Showing papers by "Sergey Chalov published in 2017"
TL;DR: Wetlands are often considered as nature-based solutions that can provide a multitude of services of great social, economic and environmental value to humankind as discussed by the authors, and they can provide great social and economic benefits to humans.
198 citations
TL;DR: In this article, the authors evaluated the pathways and mass flows of heavy metals and metalloids both in dissolved and suspended forms, taking a basin-scale perspective that previously has not been fully pursued in the Lake Baikal region.
Abstract: This paper presents the results of novel field campaigns in the extensive (447,000 km2) Selenga River basin, through which 304 samples of river water and 308 samples of suspended matter were collected during high and low water periods between 2011 and 2013. The Selenga River is the largest tributary (more than 50% of the inflow) to the Lake Baikal. Due to ongoing hydroclimatic change and human pressures under conditions of economic growth, the rivers of the area experience significant change in water quality. A key issue for improved understanding of regional impacts of the environmental change is to disentangle the influence of climate change from that of other pressures within the catchment. Our research aims to evaluate the pathways and mass flows of heavy metals and metalloids both in dissolved and suspended forms, taking a basin-scale perspective that previously has not been fully pursued in the Lake Baikal region. Results showed quality deterioration over short distances due to strong impact of hot spots from urban and industrial activities, including mining. The determined enrichment of dissolved metals in waters of Selenga River as well as the spatial and temporal variability of water and suspended sediment composition is further analyzed in the context of climatic, hydrological and land use drivers.
80 citations
TL;DR: In this paper, the authors studied the impact of geomorphological changes on the Selenga River delta and its barrier function. And they showed that geomorphology processes, which govern the partitioning of flow between different channel systems, may therefore directly govern the barrier function of the delta.
Abstract: The protection of Lake Baikal and the planning of water management measures in the Selenga River Basin require a comprehensive understanding of the current state and functioning of the delta’s ecosystem and hydrogeochemical processes. This is particularly relevant in light of recent and expected future changes involving both the hydrology and water quality in the Lake Baikal basin causing spatiotemporal changes in water flow, morphology, and transport of sediments and metals in the Selenga River delta and thus impacting on delta barrier functions. The central part of the delta had been characterized by sediment storage, especially along the main channels, causing a continuous lift of the delta surface by about 0.75 cm/year−1. Theses morphological changes have a significant impact on hydrological conditions, with historical shifts in the bulk discharge from the left to the right parts of the delta which is distinguished by a relatively high density of wetlands. Regions with a high density of wetlands and small channels, in contrast to main channel regions, show a consistent pattern of considerable contaminant filtering and removal (between 77 and 99 % for key metals), during both high-flow and low-flow conditions. The removal is associated with a significant concentration increase (2–3 times) of these substances in the bottom sediment. In consequence, geomorphological processes, which govern the partitioning of flow between different channel systems, may therefore directly govern the barrier function of the delta.
66 citations
TL;DR: In this article, the authors provide documentation of the current state of scientific knowledge, ranging from hydrological research to water quality investigations, and offer an assessment of ecosystems and the services provided by them.
Abstract: Central Asia contains one of the largest internal drainage basins in the world, and its continental location results in limited availability of both surface and groundwater. Since the twentieth century, water resources of the region have been exploited beyond sustainable levels. From small Mongolian headwater streams to the mighty Aral Sea, surface waters have been partially desiccated. Demands from the agricultural, energy and raw material sectors as well as population growth have not only increased water abstractions, but also left a diverse and strong pollution footprint on rivers, lakes and groundwater bodies. Such changes in water quantity and quality have not only led to a degradation of aquatic and riparian ecosystems, but also they have placed the region’s socioeconomic development at risk. Because of the complexity of Central Asia’s water problems, integrated assessment and management approaches are required. Despite some shortcomings in practical implementation, the widespread adoption of the Integrated Water Resources Management and water–food–energy nexus approaches may be keys to a more sustainable future. This thematic issue aims to provide documentation of the current state of scientific knowledge, ranging from hydrological research to water quality investigations, and offers an assessment of ecosystems and the services provided by them. Reviews and case studies on different management options conclude the thematic issue by providing insights into field-tested solutions for the region’s water challenges.
58 citations
TL;DR: In this paper, the contribution from natural erosion of metal-rich soil to observed increases in mass flows of metals along the Tuul River was quantified by combining field observations in the river basin with soil erosion modelling.
