scholarly journals Hydrogeological functions of obskoye and baksinskoye swamps in the southeast of West Siberian Plain

2021 ◽  
Vol 958 (1) ◽  
pp. 012018
Author(s):  
H Yang ◽  
O G Savichev
Keyword(s):  
Water Balance ◽  
Water Mass ◽  
Dry Season ◽  
West Siberian Plain ◽  
Water Runoff ◽  
Hydrological Data ◽  
Surface Evaporation ◽  
Quantitative Estimates ◽  
Bog Waters ◽  
The Impact

Abstract Based on hydrological data from 1966 to 2019, quantitative estimates of the water balance of the Baksinskoye and Obskoye fens. The decrease in surface evaporation of the swamp and the increase in water runoff occurred in the main distribution of the swamp. This will exacerbate the degree of swamping in the area. The impact of marsh water on groundwater is most likely to occur during the dry season in summer and autumn. During this period: 1) possible overflow of bog waters into underground horizons in areas of 800–900 m; 2) increased permeability. When the water mass is discharged from the fens plain into the river, the impact of the fens water reaches its maximum during the subside of the flood.

ANALYTICAL REVIEW OF INVESTIGATIONS OF THE CLIMATE CHANGE IMPACT ON RIVER WATER FLOW

2019 ◽  
pp. 64-73
Author(s):  
Hanna Bolbot ◽  
Vasyl Grebin
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Water Flow ◽  
Hydrological Modeling ◽  
Complex Method ◽  
Water Runoff ◽  
Impact Of Climate Change ◽  
Insufficient Attention ◽  
The World ◽  
The Impact

A huge number of scientific researches in the world are devoted to the research of global and regional climate change and their impact on water resources. In Ukraine, this issue is receiving insufficient attention. Researches have been done to assess current trends in river runoff, but future estimates of changes in Ukraine’s water flow have been presented in only a few papers. Present studies of this issue are conducted using hydrological modeling. The ensemble approach is widely used to increase the reliability of estimates of possible future changes in water runoff, that is, the use of data from several GCM and RCM models, with subsequent averaging of their results. Unfortunately, this methodological approach was not used in Ukraine. Using the water-balance method, local manifestations of global climate change within individual catchments can be estimated with sufficient quality. To estimate the temporal variability of the components of the water balance, a comparison of the available hydrological and climatic characteristics of the current period with the period of the climatic norm is used, as well as the method of differential integral curves, which reflects characteristic tendencies in the long-term dynamics of individual components of the water balance. Analyzing all available approaches to research on the impact of climate change on water flow, we can conclude that a complex method is the best for this investigation. Given that a large number of methods are used in the world, reliable estimates can be obtained by developing unified and validated methods and techniques. Therefore, the first step in this way should be a comparative analysis of the results obtained by the most commonly used methods. In the field of water, climate change can lead to changes in rainfall, hydrodynamic regime and water balance of rivers, increase of catastrophic floods and excessive drought, shortage of fresh water. Unfortunately, there is insufficient attention paid to the study of this issue in Ukraine. That is why assessing the impact of climate change on water flow and forecasting them is a very necessary task.

Impacts of human intervention through irrigation on hydrological responses of Lake Tana sub-basin, upper Blue Nile, Ethiopia.

2021 ◽  
Author(s):  
Meron Teferi Taye ◽  
Alemseged Tamiru Haile
Keyword(s):  
Water Balance ◽  
Irrigation Water ◽  
Water Source ◽  
Dry Season ◽  
Small Scale ◽  
Lake Tana ◽  
Blue Nile ◽  
Water Abstraction ◽  
The Impact ◽  
Small Scale Irrigation

