference mainly results from the differences in their weathering regimes. The discharge-weighted mean concentration of dissolved 238U in the Ganga (at Patna) and in the Brahmaputra (at Goalpara) are 1.81 and 0.63 μ/1, respectively. The Ganga-Brahmaputra river system constitutes the major source of dissolved uranium to the Bay of Bengal. These rivers transport annually about 1000 tons of uranium to their estuaries, about 10% of the estimated global supply of dissolved uranium to the oceans via rivers. The transport of uranium by these rivers far exceeds that of the Amazon, although their water discharge is only about 20% of that of the Amazon. The high intensity of weathering of uranium in
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Excavations at the Buller River Site (K29/8), January 2004
International Nuclear Information System (INIS)
Jacomb, C.; Tucker, B.; Walter, R.
2004-01-01
The Buller River Site (K29/8) is located on the south (true left) bank of the Buller, or Kawatiri, River directly across from Westport and approximately one kilometre from the present shoreline. This report describes the excavations at Buller River in February 2004, outlines the results to date and canvasses options for future research. 12 refs., 11 figs
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Morphology of the Zambezi River plume in the Sofala Bank ...
African Journals Online (AJOL)
In this paper, hydrographic data collected in the vicinity of the Zambezi River plume between 2004-2007 is discussed alongside historical data to infer the plume morphology. The sampling plan called for 73 CTD stations that were interspersed with sampling of shrimp recruitment. Satellite-derived wind speed and river ...
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Directory of Open Access Journals (Sweden)
Maria Ilhéu
Full Text Available Invasive species are regarded as a biological pressure to natural aquatic communities. Understanding the factors promoting successful invasions is of great conceptual and practical importance. From a practical point of view, it should help to prevent future invasions and to mitigate the effects of recent invaders through early detection and prioritization of management measures. This study aims to identify the environmental determinants of fish invasions in Mediterranean-climate rivers and evaluate the relative importance of natural and human drivers. Fish communities were sampled in 182 undisturbed and 198 disturbed sites by human activities, belonging to 12 river types defined for continental Portugal within the implementation of the European Union's Water Framework Directive. Pumpkinseed sunfish, Lepomis gibbosus (L., and mosquitofish, Gambusia holbrooki (Girard, were the most abundant non-native species (NNS in the southern river types whereas the Iberian gudgeon, Gobio lozanoi Doadrio and Madeira, was the dominant NNS in the north/centre. Small northern mountain streams showed null or low frequency of occurrence and abundance of NNS, while southern lowland river types with medium and large drainage areas presented the highest values. The occurrence of NNS was significantly lower in undisturbed sites and the highest density of NNS was associated with high human pressure. Results from variance partitioning showed that natural environmental factors determine the distribution of the most abundant NNS while the increase in their abundance and success is explained mainly by human-induced disturbance factors. This study stresses the high vulnerability of the warm water lowland river types to non-native fish invasions, which is amplified by human-induced degradation.
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Heat Transport In The Streambed Of A Large Regulated River.
Munoz, S.; Ferencz, S. B.; Neilson, B. T.; Cardenas, M. B.
2017-12-01
Dams affect over half of the Earth's large river systems. In large river systems, regulation such as hydropeaking may even have more obvious and profound effects than global warming. The downstream effects of dams are not limited only to the fluvial system, but also propagate into aquifers and hyporheic zones. Despite this, little is known about how dams affect downstream surface and subsurface temperatures. This study investigates surface and groundwater interactions in the thermal regime of a 5th order dam-regulated river on several spatial scales. Two transects of thermistors recorded temperature gradients in the riverbed over the course of several flood pulses at 5 minute intervals. One transect was perpendicular to the river flow spanning the 68 m from bank to bank with sensors spaced every 2.75 m at depths of 0.1, 0.2, 0.3 and 0.5 m in the river bed. The second was parallel to the bank with 72 thermistors spaced every meter and at the same depths as the perpendicular transect. The cross channel transect had 5 piezometers installed at 0.5 m depth at regular intervals across half the channel with instruments collecting temperature, pressure and conductivity. Flood pulses reverse head gradients daily and cause the river to fluctuate between gaining and losing on hour timescales. When the stage increases, warmer surface water penetrates into the subsurface and during the receding limb, cooler groundwater upwells as the river returns to base flow conditions. The USGS flow modeling program 1DTempPro demonstrated that the infiltration rates did not match the large head gradients associated with dam regulated stage differences, and this effect is likely due to pore pressure increases or so-called poroelastic effects. Similar responses of pore pressure increases with diminishing infiltration has been observed in shallow salt marshes with quickly increasing head gradients.
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International Nuclear Information System (INIS)
Foley, R.D.; Floyd, L.M.
1989-11-01
Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally 232 Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, the Saddle River's East Bank, from State Highway 46 to the River's Confluence with Lodi Brook, Lodi, New Jersey (LJ083), was conducted during 1988. Results of the survey demonstrated no radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions were not significantly different from normal background levels in the northern New Jersey area. 4 refs., 2 figs., 3 tabs
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agronomic performance of introduced banana varieties in lowlands
African Journals Online (AJOL)
jen
this study was to evaluate the agronomic performance of FHIA hybrids in lowlands of Rwanda. Completely ... L'objectif de cette étude était d'évaluer la performance agronomique de FHIA hybride ..... major Musa types present in Asia and the.
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Diatoms as an indicator for tile drainage flow in a German lowland catchment.
Wu, Naicheng; Faber, Claas; Ulrich, Uta; Fohrer, Nicola
2018-01-01
The separation of runoff components within a model simulation is of great importance for a successful implementation of management measures. Diatoms could be a promising indicator for tile drainage flow due to their diverse preferences to different aquatic habitats. In this study, we collected diatom samples of 9 sites (4 tile drainage, TD, and 5 river sites, Ri) in a German lowland catchment at a weekly or biweekly time step from March to July 2013 with the aim of testing the suitability of diatoms for tile drainage flow, which is typical for lowland catchment. Planothidium lanceolatum , Ulnaria biceps , and Navicula gregaria dominated in TD sites with relative abundances of 22.2, 21.5, and 10.9%, respectively. For Ri sites, the most abundant species was Navicula lanceolata (20.5%), followed by Ulnaria biceps (12.9%), Cyclotella meneghiniana (9.5%), and Planothidium lanceolatum (9.3%). Compared with Ri sites, TD had a lower diatom density, biomass, species richness, and percentage of Aquatic/Riparian diatoms (AqRi%). However, the proportion of Riparian diatoms (RiZo%) increased at TD. Indicator value method (IndVal) revealed that the two groups (Ri and TD) were characterized by different indicator species. Fifteen taxa, including Cocconeis placentula , Cyclotella meneghiniana , N. lanceolata , and U. biceps , were significant indicators for Ri sites. Planothidium lanceolatum , Achnanthidium minutissimum , and Navicula gregaria were significant indicators for TD sites. A pronounced variation was found in the species lists of diatom community between Ri and TD water body types associated with different indicator species. With respect to hydrograph separation, these findings highlight the suitability of diatoms as an indicator for tile drainage flow. However, spatial and temporal variations of diatoms should be considered in future surveys.
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Kraberger, Simona; Stainton, Daisy; Dayaram, Anisha; Zawar-Reza, Peyman; Gomez, Christopher; Harding, Jon S; Varsani, Arvind
2013-08-08
In samples of benthic and bank river sediments of two urban rivers in Christchurch city (New Zealand), we identified and recovered isolates of Sclerotinia sclerotiorum hypovirulence-associated virus-1 (SsHADV-1), a fungus-infecting circular single-stranded DNA virus. This is the first report of SsHADV-1 outside of China and in environmental samples.
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Graham, P. W.; Andersen, M. S.; McCabe, M. F.; Ajami, H.; Baker, A.; Acworth, I.
2015-03-01
Long-duration high-volume dam releases are unique anthropogenic events with no naturally occurring equivalents. The impact from such dam releases on a downstream Quaternary alluvial aquifer in New South Wales, Australia, is assessed. It is observed that long-duration (>26 days), high-volume dam releases (>8,000 ML/day average) result in significant variations in river-aquifer interactions. These variations include a flux from the river to the aquifer up to 6.3 m3/day per metre of bank (at distances of up to 330 m from the river bank), increased extent and volume of recharge/bank storage, and a long-term (>100 days) reversal of river-aquifer fluxes. In contrast, during lower-volume events (bank. A groundwater-head prediction model was constructed and river-aquifer fluxes were calculated; however, predicted fluxes from this method showed poor correlation to fluxes calculated using actual groundwater heads. Long-duration high-volume dam releases have the potential to skew estimates of long-term aquifer resources and detrimentally alter the chemical and physical properties of phreatic aquifers flanking the river. The findings have ramifications for improved integrated management of dam systems and downstream aquifers.
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Sreebha, Sreedharan; Padmalal, Damodaran
2011-01-01
In the past few decades, the demand for construction grade sand is increasing in many parts of the world due to rapid economic development and subsequent growth of building activities. This, in many of the occasions, has resulted in indiscriminate mining of sand from in-stream and floodplain areas leading to severe damages to the river basin environment. The case is rather alarming in the small catchment rivers like those draining the southwestern coast of India due to limited sand resources in their alluvial reaches. Moreover, lack of adequate information on the environmental impact of river sand mining is a major lacuna challenging regulatory efforts in many developing countries. Therefore, a scientific assessment is a pre-requisite in formulating management strategies in the sand mining-hit areas. In this context, a study has been made as a case to address the environmental impact of sand mining from the in-stream and floodplain areas of three important rivers in the southwestern coast of India namely the Chalakudy, Periyar and Muvattupuzha rivers, whose lowlands host one of the fast developing urban-cum-industrial centre, the Kochi city. The study reveals that an amount of 11.527 million ty(-1) of sand (8.764 million ty(-1) of in-stream sand and 2.763 million ty(-1) of floodplain sand) is being mined from the midland and lowland reaches of these rivers for construction of buildings and other infrastructural facilities in Kochi city and its satellite townships. Environmental Impact Assessment (EIA) carried out as a part of this investigation shows that the activities associated with mining and processing of sands have not only affected the health of the river ecosystems but also degraded its overbank areas to a large extent. Considering the degree of degradation caused by sand mining from these rivers, no mining scenario may be opted in the deeper zones of the river channels. Also, a set of suggestions are made for the overall improvement of the rivers and its
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Sreebha, Sreedharan; Padmalal, Damodaran
2011-01-01
In the past few decades, the demand for construction grade sand is increasing in many parts of the world due to rapid economic development and subsequent growth of building activities. This, in many of the occasions, has resulted in indiscriminate mining of sand from instream and floodplain areas leading to severe damages to the river basin environment. The case is rather alarming in the small catchment rivers like those draining the southwestern coast of India due to limited sand resources in their alluvial reaches. Moreover, lack of adequate information on the environmental impact of river sand mining is a major lacuna challenging regulatory efforts in many developing countries. Therefore, a scientific assessment is a pre-requisite in formulating management strategies in the sand mining-hit areas. In this context, a study has been made as a case to address the environmental impact of sand mining from the instream and floodplain areas of three important rivers in the southwestern coast of India namely the Chalakudy, Periyar and Muvattupuzha rivers, whose lowlands host one of the fast developing urban-cum-industrial centre, the Kochi city. The study reveals that an amount of 11.527 million ty-1 of sand (8.764 million ty-1 of instream sand and 2.763 million ty-1 of floodplain sand) is being mined from the midland and lowland reaches of these rivers for construction of buildings and other infrastructural facilities in Kochi city and its satellite townships. Environmental Impact Assessment (EIA) carried out as a part of this investigation shows that the activities associated with mining and processing of sands have not only affected the health of the river ecosystems but also degraded its overbank areas to a large extent. Considering the degree of degradation caused by sand mining from these rivers, no mining scenario may be opted in the deeper zones of the river channels. Also, a set of suggestions are made for the overall improvement of the rivers and its
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Schenk, E.R.; Hupp, C.R.
2009-01-01
Many rivers and streams of the Mid-Atlantic Region, United States (U.S.) have been altered by postcolonial floodplain sedimentation (legacy sediment) associated with numerous milldams. Little Conestoga Creek, Pennsylvania, a tributary to the Susquehanna River and the Chesapeake Bay, is one of these streams. Floodplain sedimentation rates, bank erosion rates, and channel morphology were measured annually during 2004-2007 at five sites along a 28-km length of Little Conestoga Creek with nine colonial era milldams (one dam was still in place in 2007). This study was part of a larger cooperative effort to quantify floodplain sedimentation, bank erosion, and channel morphology in a high sediment yielding region of the Chesapeake Bay watershed. Data from the five sites were used to estimate the annual volume and mass of sediment stored on the floodplain and eroded from the banks for 14 segments along the 28-km length of creek. A bank and floodplain reach based sediment budget (sediment budget) was constructed for the 28 km by summing the net volume of sediment deposited and eroded from each segment. Mean floodplain sedimentation rates for Little Conestoga Creek were variable, with erosion at one upstream site (-5 mm/year) to deposition at the other four sites (highest = 11 mm/year) despite over a meter of floodplain aggradation from postcolonial sedimentation. Mean bank erosion rates range between 29 and 163 mm/year among the five sites. Bank height increased 1 m for every 10.6 m of channel width, from upstream to downstream (R2 = 0.79, p channel and the floodplain. Floodplain sedimentation and bank erosion rates also appear to be affected by the proximity of the segments to one existing milldam, which promotes deposition upstream and scouring downstream. The floodplain and bank along the 28-km reach produced a net mean sediment loss of 5,634 Mg/year for 2004-2007, indicating that bank erosion was exceeding floodplain sedimentation. In particular, the three segments
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Estrany, Joan; Martinez-Carreras, Nuria
2013-04-01
Tracers have been acknowledged as a useful tool to identify sediment sources, based upon a variety of techniques and chemical and physical sediment properties. Sediment fingerprinting supports the notion that changes in sedimentation rates are not just related to increased/reduced erosion and transport in the same areas, but also to the establishment of different pathways increasing sediment connectivity. The Na Borges is a Mediterranean lowland agricultural river basin (319 km2) where traditional soil and water conservation practices have been applied over millennia to provide effective protection of cultivated land. During the twentieth century, industrialisation and pressure from tourism activities have increased urbanised surfaces, which have impacts on the processes that control streamflow. Within this context, source material sampling was focused in Na Borges on obtaining representative samples from potential sediment sources (comprised topsoil; i.e., 0-2 cm) susceptible to mobilisation by water and subsequent routing to the river channel network, while those representing channel bank sources were collected from actively eroding channel margins and ditches. Samples of road dust and of solids from sewage treatment plants were also collected. During two hydrological years (2004-2006), representative suspended sediment samples for use in source fingerprinting studies were collected at four flow gauging stations and at eight secondary sampling points using time-integrating sampling samplers. Likewise, representative bed-channel sediment samples were obtained using the resuspension approach at eight sampling points in the main stem of the Na Borges River. These deposits represent the fine sediment temporarily stored in the bed-channel and were also used for tracing source contributions. A total of 102 individual time-integrated sediment samples, 40 bulk samples and 48 bed-sediment samples were collected. Upon return to the laboratory, source material samples were
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Large thermo-erosional tunnel for a river in northeast Greenland
Docherty, Catherine L.; Hannah, David M.; Riis, Tenna; Rosenhøj Leth, Simon; Milner, Alexander M.
2017-12-01
Thermo-erosional river bank undercutting is caused by the combined action of thermal and mechanical erosion of the permafrost by Arctic rivers whilst the overlying sediment withstands collapse temporarily. Here, we report the discovery of a large thermo-erosional tunnel that formed in the banks of a meltwater-fed stream in northeast Greenland in summer 2015. The tunnel was observed over eight days (14-22 July), during which period the tunnel remained open but bank-side slumping increased. Stream solute load increased immediately downstream and remained high 800 m from the tunnel. Whilst this field observation was opportunistic and information somewhat limited, our study provides a rare insight into an extreme event impacting permafrost, local geomorphology and stream habitat. With accelerated climate change in Arctic regions, increased permafrost degradation and warmer stream water temperature are predicted thereby enhancing potential for thermo-erosional niche development and associated stream bank slumping. This change could have significant implications for stream physicochemical habitat and, in turn, stream benthic communities, through changes in aquatic habitat conditions.
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Hydrogeological properties of bank storage area in Changwon city, Korea
Hamm, S.-Y.; Kim, H.-S.; Cheong, J.-Y.; Ryu, S. M.; Kim, M. J.
2003-04-01
Bank filtrated water has been used in developed countries such as United States, France, Germany, Austria, Nederland and so on. In Korea, most of the drinking water is provided from the surface water. However, drinking water acquisition is becoming difficult due to the degradation of surface water quality. In special, the quality of drinking water source is much lower in downstream area than in upstream area. Thus, the use of bank filtrated water is getting attracted by central and local governments in Korea. The bank filtrated water was surveyed in the areas of Yeongsan river, Nakdong river, Geum river and Han river. Up to present, however, the downstream areas of Nakdong river are most suitable places to apply the bank filtration system. This study investigates hydrogeological characteristics of bank-storage area located in Daesan- Myeon, Changwon city, adjacent the downstream of Nakdong river. Changwon city is the capital city of Gyeongsangnam-Do province. Changwon city uses water derived from Nakdong river as municipal water. However, the quantity and quality of the river water are gradually decreased. Thus, Changwon city developed two sites of bank filtration system in Daesan-myeon and Buk-myeon. Pumping rate is 2,000m3/day at present and will be increased to 60,000m3/day in Daesan-myeon site at the end of the first stage of the project. For the study, we conducted pumping tests four times on seven pumping wells (PW1, PW2, PW3, PW4, PW5, PW6, and PW7) and twelve drill holes (BH-2, OW2-OW12) in the area of 370 m x 100 m. Pumping wells PW1 and PW2 were drilled in 1999 by Samjung Engineering Co. and pumping wells PW3, PW4, PW5, PW6 and PW7 were drilled in 2000 by Donga Construction Co. and Daeduk Gongyeong Co. The pumping wells are located at 45-110 meters from Nakdong riverside. The geology of the study area is composed of volcanic rocks (Palryeongsan tuff and Jusasan andesitic rock) and alluvium. Palryeongsan tuff consists of mostly green tuff with partly
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A prototype NDT inspection data bank
International Nuclear Information System (INIS)
Wells, N.S.
1978-01-01
Existing reliability data banks provide information on items with catastrophic failure modes. However, many system components in a nuclear generating station, e.g., the steam generators, have a time-dependent degradation failure mode. Non-destructive tests associated with this failure mode require a different data base to permit predictive estimates of the component service life and performance. A data base suitable for this failure mode is presently being tested at Chalk River Nuclear Laboratories. (author)
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Krohn, M.D.; Milton, N.M.; Segal, D.B.
1983-01-01
Examination of Seasat SAR images of eastern Maryland and Virginia reveals botanical distinctions between vegetated lowland areas and adjacent upland areas. Radar returns from the lowland areas can be either brighter or darker than returns from the upland forests. Scattering models and scatterometer measurements predict an increase of 6 dB in backscatter from vegetation over standing water. This agrees with the 30-digital number (DN) increase observed in the digital Seasat data. The density, morphology, and relative geometry of the lowland vegetation with respect to standing water can all affect the strength of the return L band signal.-from Authors
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A-B-O and Rh affinities between highland and lowland Quechua-speaking Peruvian populations.
Frisancho, A R; Klayman, J E
1975-09-01
According to the accounts of the Spanish chronicles and various historical analyses the Quechua-speaking population inhabiting the Province of Lamas in the Eastern Tropical Lowlands of Peru are descendants of the Chanca Tribes that migrated from the highlands about 500 years ago. The results of the present study indicate that in terms of the A-B-O and Rh systems the lowland Quechua-speaking population from the Province of Lamas and the highland Quechua population from the Province of Junin are more similar to each other than to other tropical tribes. Therefore, it is quite possible that the present lowland Quechua-speaking population from the Province of Lamas may be descendants of Andean populations.
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Change In Course Pattern Of The Teesta River: After Effect Of An Engineering Project
Ashrafi, Z. M.; Shuvo, S. D.; Mahmud, M. S.
2016-12-01
Bangladesh is blessed by rivers that contribute to country's agriculture, landscape development and water supply. Due to nature of the river's flow and morphology, several engineering project have been initiated to enhance its utility, Teesta barrage was one of them. After two decades of its construction in Northern Bangladesh, several study identified major impacts on local ecosystem due to hindrance in water flow. However, how Teesta River evolved in last 25 years after the barrage construction, has not been quantified yet. This study quantifies the downstream evolution of Teesta River in after-construction period (1990-2015). Time series earth observation satellite (Landsat) data and geo-spatial techniques have been utilized to understand the changes in course pattern. Besides, sinuosity index has been used to quantify it. Analysis shows that the river is becoming more braided with the rise of numerous `Char' areas (islands); as well as bifurcation of the main channel, creating newer channels increasingly. Statistically significant changes in Sinuosity Index (SI) of the Teesta river has found in post construction period. In some locations SI increased which indicate that the river is becoming more and more winding than straight it used to be around 1990. It is also found that the river is shifting towards the east where the number of human settlement is higher. The rate of shifting has accelerated during the 2000s. There are places where the course has moved about 3 kilometers from its earlier course. Therefore, higher number of human settlements are in threat of river bank erosion in recent years. River bank management should be developed considering the pattern of course change so that rural settlement can save from destructive river bank erosion.
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Lowland tapir distribution and habitat loss in South America
Directory of Open Access Journals (Sweden)
Jose Luis Passos Cordeiro
2016-09-01
Full Text Available The development of species distribution models (SDMs can help conservation efforts by generating potential distributions and identifying areas of high environmental suitability for protection. Our study presents a distribution and habitat map for lowland tapir in South America. We also describe the potential habitat suitability of various geographical regions and habitat loss, inside and outside of protected areas network. Two different SDM approaches, MAXENT and ENFA, produced relative different Habitat Suitability Maps for the lowland tapir. While MAXENT was efficient at identifying areas as suitable or unsuitable, it was less efficient (when compared to the results by ENFA at identifying the gradient of habitat suitability. MAXENT is a more multifaceted technique that establishes more complex relationships between dependent and independent variables. Our results demonstrate that for at least one species, the lowland tapir, the use of a simple consensual approach (average of ENFA and MAXENT models outputs better reflected its current distribution patterns. The Brazilian ecoregions have the highest habitat loss for the tapir. Cerrado and Atlantic Forest account for nearly half (48.19% of the total area lost. The Amazon region contains the largest area under protection, and the most extensive remaining habitat for the tapir, but also showed high levels of habitat loss outside protected areas, which increases the importance of support for proper management.
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Lowland tapir distribution and habitat loss in South America.
Cordeiro, Jose Luis Passos; Fragoso, José M V; Crawshaw, Danielle; Oliveira, Luiz Flamarion B
2016-01-01
The development of species distribution models (SDMs) can help conservation efforts by generating potential distributions and identifying areas of high environmental suitability for protection. Our study presents a distribution and habitat map for lowland tapir in South America. We also describe the potential habitat suitability of various geographical regions and habitat loss, inside and outside of protected areas network. Two different SDM approaches, MAXENT and ENFA, produced relative different Habitat Suitability Maps for the lowland tapir. While MAXENT was efficient at identifying areas as suitable or unsuitable, it was less efficient (when compared to the results by ENFA) at identifying the gradient of habitat suitability. MAXENT is a more multifaceted technique that establishes more complex relationships between dependent and independent variables. Our results demonstrate that for at least one species, the lowland tapir, the use of a simple consensual approach (average of ENFA and MAXENT models outputs) better reflected its current distribution patterns. The Brazilian ecoregions have the highest habitat loss for the tapir. Cerrado and Atlantic Forest account for nearly half (48.19%) of the total area lost. The Amazon region contains the largest area under protection, and the most extensive remaining habitat for the tapir, but also showed high levels of habitat loss outside protected areas, which increases the importance of support for proper management.
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The similarity of river evolution at the initial stage of channel erosion
Lin, Jiun-Chuan
2014-05-01
The study deals with a comparison study of two types of rocks at the initial stage of channel erosion in Taiwan. It is interesting that channel erosion at different types of rocks shows some similarity. There are two types of rocks: sandstone at Ta-an River, central Taiwan where river channel erosion from the nick point because of earthquake uplifting and mud rock at Tainan, southern Taiwan where rill erosion on a flat surface after artificial engineering. These two situations are both at the beginning stage of channel erosion, there are some similar landform appeared on channels. However the rate of erosion and magnitude of erosion are different. According to the using of photogrammetry method to reconstruct archive imageries and field surveying by total station and 3D scanner at different stages. The incision rate is high both at the Ta-an River and the bank erosion and it is even more obvious at mud rock area because of erodibility of mud rock. The results show that bank erosion and incision both are obvious processes. Bank erosion made channel into meander. The bank erosion cause slope in a asymmetric channel profile. The incision process will start at the site where land is relatively uplifted. This paper demonstrates such similarity and landform characters.