Abstract: Mining has become one of the main causes of increased heavy metal loading of river systems throughout the world. There is however an evident gap between assessments of soil contamination and metal release at the mined sites and estimates of river pollution. The present work focuses on Zaamar Goldfield, which is one of the largest placer gold mines in the world, located along the Tuul River, Mongolia, which ultimately drains into Lake Baikal, Russia. It combines field observations in the river basin with soil erosion modelling and aims at quantifying the contribution from natural erosion of metal-rich soil to observed increases in mass flows of metals along the Tuul River. Results show that the sediment delivery from the mining area to the Tuul River is considerably higher than the possible contribution from natural soil erosion. This is primarily due to excessive mining-related water use creating turbid wastewaters, disturbed filtering functions of deposition areas (natural sediment traps) close to the river and disturbances from infrastructures such as roads. Furthermore, relative to background levels, soils within Zaamar Goldfield contained elevated concentrations of As, Sr, Mn,V, Ni, Cu and Cr. The enhanced soil loss caused by mining-related activities can also explain observed, considerable increases in mass flows of metals in the Tuul River. The present example from Tuul River may provide useful new insights regarding the erosion and geomorphic evolution of mined areas, as well as the associated delivery of metals into stream networks.
42 citations
TL;DR: In this article, the authors investigated the relationship between patterns of increased sediment loads along the Tuul River and the area coverage of active or recently abandoned placer mines in the river vicinity.
Abstract: Surface mining can contribute to increasing riverine loads of potentially metal-enriched sediments. However, the related human disturbances and natural processes reflect a great complexity, which hinders quantitative understanding. We here consider the Zaamar Goldfield in Mongolia, one of the world's largest placer mining sites, located in the Tuul River basin (upper Lake Baikal basin). A main study aim is to investigate relations between patterns of increased sediment loads along the Tuul River and the (spatially variable) area coverage of active or recently abandoned placer mines in the river vicinity. Specifically, we compare observed loads derived from nested catchment areas with the output from spatially distributed soil erosion modelling. Results showed that riverine sediment loads in mining areas reflect soil losses both from soil erosion and direct human impacts (e.g. waste water discharge), which are two to three orders of magnitude higher than the input from natural areas dominated by soil erosion alone. Notably, the sediment load contributions from the mining areas were insensitive to changes in hydrometeorological conditions, whereas contributions from natural areas were much lower during drier periods (as expected when governed by soil erosion by water). Accordingly, the relative contribution to the total sediment load (TSL) of metal-enriched soil from mining areas is likely to be particularly pronounced (with estimated values of about 80% of TSL) under drier hydrometeorological conditions. This is consistent with observations of considerably elevated metal concentrations under low flow conditions and implies that if annual average discharge continues to decrease in the Tuul River as well as the entire Selenga River system, increased metal concentrations may be one of the consequences.
39 citations
TL;DR: Chalov et al. as mentioned in this paper studied the impact of mining activities on the ecology of the Selenga River and its tributaries, and found that heavy metals and other mining-related pollutants have a great impact on pollution delivery to Lake Baikal, storing up to 60 to 70% of the sediment load.
