Low-water Years Research Articles

Impact of Hydro Power Construction on the Solutes Content and Discharge in the Bureya River Water

Impact of hydropower construction on the solutes content and discharge in the Bureya River water in low-water year (2008) and high-water years (2012–2013) have been considered. Evening of seasonal differences in the main ions, as well as nitrogen, iron and organic matter mineral forms content has been stated. Increase of ion discharge, as well as biogenic and organic matter discharge in winter period has been revealed. During high-water years in summer-fall period micro/elements higher concentration and discharge have been registered, in comparison with the same prior to regulation. The nitrate nitrogen and iron discharge was higher, too.

First evidence of grass carp recruitment in the Great Lakes Basin

We use aging techniques, ploidy analysis, and otolith microchemistry to assess whether four grass carp Ctenopharyngodon idella captured from the Sandusky River, Ohio were the result of natural reproduction within the Lake Erie Basin. All four fish were of age 1+. Multiple lines of evidence indicate that these fish were not aquaculture-reared and that they were most likely the result of successful reproduction in the Sandusky River. First, at least two of the fish were diploid; diploid grass carp cannot legally be released in the Great Lakes Basin. Second, strontium:calcium (Sr:Ca) ratios were elevated in all four grass carp from the Sandusky River, with elevated Sr:Ca ratios throughout the otolith transect, compared to grass carp from Missouri and Arkansas ponds. This reflects the high Sr:Ca ratio of the Sandusky River, and indicates that these fish lived in a high-strontium environment throughout their entire lives. Third, Sandusky River fish were higher in Sr:Ca ratio variability than fish from ponds, reflecting the high but spatially and temporally variable strontium concentrations of southwestern Lake Erie tributaries, and not the stable environment of pond aquaculture. Fourth, Sr:Ca ratios in the grass carp from the Sandusky River were lower in their 2011 growth increment (a high water year) than the 2012 growth increment (a low water year), reflecting the observed inverse relationship between discharge and strontium concentration in these rivers. We conclude that these four grass carp captured from the Sandusky River are most likely the result of natural reproduction within the Lake Erie Basin.

Response of walleye and yellow perch to water-level fluctuations in glacial lakes

The influence of water levels on population characteristics of yellow perch, Perca flavescens (Mitchill), and walleye, Sander vitreus (Mitchill), was evaluated across a range of glacial lakes in north-eastern South Dakota, USA. Results showed that natural variation in water levels had an important influence on frequently measured fish population characteristics. Yellow perch abundance was significantly (P < 0.10) greater during elevated water levels. Yellow perch size structure, as indexed by the proportional size distribution of quality- and preferred-length fish (PSD and PSD-P), was significantly greater during low-water years, as was walleye PSD. Mean relative weight of walleye increased significantly during high-water periods. The dynamic and unpredictable nature of water-level fluctuations in glacial lakes ultimately adds complexity to management of these systems.

Update on the Effects of a Sierran Wildfire on Surface Runoff Water Quality

Wildfire has been shown to increase the short-term (1-3 yr) mobilization of mineral N and P in forest ecosystems of the Sierra Nevada Mountains and Lake Tahoe Basin. The ensuing effects on tributary and lake water quality are uncertain. The purpose of this investigation was to assess the impacts on runoff water quality over an intermediate time frame of 5 yr (2002-2007) after a wildfire event. Our design included fixed plots randomly placed within burned and unburned areas. Because each plot was sampled repeatedly during the study, we treated plots as repeated random effects in the analysis. We used a mixed model approach to analyze nutrient runoff concentrations and load for NH-N, NON and P in phosphate form (designated as ortho P or PO-P) where treatment (unburned vs. burned), time (pre-wildfire, post-wildfire year 1, year 2, etc.), and their interaction were fixed effects. Concentrations and loads of mineral N and P were higher in runoff from the burned areas immediately after wildfire. Because high water years may also contribute to higher runoff nutrient concentrations and loading, a wildfire followed by a high water year within the first season after a wildfire would likely have a much greater impact on runoff (and hence tributary) water quality than a wildfire followed by a low runoff water year.