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Morphodynamics of the Final 500 Kilometers of the Mississippi River
Wang, B.; Xu, Y. J.
2017-12-01
Channel dynamics of alluvial rivers in their lower reaches can strongly influence deltaic development. In this study, we analyzed over 6,000 single-beam cross-sectional measurements surveyed in 1992, 2004, and 2013 in the last 500-km reach of the highly engineered Mississippi River, a.k.a. the lowermost Mississippi River (LmMR), starting from the river's Gulf outlet to its avulsion into the Atchafalaya River. We applied Inverse Distance Weighted interpolation to downscale the survey records into 10 x 10 m Digital Elevation Models. We assessed riverbed deformation from bank to bank and quantified georeferenced changes in riverbed sediment volume and mass. We intended to test the hypothesis that the lower reach of a large alluvial river can function as a conduit for sediment transport under the current engineering focus of navigation safety and flood control. Our analysis shows that in the past two decades, nearly 70% of the riverine sand is trapped within the LmMR, and that continuous riverbed aggradation occurred below the Mississippi-Atchafalaya diversion, presenting favorable backwater conditions for avulsion. Backwater effects have mainly controlled riverbed deformation in the LmMR, while flow reduction may have also contributed to channel aggradation in the uppermost and lowermost reaches. The study reveals the considerable complexity of geomorphic responses of a large alluvial river to human interventions, strongly suggesting that future river engineering and management need also to focus on strategies that will improve sediment transport to the downstream river delta.
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The Hindlimb Arterial Vessels in Lowland paca (Cuniculus paca, Linnaeus 1766).
Leal, L M; de Freitas, H M G; Sasahara, T H C; Machado, M R F
2016-04-01
This study aims to describe the origin and distribution of the hindlimb arterial vessels. Five adult lowland pacas (Cuniculus paca) were used. Stained and diluted latex was injected, caudally to the aorta. After fixation in 10% paraformaldehyde for 72 h, we dissected to visualize and identify the vessels. It was found out that the vascularization of the hindlimb in lowland paca derives from the terminal branch of the abdominal aorta. The common iliac artery divides into external iliac and internal iliac. The external iliac artery emits the deep iliac circumflex artery, the pudendal epigastric trunk, the deep femoral artery; the femoral artery originates the saphenous artery, it bifurcates into cranial and caudal saphenous arteries. Immediately after the knee joint, the femoral artery is called popliteal artery, which divides into tibial cranial and tibial caudal arteries at the level of the crural inter-osseous space. The origin and distribution of arteries in the hindlimb of lowland paca resembles that in other wild rodents, as well as in the domestic mammals. © 2014 Blackwell Verlag GmbH.
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Determining Sediment Sources in the Anacostia River Watershed
Devereux, O. H.; Needelman, B. A.; Prestegaard, K. L.; Gellis, A. C.; Ritchie, J. C.
2005-12-01
Suspended sediment is a water-quality problem in the Chesapeake Bay. This project is designed to identify sediment sources in an urban watershed, the Northeast Branch of the Anacostia River (in Washington, D.C. and Maryland - drainage area = 188.5 km2), which delivers sediment directly to the Bay. This watershed spans two physiographic regions - the Piedmont and Coastal Plain. Bank sediment and suspended-sediment deposits were characterized using the following techniques: radionuclide (Cs-137) analysis by gamma ray spectrometry, trace-element analysis by ICP-MS, clay mineralogy by XRD, and particle-size analysis by use of a laser particle-size analyzer. Sampling of bank and suspended sediment was designed to: a) characterize tributary inputs from both Piedmont and Coastal Plain sources, and b) differentiate tributary inputs from bank erosion along the main stem of the Northeast Branch. Thirteen sample sites were chosen that represent tributary source areas of each physiographic region and the main stem where mixing occurs. Surface samples of the banks were compared to overbank deposits from a ten year storm (a proxy for the suspended sediments). Fingerprint components are selected from these data. Cesium-137 concentrations were analyzed for bank and overbank deposits for each physiographic region. No clear differences were seen between the two physiographic regions. Significant differences were observed between upland tributaries and the main stem of the Anacostia River. The average activity of Cs-137 for the tributaries was 5.4 bq/kg and the average for the main stem was 1.1 bq/kg. This suggests that there is significant erosion and storage of sediment in the tributaries. The low activity from Cs-137 in the main stem suggests a lack of storage of sediment along the main stem of the river. For the trace-element data, we focused on elements that showed significant variation among the sites. For the bank sediment, these elements include: Sr, V, Y, Ce, and Nd. For the
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Knigge, Ryan P; Tocheri, Matthew W; Orr, Caley M; Mcnulty, Kieran P
2015-01-01
Western gorillas (Gorilla gorilla) are known to climb significantly more often than eastern gorillas (Gorilla beringei), a behavioral distinction attributable to major differences in their respective habitats (i.e., highland vs. lowland). Genetic evidence suggests that the lineages leading to these taxa began diverging from one another between approximately 1 and 3 million years ago. Thus, gorillas offer a special opportunity to examine the degree to which morphology of recently diverged taxa may be "fine-tuned" to differing ecological requirements. Using three-dimensional (3D) geometric morphometrics, we compared talar morphology in a sample of 87 specimens including western (lowland), mountain (highland), and grauer gorillas (lowland and highland populations). Talar shape was captured with a series of landmarks and semilandmarks superimposed by generalized Procrustes analysis. A between-group principal components analysis of overall talar shape separates gorillas by ecological habitat and by taxon. An analysis of only the trochlea and lateral malleolar facet identifies subtle variations in trochlear shape between western lowland and lowland grauer gorillas, potentially indicative of convergent evolution of arboreal adaptations in the talus. Lastly, talar shape scales differently with centroid size for highland and lowland gorillas, suggesting that ankle morphology may track body-size mediated variation in arboreal behaviors differently depending on ecological setting. Several of the observed shape differences are linked biomechanically to the facilitation of climbing in lowland gorillas and to stability and load-bearing on terrestrial substrates in the highland taxa, providing an important comparative model for studying morphological variation in groups known only from fossils (e.g., early hominins). © 2014 Wiley Periodicals, Inc.
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Columbia River water quality monitoring
International Nuclear Information System (INIS)
Anon.
1983-01-01
Waste water from Hanford activities is discharged at eight points along the Hanford reach of the Columbia River. These discharges consist of backwash water from water intake screens, cooling water, river bank springs, water storage tank overflow, and fish laboratory waste water. Each discharge point is identified in an existing National Pollutant Discharge Elimination System (NPDES) permit issued by the EPA. Effluents from each of these outfalls are routinely monitored and reported by the operating contractors as required by their NPDES permits. Measurements of several Columbia River water quality parameters were conducted routinely during 1982 both upstream and downstream of the Hanford Site to monitor any effects on the river that may be attributable to Hanford discharges and to determine compliance with the Class A designation requirements. The measurements indicated that Hanford operations had a minimal, if any, impact on the quality of the Columbia River water
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Bedrock river erosion measurements and modelling along a river of the Frontal Himalaya
Lave, Jerome; Dubille, Matthieu
2017-04-01
River incision is a key process in mountains denudation and therefore in landscape evolution models. Despite its importance, most incision models for mountain rivers rely on simplified, or quite empirical relations, and generally only consider annual average values for water discharge and sediment flux. In contrast, very few studies consider mechanistic models at the timescale of a flood, and try to bridge the gap between experimental or theoretical approaches and long term river incision studies. In this contribution, we present observations made during 7 monsoon seasons on fluvial bedrock erosion along the Bakeya river across the Frontal Himalaya in Central Nepal. Along its lower gorge, this river incises alternation of indurated sandstone and less resistant claystone, at Holocene rates larger than 10mm/yr. More importantly, its upper drainage mostly drains through non-cohesive conglomerate which allows, in this specific setting, estimating the bedload characteristics and instantaneous fluxes, i.e. a pre-requisite to test mechanistic models of fluvial erosion. During the study period, we monitored and documented the channel bank erosion in order to understand the amplitude of the erosion processes, their occurrence in relation with hydrology, in order to test time-integrated models of erosion. Besides hydrologic monitoring, erosion measurements were threefold: (1) at the scale of the whole monsoon, plucking and block removal by repeated photo surveys of a 400m long channel reach, (2) detailed microtopographic surveys of channel bedrock elevation along a few sandstone bars to document their abrasion, (3) real time measurement of fluvial bedrock wear to document erosion timing using a new erosion sensor. Results indicate that: 1. Erosion is highly dependent on rock resistance, but on average block detachment and removal is a more efficient process than bedrock attrition, and operates at a rate that permit channel banks downcutting to keep pace with Holocene uplift
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Dhivert, E; Grosbois, C; Rodrigues, S; Desmet, M
2015-02-01
Floodplains are often cored to build long-term pollutant trends at the basin scale. To highlight the influences of depositional environments on archiving processes, aggradation rates, archived trace element signals and vertical redistribution processes, two floodplain cores were sampled near in two different environments of the Upper Loire River (France): (i) a river bank ridge and (ii) a paleochannel connected by its downstream end. The base of the river bank core is composed of sandy sediments from the end of the Little Ice Age (late 18th century). This composition corresponds to a proximal floodplain aggradation (sediments that settled in the distal floodplain. In this distal floodplain environment, the aggradation rate depends on the topography and connection degree to the river channel. The temporal dynamics of anthropogenic trace element enrichments recorded in the distal floodplain are initially synchronous and present similar levels. Although the river bank core shows general temporal trends, the paleochannel core has a better resolution for short-time variations of trace element signals. After local water depth regulation began in the early 1930s, differences of connection degree were enhanced between the two cores. Therefore, large trace element signal divergences are recorded across the floodplain. The paleochannel core shows important temporal variations of enrichment levels from the 1930s to the coring date. However, the river bank core has no significant temporal variations of trace element enrichments and lower contamination levels because of a lower deposition of contaminated sediments and a pedogenetic trace elements redistribution. Copyright © 2014 Elsevier B.V. All rights reserved.
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Schnick, Rosalie A.; Morton, John M.; Mochalski, Jeffrey C.; Beall, Jonathan T.
1982-01-01
Extensive information is provided on techniques that can reduce or eliminate the negative impact of man's activities (particularly those related to navigation) on large river systems, with special reference to the Upper Mississippi River. These techniques should help resource managers who are concerned with such river systems to establish sound environmental programs. Discussion of each technique or group of techniques include (1) situation to be mitigated or enhanced; (2) description of technique; (3) impacts on the environment; (4) costs; and (5) evaluation for use on the Upper Mississippi River Systems. The techniques are divided into four primary categories: Bank Stabilization Techniques, Dredging and Disposal of Dredged Material, Fishery Management Techniques, and Wildlife Management Techniques. Because techniques have been grouped by function, rather than by structure, some structures are discussed in several contexts. For example, gabions are discussed for use in revetments, river training structures, and breakwaters. The measures covered under Bank Stabilization Techniques include the use of riprap revetments, other revetments, bulkheads, river training structures, breakwater structures, chemical soil stabilizers, erosion-control mattings, and filter fabrics; the planting of vegetation; the creation of islands; the creation of berms or enrichment of beaches; and the control of water level and boat traffic. The discussions of Dredging and the Disposal of Dredged Material consider dredges, dredging methods, and disposal of dredged material. The following subjects are considered under Fishery Management Techniques: fish attractors; spawning structures; nursery ponds, coves, and marshes; fish screens and barriers; fish passage; water control structures; management of water levels and flows; wing dam modification; side channel modification; aeration techniques; control of nuisance aquatic plants; and manipulated of fish populations. Wildlife Management
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Modification of meander migration by bank failures
Motta, D.; Langendoen, E. J.; Abad, J. D.; García, M. H.
2014-05-01
Meander migration and planform evolution depend on the resistance to erosion of the floodplain materials. To date, research to quantify meandering river adjustment has largely focused on resistance to erosion properties that vary horizontally. This paper evaluates the combined effect of horizontal and vertical floodplain material heterogeneity on meander migration by simulating fluvial erosion and cantilever and planar bank mass failure processes responsible for bank retreat. The impact of stream bank failures on meander migration is conceptualized in our RVR Meander model through a bank armoring factor associated with the dynamics of slump blocks produced by cantilever and planar failures. Simulation periods smaller than the time to cutoff are considered, such that all planform complexity is caused by bank erosion processes and floodplain heterogeneity and not by cutoff dynamics. Cantilever failure continuously affects meander migration, because it is primarily controlled by the fluvial erosion at the bank toe. Hence, it impacts migration rates and meander shapes through the horizontal and vertical distribution of erodibility of floodplain materials. Planar failures are more episodic. However, in floodplain areas characterized by less cohesive materials, they can affect meander evolution in a sustained way and produce preferential migration patterns. Model results show that besides the hydrodynamics, bed morphology and horizontal floodplain heterogeneity, floodplain stratigraphy can significantly affect meander evolution, both in terms of migration rates and planform shapes. Specifically, downstream meander migration can either increase or decrease with respect to the case of a homogeneous floodplain; lateral migration generally decreases as result of bank protection due to slump blocks; and the effect on bend skewness depends on the location and volumes of failed bank material caused by cantilever and planar failures along the bends, with possible achievement of
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Directory of Open Access Journals (Sweden)
Omar Stalin Landázuri Paredes
Full Text Available Terrestrial vertebrate frugivores constitute one of the major guilds in tropical forests. Previous studies show that the meso-scale distribution of this group is only weakly explained by variables such as altitude and tree basal area in lowland Amazon forests. For the first time we test whether seasonally limiting resources (water and fallen fruit affect the dry season distribution in 25 species of terrestrial vertebrates. To examine the effects of the spatial availability of fruit and water on terrestrial vertebrates we used a standardized, regularly spaced arrangement of camera-traps within 25km2 of lowland Amazon forest. Generalized linear models (GLMs were then used to examine the influence of four variables (altitude, distance to large rivers, distance to nearest water, and presence vs absence of fruits on the number of photos on five functional groups (all frugivores, small, medium, large and very large frugivores and on seven of the most abundant frugivore species (Cuniculus paca, Dasyprocta leporina, Mazama americana, Mazama nemorivaga, Myoprocta acouchy, Pecari tajacu and Psophia crepitans. A total of 279 independent photos of 25 species were obtained from 900 camera-trap days. For most species and three functional groups, the variation in the number of photos per camera was significantly but weakly explained by the GLMs (deviance explained ranging from 6.2 to 48.8%. Generally, we found that the presence of water availability was more important than the presence of fallen fruit for the groups and species studied. Medium frugivores, large-bodied frugivores, and two of the more abundant species (C. paca and P. crepitans were recorded more frequently closer to water bodies; while none of the functional groups nor the most abundant species showed any significant relationship with the presence of fallen fruit. Two functional groups and two of the seven most common frugivore species assessed in the GLMs showed significant results with species
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Paredes, Omar Stalin Landázuri; Norris, Darren; Oliveira, Tadeu Gomes de; Michalski, Fernanda
2017-01-01
Terrestrial vertebrate frugivores constitute one of the major guilds in tropical forests. Previous studies show that the meso-scale distribution of this group is only weakly explained by variables such as altitude and tree basal area in lowland Amazon forests. For the first time we test whether seasonally limiting resources (water and fallen fruit) affect the dry season distribution in 25 species of terrestrial vertebrates. To examine the effects of the spatial availability of fruit and water on terrestrial vertebrates we used a standardized, regularly spaced arrangement of camera-traps within 25km2 of lowland Amazon forest. Generalized linear models (GLMs) were then used to examine the influence of four variables (altitude, distance to large rivers, distance to nearest water, and presence vs absence of fruits) on the number of photos on five functional groups (all frugivores, small, medium, large and very large frugivores) and on seven of the most abundant frugivore species (Cuniculus paca, Dasyprocta leporina, Mazama americana, Mazama nemorivaga, Myoprocta acouchy, Pecari tajacu and Psophia crepitans). A total of 279 independent photos of 25 species were obtained from 900 camera-trap days. For most species and three functional groups, the variation in the number of photos per camera was significantly but weakly explained by the GLMs (deviance explained ranging from 6.2 to 48.8%). Generally, we found that the presence of water availability was more important than the presence of fallen fruit for the groups and species studied. Medium frugivores, large-bodied frugivores, and two of the more abundant species (C. paca and P. crepitans) were recorded more frequently closer to water bodies; while none of the functional groups nor the most abundant species showed any significant relationship with the presence of fallen fruit. Two functional groups and two of the seven most common frugivore species assessed in the GLMs showed significant results with species
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Directory of Open Access Journals (Sweden)
Michał Nowak
2015-12-01
This suggests that overall changeover of fish assemblage reflects interspecific interactions ongoing in a given stream section and species composition might explain differences observed between various rivers better than the river discharge.
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Floodplain hydrodynamic modelling of the Lower Volta River in Ghana
Directory of Open Access Journals (Sweden)
Frederick Yaw Logah
2017-12-01
Full Text Available The impacts of dam releases from re-operation scenarios of the Akosombo and Kpong hydropower facilities on downstream communities along the Lower Volta River were examined through hydrodynamic modelling using the HEC-RAS hydraulic model. The model was used to simulate surface water elevation along the river reach for specified discharge hydrographs from proposed re-operation dam release scenarios. The morphology of the river and its flood plains together with cross-sectional profiles at selected river sections were mapped and used in the hydrodynamic modelling. In addition, both suspended and bed-load sediment were sampled and analysed to determine the current sediment load of the river and its potential to carry more sediment. The modelling results indicate that large areas downstream of the dam including its flood plains would be inundated if dam releases came close to or exceeded 2300 m3/s. It is therefore recommended to relocate communities along the banks and in the flood plains of the Lower Volta River when dam releases are to exceed 2300 m3/s. Suspended sediment transport was found to be very low in the Lower Volta River and the predominant soil type in the river banks and bed is sandy soil. Thus, the geomorphology of the river can be expected to change considerably with time, particularly for sustained high releases from the Akosombo and Kpong dams. The results obtained from this study form a basis for assessing future sedimentation problems in the Lower Volta River and for underpinning the development of sediment control and management strategies for river basins in Ghana. Keywords: Geomorphology, HEC-RAS model, Dam release, Floodplain, Lower Volta River, Ghana
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Salmonid Gamete Preservation in the Snake River Basin, 2001 Annual Report.
Energy Technology Data Exchange (ETDEWEB)
Armstrong, Robyn; Kucera, Paul
2002-06-01
Steelhead (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytscha) populations in the Northwest are decreasing. Genetic diversity is being lost at an alarming rate. Along with reduced population and genetic variability, the loss of biodiversity means a diminished environmental adaptability. The Nez Perce Tribe (Tribe) strives to ensure availability of genetic samples of the existing male salmonid population by establishing and maintaining a germplasm repository. The sampling strategy, initiated in 1992, has been to collect and preserve male salmon and steelhead genetic diversity across the geographic landscape by sampling within the major river subbasins in the Snake River basin, assuming a metapopulation structure existed historically. Gamete cryopreservation conserves genetic diversity in a germplasm repository, but is not a recovery action for listed fish species. The Tribe was funded in 2001 by the Bonneville Power Administration (BPA) and the U.S. Fish and Wildlife Service Lower Snake River Compensation Plan (LSRCP) to coordinate gene banking of male gametes from Endangered Species Act (ESA) listed steelhead and spring and summer chinook salmon in the Snake River basin. In 2001, a total of 398 viable chinook salmon semen samples from the Lostine River, Catherine Creek, upper Grande Ronde River, Lookingglass Hatchery (Imnaha River stock), Lake Creek, the South Fork Salmon River weir, Johnson Creek, Big Creek, Capehorn Creek, Marsh Creek, Pahsimeroi Hatchery, and Sawtooth Hatchery (upper Salmon River stock) were cryopreserved. Also, 295 samples of male steelhead gametes from Dworshak Hatchery, Fish Creek, Grande Ronde River, Little Sheep Creek, Pahsimeroi Hatchery and Oxbow Hatchery were also cryopreserved. The Grande Ronde chinook salmon captive broodstock program stores 680 cryopreserved samples at the University of Idaho as a long-term archive, half of the total samples. A total of 3,206 cryopreserved samples from Snake River basin steelhead and
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Soil Gas Dynamics and Microbial Activity in the Unsaturated Zone of a Regulated River
Christensen, H.; Ferencz, S. B.; Cardenas, M. B.; Neilson, B. T.; Bennett, P. C.
2017-12-01
Over 60% of the world's rivers are dammed, and are therefore regulated. In some river systems, river regulation is the dominant factor governing fluid exchange and soil gas dynamics in the hyporheic region and overlying unsaturated zone of the river banks. Where this is the case, it is important to understand the effects that an artificially-induced change in river stage can have on the chemical, plant, and microbial components of the unsaturated zone. Daily releases from an upstream dam cause rapid stage fluctuations in the Lower Colorado River east of Austin, Texas. For this study, we utilized an array of water and gas wells along a transect perpendicular to the river to investigate the biogeochemical process occurring in this mixing zone. The gas wells were installed at several depths up to 1.5 meters, and facilitated the continuous monitoring of soil gases as the pulse percolated through the river bank. Water samples collected from the screened wells penetrated to depths below the water table and were analyzed for nutrients, carbon, and major ions. Additionally, two soil cores were taken at different distances from the river and analyzed for soil moisture and grain size. These cores were also analyzed for microbial activity using the total heterotroph count method and the acetylene inhibition technique, a sensitive method of measuring denitrifying activity. The results provide a detailed picture of soil gas flux and biogeochemical processes in the bank environment in a regulated river. Findings indicate that a river pulse that causes a meter-scale change in river stage causes small, centimeter-scale pulses in the water table. We propose that these conditions create an area of elevated microbial respiration at the base of the unsaturated zone that appears to be decoupled from normal diurnal fluctuations. Along the transect, CO2 concentrations increased with increasing depth down to the water table. CO2 concentrations were highest in the time following a pulse
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Schenk, E.R.; Hupp, C.R.
2009-01-01
Many rivers and streams of the Mid-Atlantic Region, United States (U.S.) have been altered by postcolonial floodplain sedimentation (legacy sediment) associated with numerous milldams. Little Conestoga Creek, Pennsylvania, a tributary to the Susquehanna River and the Chesapeake Bay, is one of these streams. Floodplain sedimentation rates, bank erosion rates, and channel morphology were measured annually during 2004-2007 at five sites along a 28-km length of Little Conestoga Creek with nine colonial era milldams (one dam was still in place in 2007). This study was part of a larger cooperative effort to quantify floodplain sedimentation, bank erosion, and channel morphology in a high sediment yielding region of the Chesapeake Bay watershed. Data from the five sites were used to estimate the annual volume and mass of sediment stored on the floodplain and eroded from the banks for 14 segments along the 28-km length of creek. A bank and floodplain reach based sediment budget (sediment budget) was constructed for the 28 km by summing the net volume of sediment deposited and eroded from each segment. Mean floodplain sedimentation rates for Little Conestoga Creek were variable, with erosion at one upstream site (-5 mm/year) to deposition at the other four sites (highest = 11 mm/year) despite over a meter of floodplain aggradation from postcolonial sedimentation. Mean bank erosion rates range between 29 and 163 mm/year among the five sites. Bank height increased 1 m for every 10.6 m of channel width, from upstream to downstream (R2 = 0.79, p scouring downstream. The floodplain and bank along the 28-km reach produced a net mean sediment loss of 5,634 Mg/year for 2004-2007, indicating that bank erosion was exceeding floodplain sedimentation. In particular, the three segments between the existing dam and the confluence with the Conestoga River (32% of the studied reach) account for 97% of the measured net sediment budget. Future research directed at understanding channel
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Radioactive contamination of the Shagan river ecosystem components with artificial radionuclides
International Nuclear Information System (INIS)
Subbotin, S.B.; Lukashenko, S.N.; Larionova, N.V.; Yakovenko, Yu.Yu.
