River Head Research Articles

Hydrological control of the surging behaviour of the Ghujerab River Head Glacier, Karakoram (2019–2023): Insights from high-temporal-resolution remote sensing monitoring

Study regionThe northern region of the Karakoram Range. Study focusKarakoram is a region in High Mountain Asia with many surge-type glaciers. This study employed over 200 high-temporal-resolution remote sensing images and investigated the variations in elevation and velocity of the Ghujerab River Head Glacier (GRHG) from 2019 to 2023. Furthermore, we elucidated the potential controlling mechanisms. New hydrological insights for the regionOur findings revealed that the GRHG, akin to typical surge-type glaciers in Karakoram, started to surge in the spring and finished surging in the summer, with a duration of less than two years. Throughout the surging process, the glacier transferred a mass of 0.11±0.003 km³ from the reservoir area to the receiving area, resulting in a thickening of 91.59±1.04 m at the glacier terminus and thinning of 11.78±1.04 m in the upper glacier. By analysing the mass balance and glacier surface albedo during surging, we proposed that climatic disturbances in the glacier region provided essential material inputs for the surge. Additionally, based on the seasonal evolution pattern of glacier flow velocity, we inferred a close correlation between surging and variations in subglacial hydrology. The duration of acceleration and deceleration during glacier surging, as well as a comparison with existing studies, further support our conclusion. Future research integrating multi-source remote sensing and onsite observations can support numerical simulations to quantitatively reveal the key processes occurring beneath and within glaciers during surge events.

Comparative assessment of water quality classification techniques in the largest north-western river of Cambodia (Sangker River-Tonle Sap Basin)

The lack of adequate and good water quality is one of the serious issues that most developing countries are facing, yet environmental monitoring programs are not efficiently protecting ecosystem health. Here, we aimed to assess the suitability of different water quality assessment frameworks in order to define the most suitable method, especially for data-scarce environments, to quantify river ecosystem health. The study was conducted in the largest north-western river of Cambodia, the Sangker River in the Tonle Sap Lake (TSL) basin (UNESCO Biosphere Reserve). Five water quality assessment methods were selected for the study: Basic & Single Prati indices, Mekong River Commission water quality index (MRC-WQI), French water quality assessment system (SEQ-EAU) and US Environmental Protection Agency (US-EPA) framework. Overall, a physico-chemical gradient of water quality was observed along the river course. The river head was defined by high levels of dissolved oxygen (DO), low nutrients and chloride, while the middle course was marked by a gradual decrease of DO and increased concentration of nutrients up to the TSL floodplains. This degradation was explained by multiple impacts from human activities, e.g. domestic wastes, livestock, crop farming, causing simultaneous eutrophication and oxygen depletion along the river course. Despite those multiple pressures, the Sangker river health status was scored as fairly good reflecting the current situation of the river. So far, we found a convergence of the five water quality assessment methods; however, SEQ-EAU and Basic Prati seemed to be less suitable for tropical river health assessment. The study defined the US-EPA assessment method as the most suitable technique to quantify the Sangker river health. This method could potentially be used to monitor river ecosystem health in data-scarce environments. This would help overcome environmental monitoring challenges in developing countries faced by rapid global environmental changes.

China's experience in developing green finance to reduce carbon emissions: from spatial econometric model evidence.

The objective of this study is to attempt to assess the effect of green finance in reducing carbon emissions in China, analyze the transformative role of policy impact in the development of green finance markets, and investigate the impact mechanisms of how green finance affects carbon dioxide emissions. Our time frame from 2007 to 2018 is selected for the empirical study by integrating the availability of data due to the scarcity of relevant statistics in the early days of green finance. Location of this study is in China where 30 provinces are included, excluding Tibet due to severe data shortage. As for methodology, we construct a green finance evaluation index system containing five indicators by entropy weight method, choose dynamic spatial Durbin model (DSDM) for empirical research, and perform mechanism analysis of restructuring industry and greening technology as intermediary channel. Our findings demonstrate that green finance in China does significantly reduce carbon emissions, and its spatial spillover effect and long-term effect are also verified. Furthermore, green finance tends to reduce CO2 emissions through restructuring industry and greening technology. Correspondingly, policy implications are recommended. First, improving green financial market and strengthening information disclosure of green financial market are crucial to facilitate green finance development. Local governments formulate carbon emission reduction strategies focusing on space by joint conference or coordination mechanism like river head system. Lastly, a mechanism should be developed to strengthen the transformation of industrial structure and to promote greening technology.