Interannual variations in the areas of thermokarst lakes in Central Yakutia

At present, close attention is given to studies of thermokarst lakes from the standpoint of cryolite zone response to global climate warming. However, other factors, which have an effect on the variation in areas of lakes, in particular, the atmospheric precipitation, receive little attention, while the atmospheric precipitation is one of the main sources of water recharge for many water objects. In this connection, interannual variations in the areas of lakes as a function of precipitation were analyzed on the territory of Central Yakutia. The studies were based on the analysis of space images taken at different time. As the result, it was shown that precipitation has a considerable effect on variations in the areas of thermokarst lakes; there is a direct relationship between variations in lake areas and precipitation; only some single high-water or low-water years have no effect on these variations. Variations in areas of lakes during summer were also analyzed with a view to use the results in choosing the images for studies of interannual variations. It has been revealed that the areas of thermokarst lakes decrease from June to August; this means that the images obtained within a short period at the end of the summer period should be used.

Evaluation of chemical composition changes of surface water in Boguchan Reservoir (Siberia, Russia)

Mathematical transformation models of TDS (total dissolved salts) and organic substance concentration as BOD5 (biochemical oxygen demand) in water of the Angara River and the proposed Boguchan Reservoir have been developed. Having filled the reservoir to a water level of 208 m, in an average year it is shown that increase in surface water mineralization is expected in the cross-section of Boguchan Hydroelectric Power Station giving TDS of up to 20–40 mg/dm3, and values of BOD5 will increase to 2.0–3.9 mgO2/dm3. In a low-water year the value of BOD5 may be as great as 5 mgO2/dm3; mineralization, in contrast, decreases. Several years after reservoir filling, the values of BOD5 would decrease, but water quality of the upper part of the reservoir would still depend on the degree of treatment of wastewater discharged to it. Editor D. Koutsoyiannis Citation Savichev, O.G. and Matveenko, I.A., 2013. Evaluation of chemical composition changes of surface water in Boguchan Reservoir (Siberia, Russia). Hydrological Sciences Journal, 58 (3), 706–715.

Seed Germination and Reproductive Strategies in Federally Endangered Harperella (Harperella nodosumRose, Apiaceae)

ABSTRACT Harperella (Harperella nodosum) is a federally endangered plant with 26 known sites in the southeastern United States. Experiments in the greenhouse and observations in the wild demonstrated that harperella is an annual plant and its seeds can germinate immediately after seed maturation under warm-weather conditions in late summer. Harperella was observed to utilize two complementary reproductive strategies as important adaptations to survival in a frequently flooded, semiaquatic habitat, depending on flooding frequency and amplitude: (a) sexual reproduction during low-water years involving flowering and seed production and (b) asexual reproduction during high-water years involving viability of ramets produced at the nodes.

Peculiarities of the Upper Amu Darya Basin Rivers Zonal Runoff in Lowwater and High-water Years

Some peculiarities of the rivers’zonal runoff during high-water and low-water years for homogeneous hydrologic regions of the upper Amu Darya River basin have been studied. By solving the ill-posed inverse problem, the values of the zonal runoff for spring and summer periods were estimated for the selected years with high and low water. Glacial component is shown to play a larger role in the runoff during low flow years.

Raising of Major Inhibited Locations’ Water Supply Safety During Low Water Periods (the City of Yekaterinburg as a Study Case)

The paper presents analysis of the Yekaterinburg water supply problems in the conditions of extremely low-water years and discrepancies between the current water/economic system and requirements of safe water supply of major inhabited localities. Various options for the raising of the city and industrial center water supply system reliability due to modification of the current water/economic system, doubling and verification of water supply routes, expediency and variability of independent reserve water supply sources use plus associated measures have been considered.

Alternative Water Allocation in Kyrgyzstan: Lessons from the Lower Colorado River Basin and New South Wales

Focus group discussions and a modeling approach were applied to determine policy and regulatory refinements for current water allocation practices in Kyrgyzstan. Lessons from the Lower Colorado River basin, Texas and New South Wales, Australia were taken into consideration. The paper analyzes the impact of adopting some of these interventions within the socio-environmental context that currently prevails in Kyrgyzstan. The optimization model for water distribution at the river-basin scale was developed using GAMS 2.25 software. Application of the model to the Akbura River basin indicated efficiencies in the proposed institutional rules especially in low water years.