2008-01-01
Full text: The Shagan river is the only surface waterway on the Semipalatinsk Nuclear Test Site territory. It flows along the eastern boundary of the SNTS and is a left-bank tributary of the Irtysh river. The length of the Shagan riverbed is 275 km with an average slope 0.003, which changes considerably from one part of the riverbed to the other. Within the Balapan testing ground the length of the riverbed is about 50 km, and the slope angle is, on average, 0.002. The watershed area of the left-bank part of the testing ground, where testing wells are located, is about 900 km 2 . In 2006 during radio-ecological investigations of the SNTS aquatic environment, scientists determined contamination of the Shagan river with radioactive products of nuclear explosions. The main radioactive pollutant is tritium. Maximal tritium concentration in the river waters (40*10 4 Bq/l) was registered 4.7 km away from the Atomic lake at levels of more than 50 times higher than the maximal permissible level for drinking water. As the distance from the Atomic lake increases, tritium concentration in the Shagan waters considerably decreases, and in the place of its confluence with the Irtysh rivertritium concentration in water becomes 10 Bq/l, which is equal to MPL (maximal permissible level) used for equipment. A complex of scientific investigations including hydrogeological, hydrological and geophysical investigation showed that tritium contamination of the Shagan waters is caused by the discharge of contaminated ground waters from the testing ground Balapan. In 2007 additional investigations of the river ecosystem showed that surface waters of the river in addition to tritium contained 90 Sr, and bottom sedimentations were contaminated with 60 Co, 152 Eu, 154 Eu and 137 Cs. It should be noted that concentration of 90 Sr in water reaches the level comparable with intervention level established by NRB-99 (Radiation Safety Norms) for water and food intake. By the character of tritium and
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Directory of Open Access Journals (Sweden)
Gribov Nikolay N.
2013-12-01
Full Text Available The article is devoted to the research of medieval settlements Kurmysh-4 and Murzitsyy-1, located on the left bank of the Sura river in Nizhny Novgorod oblast. The sites were discovered and surveyed in 2007-2009. These are large unfortified settlements, founded in the border area between the Russian lands and the Bulgar Ulus in the 14th century. According to written sources, the Lower Sura river area belonged to the Nizhny Novgorod princes at the time. The sites reveal a number of urban features, such as a large area, multiethnic population, traces of varied craft and trade activities. The data obtained during the preliminary investigation of these sites make it possible to add new features regarding the specificity of populating the Western borderlands of the Bulgar Ulus in the Golden Horde period.
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Exploring Controls on Sinuousity, Terraces and River Capture in the Upper Dajia River, Taiwan
Belliveau, L. C.; Ouimet, W. B.; Chan, Y. C.; Byrne, T. B.
2015-12-01
Taiwan is one of the most tectonically active regions in the world and is prone to landslides due to steep topography, large earthquakes and frequent typhoons. Landslides often affect and alter the river valleys beneath them, producing knickpoints on longitudinal river profiles, segmenting valleys into mixed bedrock-alluvial rivers and affecting river incision for tens to thousands of years. This study investigates the origin and evolution of complex channel morphologies, terraces and river capture along a 20km stretch of the Upper Da-Jia River in the Heping area of Taiwan. Through GIS analysis and field studies, we explore controls on river channel sinuousity, terrace development and river capture in relation to tectonic and climatic forcing, rock erodibility and landslides. High channel sinuousity is proposed as the result of a coupling between bank erosion and landslides. We discuss three types of landslide-induced meanders and increased sinuousity: (a) depositional-push meanders, (b) failure-zone erosional meanders, and (c) complex-erosional meanders. We also investigate spatial variation in channel morphology (slope, width) and the distribution and heights of river terraces within the Upper Da-Jia watershed associated with periods of widespread valley filling from landslide activity. Examples of river capture provide further evidence of the dynamic interactions between river incision, landslides and associated changes in channel morphology and terrace development within steep rapidly uplift, eroding and evolving mountain belts.
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How Ebola impacts genetics of Western lowland gorilla populations.
Le Gouar, Pascaline J; Vallet, Dominique; David, Laetitia; Bermejo, Magdalena; Gatti, Sylvain; Levréro, Florence; Petit, Eric J; Ménard, Nelly
2009-12-18
Emerging infectious diseases in wildlife are major threats for both human health and biodiversity conservation. Infectious diseases can have serious consequences for the genetic diversity of populations, which could enhance the species' extinction probability. The Ebola epizootic in western and central Africa induced more than 90% mortality in Western lowland gorilla population. Although mortality rates are very high, the impacts of Ebola on genetic diversity of Western lowland gorilla have never been assessed. We carried out long term studies of three populations of Western lowland gorilla in the Republic of the Congo (Odzala-Kokoua National Park, Lossi gorilla sanctuary both affected by Ebola and Lossi's periphery not affected). Using 17 microsatellite loci, we compared genetic diversity and structure of the populations and estimate their effective size before and after Ebola outbreaks. Despite the effective size decline in both populations, we did not detect loss in genetic diversity after the epizootic. We revealed temporal changes in allele frequencies in the smallest population. Immigration and short time elapsed since outbreaks could explain the conservation of genetic diversity after the demographic crash. Temporal changes in allele frequencies could not be explained by genetic drift or random sampling. Immigration from genetically differentiated populations and a non random mortality induced by Ebola, i.e., selective pressure and cost of sociality, are alternative hypotheses. Understanding the influence of Ebola on gorilla genetic dynamics is of paramount importance for human health, primate evolution and conservation biology.
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How Ebola impacts genetics of Western lowland gorilla populations.
Directory of Open Access Journals (Sweden)
Pascaline J Le Gouar
2009-12-01
Full Text Available Emerging infectious diseases in wildlife are major threats for both human health and biodiversity conservation. Infectious diseases can have serious consequences for the genetic diversity of populations, which could enhance the species' extinction probability. The Ebola epizootic in western and central Africa induced more than 90% mortality in Western lowland gorilla population. Although mortality rates are very high, the impacts of Ebola on genetic diversity of Western lowland gorilla have never been assessed.We carried out long term studies of three populations of Western lowland gorilla in the Republic of the Congo (Odzala-Kokoua National Park, Lossi gorilla sanctuary both affected by Ebola and Lossi's periphery not affected. Using 17 microsatellite loci, we compared genetic diversity and structure of the populations and estimate their effective size before and after Ebola outbreaks. Despite the effective size decline in both populations, we did not detect loss in genetic diversity after the epizootic. We revealed temporal changes in allele frequencies in the smallest population.Immigration and short time elapsed since outbreaks could explain the conservation of genetic diversity after the demographic crash. Temporal changes in allele frequencies could not be explained by genetic drift or random sampling. Immigration from genetically differentiated populations and a non random mortality induced by Ebola, i.e., selective pressure and cost of sociality, are alternative hypotheses. Understanding the influence of Ebola on gorilla genetic dynamics is of paramount importance for human health, primate evolution and conservation biology.
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Can lowland dry forests represent a refuge from avian malaria for native Hawaiian birds?
Tucker-Mohl, Katherine; Hart, Patrick; Atkinson, Carter T.
2010-01-01
Hawaii's native birds have become increasingly threatened over the past century. Introduced mosquito borne diseases such as avian malaria may be responsible for the near absence of endemic Hawaiian forest birds in low-elevation habitats. The recent recognition that some native Hawaiian forest birds may be repopulating moist lowland habitats as a result of evolved resistance to this disease has increased the conservation value of these areas. Here, we investigate whether remnant low elevation dry forests on Hawaii Island provide natural 'refuges' from mosquito-transmitted malaria by nature of their low rainfall and absence of suitable natural sources of water for mosquito breeding. Unlike lowland wet forests where high rates of disease transmission may be selecting for disease resistance, lowland dry forests may provide some refuge for native forest birds without natural resistance to malaria. We mistnetted forest birds in two lowland dry forests and tested all native birds by microscopy and serology for avian malaria caused by the Plasmodium relictum parasite. We also conducted surveys for standing water and mosquito larvae. Overall prevalence of infections with Plasmodium relictum in the Hawaii Amakihi Hemignathus virens virens was 15%. Most infected birds had lowlevel parasitemias, suggesting chronic infections. Although avian malaria is present in these lowland dry forest Amakihi populations, infection rates are significantly lower than in wet forest populations at similar elevations. Sources of breeding mosquitoes in these forests appeared to be largely anthropogenic; thus, there is potential to manage dry forests as mosquito-free habitat for Hawaii Amakihi and other Hawaiian forest birds.
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Comparative ocular anatomy of the western lowland gorilla.
Knapp, Stefanie; McCulley, James P; Alvarado, Thomas P; Hogan, R Nick
2007-01-01
To examine the lowland gorilla (Gorilla gorilla gorilla) eye and determine similarities to and differences between the mountain gorilla (Gorilla gorilla beringei) and the human eye. In addition, we compare our findings of G. g. gorilla to previous reports on the eye of this subspecies. A 13-year-old deceased male lowland gorilla and a 34-year-old deceased female lowland gorilla were included in the study. Gross and microscopic examinations of the formalin-fixed right eyeball of each gorilla were carried out. Globe dimensions of G. g. gorilla were similar to G. g. beringei and to humans. The limbal conjunctival epithelium and the choroid were densely pigmented. However, the distribution of the conjunctival pigment ring was different to that of G. g. beringei and the melanocytes of the choroid were unusually round. There were deep crypts in the anterior border layer of the iris, and the epithelium of the pars plana was uniquely irregular. Vertical corneal diameter was observed to be equal or greater than horizontal diameter in G. g. gorilla, which is in contrast to humans and to previous findings for G. g. beringei. Corneal thickness was closer to that of humans than to G. g. beringei. Posterior lens capsule thickness was noticeably greater than that of humans. Although some variation between the ocular anatomy of G. g. gorilla and G. g. beringei does exist, the gross and microscopic findings closely resemble each other in these two subspecies. In addition, the eye of Gorilla appears remarkably similar to the human eye. However, comparison of measurements with those in humans is somewhat limited because formalin-fixation can introduce tissue shrinkage and artifact.
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An interactive modelling tool for understanding hydrological processes in lowland catchments
Brauer, Claudia; Torfs, Paul; Uijlenhoet, Remko
2016-04-01
Recently, we developed the Wageningen Lowland Runoff Simulator (WALRUS), a rainfall-runoff model for catchments with shallow groundwater (Brauer et al., 2014ab). WALRUS explicitly simulates processes which are important in lowland catchments, such as feedbacks between saturated and unsaturated zone and between groundwater and surface water. WALRUS has a simple model structure and few parameters with physical connotations. Some default functions (which can be changed easily for research purposes) are implemented to facilitate application by practitioners and students. The effect of water management on hydrological variables can be simulated explicitly. The model description and applications are published in open access journals (Brauer et al, 2014). The open source code (provided as R package) and manual can be downloaded freely (www.github.com/ClaudiaBrauer/WALRUS). We organised a short course for Dutch water managers and consultants to become acquainted with WALRUS. We are now adapting this course as a stand-alone tutorial suitable for a varied, international audience. In addition, simple models can aid teachers to explain hydrological principles effectively. We used WALRUS to generate examples for simple interactive tools, which we will present at the EGU General Assembly. C.C. Brauer, A.J. Teuling, P.J.J.F. Torfs, R. Uijlenhoet (2014a): The Wageningen Lowland Runoff Simulator (WALRUS): a lumped rainfall-runoff model for catchments with shallow groundwater, Geosci. Model Dev., 7, 2313-2332. C.C. Brauer, P.J.J.F. Torfs, A.J. Teuling, R. Uijlenhoet (2014b): The Wageningen Lowland Runoff Simulator (WALRUS): application to the Hupsel Brook catchment and Cabauw polder, Hydrol. Earth Syst. Sci., 18, 4007-4028.
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Yang, Xiaojun; Damen, Michiel C. J.; van Zuidam, Robert A.
Channel migration in deltaic lowlands tends to be complicated by marine processes and intensified cultural practices. Understanding the ways in which river channels have migrated through time is critical to tackling many geomorphologic and river management problems. Because of large magnitude and rapid rates of change, special surveillance systems are needed to efficiently measure and monitor channel migration. This study presents an application of geographic information technologies for the study of channel migration in the active Yellow River Delta, China. The main source of data was a series of time-sequential Landsat images spanning a period of approximately 19 years. A geographic information system (GIS) was used to support modernized channel position mapping and measurement. The spatio-temporal changes of river banks and channel centerlines were systematically examined, and an attempt was made to relate these computational results with appropriate natural and human processes affecting the delta. This study demonstrates the utility of satellite remote sensing integrated with a GIS in investigating channel migration.
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Methods of Payment to Banks: e-Banking. Comparative Study on Three Banks
Directory of Open Access Journals (Sweden)
Miranda Petronella VLAD
2012-11-01
Full Text Available E-banking website, majority offers the banks. At first it was electronic-banking, Internet-banking followed, followed by mobile-banking service. These services offer the same facilities, Customer Bank just that varies the channel used for communication with the Bank. The services offered by banks through E-banking, approves: compilation of orders; scheduled payments; orders for payment of wages; internal transfers; pay rates on internal or external; currency exchanges; view balances of accounts at any time; information about foreign exchange rates; view and print account statements; the definition of beneficiaries of direct payments by the client.
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Impacts of Climate Change on the Collapse of Lowland Maya Civilization
Douglas, Peter M. J.; Demarest, Arthur A.; Brenner, Mark; Canuto, Marcello A.
2016-06-01
Paleoclimatologists have discovered abundant evidence that droughts coincided with collapse of the Lowland Classic Maya civilization, and some argue that climate change contributed to societal disintegration. Many archaeologists, however, maintain that drought cannot explain the timing or complex nature of societal changes at the end of the Classic Period, between the eighth and eleventh centuries ce. This review presents a compilation of climate proxy data indicating that droughts in the ninth to eleventh century were the most severe and frequent in Maya prehistory. Comparison with recent archaeological evidence, however, indicates an earlier beginning for complex economic and political processes that led to the disintegration of states in the southern region of the Maya lowlands that precedes major droughts. Nonetheless, drought clearly contributed to the unusual severity of the Classic Maya collapse, and helped to inhibit the type of recovery seen in earlier periods of Maya prehistory. In the drier northern Maya Lowlands, a later political collapse at ca. 1000 ce appears to be related to ongoing extreme drought. Future interdisciplinary research should use more refined climatological and archaeological data to examine the relationship between climate and social processes throughout the entirety of Maya prehistory.
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Risk assessment for nuclear processes at the Savannah River Site
International Nuclear Information System (INIS)
Durant, W.S.
1992-01-01
The Savannah River Site, one of the US Department of Energy's nuclear materials processing facilities, has for many years conducted risk-based safety analyses for the nuclear processes conducted at the facilities. This approach has allowed comparisons of risks to established criteria for acceptability. When the risk-based program was begun, it was evident that its success would depend upon having a compilation of data that was site specific. The decision was made to create a data bank of undesirable events that had occurred at the site's nuclear fuel reprocessing facilities. From this modest beginning, five data banks have been created for nuclear fuel reprocessing, waste management, nuclear fuel fabrication, tritium operations, and the Savannah River Technology Center. In addition to the primary purpose of providing a sound basis for risk-based safety analyses, these highly versatile data banks are routinely used for equipment breakdown histories, incident investigations, design studies, project justifications, reliability studies, process problem solving, training, and audits
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ONLINE BANKING IN THE ROMANIAN BANKING SYSTEM
IMOLA DRIGĂ
2014-01-01
In the world of banking, the development of IT has a huge effect on development of more flexible payments methods and more user-friendly banking services. Recently, modern electronic banking services, internet and mobile banking, have rejuvenated banking transactions. Electronic banking over the Internet is one of the newest e-banking services with several benefits both for banks and for customers. The paper aims to provide an overview of online banking services highlighting various aspect...
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Roy, Suvendu; Sahu, Abhay Sankar
2017-07-15
Extension of transport networks supports good accessibility and associated with the development of a region. However, transport lines have fragmented the regional landscape and disturbed the natural interplay between rivers and their floodplains. Spatial analysis using multiple buffers provides information about the potential interaction between road and stream networks and their impact on channel morphology of a small watershed in the Lower Gangetic Plain. Present study is tried to understand the lateral and longitudinal disconnection in headwater stream by rural roads with the integration of geoinformatics and field survey. Significant (p development, delineation of stream corridor, regular monitoring and engineering efficiency for the construction of road and road-stream crossing might be effective in managing river geomorphology and riverine landscape. Copyright © 2017 Elsevier Ltd. All rights reserved.
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12 CFR 619.9140 - Farm Credit bank(s).
2010-01-01
... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Farm Credit bank(s). 619.9140 Section 619.9140 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9140 Farm Credit bank(s). Except as otherwise defined, the term Farm Credit bank(s) includes Farm Credit Banks...
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Nieuwenhuyse, A.
1996-01-01
The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern -
ONLINE BANKING IN THE ROMANIAN BANKING SYSTEM
Directory of Open Access Journals (Sweden)
IMOLA DRIGĂ
2014-12-01
Full Text Available In the world of banking, the development of IT has a huge effect on development of more flexible payments methods and more user-friendly banking services. Recently, modern electronic banking services, internet and mobile banking, have rejuvenated banking transactions. Electronic banking over the Internet is one of the newest e-banking services with several benefits both for banks and for customers. The paper aims to provide an overview of online banking services highlighting various aspects globally as well as in the Romanian banking system. Even if there already are several studies on web banking, this topic still remains a resourceful area for academic research in the next decade.
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The consequences of pleistocene climate change on lowland neotropical vegetation
Energy Technology Data Exchange (ETDEWEB)
De Oliveira, P.E.; Colinvaux, P.A. (Smithsonian Tropical Research Institute, Panama City (Panama))
1994-06-01
Palynological reconstructions indicate that lowland tropical America was subject to intense cooling during the last ice-age. The descent of presently montane taxa into the lowlands of Amazonia and Minas Gerais indicate temperature depressions ranging from 5[degrees]C to 9[degrees]C cooler-than-present. The strengthened incursion of southerly airmasses caused a reassortment of vegetation throughout Amazonia. Presently allopatric species are found to have been sympatric as novel forest assemblages and formed and dissolved. Modest drying, perhaps a 20% reduction in precipitation, accounts for all the records that show a Pleistocene expansion of savanna. No evidence is found to support the fragmentation of Amazonian forests during glacial times, and the hypothesis of forest refuges as an explanation of tropical speciation is rejected on empirical grounds.
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Lim, Y.; Kim, W.
2015-12-01
Meandering rivers are extremely ubiquitous on Earth, yet it is only recently that single-thread experimental channels with low sinuosity have been created. In these recent experiments, as well as in natural rivers, vegetation plays a crucial role in maintaining a meandering pattern by adding cohesion to the bank and inhibiting erosion. The ancient, highly sinuous channels found on Mars are enigmatic because presumably vegetation did not exist on ancient Mars. Under the hypothesis that Martian meandering rivers formed by chemical precipitation on levees and flood plain deposits, we conducted carbonate flume experiments to investigate the formation and evolution of a single-thread meander pattern without vegetation. The flow recirculating in the flume is designed to accelerate chemical reactions - dissolution of limestone using CO2 gas to produce artificial spring water and precipitation of carbonates to increase cohesion- with precise control of water discharge, sediment discharge, and temperature. Preliminary experiments successfully created a single-thread meandering pattern through chemical processes. Carbonate deposits focused along the channel sides improved the bank stability and made them resistant to erosion, which led to a stream confined in a narrow path. The experimental channels showed lateral migration of the bend through cut bank and point bar deposits; intermittent floods created overbank flow and encouraged cut bank erosion, which enhanced lateral migration of the channel, while increase in sediment supply improved lateral point bar deposition, which balanced erosion and deposition rates. This mechanism may be applied to terrestrial single-thread and/or meandering rivers with little to no vegetation or before its introduction to Earth and also provide the link between meandering river records on Mars to changes in Martian surface conditions.
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Public health protection through bank filtration - Kearney Nebraska case study
Esseks, E.; Bellamy, W.; Heinemann, T.; Stocker, K.
2003-04-01
The investigation of Kearney's bank filtration system provides further evidence of this technology's capability to assist in providing public health protection, as it relates to drinking water. The results of hydrogeologic and treatment studies demonstrate the capabilities of the Platte River aquifer materials, in this locale, to remove pathogens and their surrogates. Continual monitoring and evaluations will establish the system’s longevity and continued treatment efficacy. The City of Kearney is located in south central Nebraska. The City owns and operates a public water system that serves approximately 24,889 people. The water system includes 12 wells located on Killgore Island in the Platte River. In 1994, the Nebraska Department of Health and Human Services System (Department) determined that 3 wells in the wellfield serving the City of Kearney were ground water under the direct influence of surface water. This determination was based on results of microscopic particulate analysis (MPA). The City of Kearney undertook the natural bank filtration study to determine whether natural bank filtration was occurring at the site and if the filtration was sufficient to meet pathogen treatment requirements designed to protect public health. A preliminary study was undertaken from June through October 1995. This coincided with the City’s peak pumping time, which may be the time when the influence of the River is greatest on the wellfield wells. Hydrogeologic studies assisted in selecting wells that were at highest risk based on shortest travel times and greatest differential head. Data collected included particle counts, MPAs, turbidity, coliform, centrifugate pellet evaluation (CPE) volumes, pH, conductivity, and temperature. Following analysis of data collected during the preliminary 18-week study the Department granted conditional approval of 2-log credit for removal of Giardia lamblia and 1-log credit for removal of viruses through bank filtration, pending the
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Global Analysis of River Planform Change using the Google Earth Engine
Bryk, A.; Dietrich, W. E.; Gorelick, N.; Sargent, R.; Braudrick, C. A.
2014-12-01
Geomorphologists have historically tracked river dynamics using a combination of maps, aerial photographs, and the stratigraphic record. Although stratigraphic records can extend into deep time, maps and aerial photographs often confine our record of change to sparse measurements over the last ~80 years and in some cases much less time. For the first time Google's Earth Engine (GEE) cloud based platform allows researchers the means to analyze quantitatively the pattern and pace of river channel change over the last 30 years with high temporal resolution across the entire planet. The GEE provides an application programing interface (API) that enables quantitative analysis of various data sets including the entire Landsat L1T archive. This allows change detection for channels wider than about 150 m over 30 years of successive, georeferenced imagery. Qualitatively, it becomes immediately evident that the pace of channel morphodynamics for similar planforms varies by orders of magnitude across the planet and downstream along individual rivers. To quantify these rates of change and to explore their controls we have developed methods for differentiating channels from floodplain along large alluvial rivers. We introduce a new metric of morphodynamics: the ratio of eroded area to channel area per unit time, referred to as "M". We also keep track of depositional areas resulting from channel shifting. To date our quantitative analysis has focused on rivers in the Andean foreland. Our analysis shows channel bank erosion rates, M, varies by orders of magnitude for these rivers, from 0 to ~0.25 yr-1, yet these rivers have essentially identical curvature and sinuosity and are visually indistinguishable. By tracking both bank paths in time, we find that, for some meandering rivers, a significant fraction of new floodplain is produced through outer-bank accretion rather than point bar deposition. This process is perhaps more important in generating floodplain stratigraphy than
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Guo, Yongqiang; Huang, Chun Chang; Zhou, Yali; Pang, Jiangli; Zha, Xiaochun; Fan, Longjiang; Mao, Peini
2018-05-01
Palaeoflood slackwater deposits (SWDs) along the river banks have important implications for the reconstruction of the past hydro-climatic events. Two palaeoflood SWD beds were identified in the Holocene loess-soil sequences on the cliff river banks along the Gold Gorge of the upper Hanjiang River by field investigation and laboratory analysis. They have recorded two palaeoflood events which were dated by optically stimulated luminescence to 3.2-2.8 ka and 2.1-1.8 ka, respectively. The reliability of the ages obtained for the two events are further confirmed by the presence of archaeological remains and good regional pedostratigraphic correlation. The peak discharges of two palaeoflood events at the studied sites were estimated to be 16,560-17,930 m3/s. A correlation with the palaeoflood events identified in the other reaches shows that great floods occurred frequently during the episodes of 3200-2800 and 2000-1700 a BP along the upper Hanjiang River valley during the last 4000 years. These phases of palaeoflood events in central China are well correlated with the climatic variability identified by δ18O record in the stalagmites from the middle Yangtze River Basin and show apparent global linkages. Palaeoflood studies in a watershed scale also imply that strengthened human activities during the Shang dynasty (BCE 1600-1100) and Han dynasty (BCE206-CE265) may have caused accelerated soil erosion along the upper Hanjiang River valley.