<p>Lake water balance studies in Ethiopia are commonly conducted for natural conditions without considering the impact of water abstraction. However, hydrological changes are a function of changes caused by human interventions as much as through natural processes. The Lake Tana sub-basin is one of the important basins in Ethiopia as the source of the Blue Nile river and supporter of various livelihoods including considerable number of small-scale farmers. With Ethiopia’s ambitious plan to expand irrigation at different scales to feed the growing population, the Lake Tana sub-basin is one of the selected areas by the federal government for medium scale irrigation. Moreover, the basin is experiencing booming small-scale irrigation users due to initiations by local governments, NGOs and individual farmers. Small-scale community managed irrigation schemes and farmer-led irrigations schemes are common in the basin. While communities are expected to benefit from the expanding irrigation use, there is limited information on how this irrigation expansion impacts the water balance of the sub-basin.</p><p>In this study the area under small-scale irrigation is estimated through inventory survey of woredas (districts) that are within the Lake Tana sub-basin and cover the four main tributaries (Gilgel Abay, Ribb, Gumara, and Megech).  The inventory from 16 woredas showed more than 30,000 ha is under small-scale irrigation in the Lake Tana sub-basin in 2020. The dominant water source for irrigation is found to be surface water through diversion from rivers and streams. This accounts for 80% of irrigation water source. The other 20% comes from shallow groundwater sources, which are mainly located in the eastern part of the sub-basin in the floodplain in the Fogera area.</p><p>This study investigates the current situation of irrigation water abstraction through water abstraction surveys in selected locations in the dry-season and evaluates the impact of water abstraction on the long-term water balance of the sub-basin. Previous studies indicate that Gilgel Abay sub-basin, for instance, shows a decreasing dry season flow in the past decades, which might be associated with dry season water abstraction. The current survey provides the gross diversion of water from rivers to canals in the selected schemes. Preliminary results show large amount of water is being diverted by medium irrigation schemes but also collectively by small-scale irrigation schemes. Continuation of such water abstraction levels will be a concern to the water balance of the sub-basin as it increases losses without productive use and calls for better water management practices. </p>

scholarly journals Water balance study on green roof in Brazil

2020 ◽  
Vol 4 (4) ◽  
pp. 141-144
Author(s):  
Calheiros Herlane Costa ◽  
Silva Fernanda Gomes Gonçalves ◽  
Costa Luisa Silva ◽  
Silva Matheus Lins Macedo
Keyword(s):  
Water Balance ◽  
Rainy Season ◽  
Green Roof ◽  
Green Roofs ◽  
Dry Season ◽  
Water Retention Capacity ◽  
Water Runoff ◽  
Retention Capacity ◽  
Balance Study ◽  
Recovery Capacity

The present study aims to investigate the water balance in conventional and green roofs and also to monitor the development of peanut grass (Arachis repens Handro), relating the type of vegetation cover or not with its water retention capacity and, consequently, to obtain the coefficient of runoff for each scenario tested. The scenarios tested were: (1) conventional collection surface with fiber cement tile, (2) green roof structure with substrate and no plant, and (3) planted green roof. The rains incident on the roof were obtained for the city of Itajubá, in Minas Gerais, by the curve of i-d-f with 5min of duration and 5years of return period according to the recommendation of NBR 10844 (ABNT,1989). The volumes of storm water runoff and drained from the bottom of the roofs studied were collected in calibrated graduated containers. It was concluded that: the peanut grass showed satisfactory development and high recovery capacity; the peanut grass took only 1½ month to cover the entire roof; the coefficient of runoff of the green roof for intense rainy season was on average 0.569 and in the dry season it was 0.003. While the conventional roof presented average surface runoff coefficient of 0.995 for the rainy season and 0.901 for the dry season; the component of the green roof that contributed most to the rainwater retention was the substrate. Therefore, attention should be paid to the choice of substrate so that it can adequately grow the plant, retain rainwater and not contaminate the bottom drainage water of the roof that can be used for less noble uses.

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

On the benefit of the Canadian Small Lake Model to better represent the impact of small natural lakes on GEM-Hydro streamflow simulations.

2021 ◽  
Author(s):  
Etienne Gaborit ◽  
Murray MacKay ◽  
Camille Garnaud ◽  
Vincent Fortin
Keyword(s):  
Water Balance ◽  
Grid Point ◽  
Hydrologic Model ◽  
Surface Fluxes ◽  
Dew Point ◽  
Multiple Model ◽  
Small Lake ◽  
Surface Component ◽  
Lake Model ◽  
The Impact