Hydrologic Interdependencies and Human Cooperation: The Process of Adapting to Droughts

Abstract The Bear River Basin, which includes portions of Idaho, Utah, and Wyoming in the United States, has a dynamic history of human hydrologic adaptations in relation to a highly variable water supply. These adaptations are embedded in a geographical setting highly influenced by the legal, policy, and institutional contexts that govern allocation of water in this generally arid region. In response to several years of drought and a historically low water year in 2004, water users in the Bear River Basin tested the efficacy of the “law of the river” and innovative agreements that they had negotiated in recent years to help mitigate impacts related to water shortages. Three innovations were identified as being key to a successful response to the 2004 drought: 1) a precedent-setting voluntary settlement agreement, 2) technical work in river modeling and instrumentation, and 3) extraordinary communication strategies employed throughout the drought. Based on case study research and utilizing a “ways of knowing” theoretical framework, the authors report on an unfolding contemporary history of how people in the Bear River Basin have learned to deal with uncertainties and risks associated with both droughts and floods. Their story has important implications for the understanding of conflict and cooperation in water systems, management of transboundary waters, and the promotion of sustainable water resource governance.

Sources of Mistrust: An Experimental Case Study of a Central Asian Water Conflict

With the disintegration of the USSR a conflict arose between Kyrgyzstan, Uzbekistan and Kazakhstan over the transboundary Syr Darya river. Upstream Kyrgyzstan controls the Toktogul reservoir which generates hydropower demanded mainly in winter for heating. Downstream Uzbekistan and Kazakhstan need irrigation water in summer, primarily to grow an export crop (cotton). Regional agreements obliging Kyrgyzstan to higher summer discharges in exchange for fossil fuel transfers from downstream riparians in winter have been unsuccessful, due to lack of trust between the parties. Striving for self-sufficiency in irrigation water, Uzbekistan initiated new reservoir construction. This paper examines their economic impact. We report a laboratory experiment modelling the Syr Darya scenario as a multi-round, three-player trust game with non-binding contracts. Payoff schemes are estimated using real-life data. While basinwide efficiency maximisation requires regional cooperation, our results demonstrate that cooperation in the laboratory is hard to achieve. Uzbek reservoirs improve cooperation only weakly and their positive impact is limited to low-water years.

The seasonal and interannual dynamics of centric diatoms in the Kuibyshev Reservoir

Samples of centric diatom algae from the plankton of the Kuibyshev Reservoir collected in years with different hydro-meteorological conditions (1989 and 1990) have been studied using light and scanning electron microscopy technique. Twenty-nine species, varieties, and forms of Centrophyceae, including two species new for the algoflora of the Volga River plankton, have been discovered. The main body of the dominant species is formed by algae with a high frequency of occurrence. The seasonal dynamics of abundance is characterized by spring peaks formed mainly by small-celled algae and less regular late fall maximums formed by large-celled forms. During these periods the abundance of Centrophyceae determines the level of phytoplankton development in general. Under stable species richness of algae and seasonal dynamics of their abundance, the average number of Centrophyceae during the hot and low-water year of 1989 reached 3.6 million cells/l; during the cold and high-water year of 1990, there were twice as few: 1.9 million cells/l.

Stimulating a Great Lakes coastal wetland seed bank using portable cofferdams: implications for habitat rehabilitation

Coastal wetland seed banks exposed by low lake levels or through management actions fuel the reestablishment of emergent plant assemblages (i.e., wetland habitat) critical to Great Lakes aquatic biota. This project explored the effectiveness of using portable, water-filled cofferdams as a management tool to promote the natural growth of emergent vegetation from the seed bank in a Lake Erie coastal wetland. A series of dams stretching approximately 450 m was installed temporarily to isolate hydrologically a 10-ha corner of the Crane Creek wetland complex from Lake Erie. The test area was dewatered in 2004 to mimic a low-water year, and vegetation sampling characterized the wetland seed bank response at low, middle, and high elevations in areas open to and protected from bird and mammal herbivory. The nearly two-month drawdown stimulated a rapid seed-bank-driven response by 45 plant taxa. Herbivory had little effect on plant species richness, regardless of the location along an elevation gradient. Inundation contributed to the replacement of immature emergent plant species with submersed aquatic species after the dams failed and were removed prematurely. This study revealed a number of important issues that must be considered for effective long-term implementation of portable cofferdam technology to stimulate wetland seed banks, including duration of dewatering, product size, source of clean water, replacement of damaged dams, and regular maintenance. This technology is a potentially important tool in the arsenal used by resource managers seeking to rehabilitate the functions and values of Great Lakes coastal wetland habitats.