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Buffagni, Andrea; Tenchini, Roberta; Cazzola, Marcello; Erba, Stefania; Balestrini, Raffaella; Belfiore, Carlo; Pagnotta, Romano
2016-09-15
We hypothesized that reach-scale, bank and channel modification would impact benthic communities in temporary rivers of Sardinia, when pollution and water abstraction are not relevant. A range of variables were considered, which include both artificial structures/alterations and natural features observed in a stream reach. Multivariate regression trees (MRT) were used to assess the effects of the explanatory variables on invertebrate assemblages and five groups, characterized by different habitat modification and/or features, were recognized. Four node variables determined the splits in the MRT analysis: channel reinforcement, tree-related bank and channel habitats, channel modification and bank modification. Continuity of trees in the river corridor diverged among MRT groups and significant differences among groups include presence of alders, extent of channel shading and substrate diversity. Also, the percentage of in-stream organic substrates, in particular CPOM/Xylal, showed highly significant differences among groups. For practical applications, thresholds for the extent of channel reinforcement (40%) and modification (10%) and for bank alteration (≈30%) were provided, that can be used to guide the implementation of restoration measures. In moderately altered river reaches, a significant extent of tree-related habitats (≈5%) can noticeably mitigate the effects of morphological alteration on aquatic invertebrates. The outcomes highlight the importance of riparian zone management as an opportune, achievable prospect in the restoration of Mediterranean temporary streams. The impact of bank and channel modification on ecological status (sensu WFD) was investigated and the tested benthic metrics, especially those based on abundance data, showed legible differences among MRT groups. Finally, bank and channel modification appears to be a potential threat for the conservation of a few Sardo-Corsican endemic species. The introduction of management criteria that
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Banking system trust, bank trust, and bank loyalty
van Esterik-Plasmeijer, P.; van Raaij, W.F.
2017-01-01
Purpose The purpose of this paper is to test a model of banking system trust as an antecedent of bank trust and bank loyalty. Six determinants of trust and loyalty are included: competence, stability, integrity, customer orientation, transparency, and value congruence. The study provides insights
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Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J. Patrick; Salvador-Blanes, Sébastien; Manière, Louis; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie
2017-02-01
Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are known to degrade downstream environments. Accordingly, there is a need to understand soil erosion dynamics during flood events. Suspended sediment was therefore sampled in the river network and at tile drain outlets during five flood events in a lowland drained catchment in France. Source and sediment fallout radionuclide concentrations (7Be, 210Pbxs) were measured to quantify both the fraction of recently eroded particles transported during flood events and their residence time. Results indicate that the mean fraction of recently eroded sediment, estimated for the entire Louroux catchment, increased from 45 ± 20% to 80 ± 20% between December 2013 and February 2014, and from 65 ± 20% to 80 ± 20% in January 2016. These results demonstrate an initial flush of sediment previously accumulated in the river channel before the increasing supply of sediment recently eroded from the hillslopes during subsequent events. This research highlights the utility of coupling continuous river monitoring and fallout radionuclide measurements to increase our understanding of sediment dynamics and improve the management of soil and water resources in agricultural catchments.
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Mass movements of lowland areas in long range TLS and ALS monitoring
Tyszkowski, Sebastian
2015-04-01
The development of geodynamic processes in lowland areas remains an interesting issue for geomorphology and geology as well as civil engineering. Landslides, slumps, slope washes, rills and gully erosion are considered both geomorphological processes and natural hazards. In order to know precisely their origin and development, it is crucial to determine the rate and direction of their change. Previously such studies used geodesy and photogrammetry but the recent progress in the LiDAR technology allows collecting the data in a wider range and comparable or higher precision than most of geodetic methods. Airborne Laser Scanning (ALS) is also a good tool, but high costs and low frequency of the surveys make it difficult to trace the dynamics of the studied phenomena and processes. Nevertheless, this method enables gathering information from large areas, which is useful for the preliminary identification of the research issues and nomination of the areas for subsequent case studies. It is, however, more common to use Terrestrial Laser Scanning (TLS) for the detailed studies of morphology and its change. This method provides mobility and high accuracy, and enables frequent measurements. The problem in the analysis of many geoprocesses lies in the limited range of this method. This study concerns the Lower Vistula Valley located in northern Poland. It presents the results of measurements of landslides located in the escarpment zone of a big river valley. The object of the studies is mass movements developing within the quaternary deposits on the valley slopes. These processes were monitored in previous years with the traditional survey methods, mainly based on the geodesy field observations (benchmark) as well as the analyses of historical maps and archives. The ALS method used during the study enabled gathering the data on the valley with the density of 8 points per sq m, which provided the background for the consecutive monitoring study. In the surveys a terrestrial
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Caitcheon, Gary G.; Olley, Jon M.; Pantus, Francis; Hancock, Gary; Leslie, Christopher
2012-05-01
The tropics of northern Australia have received relatively little attention with regard to the impact of soil erosion on the many large river systems that are an important part of Australia's water resource, especially given the high potential for erosion when long dry seasons are followed by intense wet season rain. Here we use 137Cs concentrations to determine the erosion processes supplying sediment to two major northern Australian Rivers; the Daly River (Northern Territory), and the Mitchell River (Queensland). We also present data from five sediment samples collected from a 100 km reach of the Cloncurry River, a major tributary of the Flinders River (Queensland). Concentrations of 137Cs in the surface soil and subsurface (channel banks and gully) samples were used to derive 'best fit' probability density functions describing their distributions. These modelled distributions are then used to estimate the relative contribution of these two components to the river sediments. Our results are consistent with channel and gully erosion being the dominant source of sediment, with more than 90% of sediment transported along the main stem of these rivers originating from subsoil. We summarize the findings of similar studies on tropical Australian rivers and conclude that the primary source of sediment delivered to these systems is gully and channel bank erosion. Previously, as a result of catchment scale modelling, sheet-wash and rill erosion was considered to be the major sediment source in these rivers. Identifying the relative importance of sediment sources, as shown in this paper, will provide valuable information for land management planning in the region. This study also reinforces the importance of testing model predictions before they are used to target investment in remedial action.
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Relationship Banking in Labor Bank
三村, 聡
2012-01-01
As Labor bank is seemed as business partner of labor union, it contributes each community activities. For example, Labor bank helps retired employee, laborer and inhabitants. In addition, after the amendment of Money Lending Business Act of 2010, labor bank became clearly community based bank by consulting for heavily-indebted people and their education. This paper analyzes the new role of labor bank such as community contribution and enhancing financing service by collecting of the opinion o...
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Matthewman, Sasha; Mullen, Molly; Patuwai, Tamati
2015-01-01
On 27 February 2013, Mad Ave staged "The River Talks," a collation of linked performances in and on the banks of the Omaru River in Glen Innes, Auckland, New Zealand. The event brought together artistic and discursive works that challenged a view of this local river as always and forever degraded. An example of committed ecological…
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STS-56 Earth observation of Perth in Western Australia
1993-01-01
STS-56 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, is probably the best view of Perth in Western Australia. (For orientation purposes, note that the coastline runs north and south). The major feature on the coast is the large estuary of the Swan River. The large port city of Perth is situated on the north bank and the smaller city of Freemantle on the south bank by the sea. Smaller seaside towns trail off north and south of this center of urban life. Inland lies a prominent escarpment, more than 600 feet high, seen running down the middle of the view and dividing the lighter-colored coastal lowlands from the highlands where dark-colored tree savanna and desert scrub dominates the land. The Moore River can be seen entering the sea at the top of the frame. Rottnest Island is visible in the sea and Garden Island near bottom edge of the frame. Perth is the largest economic center in Western Australia. It receives natural gas from an offshore field hundreds of miles
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Directory of Open Access Journals (Sweden)
T.B. Khatri
2010-12-01
Full Text Available The breach of the eastern embankment of the Koshi Barrage at Paschim Kusaha Village of Sunsari District on 18 August 2008, created havoc for wildlife and their habitats, as well as people’s livelihood and welfare. The Koshi River flowed through the breach for five months. Following the breach, a population assessment survey of the Endangered Ganges River Dolphin Platanista gangetica gangetica was made between March and November 2009 in the Koshi River main channel starting from Chatara to 2km south of Koshi Barrage to ascertain their status. A direct count survey was conducted by two teams of researchers simultaneously searching for animals by boat from Chatara to the Koshi Barrage including the Triyuga River and on foot along the river banks downstream of Koshi Barrage and along the Mariya River. Standard protocols were followed to record the number of sighted dolphins. A total of 11 dolphins were recorded in the entire 49-km river stretch with an encounter rate of 0.23 dolphins per km. The current result showed an encouraging population of dolphins in the Koshi Tappu Wildlife Reserve and its buffer zone but the threats for conservation still remain challenging. Close monitoring of dolphins and their habitats involving local communities are required for long term conservation of the river dolphins in Nepal. The breach of the eastern embankment of the Koshi Barrage at Paschim Kusaha Village of Sunsari District on 18 August 2008, created havoc for wildlife and their habitats, as well as people’s livelihood and welfare. The Koshi River flowed through the breach for five months. Following the breach, a population assessment survey of the Endangered Ganges River Dolphin Platanista gangetica gangetica was made between March and November 2009 in the Koshi River main channel starting from Chatara to 2km south of Koshi Barrage to ascertain their status. A direct count survey was conducted by two teams of researchers simultaneously searching for
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Bank, Banking System, Macroprudential Supervision, Stability of Banking System
Directory of Open Access Journals (Sweden)
Tetiana Vasilyeva
2016-10-01
Full Text Available Intensification of financial development during last decade causes transformation of banking sector functioning. In particular, among the most significant changes over this period should be noted the next ones: convergence of financial market segments and appearance of cross-sector financial products, an increase of prevailing of financial sector in comparison with real economy and level of their interdependent, an intensification of crisis processes in financial and especially banking sector and a significant increase of the scale of the crisis consequences etc. thus, in such vulnerable conditions it is become very urgent to identify the relevant factors that can influence on the stability of banking sector, because its maintenance seems to be one of the most important preconditions of the stability of the national economy as a whole. Purpose of the article is to analyze key performance indicators of the Ukrainian banking system, clarify its main problems, identify relevant factors of the stability of the Ukrainian banking system and the character of their influence on the dependent variable. Realization of the mentioned above tasks was ensured by regression analysis (OLS regression. Analysis of key indicators that characterize current situation in the Ukrainian banking system found out the existence of numerous endogenous and exogenous problems, which, in turn, cause worsening most of analyzed indicators during 2013-2015. Unfavorable situation in Ukrainian banking system determined the necessity of identification of relevant factors of banking system stability to avoid transmission of financial shocks. According to the results of regression analysis on the stability of banking sector positively influence such factors as increase of interest margin to gross income ratio, reserves to assets ratio, number of branches, ratio of non-performing loans to total loans. Meanwhile, negative impact on stability of banking system has an increase of liquid
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Bertelkamp, C; van der Hoek, J P; Schoutteten, K; Hulpiau, L; Vanhaecke, L; Vanden Bussche, J; Cabo, A J; Callewaert, C; Boon, N; Löwenberg, J; Singhal, N; Verliefde, A R D
2016-02-01
This study investigated organic micropollutant (OMP) biodegradation rates in laboratory-scale soil columns simulating river bank filtration (RBF) processes. The dosed OMP mixture consisted of 11 pharmaceuticals, 6 herbicides, 2 insecticides and 1 solvent. Columns were filled with soil from a RBF site and were fed with four different organic carbon fractions (hydrophilic, hydrophobic, transphilic and river water organic matter (RWOM)). Additionally, the effect of a short-term OMP/dissolved organic carbon (DOC) shock-load (e.g. quadrupling the OMP concentrations and doubling the DOC concentration) on OMP biodegradation rates was investigated to assess the resilience of RBF systems. The results obtained in this study imply that - in contrast to what is observed for managed aquifer recharge systems operating on wastewater effluent - OMP biodegradation rates are not affected by the type of organic carbon fraction fed to the soil column, in case of stable operation. No effect of a short-term DOC shock-load on OMP biodegradation rates between the different organic carbon fractions was observed. This means that the RBF site simulated in this study is resilient towards transient higher DOC concentrations in the river water. However, a temporary OMP shock-load affected OMP biodegradation rates observed for the columns fed with the river water organic matter (RWOM) and the hydrophilic fraction of the river water organic matter. These different biodegradation rates did not correlate with any of the parameters investigated in this study (cellular adenosine triphosphate (cATP), DOC removal, specific ultraviolet absorbance (SUVA), richness/evenness of the soil microbial population or OMP category (hydrophobicity/charge). Copyright © 2015 Elsevier Ltd. All rights reserved.
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Burton, Bethany L.; Powers, Michael H.; Ball, Lyndsay B.
2014-01-01
In July 2011, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, completed a geophysical survey using electrical resistivity along an approximately 6-mile reach of the lower American River in Sacramento, California, to map near-surface lithological variations. This survey is a part of a manifold and comprehensive study of river-flow dynamics and geologic boundary-property knowledge necessary to estimate scour potential and levee erosion risk. Data were acquired on the left (south or west) bank between river mile 5 and 10.7 as well as a short section on the right bank from river mile 5.4 to 6. Thirteen direct-current resistivity profiles and approximately 8.3 miles of capacitively coupled resisistivity data were acquired along accessible areas of the floodplain between the levee and river bank. Capacitively coupled resistivity was used as a reconnaissance tool, because it allowed for greater spatial coverage of data but with lower resolution and depth of investigation than the DC resistivity method. The study area contains Pleistocene-age alluvial deposits, dominated by gravels, sands, silts, and clays, that vary in both lateral extent and depth. Several generations of lithologic logs were used to help interpret resistivity variations observed in the resistivity models.
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Geochemical and hydrodynamic phosphorus retention mechanisms in lowland catchments
van der Grift, B.
2017-01-01
The release of phosphorus (P) to surface water from heavily fertilised agricultural fields is of major importance for surface water quality. The research reported in this thesis examined the role of geochemical and hydrodynamic processes controlling P speciation and transport in lowland catchments
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Maximal exercise and muscle oxygen extraction in acclimatizing lowlanders and high altitude natives
DEFF Research Database (Denmark)
Lundby, Carsten; Sander, Mikael; van Hall, Gerrit
2006-01-01
, and is the focus of the present study. We have studied six lowlanders during maximal exercise at sea level (SL) and with acute (AH) exposure to 4,100 m altitude, and again after 2 (W2) and 8 weeks (W8) of altitude sojourn, where also eight high altitude native (Nat) Aymaras were studied. Fractional arterial muscle...... O(2) extraction at maximal exercise was 90.0+/-1.0% in the Danish lowlanders at sea level, and remained close to this value in all situations. In contrast to this, fractional arterial O(2) extraction was 83.2+/-2.8% in the high altitude natives, and did not change with the induction of normoxia....... The capillary oxygen conductance of the lower extremity, a measure of oxygen diffusing capacity, was decreased in the Danish lowlanders after 8 weeks of acclimatization, but was still higher than the value obtained from the high altitude natives. The values were (in ml min(-1) mmHg(-1)) 55.2+/-3.7 (SL), 48...
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International Nuclear Information System (INIS)
Miguel, Eduardo de; Charlesworth, Susanne; Ordonez, Almudena; Seijas, Eduardo
2005-01-01
The geochemical fingerprint of sediment retrieved from the banks of the River Manzanares as it passes through the City of Madrid is presented here. The river collects the effluent water from several Waste Water Treatment (WWT) plants in and around the city, such that, at low flows, up to 60% of the flow has been treated. A total of 18 bank-sediment cores were collected along the course of the river, down to its confluence with the Jarama river, to the south-east of Madrid. Trace and major elements in each sample were extracted following a double protocol: (a) 'Total' digestion with HNO 3 , HClO 4 and HF; (b) 'Weak' digestion with sodium acetate buffered to pH=5 with acetic acid, under constant stirring. The digests thus obtained were subsequently analysed by ICP-AES, except for Hg which was extracted with aqua regia and sodium chloride-hydroxylamine sulfate, and analysed by Cold Vapour-AAS. X-ray diffraction was additionally employed to determine the mineralogical composition of the samples. Uni- and multivariate analyses of the chemical data reveal the influence of Madrid on the geochemistry of Manzanares' sediments, clearly manifested by a marked increase in the concentration of typically 'urban' elements Ag, Cr, Cu, Pb and Zn, downstream of the intersection of the river with the city's perimeter. The highest concentrations of these elements appear to be associated with illegal or accidental dumping of waste materials, and with the uncontrolled incorporation of untreated urban runoff to the river. The natural matrix of the sediment is characterised by fairly constant concentrations of Ce, La and Y, whereas changes in the lithology intersected by the river cause corresponding variations in Ca-Mg and Al-Na contents. In the final stretch of the river, the presence of carbonate materials seems to exert a strong geochemical control on the amount of Zn and, to a lesser extent, Cu immobilised in the sediments. This fact suggests that a variable but significant
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Directory of Open Access Journals (Sweden)
Murti Lestari
2010-05-01
Full Text Available This study analyzes the responses of performances of BankMandiri, Bank Danamon, and Bank Permata to merger strategy.This paper harnesses the quantitative approach with structuralbreak analysis method and impulse response function. Theplausible findings indicate that the merger of Bank Permataproduces a better performance response in comparison to theconsolidation of Bank Mandiri and the merger of Bank Danamon.The merger of Bank Permata does not result in performanceshocks, and the structural break does not prevail either. On theother hand, the consolidation of Bank Mandiri and the mergerof Bank Danamon result in structural breaks, particularly in thespread performance. In order to return to the stable position, themergers of Bank Mandiri and Bank Danamon require a longertime than does the merger of Bank Permata. This researchindicates that for large banks, the mergers and acquisitions(retaining one existing bank will deliver a better performanceresponse than will the consolidations (no existing bank. Keywords: impulse response function; merger; structural break
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River-Based Experiential Learning: the Bear River Fellows Program
Rosenberg, D. E.; Shirley, B.; Roark, M. F.
2012-12-01
The Department of Civil and Environmental Engineering, Outdoor Recreation, and Parks and Recreation programs at Utah State University (USU) have partnered to offer a new, unique river-based experiential learning opportunity for undergraduates called the Bear River Fellows Program. The program allows incoming freshmen Fellows to experience a river first hand during a 5-day/4-night river trip on the nearby Bear River two weeks before the start of their first Fall semester. As part of the program, Fellows will navigate the Bear River in canoes, camp along the banks, interact with local water and environmental managers, collect channel cross section, stream flow, vegetation cover, and topological complexity data, meet other incoming freshmen, interact with faculty and graduate students, develop boating and leadership skills, problem solve, and participate as full members of the trip team. Subsequently, Fellows will get paid as undergraduate researchers during their Fall and Spring Freshman semesters to analyze, synthesize, and present the field data they collect. The program is a collaborative effort between two USU academic units and the (non-academic) division of Student Services and supports a larger National Science Foundation funded environmental modelling and management project for the lower Bear River, Utah watershed. We have advertised the program via Facebook and emails to incoming USU freshmen, received 35 applications (60% women), and accepted 5 Fellows into the program (3 female and 2 male). The river trip departs August 14, 2012. The poster will overview the Bear River Fellows Program and present qualitative and preliminary outcomes emerging from the trip and Fellows' work through the Fall semester with the field data they collect. We will also undertake more rigorous and longer longitudinal quantitative evaluation of Program outcomes (for example, in problem-solving and leadership) both in Spring 2013 and in subsequent 2013 and 2014 offerings of the
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Long-term morphological developments of river channels separated by a longitudinal training wall
Le, T.B.; Crosato, A.; Uijttewaal, W.S.J.
2018-01-01
Rivers have been trained for centuries by channel narrowing and straightening. This caused important damages to their ecosystems, particularly around the bank areas. We analyse here the possibility to train rivers in a new way by subdividing their channel in main and ecological channel with a
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Plan form changes of Gumara River channel over 50 years (Upper Blue Nile basin, Ethiopia)
Abate, Mengiste; Nyssen, Jan; Mehari, Michael
2014-05-01
Channel plan form changes were investigated along the 65 km long Gumara River in Lake Tana basin (Ethiopia) by overlaying information from aerial photographs and SPOT imagery. Two sets of aerial photographs (1957 and 1980) were scanned, and then orthorectified in ENVI 4.2 environment. Recent channel plan form information was extracted from SPOT images of 2006. ERDAS 2010 and ArcGIS 10.1 tools were used for the data preparation and analysis. The information on river plan form changes spans from 1957 to 2006 (49 years), during which time the Gumara catchment has been subjected to changes in land use/cover and increasing water abstraction, which may have affected its hydrogeomorphology. The results indicated that the lower reach of Gumara at its mouth has undergone major plan form changes. A delta of 1.12 km² was created between 1957 and 1980 and additional 1.00 km² land has been created between 1980 and 2006. The sinuosity of the plan form changed only slightly through the study period: 1.78 in 1957, 1.76 in 1980, and 1.81 in 2006. Comparison of cross sections at the hydrological gauging station showed that the river bed aggraded in the order of 1.5 m to 2.5 m for the period 1963-2009. The trend analysis of stream flow of Gumara River versus rainfall in the catchment also indicated that the bed level of the Gumara river at its gauging station has risen. From field observations, the impact of direct human interventions was identified. The building of artificial levees along the river banks has contributed to huge deposition in the river bed. At locations where intensive irrigation takes place in the floodplain, seepage water through the banks created river bank failure and modifications in plan form. The unstable segments of the river reach were identified and will be further analysed.
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“Yonne River Corridor” Network of Yonne Cities: the River as Tourist Route
Directory of Open Access Journals (Sweden)
Christina Matika
2014-12-01
Full Text Available Long living space for many animal and plant species, the river system and its tributaries represent a principal wealth, always valid for human settlements in the Yonne valley, France. In my case study the major questions raised as starting points are: 1. How the infrastructure is related to the landscape of Yonne. 2. Which could be the possibilities and potentialities to treat this local resource. 3. How local authorities could start a project of exploitation and valorization of the water region. 4. Which interventions could enforce the dynamics of the region. 5. How to articulate cities in discontinuity around the Yonne river, taking into account the flood threat, but in a sustainable way. 6. And last but not least, how can we face the problem of rupture between the banks of the river and the urban space, regaining the docks.
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Solans, Mariana; Scervino, Jose Martin; Messuti, María Inés; Vobis, Gernot; Wall, Luis Gabriel
2016-11-01
Control of fungal plant diseases by using naturally occurring non-pathogenic microorganisms represents a promising approach to biocontrol agents. This study reports the isolation, characterization, and fungal antagonistic activity of actinobacteria from forage soils in the Flooding Pampa, Argentina. A total of 32 saprophytic strains of actinobacteria were obtained by different isolation methods from rhizospheric soil of Lotus tenuis growing in the Salado River Basin. Based on physiological traits, eight isolates were selected for their biocontrol-related activities such as production of lytic extracellular enzymes, siderophores, hydrogen cyanide (HCN), and antagonistic activity against Cercospora sojina, Macrophomia phaseolina, Phomopsis sp., Fusarium oxysporum, and Fusarium verticilloides. These actinobacteria strains were characterized morphologically, physiologically, and identified by using molecular techniques. The characterization of biocontrol-related activities in vitro showed positive results for exoprotease, phospholipase, fungal growth inhibition, and siderophore production. However, none of the strains was positive for the production of hydrogen cyanide (HCN). Streptomyces sp. MM140 presented the highest index for biocontrol, and appear to be promising pathogenic fungi biocontrol agents. These results show the potential capacity of actinobacteria isolated from forage soils in the Argentine Pampas lowlands as promising biocontrol agents, and their future agronomic applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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DEFF Research Database (Denmark)
Vermonden, K.; Brodersen, Klaus Peter; Jacobsen, Dean
2011-01-01
, in urban waters strongly influenced by seepage of large rivers. Chironomid assemblages were studied in urban surface-water systems (man-made drainage ditches) in polder areas along lowland reaches of the rivers Rhine-Meuse in The Netherlands. Multivariate analysis was used to identify the key environmental...... factors. Taxon richness, Shannon index (H'), rareness of species, and life-history strategies at urban locations were compared with available data from similar man-made water bodies in rural areas, and the effectiveness of dredging for restoring chironomid diversity in urban waters was tested. Three...... diversity of chironomid communities in urban waters affected by nutrient-rich seepage or inlet of river water...