<p>This study aims at assessing the impact of a new lake model on streamflow simulations performed with the GEM-Hydro hydrologic model developed at ECCC. GEM-Hydro is at the heart of the National Surface and River Prediction System (NSRPS) which ECCC uses to forecast river flows over most of Canada. The GEM-Hydro model mainly consists of the GEM-Surf component to represent surface processes, and of the Watroute model to represent river and lake routing, in order to perform streamflow simulations and forecasts. The surface component of GEM-Hydro can simulate 5 different types of surfaces.  Currently, the water tile consists of a very simple algorithm which, in terms of water balance, consists of producing runoff fluxes simply equal to precipitation minus evaporation. This runoff over water surfaces is then provided as input, along with runoff and drainage generated over other surface tiles, to the Watroute model. The Watroute version used in GEM-Hydro currently only represents major lakes (area greater than 100km<sup>2</sup>) along the river networks, and does not represent the impact that small lakes can have on streamflow, which mainly consists in slowing down runoff before it reaches the main streams of the network.</p><p>Recently, the Canadian Small Lake Model (CSLM) was implemented in the surface component of GEM-Hydro to represent the energy and water balance over water tiles more accurately. So far, CSLM simulations have been shown promising in terms of evaporation, ice cover, absolute and dew point temperature simulations, compared with the former algorithm used over water. However, the impact of CSLM on the resulting streamflow simulations performed with GEM-Hydro has not been evaluated yet. This study aims first at evaluating the impact of CSLM on streamflow simulations, and secondly at testing different CSLM configurations as well as different coupling strategies with Watroute, with the objective of finding the best set up for the prediction of streamflow in Canada. For example, overland runoff generated by the land tile can be provided to the water tile of the same grid point in different ways, and the outflow computed at the outlet of the water tile can be computed with different parameters. Moreover, different outflow computations have to be taken into account depending on if the water tile of a grid point represents subgrid-scale lakes, or if on the contrary it belongs to a lake spanning over multiple model grid points.</p><p>To do so, different GEM-Hydro open-loop simulations have been performed on the Lake of the Woods watershed, located in Canada, with and without CSLM to represent water tiles. The CSLM configurations leading to the best results are presented here. CSLM simulations are also evaluated in terms of surface fluxes, to ensure that the main purpose of the model, which is to improve surface fluxes to ultimately improve atmospheric forecasts, is preserved, compared to the default configuration of the model. Ideas for further improving the coupling between the GEM-Hydro surface and routing components, in terms of lake processes, are also presented and will be tested in future work.</p>

scholarly journals Probabilistic inference of ecohydrological parameters using observations from point to satellite scales

2018 ◽  
Vol 22 (6) ◽  
pp. 3229-3243 ◽  
Author(s):  
Maoya Bassiouni ◽  
Chad W. Higgins ◽  
Christopher J. Still ◽  
Stephen P. Good
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Dry Season ◽  
Soil Water Balance ◽  
Rainfall Pattern ◽  
Site Specific ◽  
Soil Moisture Dynamics ◽  
Soil Saturation ◽  
Moisture Dynamics

Abstract. Vegetation controls on soil moisture dynamics are challenging to measure and translate into scale- and site-specific ecohydrological parameters for simple soil water balance models. We hypothesize that empirical probability density functions (pdfs) of relative soil moisture or soil saturation encode sufficient information to determine these ecohydrological parameters. Further, these parameters can be estimated through inverse modeling of the analytical equation for soil saturation pdfs, derived from the commonly used stochastic soil water balance framework. We developed a generalizable Bayesian inference framework to estimate ecohydrological parameters consistent with empirical soil saturation pdfs derived from observations at point, footprint, and satellite scales. We applied the inference method to four sites with different land cover and climate assuming (i) an annual rainfall pattern and (ii) a wet season rainfall pattern with a dry season of negligible rainfall. The Nash–Sutcliffe efficiencies of the analytical model's fit to soil observations ranged from 0.89 to 0.99. The coefficient of variation of posterior parameter distributions ranged from < 1 to 15 %. The parameter identifiability was not significantly improved in the more complex seasonal model; however, small differences in parameter values indicate that the annual model may have absorbed dry season dynamics. Parameter estimates were most constrained for scales and locations at which soil water dynamics are more sensitive to the fitted ecohydrological parameters of interest. In these cases, model inversion converged more slowly but ultimately provided better goodness of fit and lower uncertainty. Results were robust using as few as 100 daily observations randomly sampled from the full records, demonstrating the advantage of analyzing soil saturation pdfs instead of time series to estimate ecohydrological parameters from sparse records. Our work combines modeling and empirical approaches in ecohydrology and provides a simple framework to obtain scale- and site-specific analytical descriptions of soil moisture dynamics consistent with soil moisture observations.

scholarly journals Variations of global and continental water balance components as impacted by climate forcing uncertainty and human water use