Numerical Simulations of the Transparency of Waterfront Bodies

Measured field data was used to analyze the factors which influence the transparency of the Nei River and to develop a multi-factor correlation for the transparency. A 2-D unsteady model which coupled analyses of the water flow, water quality, suspended sediments, and Chl-a was developed to simulate the changes in the transparency for various conditions. The model was then used to forecast the transparency of the Nei River. The suspended sediment concentration (SSC) was found to be the most important factor influencing the transparency, with high concentrations of COD Mn and Chl-a also reducing the transparency to some extent. The transparency model is stable and precise, with relative errors between measured and calculated values of less than 15%. With the environmental scheduling schemes, the Nei River transparency can be significantly improved with a mean transparency in high-water years of 69.3 cm, normal-water years of 70.8 cm, and low-water years of 69.8 cm.

Resistance and resilience of macroinvertebrates to irrigation water withdrawals

Summary1. Water withdrawal for irrigated agriculture is one of the leading uses of freshwater resources in the world; however, effects of low flow disturbances on lotic ecosystems are poorly understood. We studied an intensively managed agricultural catchment to determine: (i) how macroinvertebrate assemblages and environmental variables respond to water withdrawals of varying magnitude and duration; (ii) what environmental variables are associated with macroinvertebrate responses and (iii) the resiliency of macroinvertebrate communities to irrigation water withdrawals.2. We sampled above and below four irrigation diversions that create a gradient of increasing water withdrawal from upstream to downstream (i.e. 0%, 22%, 87%, 90% and 97% water withdrawn) along a 36 km river section. Three reaches were sampled above and below each point of diversion from June to September 2004 and 2005, which represented average and drought water conditions respectively.3. Irrigation water withdrawals were associated with both direct and indirect changes to the physicochemical environment. Direct effects (e.g. decreased velocity, depth and wetted habitat) were approximately proportional to the amount of water withdrawn, while indirect effects (e.g. increased conductivity and temperature) occurred when water withdrawals exceeded 85% of ambient levels.4. Changes in macroinvertebrate communities were more strongly related to indirect than direct effects of irrigation water withdrawals. In an average water year, community changes were associated with interacting thresholds of reduced discharge and increased conductivity. During a drought year, community changes were related to the interacting thresholds of reduced discharge and increased temperature.5. Between years, macroinvertebrate responses differed with the magnitude and duration of low flow conditions. In 2004, high‐intensity, relatively short‐duration water withdrawals (&lt;2 months) and alterations to the physicochemical environment changed the relative abundance of macroinvertebrate communities, while macroinvertebrate indices and proportional abundances of functional feeding groups remained unchanged. In contrast, discharge reductions exceeding 90% of ambient levels and temperatures above 30 °C from July to September 2005 were associated with shifts in community composition from a dominance of collector‐gatherer and filterer Ephemeroptera, Plecoptera and Trichoptera taxa to predatory insects, non‐insect taxa and scraping elmid beetles.6. On an annual basis macroinvertebrate communities appeared resilient to the impacts of water withdrawals following winter high flows. In contrast, recovery was not observed after discharge and physicochemical variables returned to predisturbance conditions for only one month.7. Irrigation water withdrawals appear to impact macroinvertebrates through indirect effects that intensify with the magnitude and duration of water withdrawals and annual water availability. Preserving environmental conditions within natural ranges of variability, especially during low water years, appears critical to mitigating adverse biological responses to water withdrawals.

Sediment yield computation of the sandy and gritty area based on the digital watershed model

The Yellow River is well known as a sediment-laden river, which is the main reason that it cannot be controlled as easily as other rivers. Many researchers, such as Qian Ning et al., have found that the sediment load of the Yellow River comes mainly from the sandy and gritty area of the Loess Plateau. Therefore, it is very important to simulate the sediment yield in this area. This paper proposes a method to compute the sediment production in the sandy and gritty area based on the digital watershed model. The suggested model is calibrated and validated in the Chabagou basin, which is a small catchment in the study area. Finally, the model simulates the sediment yield of the sandy and gritty area in 1967, 1978, 1983, 1994 and 1997, which represents a high water and high sediment year, a mean water and mean sediment year, a high water and low sediment year, a low water and high sediment year, and a low water and low sediment year separately. The simulation results, including the runoff depth and erosion modulus, can well explain the “low water and high sediment” phenomena in the Yellow River basin. The total amount of the sediment production and its distribution generated by the model is very useful for water and soil conservation in the sandy and gritty area of the Loess Plateau.