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Miroshnikov, A; Semenkov, I
2012-11-01
This article provides an assessment of the impact of global fallout on (137)Cs contamination in the bottom sediments of Kara Sea. The erosiveness of 10th-level river basins was estimated by landscape-geochemical and geomorphological characteristics. All 10th-level basins (n=154) were separated into three groups: mountain, mountain-lowland and plain. Four different types of basins were identified depending on the geochemical conditions of the migration of radiocaesium in the plain and mountain-lowland. Classifications of types were carried out using the geographic information systems-based approach. The Ob River's macroarena covers 3.5 million km(2). Internal drainage basins cover 23 % of the macroarena and accumulate whole radiocaesium from the global fallout. The remaining territory is transitional for the (137)Cs. The field research works performed in the three plain first-level basins allow one to estimate the radiocaesium run-off. The calculations show that 7 % of (137)Cs was removed from the first-level basin in arable land. Accumulation of radiocaesium in the first-level basin under undisturbed forest is 99.8 %. The research shows that (137)Cs transfer from the humid basins is in the range of 6.9-25.5 TBq and for semi-humid basins 5.6-285.5 TBq. The areas of these basins cover 40 and 8 % of the Ob River's macroarena, respectively. Drainage lakes and reservoir drainage basins make up 22 % of the macroarena. Mountainous and semi-arid drainage basins cover 7 % of the macroarena.
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Improvement of fish habitat in a Norwegian river channelization scheme
International Nuclear Information System (INIS)
Brittain, J.E.; Brabrand, A.; Saltveit, S.J.; Heggenes, J.
1993-01-01
Techniques for reducing adverse effects of river and lake regulation are being developed and tested within the framework of the Norwegian Biotope Adjustment Programme. The programme is illustrated by studies of a river flowing through the wetland area, Lesjaleirene, which has been drained and channelized to provide additional agricultural land. The channelized river has a homogeneous sand substrate. Experimental placement of rocks and stones increased brown trout densities, especially in areas in contact with the river banks. The new areas of rocks and stones provide cover for fish as well as a greater variation in depth and flow conditions. (Author)
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Survival and growth rates of juvenile salmonids reared in lowland streams
Directory of Open Access Journals (Sweden)
Golski Janusz
2016-12-01
Full Text Available The aim of this study was to assess the efficiency of propagating juvenile trout, Salmo trutta L. in small lowland streams and to evaluate the impact of the environmental conditions in the streams on the juvenile fish. Brown trout (Salmo trutta fario and sea trout (Salmo trutta trutta early fry fed under controlled conditions were used to stock third-order lowland streams. During summer, fall, and spring catches, fry were counted, measured, and weighed. The following parameters were calculated using the data collected: fry stocking density (ind. m-2; survival; specific mortality rate (SMR; length range; mean specimen length; body weight; mean body weight; specific growth rate (SGR; body condition (Fulton’s index. The ichthyological studies were accompanied by simultaneous analyses of environmental conditions that were performed monthly, and benthic macroinvertebrates were sampled in spring and fall. No differences were observed in the biological parameters analyzed between sea trout and brown trout. Variability in environmental parameters such as temperature, oxygenation, conductivity, and stream width and depth were associated with differentiation in the biological parameters of the fry. The results clearly indicate that the considerable potential of small lowland streams for the propagation of salmonid juvenile stages is currently underexploited.
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Xia, Hui; Huang, Weixia; Xiong, Jie; Tao, Tao; Zheng, Xiaoguo; Wei, Haibin; Yue, Yunxia; Chen, Liang; Luo, Lijun
2016-01-01
The stress-induced epimutations could be inherited over generations and play important roles in plant adaption to stressful environments. Upland rice has been domesticated in water-limited environments for thousands of years and accumulated drought-induced epimutations of DNA methylation, making it epigenetically differentiated from lowland rice. To study the epigenetic differentiation between upland and lowland rice ecotypes on their drought-resistances, the epigenetic variation was investig...
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Hoitink, A.J.F.; Buschman, F.A.; Vermeulen, B.
2009-01-01
Acoustic Doppler current profilers (ADCPs) can be mounted horizontally at a river bank, yielding single-depth horizontal array observations of velocity across the river. This paper presents a semideterministic, semistochastic method to obtain continuous measurements of discharge from horizontal ADCP
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International Nuclear Information System (INIS)
Neal, Colin; Rowland, Phil; Scholefield, Paul; Vincent, Colin; Woods, Clive; Sleep, Darren
2011-01-01
Information on a new observatory study of the water quality of two major river basins in northwestern England (the Ribble and Wyre) is presented. It covers upland, intermediate and lowland environments of contrasting pollution history with sufficient detail to examine transitional gradients. The upland rivers drain acidic soils subjected to long-term acidic deposition. Nonetheless, the acidic runoff from the soils is largely neutralised by high alkalinity groundwaters, although the rivers retain, perhaps as colloids, elements such as Al and Fe that are mobilised under acid conditions. The lowland rivers are contaminated and have variable water quality due to variable urban/industrial point and diffuse inputs reflecting local and regional differences in historic and contemporary sources. For most determinands, pollutant concentrations are not a major cause for concern although phosphate levels remain high. Set against earlier studies for other regions, there may be a general decline in pollutant levels and this is most clearly observed for boron where effluent inputs have declined significantly due to reductions in household products that are flushed down the drain. High concentrations of sodium and chloride occurred briefly after a severe cold spell due to flushing of road salts. A major inventory for water quality within rural, urban, industrial and agricultural typologies is provided within data summary attachments for over 50 water quality determinands. Within the next year, the full dataset will be made available from the CEH website. This, with ongoing monitoring, represents a platform for water quality studies across a wide range of catchment typologies pertinent to environmental management of clean and impacted systems within the UK. The study provides a base of research 'from source to sea' including extensions to the estuary and open sea for a semi-confined basin, the Irish Sea, where there are many issues of pollution inputs and contamination. - Research
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Energy Technology Data Exchange (ETDEWEB)
Neal, Colin [Centre for Ecology and Hydrology, Wallingford, Crowmarsh Gifford, Wallingford, OXON, OX10 8BB (United Kingdom); Rowland, Phil, E-mail: apr@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster. Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Scholefield, Paul; Vincent, Colin; Woods, Clive; Sleep, Darren [Centre for Ecology and Hydrology, Lancaster. Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom)
2011-03-15
Information on a new observatory study of the water quality of two major river basins in northwestern England (the Ribble and Wyre) is presented. It covers upland, intermediate and lowland environments of contrasting pollution history with sufficient detail to examine transitional gradients. The upland rivers drain acidic soils subjected to long-term acidic deposition. Nonetheless, the acidic runoff from the soils is largely neutralised by high alkalinity groundwaters, although the rivers retain, perhaps as colloids, elements such as Al and Fe that are mobilised under acid conditions. The lowland rivers are contaminated and have variable water quality due to variable urban/industrial point and diffuse inputs reflecting local and regional differences in historic and contemporary sources. For most determinands, pollutant concentrations are not a major cause for concern although phosphate levels remain high. Set against earlier studies for other regions, there may be a general decline in pollutant levels and this is most clearly observed for boron where effluent inputs have declined significantly due to reductions in household products that are flushed down the drain. High concentrations of sodium and chloride occurred briefly after a severe cold spell due to flushing of road salts. A major inventory for water quality within rural, urban, industrial and agricultural typologies is provided within data summary attachments for over 50 water quality determinands. Within the next year, the full dataset will be made available from the CEH website. This, with ongoing monitoring, represents a platform for water quality studies across a wide range of catchment typologies pertinent to environmental management of clean and impacted systems within the UK. The study provides a base of research 'from source to sea' including extensions to the estuary and open sea for a semi-confined basin, the Irish Sea, where there are many issues of pollution inputs and contamination
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BANKING BUSINESS MODELS IN UKRAINIAN BANKING SYSTEM
Directory of Open Access Journals (Sweden)
Yuliya Onyshchenko
2015-11-01
Full Text Available The purpose of the paper is to work out and characterize bank business models that are formed in Ukraine. Methodology. Our research we will spend among banks that are functioning on the Ukrainian financial market and are not on the stage of liquidation, so the sample under study in our work is comprised of 131 banks which are different in their ownership structure and size. The core of the methodology is a statistical clustering algorithm that allows identifying the groups of banks (clusters with similar business models as banks with similar business model strategies have made similar choices regarding the composition of their assets and liabilities. The cluster analyses were taken on the base of seven chosen indicators: bank loans, bank liabilities, enterprise loans, enterprise liabilities, household loans, household liabilities and trading assets. Results. The traditional business model of bank is worked out. The bank business models that are functioning in Ukraine are identified on the base of cluster analyses using balance sheet characteristics of 131 Ukrainian banks. We find that in Ukraine were formed three types of bank business models: “Focused retail”, “Diversified retail” and “Corporative retail”. The description of each model is given. Practical implications. More detailed research of distinguished models allows not only to find out the main advantages and disadvantages of each bank model, but also the main problems that follow the development of Ukrainian banking sector. Identifying of bank models and their studying simplifies searching and elaboration of regulatory instruments as there is a two-way causation between regulation and bank business models. This implies a symbiotic relationship between regulation and bank business models: business models respond to regulation which in turn responds to the evolution of new business models. Value/originality. Such survey is conducted at the first time among Ukrainian banks. The
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Pijl, Anton; Brauer, Claudia; Sofia, Giulia; Teuling, Ryan; Tarolli, Paolo
2017-04-01
, that will need to adapt to prevent largescale floods or crop-failure. Additionally, simulations under 'business-as-usual' pathway RCP8.5 would likely amplify the polarising effects on the hydrological regime as presented here, further stressing the need for adequate adaptation. The proposed presentation at EGU 2017 will contain clear visual results of the model and quantitative scenario simulations. These results are particularly interesting, firstly because they prove how a simple conceptual model can become a powerful tool in scenario analysis of future pathways. Furthermore, they clearly indicate major challenges that lowland areas are facing in modern times - not only the 46.000 km2 Po valley, but all around the world where lowlands often host the centres of our societies and economies. REFERENCES Brauer, C., Teuling, A., Torfs, P., Uijlenhoet, R., 2014. The Wageningen Lowland Runoff Simulator (WALRUS): a lumped rainfall-runoff model for catchments with shallow groundwater. Geoscientific Model Development 7 (5), 2313-2332. Rockel, B., Will, A., Hense, A., 2008. The regional climate model COSMO-CLM (CCLM). Meteorologische Zeitschrift 17 (4), 347-348. Tarolli, P., Sofia, G., 2016. Human topographic signatures and derived geomorphic processes across landscapes. Geomorphology 255, 140-161. Vezzoli, R., Mercogliano, P., Pecora, S., Zollo, A., Cacciamani, C., 2015. Hydrological simulation of Po River (North Italy) discharge under climate change scenarios using the RCM COSMO-CLM. Science of The Total Environment 521, 346-358.
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FLOODPLAIN-CHANNEL COMPLEX OF SMALL RIVER: ASSESSMENT OF CURRENT STATE, OPTIMIZATION MEASURES
Directory of Open Access Journals (Sweden)
Kovalchuk I.
2016-05-01
, located close to the river head, is in almost optimal condition, a set of urgent measures to stop destructive for the river and its ecosystem processes, to rehabilitate the river and to preserve its resources should be made. Primary measures to improve the river condition should be: to clean off the stream-way and bank-line protective zone from domestic garbage and natural waste; to comply with behaviour requirements in respect of the bank-line protective zone and setting its limits; to fix eroded banks; to limit alluvium extracting from the bed and banks; to organize watering sites for animals; to provide better treatment of wastewater at municipal wastewater treatment plants located in Morshyn city and Dashava village, industrial effluents of Dashava production office of underground gas storage, Dashava composites plant, and Dashava construction materials plant management through their renovation; to reduce possibilities of getting water contaminated with the toxic waste from toxic waste landfill “Shkiryanyk”, into the river and to ensure the oil pipelines crosses the stream-way under the due protection. It is also important to reduce the regulation of a runoff because ponds are mainly lifeless and used for purposes other than intended ones. It is necessary to reduce the intensity of agricultural activity over the flood-plain lands.
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RELATION BETWEEN ISLAMIC BANK AND CENTRAL BANK
PAKSOY, H. Mustafa; ABAROSS, Nour
2015-01-01
This study deals with the nature of Islamic banks and their features, and requirements of these features in terms of control tools and methods appropriate with the particularity of their business and their relation with the traditional central bank. At the same time aims to view the relationship between Islamic bank and central bank. To explain this relation the researcher started to explain what is the central bank, objectives of central bank, and characteristics, what is Islamic bank and ob...
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Habitats and landscapes associated with bird species in a lowland conifer-dominated ecosystem
Directory of Open Access Journals (Sweden)
Edmund J. Zlonis
2017-06-01
Full Text Available Human-induced effects on lowland conifer forests in hemiboreal regions are increasing because of expanded use of these northern ecosystems for raw materials, energy, and minerals as well as the potential effects of climatic changes. These forests support many breeding bird species across the Holarctic and allow the persistence of several boreal bird species in hemiboreal and even temperate regions. These bird species are of particular conservation concern as shifting patterns northward in forest composition caused by climate change will likely affect their populations. However, effective management and conservation options are limited because the specifics of these species' breeding habitats are not well understood. We modeled and mapped habitat suitability for 11 species of boreal birds that breed in the lowland conifer forests of the Agassiz Lowlands Ecological Subsection in northern Minnesota and are likely to have reduced breeding habitat in the future: Spruce Grouse (Falcipennis canadensis, Black-backed Woodpecker (Picoides arcticus, Olive-sided Flycatcher (Contopus cooperi, Yellow-bellied Flycatcher (Empidonax flaviventris, Boreal Chickadee (Poecile hudsonicus, Golden-crowned Kinglet (Regulus satrapa, Ruby-crowned Kinglet (Regulus calendula, Swainson's Thrush (Catharus ustulatus, Connecticut Warbler (Oporornis agilis, Palm Warbler (Setophaga palmarum, and Dark-eyed Junco (Junco hyemalis. Sets of 7 to 16 potential environmental covariates, including both stand-level and landscape attributes, were used to develop individual species models. Within this lowland conifer-dominated ecosystem, we found significant selection for specific forest and landscape characteristics by all but one of these species, with the best models including between one and nine variables. Habitat suitability maps were developed from these models and predictions tested with an independent dataset. Model performance depended on species, correctly predicting 56-96% of
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Directory of Open Access Journals (Sweden)
Barkasi Z.
2016-12-01
Full Text Available The present paper contains information on a new beaver colony discovered in the Chornyi mochar tract, which is located in the lowland part of Transcarpathia (= Zakarpattia Region. This rodent species disappeared from the territory of Transcarpathia most likely in the 18th century. Its first reappearance was recorded in 2003. Since, the Eurasian beaver has demonstrated a rapid expansion, primarily along the main rivers. The discovered by us colony allows to suggest that the beaver is continuing its dispersal, entering far into the main river’s tributaries and other shallower water bodies. Consequently, we are witnessing not only the expansion of the species’ geographical range, but also the enlargement of the number of habitat types occupied by the animal. The possibilities and supposed consequences of the species’ further expansion within the tract are shown as well.
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Cyclic Sediment Trading Between Channel and River Bed Sediments
Haddadchi, A.
2015-12-01
Much of the previous work on sediment tracing has focused on determining either the initial sources of the sediment (soils derive from a particular rock type) or the erosion processes generating the sediment. However, alluvial stores can be both a source and sink for sediment transported by streams. Here geochemical and fallout radionuclide tracing of river-bed and alluvial sediments are used to determine the role of secondary sources, sediment stores, as potential sources of sediment leaving Emu Creek catchment, southeastern Queensland, Australia. Activity concentrations of 137Cs on the river sediments are consistent with channel erosion being the dominant source at all sites sampled along the river. To characterise the deposition and remobilisation cycles in the catchment, a novel geochemical tracing approach was used. Successive pockets of alluvium were treated as discrete sink terms within geochemical mixing models and their source contributions compared with those of river bed sediments collected adjacent to each alluvial pocket. Three different size fractions were examined; silts and clays (banks indicates a high degree of 'trading' between the fluvial space and the alluvial space. Hence, management works aimed at primarily reducing the supply of sediments to the outlet of Emu Creek should focus on rehabilitation of channel banks in the lower catchment.
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Assessment of heavy metals, pH and EC in effluent run-off, river and ...
African Journals Online (AJOL)
Heavy metal contents from effluent run-off, neighboring Holeta River, and adjacent soils around floriculture greenhouses in Holeta town, Ethiopia were determined using Atomic Absorption Spectrophotometer (AAS) to assess their potentialities as pollutants. Samples were taken from four sites for the effluent, two river bank ...
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Population dynamics of Rodents and Insectivores in lowland tropical ...
African Journals Online (AJOL)
The community structure of rodents and insectivores in the lowland tropical rainforest of Okomu National Park, Edo State, Nigeria was assessed using a combination of live-trapping and sighting techniques during the dry and wet seasons. Seventeen species (14 species of rodent, 3 species of insectivores) were captured, ...
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Hoorn, Carina; Bogotá-A, Giovanni R.; Romero-Baez, Millerlandy; Lammertsma, Emmy I.; Flantua, Suzette G. A.; Dantas, Elton L.; Dino, Rodolfo; do Carmo, Dermeval A.; Chemale, Farid
2017-06-01
The Amazon submarine fan is a large sediment apron situated offshore Pará (Brazil) and represents the most distal extent of the Amazon River. The age of onset of this transcontinental river remains debated, yet is of great importance for understanding biotic evolutionary processes on land and at sea. Here we present new geochemical and palynological data from a borehole drilled at the continental slope and dated based on nannofossil biostratigraphy. We found that sediments of mixed source (craton and adjacent) occur at least from the late Oligocene (NP25) to late Miocene (NN9), and that the earliest Andes-derived sediments occur in NN10 (late Miocene). Our geochemical record indicates an onset of the transcontinental Amazon River between 9.4 and 9 Ma, which postdates the regional unconformity by 1 to 1.5 My. The shift in sediment geochemistry is more gradually replicated in the palynological record by a change from coastal plain and tropical lowland taxa to a mixture of tropical lowland, and montane forest to open Andean taxa. In particular, the appearance of taxa such as Jamesonia and Huperzia, followed by Valeriana, Polylepis-Acaena, Lysipomia and Plantago (with a current altitudinal range from 3200 to 4000 m) suggests the development of open, treeless, vegetation between 9.5 and 5.4 Ma, and highlight the presence of a high Andes in the late Miocene hinterland. Poaceae progressively increased from 9 Ma, with a notable rise from 4 Ma onwards, and percentages well above post-glacial and modern values, particularly between 2.6 and 0.8 Ma. We hypothesize that the rise of the grasses is a basin-wide phenomenon, but that the Plio-Pleistocene expansion of open, treeless vegetation on the Andean slopes and foothills are the main contributor. This rise in grasses was likely caused by climatic fluctuations, and subsequent changes in relief and erosion rates. We conclude that the onset of the Amazon River is coupled with Neogene Andean tectonism and that subsequent
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Lowland rice yield estimates based on air temperature and solar radiation
International Nuclear Information System (INIS)
Pedro Júnior, M.J.; Sentelhas, P.C.; Moraes, A.V.C.; Villela, O.V.
1995-01-01
Two regression equations were developed to estimate lowland rice yield as a function of air temperature and incoming solar radiation, during the crop yield production period in Pindamonhangaba, SP, Brazil. The following rice cultivars were used: IAC-242, IAC-100, IAC-101 and IAC-102. The value of optimum air temperature obtained was 25.0°C and of optimum global solar radiation was 475 cal.cm -2 , day -1 . The best agrometeorological model was the one that related least deviation of air temperature and solar radiation in relation to the optimum value obtained through a multiple linear regression. The yield values estimated by the model showed good fit to actual yields of lowland rice (less than 10%). (author) [pt
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Is shadow banking really banking?
Bryan J. Noeth; Rajdeep Sengupta
2011-01-01
To those who don't know, the term "shadow banking" probably has a negative connotation. This primer draws parallels between what has been termed the shadow banking sector and the traditional banking sector—showing that they are similar in many ways.
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Yield constraint analysis of rainfed lowland rice in Souteast Asia
Boling, A.A.
2007-01-01
Keywords: Fertilizer application, field hydrology, plant nutrient uptake, toposequence, weed control, yield loss. Rainfed lowland rice yields are low and unstable due to uncertain water supply, low soil fertility, and pest infestation. To design management interventions aimed at increasing
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BANK RUN AND STABILITY OF ISLAMIC BANKING IN INDONESIA
Directory of Open Access Journals (Sweden)
Rahmatina A. Kasri
2017-08-01
Full Text Available Bank run is an important economic phenomenon which increasingly occurred in in modern banking system and potentially threatened banking stability as it could trigger a banking crisis. However, most studies related to bank run focus on the occurrence of bank run in conventional banking system. Very few of them discuss the bank run phenomenon under Islamic banking system or dual banking system where Islamic banks jointly operating with conventional banks. Therefore, this study attempts to analyze the determinants of bank run in the Indonesian Islamic banking industry by employing primary data from 256 customers of Indonesia Islamic banks in 2015 and by utilizing factor analysis and descriptive statistics. In theory, Islamic banks tend to be more resilient towards any macroeconomic or financial shocks as compared to conventional banks due to the nature of its asset-based and risk-sharing arrangement. However, the result exhibits that both psychological and fundamental factors (i.e. macroeconomics and bank fundamentals strongly influence the behaviors of Islamic banking depositors to withdraw their funds, which might trigger the occurrence of bank runs in the country. Insider information, macroeconomic condition and bank fundamental factors are also shown to have the highest impacts among all variables. Hence, in the context of banking stability, the finding implies that Islamic banks are not completely immune to the impacts of macroeconomic shocks or financial crisis. As a country with a dual banking system, Indonesia had experienced several bank runs since 1990s. Therefore, the findings of the study should provide the policy makers important insight into research based-policy in order to attain financial stability as one of the main economic goals of the country. Keywords: Bank run, Islamic bank, Factor analysis, Indonesia JEL Classification: C83, G21, G28
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33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.
2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Hudson River Lock at Troy, N.Y..., DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.50 Hudson River Lock at Troy, N.Y.; navigation. (a...) [Reserved] (n) Trespass on U.S. property. Trespass on U.S. property, or willful injury to the banks, masonry...
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Spatial dynamic of mobile dunes, soil crusting and Yobe's bank ...
African Journals Online (AJOL)
In the fluvio-deltaic area of Kadzell, the soil crusting and the Yobe River retreat remain the major damages. The crusting area has been multiplied by more than two while the lateral migration of the Yobe bank reached near of 3 m.yr-1. This study highlights the key role of man in the process of degradation related to climate ...
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Simulating Retail Banking for Banking Students
Supramaniam, Mahadevan; Shanmugam, Bala
2009-01-01
The purpose of this study was to examine the implementation flow and development of retail bank management simulation based training system which could provide a comprehensive knowledge about the operations and management of banks for the banking students. The prototype of a Retail banking simulation based training system was developed based on…
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Red River Below Denison Dam, Texas, Oklahoma, Arkansas, and Louisiana
National Research Council Canada - National Science Library
Copeland, Ronald
2002-01-01
A numerical model study was conducted to evaluate the effect that reducing bank erosion between Arthur City, TX, and Index, AR, would have on deposition rates in the J. Bennett Johnston (Red River) Waterway...
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Sediment composition mediated land use effects on lowland streams ecosystems
Dos Reis Oliveira, P.C.; Kraak, M.H.S.; van der Geest, H.G.; Naranjo, S.; Verdonschot, P.F.M
2018-01-01
Despite the widely acknowledged connection between terrestrial and aquatic ecosystems, the contribution of runoff to the sediment composition in lowland stream deposition zones and the subsequent effects on benthic invertebrates remain poorly understood. The aim of this study was therefore to
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DEFF Research Database (Denmark)
Prinds, Christian; Petersen, Rasmus Jes; Iversen, Bo Vangsø
2016-01-01
as well as novel approaches e.g. remote sensing using UAV’s (Unmanned Aerial Vehicles commonly known as drones), a newly developed redox probe, and novel uses of geophysical methods. More information about TReNDS can be found at www.nitrat.dk. The project is funded by Innovation Fund Denmark......Riparian lowlands may have significant impact on the catchment nitrate balance. As a part of the strategic research project TReNDS (“Transport and reduction of nitrate in Danish landscapes at various scales”) extensive field investigations have commenced in the Fensholt subcatchment situated within...... Norsminde Fjord catchment, Odder, Denmark. The riparian lowlands are surrounded by a hilly landscape composed of mainly clayey till, and hence the landscape is heavily drained. Drainpipes are either disconnected at the hillslope bordering the riparian lowland or discharging partly through the riparian zone...