2016 ◽  
Vol 20 (7) ◽  
pp. 2877-2898 ◽  
Author(s):  
Hannes Müller Schmied ◽  
Linda Adam ◽  
Stephanie Eisner ◽  
Gabriel Fink ◽  
Martina Flörke ◽  
...  
Keyword(s):  
Water Resources ◽  
Water Balance ◽  
Water Use ◽  
Climate Forcing ◽  
Land Area ◽  
Water Balance Components ◽  
Climate Forcings ◽  
The Impact ◽  
Global Water

Abstract. When assessing global water resources with hydrological models, it is essential to know about methodological uncertainties. The values of simulated water balance components may vary due to different spatial and temporal aggregations, reference periods, and applied climate forcings, as well as due to the consideration of human water use, or the lack thereof. We analyzed these variations over the period 1901–2010 by forcing the global hydrological model WaterGAP 2.2 (ISIMIP2a) with five state-of-the-art climate data sets, including a homogenized version of the concatenated WFD/WFDEI data set. Absolute values and temporal variations of global water balance components are strongly affected by the uncertainty in the climate forcing, and no temporal trends of the global water balance components are detected for the four homogeneous climate forcings considered (except for human water abstractions). The calibration of WaterGAP against observed long-term average river discharge Q significantly reduces the impact of climate forcing uncertainty on estimated Q and renewable water resources. For the homogeneous forcings, Q of the calibrated and non-calibrated regions of the globe varies by 1.6 and 18.5 %, respectively, for 1971–2000. On the continental scale, most differences for long-term average precipitation P and Q estimates occur in Africa and, due to snow undercatch of rain gauges, also in the data-rich continents Europe and North America. Variations of Q at the grid-cell scale are large, except in a few grid cells upstream and downstream of calibration stations, with an average variation of 37 and 74 % among the four homogeneous forcings in calibrated and non-calibrated regions, respectively. Considering only the forcings GSWP3 and WFDEI_hom, i.e., excluding the forcing without undercatch correction (PGFv2.1) and the one with a much lower shortwave downward radiation SWD than the others (WFD), Q variations are reduced to 16 and 31 % in calibrated and non-calibrated regions, respectively. These simulation results support the need for extended Q measurements and data sharing for better constraining global water balance assessments. Over the 20th century, the human footprint on natural water resources has become larger. For 11–18% of the global land area, the change of Q between 1941–1970 and 1971–2000 was driven more strongly by change of human water use including dam construction than by change in precipitation, while this was true for only 9–13 % of the land area from 1911–1940 to 1941–1970.

scholarly journals Environmental impact of the Midia Port - Black Sea (Romania), on the coastal sediment quality

2016 ◽  
Vol 8 (1) ◽  
pp. 174-194 ◽  
Author(s):  
Irina Catianis ◽  
Constantin Ungureanu ◽  
Luca Magagnini ◽  
Elisa Ulazzi ◽  
Tiziana Campisi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Oil Spills ◽  
Environmental Concern ◽  
Sediment Quality ◽  
Industrial Wastes ◽  
Anthropogenic Sources ◽  
Water Runoff ◽  
Quality Of Water ◽  
Wide Range ◽  
The Impact

AbstractThe aim of the study was to evaluate the impact of potential pollution sources, mainly from the upstream anthropogenic sources and port-related activities. The in-vestigated area covered a wide range of anthropogenic im-pacts (e.g., industrial wastes, storm water runoff, acciden-tal oil spills, intentional discharges and shipping activities). The quality of water and Sediments was assessed us-ing Standard methods, as physical-chemical parameters, chemistry and biology (microbiology, ecotoxicology) aim-ing to figure the level of pollution and the effect of port-related activities. Seawater quality results agreed generally with environmental Standards. Though, in some samples the concentrations of sulphates (mg/1) and heavy metals (μg/1), as B, As and Se exceeded the recommended lim-its, without posing a serious environmental concern. Most of the surface sediment samples contain critical levels of hydrocarbons (C>12), (mg/kg), polycyclic aromatic hydrocarbons (ng/g) and polychlorobiphenyls (ng/g). For some heavy metals (mg/kg), exchangeable concentrations were found to be very close or above the regulations. The signifi-cance of this study is incontestable taking into account the lack of previous relevant historical data of this area. In this sense, it was possible to indicate, in general, good environmental conditions, despite the industrial and concentrated local port-related activities in the investigated area.

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