Abstract: Lake Baikal’s most important tributary is the Selenga River, which contributes about 50 to 60% of its surface water influx (Chalov et al. 2015; Opp 1994; Törnqvist et al. 2015). Moreover, the Selenga’s 447.060-km watershed covers 82% of the Lake Baikal Basin (Nadmitov et al. 2014) (Fig. 1), which means that any environmental changes along the Selenga and its tributaries may ultimately impact Lake Baikal. However, north of the Buryatian capital Ulan Ude, the Selenga River branches into the largest freshwater inland delta in the world (Logachev 2003). The associated wetland constitutes a unique ecosystem (Гармаев and Христофоров 2010) and acts as the final geobiochemical barrier before the Selenga discharges into Lake Baikal (Chalov et al. 2016). Therefore, it has a great impact on pollution delivery to Lake Baikal, storing up to 60–70% of the sediment load of the Selenga River (Chalov et al. 2017). The protection of Lake Baikal and the planning of water management measures in the Selenga river basin require a good understanding of current trends regarding hydrology, water quality, aquatic and riparian zone ecology of the Selenga and its key tributaries (Karthe et al. 2016), and geoand biochemical processes governing the ecological functioning of the Selenga delta (Khazheeva et al. 2004). The following anthropogenic impacts constitute threats to the ecology of the Selenga from its tributaries down to its delta: Various mining activities are found in the Selenga river basin, including the exploitation of coal, gold, copper, molybdenum and wolfram (Sandmann 2012; Timofeev et al. 2015). As a consequence, elevated levels of heavy metals and other mining-related pollutants (cyanides, phosphorus) have been detected in the water and sediments of the Selenga and its tributaries, as well as floodplain soils and groundwater (Battogtokh et al. 2014; Brumbaugh et al. 2013; Chalov et al. 2015; Inam et al. 2011; McIntyre et al. 2016; Nadmitov et al. 2014; Pavlov et al. 2008; Pfeiffer et al. 2015; Stubblefield et al. 2005; Thorslund et al. 2012). Even though contaminant transport towards the Selenga delta does take place (Chalov et al. 2015; Khazheeva et al. 2004; Karthe et al. 2014), it should be noted that contaminations currently have the largest effects in local hot spots (Hofmann et al. 2010; Inam et al. 2011; Pfeiffer et al. 2015). Currently, there are different views regarding their impact on Lake Baikal itself (Chebykin et al. 2010; Pavlov et al. 2008). However, bioaccumulation and toxicological effects observed in aquatic biota ranging from insects to fish provide indication that water quality deterioration in the Selenga river system does have an ecological impact (Avlyush 2011; Kaus et al. 2016; Komov et al. 2014). * Sergey Chalov hydroserg@mail.ru
36 citations
TL;DR: In this paper, the authors assess current trends in hydrology and water quality in the Selenga-Baikal basin, identify their drivers and set up models (WaterGAP3 framework and ECOMAG) for the prediction of future changes.
Abstract: The Selenga River is the main artery feeding Lake Baikal. It has a catchment of ~450000 km² in the boundary region between Northern Mongolia and Southern Siberia. Climate, land use and dynamic socioeconomic changes go along with rising water abstractions and contaminant loads originating from mining sites and urban wastewater. In the future, these pressures might have negative impacts on the ecosystems of Lake Baikal and the Selenga River Delta, which is an important wetland region in itself and forms the last geobiochemical barrier before the Selenga drains into Lake Baikal. The following study aims to assess current trends in hydrology and water quality in the Selenga-Baikal basin, identify their drivers and to set up models (WaterGAP3 framework and ECOMAG) for the prediction of future changes. Of particular relevance for hydrological and water quality changes in the recent past were climate and land use trends as well as contaminant influx from mining areas and urban settlements. In the near future, additional hydrological modifications due to the construction of dams and abstractions/water diversions from the Selenga’s Mongolian tributaries could lead to additional alterations.
31 citations
TL;DR: The speciation of metals in aqueous systems is central to understanding their mobility, bioavailability, toxicity and fate as mentioned in this paper, and although several geochemical speciation models exist for metals, the equi...
Abstract: The speciation of metals in aqueous systems is central to understanding their mobility, bioavailability, toxicity and fate. Although several geochemical speciation models exist for metals, the equi ...
29 citations
TL;DR: In this article, the state-of-the-art in sediment budget research for small catchments is discussed and nine independent approaches in the sediment transport assessment and applied them in 11 catchments across Eurasia.
Abstract: Sediment monitoring and assessment remain one of the most challenging tasks in fluvial geomorphology and water quality studies. As a response to various environmental and human disturbance effects, the main sources and pathways of the sediments transported within catchments, especially most pristine small one, may change. The paper discusses state-of-the-art in the sediment budget research for small catchments. We identified nine independent approaches in the sediment transport assessment and applied them in 11 catchments across Eurasia in the framework of an FP – 7 Marie Curie – International Research Staff Exchange Scheme in 2012-2016. These methods were classified as: i) Field-based methods (In-situ monitoring of sediment transport;– Soil morphological methods and dating techniques; Sediment source fingerprinting; Sediment-water discharge relationships), ii) GIS and remote sensing approaches (Riverbed monitoring based on remote sensing/historical maps; parametrization of the channel sediment connectivity; Sediment transport remote sensing modeling), and iii) Numerical approaches (Soil erosion modeling and gully erosion (stochastic and empirical models); channel hydrodynamic modeling). We present the background theory and application examples of all selected methods. Linking fieldbased methods and datasets with numerical approaches, process measurements as well as monitoring can provide enhanced insights into sediment transfer and related water quality impacts. Adopting such integrated and multi-scale approaches in a sediment budget framework might contribute to improved understanding of hydrological and geomorphological responses.