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Saltcedar control and water salvage on the Pecos River, Texas, 1999 to 2003
Charles R. Hart; Larry D. White; Alyson McDonald; Zhuping Sheng
2007-01-01
A large scale ecosystem restoration program was initiated in 1997 on the Pecos River in western Texas. Saltcedar (Tamarix spp.), a non-native invasive tree, had created a near monoculture along the banks of the river by replacing most native vegetation. Local irrigation districts, private landowners, federal and state agencies, and private industry...
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Bank Diversification Effects on Bank Performance and Risk Profile of Bank in Indonesia
Directory of Open Access Journals (Sweden)
Anthony Lukmawijaya
2015-05-01
Full Text Available We investigate the relationship of Indonesian bank diversification towards its long term performance and risk profile with Indonesian bank data from 2009 to 2013. Non-interest income to total operating income of the bank measures its bank diversification level. Bank value is measured by the adjusted Tobin's Q and risk profile which is broken down into total risk, idiosyncratic risk, and systematic risk. The result shows that bank non-interest income diversification has a positive influence on its franchise value. There is, however, no strong evidence that diversification can lower a bank's risk profile.
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Denying Foreign Bank Entry: Implications For Bank Interest Margins
Ross Levine
2003-01-01
This paper examines the impact of restricting foreign bank entry on bank net interest margins while controlling for (a) impediments to domestic bank entry, (b) the degree of foreign bank ownership of the domestic banking industry, (c) an array of bank-specific characteristics, (c) banking sectorconcentration, and (d) various country traits. Using data on almost 1200 banks across 47 countries, the results suggest that restricting foreign bank entry boosts bank net interest margins. Also, restr...
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E-BANKING- MODERN BANKING SERVICES
Directory of Open Access Journals (Sweden)
MIRANDA PETRONELLA VLAD
2009-05-01
Full Text Available E-banking is the first of those banking services that really economize time, because it allows to the user to accomplish from behind the computer many operations in the bank account, represents the computational solution that allows to the holder to have
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Assessment of River Habitat Quality in the Hai River Basin, Northern China
Directory of Open Access Journals (Sweden)
Yuekui Ding
2015-09-01
Full Text Available We applied a river habitat quality (RHQ assessment method to the Hai River Basin (HRB; an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 104 km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 104 km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m; lower coverage of riparian vegetation (≤40%; artificial land use patterns (public and industrial land; frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m3; single flow channels; and rare aquatic plants (≤1 category. At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p < 0.01 and urban land (r = 0.998; p < 0.05; and was significantly and positively correlated with grassland and woodland (r = 1.000; p < 0.01. Intensive artificial land use; created through urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08–16.56; caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated.
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ADAPTATION OF LOCAL SWEET POTATO CLONES IN THA LOWLANDS OF PAPUA
Directory of Open Access Journals (Sweden)
Demas Wamaer
2017-07-01
Full Text Available Objective of study was to obtain local clones of adaptive lowland ubijalar in Papua. Experiment was conducted in lowland dry season 2012/2013 in two locations, namely Keerom and Jayapura districts. Randomized Block Design (RAK, 10 local varieties of adaptive lowland Papua and two national superior varieties (Beta 2 and Cangkuang were used. Cultivation technique used is a bund system. Results: there were three local varieties with higher yield and yield potential than Beta-2 comparison varieties (22.4 t/ha with yield potential 22.9 t/ha and Cangkuang (20.6 t/ha with potential yield 21,6 ta/ha, while the three local varieties are Ningkay-3 having average productivity 27,5 t/ha (yield potential 28,0 t/ha Ningkay-6 has productivity 24,9 t ha yield potential 28.1 t/ha and Ordinance Tingkamang-1 has an average productivity of 23.8 t/ha (yield potential of 24.5 t/ha. These three varieties are Ningkay-3, Ningkay-6, and Oringking Tingkamang-1 each also has a very high tuber-dry production either compared to other test varieties or with a comparison variety, the averaged average is 9,3; 8,0 and 7.3 t/ha with dry matter 33.8; 32.3 and 30.8 percent respectively. Further testing with various seasons and more locations and varying altitude is required
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Cerebral pressure-flow relationship in lowlanders and natives at high altitude.
Smirl, Jonathan D; Lucas, Samuel J E; Lewis, Nia C S; duManoir, Gregory R; Dumanior, Gregory R; Smith, Kurt J; Bakker, Akke; Basnyat, Aperna S; Ainslie, Philip N
2014-02-01
We investigated if dynamic cerebral pressure-flow relationships in lowlanders are altered at high altitude (HA), differ in HA natives and after return to sea level (SL). Lowlanders were tested at SL (n=16), arrival to 5,050 m, after 2-week acclimatization (with and without end-tidal PO2 normalization), and upon SL return. High-altitude natives (n=16) were tested at 5,050 m. Testing sessions involved resting spontaneous and driven (squat-stand maneuvers at very low (VLF, 0.05 Hz) and low (LF, 0.10 Hz) frequencies) measures to maximize blood pressure (BP) variability and improve assessment of the pressure-flow relationship using transfer function analysis (TFA). Blood flow velocity was assessed in the middle (MCAv) and posterior (PCAv) cerebral arteries. Spontaneous VLF and LF phases were reduced and coherence was elevated with acclimatization to HA (Pflow coupling. However, when BP was driven, both the frequency- and time-domain metrics were unaltered and comparable with HA natives. Acute mountain sickness was unrelated to TFA metrics. In conclusion, the driven cerebral pressure-flow relationship (in both frequency and time domains) is unaltered at 5,050 m in lowlanders and HA natives. Our findings indicate that spontaneous changes in TFA metrics do not necessarily reflect physiologically important alterations in the capacity of the brain to regulate BP.
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Internet Banking integration within the banking system
Directory of Open Access Journals (Sweden)
Constantin Marian MATEI
2008-01-01
Full Text Available Internet Banking developed due to increasing demand of online banking transactions. The biggest advantages of Internet Banking consist of complex banking solutions, 24 hours availability, quick and secure access to the back-end application through Internet. These advantages are due to the use of SOA (service-oriented architecture. SOA appeared as a necessity of companies to integrate big and independent portions of applications, in order to obtain an homogeneous functionality of the system. For the Internet Banking applications, SOA proved to be the optimal architectural solution, for a smoth integration between banking services from the front-end to the back-end.This paper intend to offer an insite analyse of the Internet Banking applications architecture integrated with other banking systems. A SOA oriented analyse will establish the scope of the integration architecture.
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Fluvial Geomorphology and River Restoration: Uneasy Allies (Invited)
Kondolf, G. M.
2009-12-01
A growing body of literature demonstrates that river restoration based on understanding of geomorphic and ecological process is more likely to be sustainable than form-based approaches. In the early days of river ‘restoration’ in North America, most projects involved bank stabilization, habitat structure placement, or construction of rocked meandering channels, at odds with restoration of the dynamic processes we now see as fundamental to effective, sustainable restoration. Recent years have seen a growing body of restoration programs emphasizing restoration of connectivity and geomorphic process. This evolution has been reflected in publications, from the form-based approach advocated in the early 1990s by an NRC panel (which did not include a geomorphologist) to more recent works by interdisciplinary panels emphasizing process restoration. Large-scale river restoration came later to Europe, motivated by the EU Water Framework Directive (2000) requirements that member states implement measures to improve ecological status of degraded rivers. Interestingly, European approaches to restoration have often reflected a more nuanced understanding of process, including deliberate recreation of unstable braided channels, removal of bank protection, and reconnecting floodplains. In part this may reflect a reaction to the more thorough post-war channelization of rivers in western Europe. In part it may also reflect a greater influence of academic and research laboratories upon practitioners than in the US, where a strong anti-intellectual strain, cultural preference for easy fixes, and reluctance to conduct objective post-project assessments have contributed to the adoption of form-based approaches by many public agencies.
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Interest Free Banking in Nigeria - Welcome Islamic Banking ...
African Journals Online (AJOL)
Interest Free Banking in Nigeria - Welcome Islamic Banking; Welcome Christian Banking. ... banks pay interest on deposits, and charge interest on loans and advances, ... However, the literature on interest rates, in relation to Commercial Bank ...
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Fischer, Helmut; Pusch, Martin
1999-01-01
Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [14C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sedi...
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75 FR 55272 - Safety Zone; Mississippi River, Mile 212.0 to 214.5
2010-09-10
...-AA00 Safety Zone; Mississippi River, Mile 212.0 to 214.5 AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone for waters of the Upper Mississippi River, Mile 212.0 to 214.5, extending West of Portage Island to the right descending bank of the...
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Changes in freshwater mussel communities linked to legacy pollution in the Lower Delaware River
Blakeslee, Carrie J.; Silldorff, Erik L.; Galbraith, Heather S.
2018-01-01
Freshwater mussels are among the most-imperiled organisms worldwide, although they provide a variety of important functions in the streams and rivers they inhabit. Among Atlantic-slope rivers, the Delaware River is known for its freshwater mussel diversity and biomass; however, limited data are available on the freshwater mussel fauna in the lower, non-tidal portion of the river. This section of the Delaware River has experienced decades of water-quality degradation from both industrial and municipal sources, primarily as a function of one of its major tributaries, the Lehigh River. We completed semi-quantitative snorkel surveys in 53.5 of the 121 km of the river to document mussel community composition and the continued impacts from pollution (particularly inputs from the Lehigh River) on mussel fauna. We detected changes in mussel catch per unit effort (CPUE) below the confluence of the Lehigh River, with significant declines in the dominant species Elliptio complanata (Eastern Elliptio) as we moved downstream from its confluence—CPUE dropped from 179 to 21 mussels/h. Patterns in mussel distribution around the Lehigh confluence matched chemical signatures of Lehigh water input. Specifically, Eastern Elliptio CPUE declined more quickly moving downstream on the Pennsylvania bank, where Lehigh River water input was more concentrated compared to the New Jersey bank. A definitive causal link remains to be established between the Lehigh River and the dramatic shifts in mussel community composition, warranting continued investigation as it relates to mussel conservation and restoration in the basin.
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Theisen, Giovani
2017-01-01
Agriculture in the lowlands of south Brazil is of strategic importance at the national level, since it supplies around 80% of the rice consumed by the Brazilian population. In Rio Grande do Sul, the southernmost state in Brazil, three million hectares of lowlands are ready for grain-based
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Impact of E-Banking on Traditional Banking Services
Vyas, Shilpan Dineshkumar
2012-01-01
Internet banking is changing the banking industry, having the major effects on banking relationships. Banking is now no longer confined to the branches were one has to approach the branch in person, to withdraw cash or deposit a cheque or request a statement of accounts. In true Internet banking, any inquiry or transaction is processed online without any reference to the branch (anywhere banking) at any time. Providing Internet banking is increasingly becoming a "need to have" than a "nice to...
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Directory of Open Access Journals (Sweden)
Aditya Wardhana
2015-09-01
Full Text Available The research aim was to assess the influence of the service quality of mobile banking (m-banking against customer satisfaction at the greatest banks in Indonesia. Elements of the quality of mobile banking services (m-banking were speed, security, accuracy, and trust. The population of this study was bank customers from eight of the greatest bank in Indonesia -- Bank Mandiri, Bank BRI, Bank BCA, Bank BNI, Bank CIMB Niaga, Bank Danamon, Bank Permata, and Bank Panin -- who used mobile banking which totaled 19.9 million customers with the size of the sample being 400 respondents. The sampling method used nonprobability sampling by incidental sampling. The results by using a structural equation modeling (SEM found significant influences between service quality of mobile banking (m-banking partially and simultaneously to customer satisfaction.
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Development of Nile River islands between Old Aswan Dam and new Esna barrages
Directory of Open Access Journals (Sweden)
Yasser Raslan
2015-04-01
Full Text Available This paper investigates the development of Nile River islands in the first reach which extends between Aswan and new Esna barrages. A wide range of data compiled and used in this investigation which include produced maps in 1939, 1982 and 2003, and hydrological data. Compiled data drew a complete picture for up-to-date information on morphological changes since 1939. The analysis indicated that islands length; thus, area has reduced since 1939. Also, islands tend to reshape by elongating. The reduction in area is attributed in part to the merging of islands in either bank and adjustment of the river to the new flow conditions after the operation of High Aswan Dam. El-Mansouria Island which is the largest island in area was focused on. Recent human interferences accelerated the merging of island in the west bank. Consequently, river morphology has changed around the islands.
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Planning for environmental restoration of the contaminated banks near NPP Bohunice
International Nuclear Information System (INIS)
Slavik, O.; Moravek, J.; Vladar, M.
1995-01-01
The 18 km long banks of the Bohunice NPP waste water recipient are contaminated by cesium-137 as a result of two accidents on the CO 2 cooled NPP A 1 unit in 1976 and 1977. Since 1992, all he contaminated waste waters dumping from NPP Bohunice has been carried out directly to the Vah River through a specially constructed 15 km long pipeline. The final extent of contamination in the Bohunice site is represented. The overall contaminated area in this site with cesium-137 activity above 1 Bq/g of soil is about 67000 m 2 and thus, the corresponding volume of top 20 cm thick soil layer is about 13000 m 3 . For optimizing less costly remedial measures (warning signs...) an agreed scenario with a pre-estimated factor factor collective dose 2.10 -7 man.Sv.y -1 /(m 2 .Bq 137 Cs.g -1 ) was applied. Limitation of individual effective doses according to a site specific stay scenario was also considered for this purposes with a limiting value of 0.25 mSv/y. Cost analysis of available remedial techniques were carried out, too. Two techniques have been selected for the contaminated banks restoration project: 1) removing/disposal of 20 cm soil top layer from steep and unengineered banks, and 2) mechanical dilution/fixation of contamination by clean 15 cm soil cover for the contaminated flat areas. Two-fold reduction of anticipated potential radiation risk were accepted, maximally, for the lastly mentioned technique, however cost saving is considerable (about 10-time lower the cost comparing to removing/disposal technique one). The basic acceptance limits AL for 137 Cs in soil and criteria size of continuously contaminated bank areas were derived as: AL 200 = 6.0 Bq/g and 800 m 2 (300 m) or AL 50 8.0 Bq/g and 200 m 2 (80 m) for removing/disposal of the soil on steep unengineered banks. For clean soil covering technique the resulting limits are in an interval AL 50C = 8 up to 16 Bq/g. According to the criteria developed, it is necessary to subject to restoration about 11000 m 2 of
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Effects of riparian vegetation development in a restored lowland stream
Vargas-Luna, A.; Crosato, A.; Hoitink, A.J.F.; Groot, J.; Uijttewaal, W.S.J.
2016-01-01
This paper presents the morphodynamic effects of riparian vegetation growth in a lowland restored stream. Hydrological series, high-resolution bathymetric data and aerial photographs are combined in the study. The vegetation root system was found to assert a strong control on soil stabilization,
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Streamflow, a GIS-based Environmental Assessment Tool for Lowland Streams
Pieterse, N.M.; Olde Venterink, H.; Schot, P.P.; Verkroost, A.W.M.
1998-01-01
Human activities, such as stream management, drainage, urbanization and agriculture, heavily influence the aquatic ecosystems in small lowland streams. For the assessment of the impact of human activities of aquatic ecosystems, a modeling tool is created. This modeling tool is part of the EU-life
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An Indian Federation in Lowland Ecuador. IWGIA Document 28.
Salazar, Ernesto
Official involvement of the Ecuadorian government with colonization of the southern lowlands, lands traditionally belonging to the Shuar Indians, began in the early 60's when the CREA (Centro de Reconversion Economica del Azuay) was created to provide assistance to white settlers. Until that time, the Shuar lands had been dominated by the Salesian…
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Role of Foreign Banks in Integration of Banking Industry
Directory of Open Access Journals (Sweden)
Roman Šubić
2009-12-01
Full Text Available Dynamic development of financial industry in some last ten years that, considering the kind of financial agents, remained bank-oriented represents a suficient reason to investigate the causes that brought to the present structure of banking system. After having presented theoretical bases of the integration forms and banks connection, the paper analyzes the influence of foreign banks on the development of Croatian bank system. Thus, beside the knowledge of quantitative changes in the banking system, the paper researched the motivations of the banks regarding integration that, among other things, brought to creating the effects of scale and scope economies. However, the concentrations among banks can lead to creation of negative externalities that later become potential dangers for the banking. Pre-cognitions on development of banking system are used to create projection of future banking development while the data basis of the countries from the region enabled the comparative analysis of banks integration in these countries. The conclusion is that the foreign banks have been the largest promoters of bank integration in the Republic of Croatia contributing also to qualitative development of banking market and to deepening of financial market spectrum.
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Brodie, R. S.; Lawrie, K.; Somerville, P.; Hostetler, S.; Magee, J.; Tan, K. P.; Clarke, J.
2013-12-01
Multiple lines of evidence were used to develop a conceptual model for interaction between the Darling River and associated floodplain aquifers in western New South Wales, Australia. Hydrostratigraphy and groundwater salinities were mapped using airborne electromagnetics (AEM), validated by sonic-core drilling. The AEM was highly effective in mapping groundwater freshening due to river leakage in discrete zones along the river corridor. These fresh resources occurred in both the unconfined Quaternary aquifers and the underlying, largely semi-confined Pliocene aquifers. The AEM was also fundamental to mapping the Blanchetown Clay aquitard which separates these two aquifer systems. Major-ion chemistry highlighted a mixing signature between river waters and groundwaters in both the Quaternary and Pliocene aquifers. Stable isotope data indicates that recharge to the key Pliocene aquifers is episodic and linked to high-flow flood events rather than river leakage being continuous. This was also evident when groundwater chemistry was compared with river chemistry under different flow conditions. Mapping of borehole levels showed groundwater mounding near the river, emphasising the regional significance of losing river conditions for both aquifer systems. Critically, rapid and significant groundwater level responses were measured during large flood events. In the Pliocene aquifers, continuation of rising trends after the flood peak receded confirms that this is an actual recharge response rather than hydraulic loading. The flow dependency of river leakage can be explained by the presence of mud veneers and mineral precipitates along the Darling River channel bank when river flows are low. During low flow conditions these act as impediments to river leakage. During floods, high flow velocities scour these deposits, revealing lateral-accretion surfaces in the shallow scroll plain sediments. This scouring allows lateral bank recharge to the shallow aquifer. During flood
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Analisis Perbandingan Bank Umum Konvensional Dan Bank Umum Syariah
Nuryati; Gendis Gumilar, Amethysa
2011-01-01
This study analyzes and compares the financial risk of the two types of commercial banks, namely conventional commercial bank and Islamic commercial bank. Analysis tools used in this study is to use financial ratios and dicriminant values (Z values). Analysis showed that the ratio of liquidity and solvability ratios higher islamic commercial bank than conventional commercial bank. Z values higher islamic commercial bank than conventional commercial bank. The commercial banks are in a state of...
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Pratt, Linda W.; VanDeMark, Joshua R.; Euaparadorn, Melody
2011-01-01
Two endangered plant species (Portulaca sclerocarpa, `ihi mākole, and Sesbania tomentosa, `ōhai) and a species of concern (Bobea timonioides, `ahakea) native to the coastal lowlands and dry mid-elevation woodlands of Hawai`i Volcanoes National Park were studied for more than two years to determine their stand structure, short-term mortality rates, patterns of reproductive phenology, success of fruit production, seed germination rates in the greenhouse, presence of soil seed bank, and survival of both natural and planted seedlings. The role of rodents as fruit and seed predators was evaluated using exclosures and seed offerings in open and closed stations or cages. Rodents were excluded from randomly selected plants of P. sclerocarpa and from branches of S. tomentosa, and flower and fruit production were compared to that of adjacent unprotected plants. Tagged S. tomentosa fruit were also monitored monthly to detect rodent predation.
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River crossing: combining basic hydraulics with pipe protection
Energy Technology Data Exchange (ETDEWEB)
Carnicero, Martin [TGN Transportadora de Gas del Norte, Buenos Aires (Argentina). Integrity Dept.], e-mail: Martin.Carnicero@tgn.com.ar
2009-07-01
As a complement to the paper presented in 2003 (IBP505-03 River crossings: a decision making scheme for the execution of protection works), this paper is about sharing the experience collected during the following 6 years, regarding the performance of remediation works. At that time, alternatives were presented for erosion control in river beds (free spanning, unburied and buried pipe), river banks (curves and meanders), flood plains, river diversions through the right of way, and rivers subject to debris flow. While developing a solution, basic hydraulic principles must be taken into consideration, keeping in mind that the primary objective is to protect a pipeline. For each of the typical solutions discussed in the 2003 paper, there will be an example with a brief theoretical explanation, a conceptual justification of the solution adopted, and recommendations for construction details which become critical for the success of the projects implemented. (author)
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Weed communities of rain-fed lowland rice vary with infestation by Rhamphicarpa fistulosa
Houngbédji, Tossimidé; Dessaint, Fabrice; Nicolardot, Bernard; Shykoff, Jacqui A.; Gibot-Leclerc, Stéphanie
2016-11-01
The facultative hemiparasitic plant Rhamphicarpa fistulosa (Orobanchaceae) thrives in seasonally wet soils in sub-Saharan Africa, mainly in marginal lowland rice growing environments where weeds are already a major constraint for rice production. Because lowland rice production is increasing in tropical Africa, it is important to ascertain the influence of R. fistulosa on weed plant communities in these rice-growing habitats. We investigated weed plant community richness and composition at four different levels of R. fistulosa infestation across two years of surveys from lowland rice fields in northern Togo (West Africa). Despite a lack of significant differences in community richness among sites with different R. fistulosa infestation levels, there were significant differences in community composition, both when estimated from presence-absence data and from relative abundance data, after controlling statistically for geographic proximity among sites. Rhamphicarpa fistulosa infestation, therefore, may influence the competitive balance between rice and its weeds and shape weed community structure. However, experimental studies are required to elucidate the weed host range of R. fistulosa and the direct and indirect effects of this hemiparasite in rice fields in order to predict its net impact on rice and its weed species.
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Simon, A.; Pollen, N. L.; Langendoen, E. J.
2005-05-01
The Upper Truckee River is the single largest contributor of sediment to Lake Tahoe with a large proportion of the suspended-sediment load coming from eroding streambanks. Recent advances in quantifying streambank processes highlight the combined effects of hydraulic erosion at the bank toe with geotechnical stability of the upper part of the bank and resulted in the development of a deterministic model of bank-toe erosion and streambank stability (Simon et al., 1999). The use of riparian vegetation in schemes of bank stabilization and stream restoration have become popular but are often implemented on a trial and error basis because of a lack of quantifiable information on the mechanical and hydrologic effects of vegetation on bank stability. This study, conducted along an unstable reach of the Upper Truckee River, combines field data with numerical modeling to quantify (1) hydraulic and geotechnical driving and resisting forces that control bank failures, (2) the mechanical and hydrologic effects of vegetation on shear strength, and (3) the critical conditions for bank stability with and without indigenous riparian species. Tests were conducted using three top-bank treatments: bare (control), Lemmon's willow, and young Lodgepole pine. The susceptibility of the bank toe to erosion by hydraulic forces was quantified by conducting submerged jet tests of in situ material to determine the erodibility coefficient (k) and the critical shear stress of the material. Drained, shear-strength parameters (cohesion and friction angle) of the banks were determined from borehole shear tests at various depths. Pore-water pressure and matric suction were monitored at three depths (30, 100, and 150 cm) with digital tensiometers to calculate changes in apparent cohesion for the period (September 2003 - May 2004) and to differentiate between the hydrologic effects of the two species. Root reinforcement of the two species was quantified by determining the relation between root
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Directory of Open Access Journals (Sweden)
Luis A. de Avila
2000-08-01
Full Text Available Num ecossistema agrícola, a redução do banco de sementes é um dos aspectos mais importantes no manejo de plantas daninhas; e em solos de várzeas, o arroz vermelho (Oryza sativa L. é atualmente considerado a principal planta daninha. Nesse sentido, conduziu-se um experimento com o objetivo de avaliar a evolução do banco de sementes de arroz vermelho no solo em diferentes sistemas de semeadura de arroz irrigado e em alternativas de manejo do solo de várzea. O experimento foi instalado em campo por dois anos consecutivos na mesma área (safras agrícolas 1996/97 e 1997/98 em Santa Maria, RS, em solo classificado como Planossolo, com infestação média de 516 sementes viáveis de arroz vermelho/m². A estimativa do banco de sementes de arroz vermelho foi realizada através de 10 coletas de solo, utilizando um cilindro com 0,10m de diâmetro a 0,10m de profundidade. Após a coleta, os grãos foram separados do solo e realizado teste de tetrazólio para determinar a quantidade de sementes viáveis na amostra. As coletas foram realizadas antes da instalação do experimento (set/1996, após a colheita do primeiro ano (mai/1997 e após a colheita do segundo ano (mai/1998. Os resultados mostraram que o cultivo do arroz no sistema convencional promove aumento no banco de sementes de arroz vermelho, enquanto que a semeadura de arroz em solo inundado (mix de pré-germinado, prégerminado ou transplante de mudas é tão eficiente na redução do banco de sementes de arroz vermelho quanto a rotação com o sorgo, o pousio do solo sem a presença de animais e também o preparo de verão.In an agricultural ecosystem, the redution of weed seed bank is of utmost importance. In lowland areas, red rice (Oryza sativa is the most important weed. Therefore, an experiment was conducted to evaluate the evolution of the red rice seed bank under different seeding systems and alternatives of soil management. The experiment was conducted during two years (1996
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A drifter for measuring water turbidity in rivers and coastal oceans.