Anthropogenic land use and urbanization alter the dynamics and increase the export of dissolved carbon in an urbanized river system

Greenhouse gas emissions from urban rivers play a crucial role in global carbon (C) cycling, this is tightly linked to dissolved C in rivers but research gaps remain. The effects of urbanization and anthropogenic land-use change on riverine dissolved carbon dynamics were investigated in a temperate river, the River Kelvin in UK. The river was constantly a source of methane (CH4) and carbon dioxide (CO2) to the atmosphere (excess concentration of CH4 ranged from 13 to 4441 nM, and excess concentration of CO2 ranged from 2.6 to 230.6 μM), and dissolved C concentrations show significant spatiotemporal variations (p < 0.05), reflecting a variety of proximal sources and controls. For example, the concentration variation of dissolved CH4 and dissolved CO2 were heavily controlled by the proximity of coal mine infrastructure in the tributary near the river head (~ 2 km) but were more likely controlled by adjacent landfills in the midstream section of the rivers main channel. Concentration and isotopic evidence revealed an important anthropogenic control on the riverine export of CO2 and dissolved organic carbon (DOC). However, dissolved inorganic carbon (DIC) input via groundwater at the catchment scale primarily controlled the dynamics of riverine DIC. Furthermore, the positive relationship between the isotopic composition of DIC and CO2 (r = 0.79, p < 0.01) indicates the DIC pool was at times also significantly influenced by soil respiratory CO2. Both DIC and DOC showed a weak but significant correlation with the proportion of urban/suburban land use, suggesting increased dissolved C export resulting from urbanization. This research elucidates a series of potentially key effects anthropogenic activities and land-use practices can have on riverine C dynamics and highlights the need for future consideration of the direct effects urbanization has on riverine C dynamics.

Projection of Streamflow Changes Under CMIP6 Scenarios in the Urumqi River Head Watershed, Tianshan Mountain, China

Analyzing climate change impacts on hydrology and future water supply projections is essential for effective water resource management and planning in the large river basins of Asia. In these regions, streamflow and glacier melt remain subject to significant uncertainties due to the lack of confidence in climate change projections and modeling methods. In this study, a glacier dynamics model (the Open Global Glacier Model was coupled with a glacio-hydrological model [the Glacio-hydrological Degree-day Model (GDM)] to predict possible hydrological changes in the head watershed of the Urumqi River under three shared socioeconomic pathways SSP2-4.5, SSP3-7.0, and SSP5-8.5. The GDM was calibrated and validated against in situ observed discharge data for the 2007–2011 and 2012–2018 periods. The resulting Nash–Sutcliffe efficiency (NSE) values were 0.82 and 0.81, respectively. The GDM was driven with an ensemble of five downscaled CMIP6 datasets to examine the potential impacts of climate change on hydrologic processes in the basin. Four runoff components were simulated with the GDM: base flow, rainfall, ice melt, and snow melt. It was determined that rainfall constituted the predominant source of runoff, followed by baseflow and ice melt. During the calibration and validation periods, snow and ice melt contributed 25.14 and 25.62%, respectively, to the total runoff. Under all SSP scenarios, the projected runoff decline indicated that the peak runoff time had passed. It was revealed that a 2°C increase in the monthly average temperature could result in a 37.7% increase in the total discharge of the basin. Moreover, the GDM was more responsive to changes in air temperature than to changes in glacier extent.