Optimizing long-term water allocation in the Amudarya River delta: a water management model for ecological impact assessment

In the semi-arid Amudarya delta region (Aral Sea Basin) the human-controlled hydrological regime is a major factor influencing ecosystem dynamics. Alterations to the flow of the Amudarya River, mainly to serve the needs of irrigated agriculture during Soviet times, have caused severe environmental degradation. Since independence, the former Soviet Union states of the basin are searching for new, ecologically sound, water management strategies to mitigate the damages to economy, human populations and ecosystems. To assist in the evaluation of tradeoffs in water allocation and the determination of restoration goals, we created a simple water management model for the Amudarya River and its delta region with the modeling system EPIC (originally developed by the USAID project ‘Environmental Policies and Institutions for Central Asia’). The water management model determines optimal water allocation in the irrigation network by multi-objective optimization in monthly time steps. Water management alternatives can be developed for a time period of up to 15 years based on changing requirements of the water users (e.g. as a result of increased water use efficiency in agriculture), inflow to the delta (e.g. increase in water use upstream), priorities of the optimization criteria (e.g. reflecting policy decisions) or introducing minimum flow requirements to selected canals. Historic salt dynamics of the Tyuyamuyun reservoir system at the entrance to the Amudarya delta were investigated and EPIC was extended to treat such multi-body reservoir systems. The model was calibrated and tested using a high water (1994) and a low water (1997) year. Modeled water allocation takes place in accordance with observational data. The model reacts well to changes in allocation priorities given by the user. Application of the model to a 14-year characteristic time period was successful. The model constitutes a main module of an integrated GIS-based simulation tool that facilitates the evaluation of the ecological effects of alternative water management strategies in the Northern Amudarya delta.

Modeling the Mozhaisk Reservoir Genetic Structure

A box model of water mass composition is used to determine the genetic structure of the main water mass (MWM) of the Mozhaisk Reservoir in the high-water 1986–1987 and for four constructed scenarios. The greatest difference between the genetic compositions of the spring, summer, and autumn modifications of MWM manifested itself in that the winter reservoir water of the previous water management year predominates in a low-water year. Elevated proportions of snowmelt flood water were recorded in the spring and summer of a medium-water year (with high snowmelt flood and low rain floods) and in the winter of a low-water year. Possible variations (up to 27%) in the salinity and color index of MWM in years with different genetic composition are demonstrated and shown to be attributable to different water abundance in these years. The genetic structure of the reservoir water is supposed to affect possible variations in the phosphorus content of the reservoir MWM.

Diversity Comparisons Between Diked and Undiked Coastal Freshwater Marshes on Lake Erie During a High-water Year

The effect of high water on floristic composition and diversity was compared at a diked, managed marsh, and an undiked, unmanaged marsh. Species richness and alpha diversity were determined for Cells A through D at Pipe Creek Wetland (PCW), a restored, managed marsh, and MHD Wetland, an undiked, unmanaged marsh. Both wetlands are located on Sandusky Bay in the western basin in Lake Erie, Ohio. Water levels were unusually high during 1997 when this study was conducted. Thus, the flora of Cells C and D at PCW in 1997 were compared to results from a vegetation survey of these cells conducted in 1994, a low-water year. Values for species richness in 1997 ranged from 25 (Cell A) to 42 (Cell D). Pipe Creek Wetland, and Cell D in particular, had higher species richness than MHD Wetland. Average alpha diversity values in 1997 ranged from 0.95 to 1.34; Cell D had significantly higher alpha diversity than Cell C at PCW and MHD Wetland. Species richness of Cells C and D at PCW declined substantially between 1994 and 1997 and species composition changed considerably. These findings reflect the combined effects of the very different marsh surfaces, hydrologic regimes, and human influences at Pipe Creek and MHD Wetlands. It is suggested that species richness and alpha diversity at Pipe Creek Wetland would be even higher in a low-water year. However, MHD Wetland would not become more diverse if water levels dropped due to the extreme dominance of stress-tolerant, aggressive plant species at MHD.