27 citations
TL;DR: In this paper, Li et al. found that heavy metal (Cr, Ni, Cu) concentrations and physico-chemical characteristics (salinity and pH) played an important role in the distribution of heavy metal concentrations.
Abstract: Chongming Island is located in the lower Yangtze Estuary in China. Due to the Leachate from a refuse landfill and the hydrodynamics of the Yangtze Estuary, the groundwater environment is particularly complicated on Chongming Island. Field observations were carried out around the landfill disposal site. The groundwater table, temperature, pH, salinity, and dissolved oxygen were measured in the field by portable equipment, and 192 water samples were collected at eight groundwater sites and one surface water site. Through laboratory analysis we found the highest measured concentration of Cr to be 54.07 μg/L, and the measured concentration of Zn was in the range of 8 μg/L to more than 200 μg/L, which were both higher than their background values. Strong correlations were found between the heavy metal (Cr, Ni, Cu) concentrations and physico-chemical characteristics (salinity and pH), which indicated that both the landfill and the tides played an important role in the distribution of heavy metal concentrations. Both the HPI and PoS Indices were greater than their critical values near the disposal site, indicating groundwater pollution by heavy metals. We show that Cr and Ni are the major heavy metals causing groundwater contamination in the study region.
TL;DR: In this article, the effect of tide-induced groundwater table fluctuations and on the pollutants migration in beach aquifers is investigated by constructing a two-dimensional sand trough physical experimental model.
Abstract: The problem of current urban groundwater pollution is very serious, which has influenced social development and people’s daily life. Around the land-sea interface, tide obviously changes nearshore the groundwater flow regime and makes the pollutant migration process become more complex. In the present study, the effect of tide-induced groundwater table fluctuations and on the pollutants migration in beach aquifers is investigated by constructing a two-dimensional sand trough physical experimental model. The model considered brackish-water density differences and the tide by controlling experimental medium properties and boundary conditions. The results showed that the groundwater table fluctuation cycle is the same as the tidal cycle and the fluctuation lag time increases linearly with the increase of the offshore distance. Tidal fluctuation flattens brackish-freshwater interface, widens the dispersion zone, and generates the upper saline and the freshwater belt. Time lag corresponding relationships between saline water and tidal fluctuation was observed. With the pollutant approaching the saline water area, the profile of the pollutant migration is gradually developed into a spindle shape until the strip shape, and the pollutant enters the saline water body along the curved edge of the upper part of the saline water. The transverse dispersion of pollutants is larger than the longitudinal dispersion in a tidal cycle and its outline presents a strip shape development. No mixing or exchange between the pollutants and the saline water body happened during the whole process. This study can provide scientific references for nearshore groundwater pollution prevention and control in the future.
03 Mar 2017
TL;DR: In this article, the seasonal variability in suspended sediment retention during the period 1989 to 2015 was calculated, and the results suggest that sediment storage in the Selenga delta is observed during high discharges (>1500m3/s−1), whereas sediment export increases under lower flow conditions.
Abstract: . The Selenga River is the largest tributary of Baikal Lake and it's delta covers around 600 km2. Suspended sediment concentrations (SSC) in the Selenga river delta were modelled based on LandSat images data. The seasonal variability in suspended sediment retention during the period 1989 to 2015 was calculated. The results suggest that sediment storage in the Selenga delta is observed during high discharges (> 1500 m3 s−1), whereas sediment export increases under lower flow conditions (
TL;DR: In this article, the authors focus on the 1stMutnaya catchment which drains the southern slopes of two active volcanoes: Avachinsky and Koryaksky and elaborate a cartographic approach which integrates classic geomorphology with state of the art GIS and remote sensing techniques.