Marchant, Ross; Reading, Dean; Ridd, James; Campbell, Sean; Ridd, Peter
2015-02-15
A disposable instrument for measuring water turbidity in rivers and coastal oceans is described. It transmits turbidity measurements and position data via a satellite uplink to a processing server. The primary purpose of the instrument is to help document changes in sediment runoff from river catchments in North Queensland, Australia. The 'river drifter' is released into a flooded river and drifts downstream to the ocean, measuring turbidity at regular intervals. Deployment in the Herbert River showed a downstream increase in turbidity, and thus suspended sediment concentration, while for the Johnstone River there was a rapid reduction in turbidity where the river entered the sea. Potential stranding along river banks is a limitation of the instrument. However, it has proved possible for drifters to routinely collect data along 80 km of the Herbert River. One drifter deployed in the Fly River, Papua New Guinea, travelled almost 200 km before stranding. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Risk assessment for arsenic-contaminated groundwater along River Indus in Pakistan.
Rabbani, Unaib; Mahar, Gohar; Siddique, Azhar; Fatmi, Zafar
2017-02-01
The study determined the risk zone and estimated the population at risk of adverse health effects for arsenic exposure along the bank of River Indus in Pakistan. A cross-sectional survey was conducted in 216 randomly selected villages of one of the districts along River Indus. Wells of ten households from each village were selected to measure arsenic levels. The location of wells was identified using global positioning system device, and spatial variations of the groundwater contamination were assessed using geographical information system tools. Using layers of contaminated drinking water wells according to arsenic levels and population with major landmarks, a risk zone and estimated population at risk were determined, which were exposed to arsenic level ≥10 µg/L. Drinking wells with arsenic levels of ≥10 µg/L were concentrated within 18 km near the river bank. Based on these estimates, a total of 13 million people were exposed to ≥10 µg/L arsenic concentration along the course of River Indus traversing through 27 districts in Pakistan. This information would help the researchers in designing health effect studies on arsenic and policy makers in allocating resources for designing focused interventions for arsenic mitigation in Pakistan. The study methods have implication on similar populations which are affected along rivers due to arsenic contamination.
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Is banking supervision central to central banking?
Joe Peek; Eric S. Rosengren; Geoffrey M. B. Tootell
1997-01-01
Whether central banks should play an active role in bank supervision and regulation is being debated both in the United States and abroad. While the Bank of England has recently been stripped of its supervisory responsibilities and several proposals in the United States have advocated removing bank supervision from the Federal Reserve System, other countries are considering enhancing central bank involvement in this area. Many of the arguments for and against these proposals hinge on the effe...
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Directory of Open Access Journals (Sweden)
Wayne M Koster
Full Text Available Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007-2011. Fish were tagged and released in autumn 2007-2009 in the mid-Murray (n = 42 and lower Goulburn (n = 37 rivers within 3-6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem-tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem-tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers.
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Koster, Wayne M; Dawson, David R; O'Mahony, Damien J; Moloney, Paul D; Crook, David A
2014-01-01
Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007-2011). Fish were tagged and released in autumn 2007-2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3-6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem-tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem-tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers.
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Koster, Wayne M.; Dawson, David R.; O’Mahony, Damien J.; Moloney, Paul D.; Crook, David A.
2014-01-01
Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007–2011). Fish were tagged and released in autumn 2007–2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3–6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem–tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem–tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers. PMID:24788137
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Bauwe, Andreas; Eckhardt, Kai-Uwe; Lennartz, Bernd
2017-04-01
Eutrophication is still one of the main environmental problems in the Baltic Sea. Currently, agricultural diffuse sources constitute the major portion of phosphorus (P) fluxes to the Baltic Sea and have to be reduced to achieve the HELCOM targets and improve the ecological status. Eco-hydrological models are suitable tools to identify sources of nutrients and possible measures aiming at reducing nutrient loads into surface waters. In this study, the Soil and Water Assessment Tool (SWAT) was applied to the Warnow river basin (3300 km2), the second largest watershed in Germany discharging into the Baltic Sea. The Warnow river basin is located in northeastern Germany and characterized by lowlands with a high proportion of artificially drained areas. The aim of this study were (i) to estimate P loadings for individual flow fractions (point sources, surface runoff, tile flow, groundwater flow), spatially distributed on sub-basin scale. Since the official version of SWAT does not allow for the modeling of P in tile drains, we tested (ii) two different approaches of simulating P in tile drains by changing the SWAT source code. The SWAT source code was modified so that (i) the soluble P concentration of the groundwater was transferred to the tile water and (ii) the soluble P in the soil was transferred to the tiles. The SWAT model was first calibrated (2002-2011) and validated (1992-2001) for stream flow at 7 headwater catchments at a daily time scale. Based on this, the stream flow at the outlet of the Warnow river basin was simulated. Performance statistics indicated at least satisfactory model results for each sub-basin. Breaking down the discharge into flow constituents, it becomes visible that stream flow is mainly governed by groundwater and tile flow. Due to the topographic situation with gentle slopes, surface runoff played only a minor role. Results further indicate that the prediction of soluble P loads was improved by the modified SWAT versions. Major sources of
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Energy Technology Data Exchange (ETDEWEB)
Seiler, K.P. [comp.] [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Hydrologie
1997-02-01
Main topics of this meeting are: bank filtration; surface water; groundwater; german rivers; water quality; organic pollutants; inorganic pollutants; pollutants transport; particulates; radiohydrometric analyses of bank filtration; mathematical models for materials balances; transport models. (SR)
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Environmental Degradation: A Review on the Potential Impact of River Morphology
Directory of Open Access Journals (Sweden)
Awang Ali Awang Nasrizal
2017-01-01
Full Text Available River morphology involves the lateral migration of matters deposited by flowing water in the river channel across its floodplain. This is driven by the erosion along the river banks and point bar deposition over time. This paper presents a review on river morphology studies and its potential impact to the society. The reviewed studies include mathematical models and computer simulation such as FLUVIAL-11 and RVR Meander Package that are significant to illustrate a continuous research development on channel adjustment. The findings also shows that a lot more area can still be explored to aid the fundamental of understanding river morphology and that East Malaysia will provide a good platform for the researchers to investigate the lateral migration of a river due to its diversity environment.
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Directory of Open Access Journals (Sweden)
Muhammad Irham
2016-08-01
Full Text Available Dynamic interactions of hydrological and geomorphological processes in the fluvial system result in accumulated deposit on the bed because the capacity to carry sediment has been exceeded. The bed load of the Aceh fluvial system is primarily generated by mechanical weathering resulting in boulders, pebbles, and sand, which roll or bounce along the river bed forming temporary deposits as bars on the insides of meander bends, as a result of a loss of transport energy in the system. This dynamic controls the style and range of deposits in the Aceh River. This study focuses on the spatial distribution of bed-load transport of the Aceh River. Understanding the spatial distribution of deposits facilitates the reconstruction of the changes in controlling factors during accumulation of deposits. One of the methods can be done by sieve analysis of sediment, where the method illuminates the distribution of sediment changes associated with channel morphology under different flow regimes. Hence, the purpose of this mini review is to investigate how the sediment along the river meander spatially dispersed. The results demonstrate that channel deposits in the Aceh River are formed from four different type of materials: pebble deposited along upstream left bank; sand located on the upstream, downstream, and along meander belts; and silt and clay located along the cut bank of meander bends. Because of different depositional pattern, the distribution of the sediment along the river can be used as a surrogate to identify bank stability, as well as to predict critical geometry for meander bend initiation
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Regional Banks in the Russian Banking System
Directory of Open Access Journals (Sweden)
Mikhail Vitalyevich Leonov
2015-06-01
Full Text Available Despite the lack of a uniform definition of «a regional bank», problems of their activities are widely discussed in the context of increasing regulation of the banking sector and creation of conditions for accelerated development of certain regions. The author analyses the Russian-language scientific literature in order to define «a regional bank» and systematize its key differences from other commercial banks. The researcher shows that the allocation of regional banks in a separate group should be related to specific features of the environment and not by endogenous factors associated with the selection of activities and balance sheet structure. The low level of financial market development and concentration of specific undiversified risks are the principal qualifiers differentiating between regional banks and other credit institutions in Russia. As classification criteria the author uses following: spatial representation (the bank does not have structural subdivisions in Moscow and the ownership structure (among the bank’s owners there are no national and international financial groups that have a direct impact on the operations of the bank
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Mobile banking: New trend in the contemporary banking sector
Directory of Open Access Journals (Sweden)
Sanader Dušica
2014-01-01
Full Text Available In the late 1990s and early 2000s, banking has undergone and is still undergoing some considerable changes, adjusting itself to the new circumstances and challenges in its environment. Modern information technologies have granted an opportunity to banks to expand their operations and adjust their offer of products and services, placing them through the new communication channels. The increasing reliance on mobile devices, especially the so-called smart phones, has facilitated the development of a new form of banking, known as mobile banking. Mobile banking is a specific channel of electronic banking, enabling clients to communicate with the bank via mobile devices. The bank's products and services are, thus, available to the clients at any time and at any place, and the banking sector is expected to perfectly understand the needs of today's clients, before implementing mobile banking. The research in this paper focuses on mobile banking, as a segment of electronic banking, which has developed under the influence of modern information technologies. The paper elaborates on the main characteristics of mobile banking, its advantages, but also its drawbacks that the banks and their clients are facing in the process of its utilization (or its implementation in practice. Moreover, the paper presents the trends of using mobile banking in the world and in Serbia, along with the tendencies for developing new services.
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Maria Klimikova
2010-01-01
Understanding the reasons of the present financial problems lies In understanding the substance of fractional reserve banking. The substance of fractional banking is in lending more money than the bankers have. Banking of partial reserves is an alternative form which links deposit banking and credit banking. Fractional banking is causing many unfavorable economic impacts in the worldwide system, specifically an inflation.
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Vistula River bed erosion processes and their influence on Warsaw’s flood safety
Directory of Open Access Journals (Sweden)
A. Magnuszewski
2015-03-01
Full Text Available Large cities have historically been well protected against floods as a function of their importance to society. In Warsaw, Poland, located on a narrow passage of the Vistula River valley, urban flood disasters were not unusual. Beginning at the end of the 19th century, the construction of river embankment and training works caused the narrowing of the flood passage path in the downtown reach of the river. The process of bed erosion lowered the elevation of the river bed by 205 cm over the 20th century, and the consequences of bed lowering are reflected by the rating curve change. Conditions of the flood passage have been analysed by the CCHE2D hydrodynamic model both in retro-modelling and scenario simulation modelling. The high water mark of the 1844 flood and iterative calculations in retro-modelling made possible estimation of the discharge, Q = 8250 m3 s−1. This highest observed historical flood in a natural river has been compared to recent conditions of the Vistula River in Warsaw by scenario modelling. The result shows dramatic changes in water surface elevation, velocities, and shear stress. The vertical velocity in the proximity of Port Praski gauge at km 513 can reach 3.5 m s−1, a very high value for a lowland river. The average flow conveyance is improving due to channel erosion but also declining in the case of extreme floods due to high resistance from vegetation on the flood plains.
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Disentailment and agricultural intensification of river banks: the vega de Aranjuez
International Nuclear Information System (INIS)
Lopez Garcia, M. J.; Mateu Belles, J. F.
2009-01-01
In Spain, successive appropriations by the state of river flood terraces which had previously been in communal or private hands led to apart from notorious social repercussions-increased pressure on the limited water resources, loss of the diversity of agricultural uses as practices became more uniform, and accelerated destruction of the few remaining fragments or riverside woodlands. later water laws (1866 and 1879) and court rulings permitted the aggregation of adjacent fields on river margins, the disappearance of customary uses (including settled and transhumant grazing) and the expansion of horticulture and other intensive arable crops. (Author) 8 refs.
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Huntley, Jerry W; Voelker, Gary
2016-06-01
Recent investigations of distributional patterns of Afro-tropical lowland forest species have demonstrated to some degree our overall lack of understanding involving historical diversification patterns. Traditionally, researchers have relied upon two hypotheses, each of which views the lowland forest of Africa in differing roles. The Pleistocene Forest Refuge Hypothesis (PFRH) posits that biogeographic patterns of avian lowland species are explained via allopatric speciation during forest fragmentation cycles in the Pleistocene epoch (c. 1.8Ma-11,700Ka). The Montane Speciation Hypothesis (MSH) countered by suggesting that lowland forests are "evolutionary museums" where species, which originally evolved in montane forest refuge centers, remained without further diversification. Furthermore, investigations have largely regarded widespread, avian species which lack phenotypic variability as biogeographically "uninformative", with regards to historical biogeographic patterns. To test the tenets of these ideas, we investigated the systematics and biogeography of the genus Bleda, whose constituent species are restricted to lowland forest and are lacking in phenotypic variation. Using extracted DNA from 179 individuals, we amplified two mitochondrial genes and three nuclear loci and utilized Bayesian phylogenetic methods and molecular clock dating to develop a time-calibrated phylogeny of Bleda. We used LaGrange to develop an ancestral area reconstruction for the genus. Haplotype networks for three species were generated using Network. We recovered the four currently recognized species of Bleda, plus a monophyletic B. ugandae, a current sub-species which may warrant full species status. We found that the origins of the genus Bleda are estimated to be in the Upper Guinean forests of West Africa, dating to the Miocene (c. 7.5Ma), while the speciation events for the rest of the genus are dated to the Pliocene (c. 5-1.8Ma). Our analyses recovered discrete and highly
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Bibler, Sarah; Zuckerman, Elaine
2013-01-01
With the aim of reducing women's greater unpaid care work than men&'s and increasing women's paid employment, this paper examines the extent to which World Bank investments address unpaid care work. The paper conducts an in-depth gender analysis of 36 World Bank employment-related projects in Malawi, Mali, Niger, and Rwanda. It concludes that the vast majority (92 per cent) of reviewed projects fail to account for unpaid care work. Exceptionally, Malawi's Shire River Basin Management Program ...
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Lunzer, J.; Williams, K. H.; Malenda, H. F.; Nararne-Sitchler, A.
2016-12-01
An improved understanding of the geochemical gradient created by the mixing of surface and groundwater of a river system will have considerable impact on our understanding of microorganisms, organic cycling and biogeochemical processes within these zones. In this study, the geochemical gradient in the hyporheic zone is described using a variety of geochemical properties. A system of shallow groundwater wells were installed in a series of transects along a stream bank. Each transect consists of several wells that progress away from the river bank in a perpendicular fashion. From these wells, temperature, conductivity and pH of water samples were obtained via hand pumping or bailing. These data show a clear geochemical gradient that displays a distinct zone in the subsurface where the geochemical conditions change from surface water dominated to groundwater dominated. For this study, the East River near Crested Butte, Colorado has been selected as the river of interest due the river being a relatively undisturbed floodplain. Additionally, the specific section chosen on the East River displays relatively high sinuosity meaning that these meandering sections will produce hyporheic zones that are more laterally expansive than what would be expected on a river of lower sinuosity. This increase in lateral extension of the hyporheic zone will make depicting the subtle changes in the geochemical gradient much easier than that of a river system in which the hyporheic zone is not as laterally extensive. Data has been and will be continued to be collected at different river discharges to evaluate the geochemical gradient at differing rates. Overall, this characterization of the geochemical gradient along stream banks will produce results that will aid in the further use of geochemical methods to classify and understand hyporheic exchange zones and the potential expansion of these techniques to river systems of differing geologic and geographic conditions.
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Influence of Disturbance on Habitats and Biological Communities in Lowland Streams
DEFF Research Database (Denmark)
Pedersen, Morten Lauge; Friberg, N.
2009-01-01
). The results indicate that disturbance cascades through the stream ecosystem, primarily meditated by changes in macrophyte communities that are essential providers of habitat in unshaded lowland streams in which other structural elements, as coarse inorganic substrates and woody debris, are scarce...
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Colas, Fanny; Archaimbault, Virginie; Devin, Simon
2011-03-01
Due to their nutrient recycling function and their importance in food-webs, macroinvertebrates are essential for the functioning of aquatic ecosystems. These organisms also constitute an important component of biodiversity. Sediment evaluation and monitoring is an essential aspect of ecosystem monitoring since sediments represent an important component of aquatic habitats and are also a potential source of contamination. In this study, we focused on macroinvertebrate communities within run-of-river dams, that are prime areas for sediment and pollutant accumulation. Little is known about littoral macroinvertebrate communities within run-of-river dam or their response to sediment levels and pollution. We therefore aimed to evaluate the following aspects: the functional and structural composition of macroinvertebrate communities in run-of-river dams; the impact of pollutant accumulation on such communities, and the most efficient scales and tools needed for the biomonitoring of contaminated sediments in such environments. Two run-of-river dams located in the French alpine area were selected and three spatial scales were examined: transversal (banks and channel), transversal x longitudinal (banks/channel x tail/middle/dam) and patch scale (erosion, sedimentation and vegetation habitats). At the patch scale, we noted that the heterogeneity of littoral habitats provided many available niches that allow for the development of diversified macroinvertebrate communities. This implies highly variable responses to contamination. Once combined on a global 'banks' spatial scale, littoral habitats can highlight the effects of toxic disturbances. Copyright © 2011 Elsevier B.V. All rights reserved.
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DeJager, Nathan R.; Rohweder, Jason J.; Yin, Yao; Hoy, Erin E.
2016-01-01
Questions How is the distribution of different plant communities associated with patterns of flood inundation across a large floodplain landscape? Location Thirty-eight thousand nine hundred and seventy hectare of floodplain, spanning 320 km of the Upper Mississippi River (UMR). Methods High-resolution elevation data (Lidar) and 30 yr of daily river stage data were integrated to produce a ‘floodscape’ map of growing season flood inundation duration. The distributions of 16 different remotely sensed plant communities were quantified along the gradient of flood duration. Results Models fitted to the cumulative frequency of occurrence of different vegetation types as a function of flood duration showed that most types exist along a continuum of flood-related occurrence. The diversity of community types was greatest at high elevations (0–10 d of flooding), where both upland and lowland community types were found, as well as at very low elevations (70–180 d of flooding), where a variety of lowland herbaceous communities were found. Intermediate elevations (20–60 d of flooding) tended to be dominated by floodplain forest and had the lowest diversity of community types. Conclusions Although variation in flood inundation is often considered to be the main driver of spatial patterns in floodplain plant communities, few studies have quantified flood–vegetation relationships at broad scales. Our results can be used to identify targets for restoration of historical hydrological regimes or better anticipate hydro-ecological effects of climate change at broad scales.
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Two-Dimensional (2-D) Acoustic Fish Tracking at River Mile 85, Sacramento River, California
2013-06-01
on fish become known (USACE 2004). Levee repair and constructed habitat features included (1) protection of the toe and upper slopes of the bank...be recovered rather than being lost due to sediment dunes , large woody material floating downstream, and vandalism. The RM 85 site was a relatively...into the river channel. The addition of this material narrowed the channel and created a scour feature along the toe of the repair site. VPS array
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Re-Meandering of Lowland Streams
DEFF Research Database (Denmark)
Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai
2014-01-01
We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats...... and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled...... along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored...
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International Nuclear Information System (INIS)
Durant, W.S.
1980-01-01
The Savannah River Laboratory has developed an integrated risk assessment methodology that has been applied to systems in the nuclear fuel reprocessing facilities at the Savannah River Plant. The methodology can be applied to several types of design and operational problems. Basically, the analysis is subdivided into individual modules that can be either utilized separately or integrated into an overall risk analysis. Computer codes and computer data banks are utilized extensively to minimize the manual effort. The flow of information begins with a definition of the system to be analyzed followed by an evaluation of sources of fault information, storage of this information in data banks, design analysis and data treatment, risk calculations, and end product options
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Salmonid Gamete Preservation in the Snake River Basin : 2000 Annual Report.
Energy Technology Data Exchange (ETDEWEB)
Armstrong, Robyn; Kucera, Paul A. [Nez Perce Tribe. Dept. of Fisheries Resource Management, Lapwai, ID (US)
2001-06-01
Steelhead (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytscha) populations in the Northwest are decreasing. Genetic diversity is being lost at an alarming rate. The Nez Perce Tribe (Tribe) strives to ensure availability of genetic samples of the existing male salmonid population by establishing and maintaining a germplasm repository. The sampling strategy, initiated in 1992, has been to collect and preserve male salmon and steelhead genetic diversity across the geographic landscape by sampling within the major river subbasins in the Snake River basin, assuming a metapopulation structure existed historically. Gamete cryopreservation conserves genetic diversity in a germplasm repository, but is not a recovery action for listed fish species. The Tribe was funded in 2000 by the Bonneville Power Administration (BPA) and the U.S. Fish and Wildlife Service Lower Snake River Compensation Plan (LSRCP) to coordinate gene banking of male gametes from Endangered Species Act listed steelhead and spring and summer chinook salmon in the Snake River basin. In 2000, a total of 349 viable chinook salmon semen samples from the Lostine River, Catherine Creek, upper Grande Ronde River, Lookingglass Hatchery (Imnaha River stock), Rapid River Hatchery, Lake Creek, the South Fork Salmon River weir, Johnson Creek, Big Creek, Capehorn Creek, Marsh Creek, Pahsimeroi Hatchery, and Sawtooth Hatchery (upper Salmon River stock) were cryopreserved. Also, 283 samples of male steelhead gametes from Dworshak Hatchery, Fish Creek, Grande Ronde River, Imnaha River, Little Sheep Creek, Pahsimeroi Hatchery and Oxbow Hatchery were also cryopreserved. The Tribe acquired 5 frozen steelhead samples from the Selway River collected in 1994 and 15 from Fish Creek sampled in 1993 from the U.S. Geological Survey, for addition into the germplasm repository. Also, 590 cryopreserved samples from the Grande Ronde chinook salmon captive broodstock program are being stored at the University of Idaho as
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Energy Technology Data Exchange (ETDEWEB)
Jordanoski, Momchulo; Veljanoska-Serafiloska, Elizabeta [Hydrobiological Institute, Ohrid (Macedonia, The Former Yugoslav Republic of)
2001-07-01
From the Rivers, which are subject of our investigation, only River Brajcinska and River Kranska are mountain rivers, while River Golema is lowland river. This has influence on water quality, which is evidently from the dates we found for the investigated parameters. Water quality moves from distinctly clear oligo trophic water (winter period), to strongly eytrophic polluted water (summer, autumn,). Great organic loading of River Golema in the summer period is evidential. Although, there are small possibilities of many investigations on this part, our obligation is to find possibilities, even to reduce some of sampling points of this project, to define the real state in long time period, so we could find appropriate conclusions and suggestions to eliminate that situation. Fields watching of the river beds and results from the laboratory investigations, shows how big is mans negligence for this natural resources. Practically, this rivers are recipients of all wastes that man made, like solid waste, communal waste water, waste water from pig farms, etc. International character of Lake Prespa enforces need of much completely and sensible engagement for reclaiming the state of the rivers inflow, in aim to protect the Lake. (Original)
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A water storage adaptation in the maya lowlands.
Scarborough, V L; Gallopin, G G
1991-02-08
Prehispanic water management in the Maya Lowlands emphasized collection and storage rather than the canalization and diversion accentuated in highland Mexico. Reexamination of site maps of the ancient Maya city of Tikal, Guatemala, has revealed an important, overlooked factor in Maya centralization and urban settlement organization. In a geographical zone affected by an extended dry season and away from permanent water sources, large, well-planned reservoirs provided resource control as well as political leverage.