Abstract: The Kamchatka Peninsula–situated in the Pacific “Ring of Fire”–has 29 active and over 400 extinct volcanoes. Since it is situated in the northeastern extremity of Russia, in subarctic climate, the volcanic landforms are overprinted by the 446 glaciers. This research focuses on the 1stMutnaya catchment which drains the southern slopes of two active volcanoes: Avachinsky and Koryaksky. Those volcanoes are a permanent threat for the cities of Petropavlovsk and Elizovo, which are the 2 of 3 cities of the peninsula. Hence, most of the studies carried out in the area dealt with the natural hazards and only few focus on landscape evolution. Thus, the purpose of this study was to elaborate a cartographic approach which integrates classic geomorphology with state of the art GIS and remote sensing techniques. As result, different landforms and related processes have been analysed and included in the first general geomorphologic map of the 1stMutnaya catchment.
TL;DR: In this article, the authors investigated spatiotemporal water discharge and sediment transport from upstream sources in one of the numerous headwater catchments located in the lahar valleys of the Kamchatka Peninsula Sukhaya Elizovskaya River near Avachinskii and Koryakskii volcanoes.
Abstract: Due to specific environmental conditions, headwater catchments located on volcanic slopes and valleys are characterized by distinctive hydrology and sediment transport patterns. However, lack of sufficient monitoring causes that the governing processes and patterns in these areas are rarely well understood. In this study, spatiotemporal water discharge and sediment transport from upstream sources was investigated in one of the numerous headwater catchments located in the lahar valleys of the Kamchatka Peninsula Sukhaya Elizovskaya River near Avachinskii and Koryakskii volcanoes. Three different subcatchments and corresponding channel types (wandering rivers within lahar valleys, mountain rivers within volcanic slopes and rivers within submountain terrains) were identified in the studied area. Our measurements from different periods of observations between years 2012–2014 showed that the studied catchment was characterized by extreme diurnal fluctuation of water discharges and sediment loads that were influenced by snowmelt patterns and high infiltration rates of the easily erodible lahar deposits. The highest recorded sediment loads were up to 9∙104 mg/L which was related to an increase of two orders of magnitude within a one day of observations. Additionally, to get a quantitative estimate of the spatial distribution of the eroded material in the volcanic substrates we applied an empirical soil erosion and sediment yield model–modified universal soil loss equation (MUSLE). The modeling results showed that even if the applications of the universal erosion model to different non-agricultural areas (e.g., volcanic catchments) can lead to irrelevant results, the MUSLE model delivered might be acceptable for non-lahar areas of the studied volcanic catchment. Overall the results of our study increase our understanding of the hydrology and associated sediment transport for prediction of risk management within headwater volcanic catchments.
TL;DR: In this paper, the results of processing a series of 82 Landsat images are used to assess the seasonal variability of suspended sediment balance in the Selenga delta in period from 1989 up to the present time.
Abstract: Adaptation of the technology of water turbidity simulation by satellite image data for the delta of the Selenga R, the largest Baikal tributary is given The results of processing a series of 82 Landsat images are used to assess the seasonal variability of suspended sediment balance in the Selenga delta in period from 1989 up to the present time It is shown that, at higher water discharges (>1500 m3/s), suspended material will accumulate in the delta (on the average 15% of the total sediment transport at the delta head), governed by material precipitation within inundated floodplain area and lakes in the lower part of the delta At lower water discharges (<1500 m3/s), a longitudinal increase in suspended sediment transport may take place, caused by setups from Baikal side and channel erosion in the branches
01 Jan 2017
TL;DR: Pan-Eurasian Experiment (PEEX) as mentioned in this paper is an international, multi-disciplinary, multiscale program focused on solving interlinked global challenges influencing societies in the Northern Eurasian region and in China.
Abstract: Pan-Eurasian Experiment (PEEX) initiative (https://www.atm.helsinki.fi/peex/), initiated in 2012, is an international, multi disciplinary, multiscale program focused on solving interlinked global challenges influencing societies in the Northern Eurasian region and in China. As a part of the program, PEEX is aimed to establish an in situ observation network, which would cover environments from the Arctic coastal regions, tundra to boreal forests, from pristine to urban megacities. The PEEX network will be based on two components: (i) the existing stations activities and (ii) establishing new stations. The upgrading plans of the existing stations as well as the new stations will be based a SMEAR (Stations for Measuring Earth surface Atmosphere Relations) concept. The development of the coordinated, comprehensive PEEX observation network is contributing the sustainable development of the Northern Eurasian regions. It is aimed to provide quantified information on climate relevant variables for the research communities and for constructing services, such as early warning systems, for the society.