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Hyperspectral remote sensing of canopy biodiversity in Hawaiian lowland rainforests
Kimberly M. Carlson; Gregory P. Asner; R. Flint Hughes; Rebecca Ostertag; Roberta E. Martin
2007-01-01
Mapping biological diversity is a high priority for conservation research, management and policy development, but few studies have provided diversity data at high spatial resolution from remote sensing. We used airborne imaging spectroscopy to map woody vascular plant species richness in lowland tropical forest ecosystems in Hawaii. Hyperspectral signatures spanning...
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Simulation and comparison of stream power in-channel and on the floodplain in a German lowland area
Directory of Open Access Journals (Sweden)
Song Song
2014-06-01
Full Text Available Extensive lowland floodplains cover substantial parts of the glacially formed landscape of Northern Germany. Stream power is recognized as a force of formation and development of the river morphology and an interaction system between channel and floodplain. In order to understand the effects of the river power and flood power, HEC-RAS models were set up for ten river sections in the Upper Stör catchment, based on a 1 m digital elevation model and field data, sampled during a moderate water level period (September, 2011, flood season (January, 2012 and dry season (April, 2012. The models were proven to be highly efficient and accurate through the seasonal roughness modification. The coefficients of determination (R2 of the calibrated models were 0.90, 0.90, 0.93 and 0.95 respectively. Combined with the continuous and long-term data support from SWAT model, the stream power both in-channel and on the floodplain was analysed. Results show that the 10-year-averaged discharge and unit stream power were around 1/3 of bankfull discharge and unit power, and the 10-year-peak discharge and unit stream power were nearly 1.6 times the bankfull conditions. Unit stream power was proportional to the increase of stream discharge, while the increase rate of unit in-channel stream power was 3 times higher than that of unit stream power on the floodplain. Finally, the distribution of the hydraulic parameters under 10-years-peak discharge conditions was shown, indicating that only 1-10% of flow stream was generated by floodplain flow, but 40-75% volume of water was located on the floodplain. The variation of the increasing rate of the stream power was dominated by the local roughness height, while the stream power distributed on the floodplain mainly depended on the local slope of the sub-catchment.
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Directory of Open Access Journals (Sweden)
A. Liaghat
2017-04-01
Full Text Available The establishment of stability in rivers is dependent on a variety of factors, and yet the established stability can be interrupted at any moment or time. One factor that can strongly disrupt the stability of rivers is the construction of dams. For this study, the identification and evaluation of morphological changes occurring to the Karkheh River, before and after the construction of the Karkheh Dam, along with determining the degree of changes to the width and length of the downstream meanders of the river, have been performed with the assistance of satellite images and by applying the CCHE2D hydrodynamic model. Results show that under natural circumstances the width of the riverbed increases downstream parallel to the decrease in the slope angle of the river. The average width of the river was reduced from 273 meters to 60 meters after dam construction. This 78% decrease in river width has made available 21 hectares of land across the river bank per kilometer length of the river. In the studied area, the average thalweg migration of the river is approximately 340 meters, while the minimum and maximum of river migration measured 53 and 768 meters, respectively. Evaluations reveal that nearly 56% of the migrations pertain to the western side of the river, while over 59% of these migrations take place outside the previous riverbed. By average, each year, the lateral migration rate of the river is 34 meters in the studied area which signifies the relevant instability of the region.
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Comparison of different base flow separation methods in a lowland catchment
Directory of Open Access Journals (Sweden)
S. Uhlenbrook
2009-11-01
Full Text Available Assessment of water resources available in different storages and moving along different pathways in a catchment is important for its optimal use and protection, and also for the prediction of floods and low flows. Moreover, understanding of the runoff generation processes is essential for assessing the impacts of climate and land use changes on the hydrological response of a catchment. Many methods for base flow separation exist, but hardly one focuses on the specific behaviour of temperate lowland areas. This paper presents the results of a base flow separation study carried out in a lowland area in the Netherlands. In this study, field observations of precipitation, groundwater and surface water levels and discharges, together with tracer analysis are used to understand the runoff generation processes in the catchment. Several tracer and non-tracer based base flow separation methods were applied to the discharge time series, and their results are compared.
The results show that groundwater levels react fast to precipitation events in this lowland area with shallow groundwater tables. Moreover, a good correlation was found between groundwater levels and discharges suggesting that most of the measured discharge also during floods comes from groundwater storage. It was estimated using tracer hydrological approaches that approximately 90% of the total discharge is groundwater displaced by event water mainly infiltrating in the northern part of the catchment, and only the remaining 10% is surface runoff. The impact of remote recharge causing displacement of near channel groundwater during floods could also be motivated with hydraulic approximations. The results show further that when base flow separation is meant to identify groundwater contributions to stream flow, process based methods (e.g. the rating curve method; Kliner and Knezek, 1974 are more reliable than other simple non-tracer based methods. Also, the recursive filtering method -
SUSPENDED AND DISSOLVED MATTER FLUXES IN THE UPPER SELENGA RIVER BASIN
Directory of Open Access Journals (Sweden)
Sergey Chalov
2012-01-01
Full Text Available We synthesized recent field-based estimates of the dissolved ions (K+ Na+ Ca2+ Mg2+ Cl- SO42- HCO3-, biogens (NO3-, NO2-, PO43-(C, mg/l, heavy metal (Fesum, Mn, Pb and dissolved load (DL, kg/day, as far as suspended sediment concentration (SSC, mg/l and suspended load (SL, kg/day along upper Selenga river and its tributaries based on literature review and preliminary results of our 2011 field campaign. The crucial task of this paper is to provide full review of Russian, Mongolian and English-language literature which concern the matter fluxes in the upper part of Selenga river (within Mongolia. The exist estimates are compared with locations of 3 main matter sources within basin: mining and industry, river-bank erosion and slope wash. The heaviest increase of suspended and dissolved matter transport is indicated along Tuul-Orkhon river system (right tributary of the Selenga River where Mongolia capital Ulanbaatar, gold mine Zaamar and few other mines are located. In measurement campaigns conducted in 2005, 2006 and 2008 the increase directly after the Zaamar mining site was between 167 to 383 kg/day for Fe, between 15 and 5260 kg/day for Mn. Our field campaign indicated increase of suspended load along Tuul river from 4280 kg/day at the upstream point to 712000 kg/day below Ulaanbaatar and Zaamar. The results provide evidence on a potential connection between increased dissolved and suspended matter fluxes in transboundary rivers and zones of matter supply at industrial and mining centers, along eroded river banks and pastured lands. The gaps in the understanding of matter load fluxes within this basin are discussed with regards to determining further goals of hydrological and geochemical surveys.
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Sediment deposition rate in the Falefa River basin, Upolu Island, Samoa
International Nuclear Information System (INIS)
Terry, James P.; Kostaschuk, Ray A.; Garimella, Sitaram
2006-01-01
The 137 Cs method was employed to investigate the recent historical rate of sediment deposition on a lowland alluvial floodplain in the Falefa River basin, Upolu Island, Samoa. Caesium stratigraphy in the floodplain sediment profile was clearly defined, with a broad peak at 145-175 cm depth. The measured rate of vertical accretion over the last 40 years is 4.0 ± 0.4 cm per year. This rate exceeds observations in humid environments elsewhere, but is similar to that recorded on other tropical Pacific Islands. Available flow data for the Vaisigano River in Samoa give a 'near-catastrophic' index value of 0.6 for flood variability. This is associated with the occurrence of tropical cyclones and storms in the Samoa area. Large floods therefore probably contribute to the high rate of floodplain sedimentation on Upolu Island. A small but growing body of evidence suggests that fluvial sedimentation rates on tropical Pacific islands are some of the highest in the world
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Angel, Christania Graciella
2014-01-01
Bank performance appraisal is based on bank financial report itself. The financial report can be form balance report which give information about the financial position to the outside of bank that can be used of eksternal to assess the level of risk exist in a bank. Based on ownership consist of national bank, mixture bank and foreign bank. These banks has tight compete to show a good performance to the public. This research aimed to analyze the financial performance difference of national ba...
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LBA-ECO LC-07 Wetland Extent, Vegetation, and Inundation: Lowland Amazon Basin
National Aeronautics and Space Administration — This data set provides a map of wetland extent, vegetation type, and dual-season flooding state of the entire lowland Amazon basin. The map was derived from mosaics...
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Setiawan, B B
2002-01-01
The settlement along the bank of the Code River in Yogyakarta, Indonesia provides housing for a large mass of the city's poor. Its strategic location and the fact that most urban poor do not have access to land, attracts people to "illegally" settle along the bank of the river. This brings negative consequences for the environment, particularly the increasing domestic waste along the river and the annual flooding in the rainy season. While the public controversies regarding the existence of the settlement along the Code River were still not resolved, at the end of the 1980s, a group of architects, academics and community members proposed the idea of constructing a dike along the River as part of a broader settlement improvement program. From 1991 to 1998, thousands of local people mobilized their resources and were able to construct 6,000 metres of riverside dike along the Code River. The construction of the riverside dike along the River has become an important "stimulant" that generated not only settlement improvement, but also a better treatment of river water. As all housing units located along the River are now facing the River, the River itself is considered the "front-yard". Before the dike was constructed, the inhabitants used to treat the River as the "backyard" and therefore just throw waste into the River. They now really want to have a cleaner river, since the River is an important part of their settlement. The settlement along the Code River presents a complex range of persistent problems with informal settlements in Indonesia; such problems are related to the issues of how to provide more affordable and adequate housing for the poor, while at the same time, to improve the water quality of the river. The project represents a good case, which shows that through a mutual partnership among stakeholders, it is possible to integrate environmental goals into urban redevelopment schemes.
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CUSTOMER SATISFACTION WITH INTERNET BANKING IN PUBLIC AND PRIVATE BANK
Inder Pal Singh S/o Roop singh*, Dr. Payal Bassi
2017-01-01
E- Banking is about using the infrastructure for digital age to create opportunities, both local & global. IT enables the dramatic lowering of transaction cost and the creation of new types of banking opportunities that address the barriers of time and distance. Banking opportunities are local, global and immediate in e-banking. Internet banking has many advantages over other traditional banking delivery methods. Internet banking provides banks with an increased customer base, cost savings, m...
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Electronic Banking And Bank Performance In Nigeria
African Journals Online (AJOL)
2013-03-01
Mar 1, 2013 ... deploying information Technology in banks therefore can ... profitability indices and other control of financial ..... impact of e-banking on bank profitability ..... [13] Nikolai L. and Bazlay J.D (1997) Intermediate Accounting, South-.
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2010-04-21
... Carolina, Seneca National Bank, Seneca, South Carolina, and The Peoples National Bank, Easley, South... FEDERAL RESERVE SYSTEM Change in Bank Control Notices; Acquisition of Shares of Bank or Bank Holding Companies The notificants listed below have applied under the Change in Bank Control Act (12 U.S.C...
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Electronic Banking And Bank Performance In Nigeria | Abaenewe ...
African Journals Online (AJOL)
This study investigated the profitability performance of Nigerian banks following the full adoption of electronic banking system. The study became necessary as a result of increased penetration of electronic banking which has redefined the banking operations in Nigeria and around the world. Judgmental sampling method ...
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12 CFR 211.22 - Interstate banking operations of foreign banking organizations.
2010-01-01
... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Interstate banking operations of foreign banking organizations. 211.22 Section 211.22 Banks and Banking FEDERAL RESERVE SYSTEM BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM INTERNATIONAL BANKING OPERATIONS (REGULATION K) Foreign Banking...
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2010-08-13
... Peoples Bank and Trust Company, both of North Carrollton, Mississippi. B. Federal Reserve Bank of Dallas... FEDERAL RESERVE SYSTEM Change in Bank Control Notices; Acquisition of Shares of Bank or Bank Holding Companies The notificants listed below have applied under the Change in Bank Control Act (12 U.S.C...
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Modeling the fate of organic micropollutants during river bank filtration (Berlin, Germany).
Henzler, Aline F; Greskowiak, Janek; Massmann, Gudrun
2014-01-01
Emerging organic contaminants (EOCs) are frequently detected in urban surface water and the adjacent groundwater and are therefore an increasing problem for potable water quality. River bank filtration (RBF) is a beneficial pretreatment step to improve surface water quality for potable use. Removal is mainly caused by microbial degradation of micropollutants, while sorption retards the transport. The quantification of biodegradation and adsorption parameters for EOCs at field scale is still scarce. In this study, the fate and behavior of a range of organic compounds during RBF were investigated using a two dimensional numerical flow- and transport model. The data base used emanated from a project conducted in Berlin, Germany (NASRI: Natural and Artificial Systems for Recharge and Infiltration). Oxygen isotope signatures and hydraulic head data were used for model calibration. Afterwards, twelve organic micropollutants were simulated with a reactive transport model. Three compounds (primidone, EDTA, and AMDOPH) showed conservative behavior (no biodegradation or sorption). For the nine remaining compounds (1.5 NDSA, AOX, AOI, MTBE, carbamazepine, clindamycin, phenazone, diclofenac and sulfamethoxazole), degradation and/or sorption was observed. 1.5 NDSA and AOX were not sorbed, but slightly degraded with model results for λ=2.25e(-3) 1/d and 2.4e(-3) 1/d. For AOI a λ=0.0106 1/d and R=1 were identified. MTBE could be characterized well assuming R=1 and a low 1st order degradation rate constant (λ=0.0085 1/d). Carbamazepine degraded with a half life time of about 66 days after a threshold value of 0.2-0.3 μg/L was exceeded and retarded slightly (R=1.7). Breakthrough curves of clindamycin, phenazone, diclofenac and sulfamethoxazole could be fitted less well, probably due to the dependency of degradation on temperature and redox conditions, which are highly transient at the RBF site. Conditions range from oxic to anoxic (up to iron-reducing), with the oxic and
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PRIVATE BANKING AND WEALTH MANAGEMENT SERVICES OFFERED BY BANKS
IMOLA DRIGĂ; DORINA NIŢĂ; IOAN CUCU
2009-01-01
The paper examines the features of private banking business focusing on the substantial growth in private banking over the last decade as commercial banks have targeted upmarket high net worth individuals. The accumulation of wealth has prompted the development of private banking services for high net worth individuals, offering special relationships and investment services. Private banking is about much more than traditional banking services of deposits and loans. It's about providing a one-...
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Durčáková, Klára
2010-01-01
Resumé - Bank Contracts Bank Contracts are an integral part of our everyday lives. Citizen and bussines entities used bank contracts very often. Despite this fact we can't find legal definition in the Czech law. Banking contracts understand contracts that are signed by banks in their business activities and obligations under these contracts arise. While the banking contracts have been widely used, in Czech law there is not too much literature and judgements abou this issue. Lack of legislatio...
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Directory of Open Access Journals (Sweden)
Buddi Wibowo
2016-08-01
Full Text Available Abstract. The"Competition-fragility" view and The "Competition-stability" view has a contrary logical flow in predicting the relationship between bank stability and competition among banks. According to Berger et al (2009, these two views differ on credit risk aspect of loan portfolio, but on the risks faced by the bank as a whole, these two views have the same prediction. In the credit market which is dominated by few banks with substantial market power, the risk of bank credit portfolio increases as predicted by the view "competition-fragility", but the bank's overall risk does not always go up with the jump in credit portfolio risk. The paper shows that empirical test of the Indonesian banking system support this hypothesis, except in foreign bank group that has its own business model. The relationship of competition and the credit risk of banks in Indonesia also have a U -shape pattern that increasing competition in the early stages can reduce credit risk, which is due to increasing income diversification and diversification of bank credit type, but at a certain point the increasing competition has worsened the quality of bank credit portfolio. Key word: banking competition, risk, stability, fragility, diversification
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Directory of Open Access Journals (Sweden)
Sojka Mariusz
2016-09-01
Full Text Available The purpose of the presented research is analysis and assessment of the Stare Miasto reservoir impact on the hydrological regime changes of the Powa River. The reservoir was built in 2006 and is located in the central part of Poland. The total area of inundation in normal conditions is 90.68 ha and its capacity is 2.159 mln m3. Hydrological regime alteration of the Powa River is analysed on the basis of daily flows from the Posoka gauge station observed during period 1974–2014. Assessment of hydrological regime changes is carried out on the basis of Range of Variability Approach (RVA method. All calculations are made by means of Indicators of Hydrologic Alteration (IHA software version 7.1.0.10. The analysis shows that the Stare Miasto reservoir has a moderate impact on hydrological regime of the Powa River. Construction of the reservoir has positive effect on stability of minimal flows, which are important for protection of river ecosystems. The results obtained indicate that the Stare Miasto reservoir reduces a spring peak flow and enables to moderate control of floods.
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Anthony, Edward J.; Gardel, Antoine; Proisy, Christophe; Fromard, François; Gensac, Erwan; Peron, Christina; Walcker, Romain; Lesourd, Sandric
2013-07-01
The morphology and sediment dynamics of the 1500 km-long coast of South America between the mouths of the Amazon and the Orinoco Rivers are largely dependent on the massive suspended-sediment discharge of the Amazon, part of which is transported alongshore as mud banks. These mud banks have an overwhelming impact on the geology, the geomorphology, the ecology and the economy of this coast. Although numerous field investigations and remote sensing studies have considerably enhanced our understanding of the dynamics of this coast over the last three decades, much still remains to be understood of the unique functional mechanisms and processes driving its evolution. Among the themes that we deem as requiring further attention three come out as fundamental. The first concerns the mechanisms of formation of individual mud banks from mud streaming on the shelf off the mouth of the Amazon. An unknown quantity of the fluid mud generated by offshore estuarine front activity is transported shoreward and progressively forms mud banks on the Amapá coast, Brazil. The volume of each mud bank can contain from the equivalent of the annual mud supply of the Amazon to several times this annual sediment discharge. The mechanisms by which individual banks are generated from the Amazon turbidity maximum are still to be elucidated. Areas of research include regional mesoscale oceanographic conditions and mud supply from the Amazon. The second theme is that of variations in rates of migration of mud banks, which influence patterns of coastal accretion. Research emphasis needs to be placed on the analysis of both regional meteorological-hydrodynamic forcing and distant Atlantic forcing, as well as on the hydrology of the large rivers draining the Guyana Shield. The rivers appear to generate significant offshore deflection of mud banks in transit alongshore, through a hydraulic-groyne effect. This may favour both muddy accretion on the updrift coast and downdrift mud liquefaction with
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Internet Banking integration within the banking system
Constantin Marian MATEI; Catalin Ionut SILVESTRU; Dragos Stefan SILVESTRU
2008-01-01
Internet Banking developed due to increasing demand of online banking transactions. The biggest advantages of Internet Banking consist of complex banking solutions, 24 hours availability, quick and secure access to the back-end application through Internet. These advantages are due to the use of SOA (service-oriented architecture). SOA appeared as a necessity of companies to integrate big and independent portions of applications, in order to obtain an homogeneous functionality of the system....
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Miyazawa, N.
2011-12-01
River-channel changes are a key factor affecting physical, ecological and management issues in the fluvial environment. In this study, long-term channel changes in the Mekong River were assessed using remote sensing and a channel-evolution model. A channel-evolution model for calculating long-term channel changes of a measndering river was developed using a previous fluid-dynamic model [Zolezzi and Seminara, 2001], and was applied in order to quantify channel changes of two meandering reaches in the Mekong River. Quite few attempts have been made so far to combine remote sensing observation of meandering planform change with the application of channel evolution models within relatively small-scale gravel-bed systems in humid temperate regions. The novel point of the present work is to link state-of-art meandering planform evolution model with observed morphological changes within large-scale sand-bed rivers with higher bank height in tropical monsoonal climate regions, which are the highly dynamic system, and assess the performance. Unstable extents of the reaches could be historically identified using remote-sensing technique. The instability caused i) bank erosion and accretion of meander bends and ii) movement or development of bars and changes in the flow around the bars. The remote sensing measurements indicate that maximum erosion occurred downstream of the maximum curvature of the river-center line in both reaches. The model simulations indicates that under the mean annual peak discharge the maximum of excess longitudinal velocity near the banks occurs downstream of the maximum curvature in both reaches. The channel migration coefficients of the reaches were calibrated by comparing remote-sensing measurements and model simulations. The diffrence in the migration coefficients between both reaches depends on the diffrence in bank height rather than the geotechnical properties of floodplain sediments. Possible eroded floodplain areas and accreted floodplain
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Alin, S. R.; Aalto, R.; Remington, S. M.; Richey, J. E.
2003-12-01
The Fly-Strickland fluvial dispersal system comprises one of the largest river basins in tropical Oceania, ranking among the top 20 rivers in the world for water and sediment discharge. From the New Guinea highlands, these rivers flow >1000 km across lowland tropical floodplains to the Gulf of Papua, with an average annual depth of runoff 100 times that of the Amazon. Within the system, the Strickland has greater sediment discharge and a steeper gradient than the Fly, providing an opportunity to investigate biogeochemical differences associated with particulate flux. For eight lowland sites across the Fly-Strickland river system, we analyzed water and suspended sediment (SS) samples for an initial survey of various carbon cycle parameters. Both the Fly and Strickland Rivers were strongly supersaturated with carbon dioxide (2008-10,479 uatm CO2) and undersaturated with oxygen (1.10-5.48 mg/l O2), with the Fly having higher CO2 and lower O2 concentrations than the Strickland River. These pCO2 and O2 concentrations are comparable to and lower than (respectively) typical values in the Amazon. Measured Fly-Strickland alkalinity values fell in the range of 0.893-1.888 meq, and pH measurements were neutral to slightly alkaline (6.916-7.852). In a sample from a sediment-impoverished tributary from Lake Murray to the Strickland (Herbert R.), pH was neutral (7.060), and alkalinity and pCO2 had their lowest observed values at 0.234 meq and 1407 uatm, respectively. Nutrient concentrations were generally higher in the Strickland ([NO3]=3.36+/-0.69 uM, [PO4]=0.09+/-0.10 uM, and [Si(OH)4]=176.6+/-41.7 uM) than in the Fly River ([NO3]=1.09+/-0.04 uM, [PO4]=0.01+/-0.01 uM, and [Si(OH)4]=110.6+/-4.8 uM). NO3 and PO4 concentrations in the Fly-Strickland river system were lower than in the Amazon, and silicate was comparable. SS concentrations were higher in the Strickland than in the Fly (49.4-231.1 mg/l vs. 19.5-59.6 mg/l). Coarse particulates were organic-poor in the Fly and
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Directory of Open Access Journals (Sweden)
Marta Leiva
2017-12-01
Full Text Available Abstract Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow into a network of irrigation channels and the other downstream that weir, in the assessment of the fluvial discontinuity. We assess the differences among reaches and sites, environmental variables, invertebrate density, richness and Shannon-Wiener index applying non-parametric analyses of variance Kruskal Wallis. The similarity percentage analysis (SIMPER was used to identify which species contributed to the dissimilarities on macroinvertebrate assemblage structure. Canonical Correspondence Analysis (CCA was performed with the total set of samples to explore macroinvertebrate distribution in reaches and associations of the assemblages with habitat variables. Results The density, richness and Shannon index values did not show differences between the reaches located upstream and downstream. Beta diversity (Whittaker was 0.72 among upstream sites, 0.56 among downstream sites and higher species turnover (0.73 was obtained between both reaches. The Canonical Correspondence Analysis explained 46.71% of the variance differentiating upstream sites explained by higher values of organic matter of bottom sediments and discharge, high density of Nais communis, Bothrioneurum americanum, Pelomus, Stephensoniana trivandrana, Pristina menoni, P. jenkinae, P.longidentata, P. americana, Dero obtusa, Endotribelos, Heleobia and Turbellaria. The downstream sites were associated to coarser substratum and higher density of Lopescladius, Polypedilum, Cricotopus, Thienamaniella, Cryptochironomus, Baetidae, Nematoda and Corbicula fluminea. Conclusions The low-flow disturbance had effects on the composition of the benthic invertebrate assemblages, but attributes (such as density and richness showed a lower variability probably
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75 FR 5322 - Change in Bank Control Notices; Acquisition of Shares of Bank or Bank Holding Companies
2010-02-02
... FEDERAL RESERVE SYSTEM Change in Bank Control Notices; Acquisition of Shares of Bank or Bank Holding Companies The notificants listed below have applied under the Change in Bank Control Act (12 U.S.C. 1817(j)) and Sec. [thinsp]225.41 of the Board's Regulation Y (12 CFR 225.41) to acquire a bank or bank...