Metallic and glass spherules in the loose deposits of the Put river head (Middle Urals)

Research subject. The article examines exotic mineral formations - spherules (balls) of various composition and structure, found in the Neogene sediments of the interfluve of the Put-Bisert rivers within the eastern wing of the Yurizan-Sylva de-pression.Materials and methods. The work was carried out using the authors' research results, the available data on similar formations both from the modern soil-vegetation layer, including peat and technogenic formations, and from more ancient Phanerozoic sedimentary, magmatic and ore complexes. The article uses the results of studies obtained by a scanning electron microscope “EVO MA 15” from ZEISS with an energy-dispersive attachment EDS “X-MAX 80” at the JSC “Mekhanobr” analytical laboratory.Results. A detailed study of the surface morphology, dimensions, chemical and mineral composition of three types of spherules - magnetite, iron-chromium composition and barium and titanium oxide, similar to the stoichiometric formula of sanbornite - was carried out. The surface of the balls of the second type is heterogeneous in structure and contains growths, some of which have the form of a flat, flattened, square, skeletal crystal of a sectorial structure. The inner surface of the crystal has a fine-mesh structure. The cells have a complex, elongated structure. At the periphery of the crystal, the cells transform into hollow channels, indicating growth from the gas phase. In composition, the sectoral crystal corresponds to a solid solution between magnesio-chromite and herzenite with an admixture of nickel, calcium and silicon. The internal microstructure of iron-chromium spherules has a myrmekite, two-phase structure.Conclusions. The obtained data indicate that such heterogeneous formations can be formed only in specific deep fluid-saturated high-temperature magmatic systems and delivered to the surface by hydrothermal fluids along weakened tectonic zones. The detection of these formations in the overlying sediments of the western wing of the Artinskaya anticline may indicate the proximity of large fluid-supplying deep structures that control the Bukharovskoye gas show.

Metal geochemistry in suspended and bed sediments in the eutrophic lowland Salado River basin (Buenos Aires, Argentina)

The Salado River is a lowland river that drains a vast and productive region of central Argentina into the Río de la Plata estuary. To evaluate water quality and the geochemistry of major and trace metals (Fe, Mn, Zn, Cu, Pb, Cr and Ni), water and sediments samples were collected along 500 km of the Salado River basin (n = 21). Waters were highly alkaline (pH: 8.8 ± 0.4), saline (5.2 ± 1.8 mS/cm), turbid (467 ± 237 NTU) and eutrophic (chlorophyll a: 187 ± 119 µg/l) with a decreasing gradient towards the river mouth reflecting the contribution of alkaline ground waters and eutrophication at the river head. Suspended particles (70–595 mg/l) were enriched in total organic carbon, nitrogen (5–7 times) and metals (1–4 times) relative to bed sediments, but metal concentrations were 2–10 times below the world river’s average. Consistently, metal concentrations in bed sediments were lower than sediment quality guidelines with an increasing downriver trend following the enrichment of clays. The enrichment factors (EF) and geoaccumulation index (Igeo), calculated with local background metal levels from the deepest layers of a dated sediment core, indicate a general prevalence of natural metal sources (EF < 1.5) with unpolluted sediments (Igeo ≤ 0), excepted for the Chivilcoy stream, which showed a significant enrichment of Zn, Cu and Pb (EF = 2–12; 0 ≤ Igeo ≤ 1) constituting a clear pollution hot spot in the basin.

石狩川頭首工の設計・施工・管理の特徴

石狩川頭首工の設計・施工・管理の特徴

Dynamics of structure and abundance of night migratory community in the littoral zone of lake Baikal

Monthly observations of night migratory community of the hydrobionts in the southern part of Lake Baikal near the Angara river head were conducted between November 2017 and January 2018. Distinctions in structure and abundance of different hydrobiont groups depending on the month of the observation were shown. Thus, the pelagic amphipod Macrohectopus branickii was present as a part of night migratory complex only on November 2017 and the peak of benthic amphipod numbers was observed on December 2017. The decrease of migration activity during the period was probably associated with a lowering of water temperature. Key words: Baikal, migratory community, amphipods, light pollution.

Análise morfométrica da bacia do ribeirão da laje, no Sudoeste de Goiás, Brasil

Devido aos impactos ambientais negativos causados pelo uso intensivo do solo, expansão urbana e industrial e à importância dos recursos hídricos para manutenção das diversas formas de vida na Terra, tornam-se necessários dados para o planejamento e a gestão ambiental de bacias hidrográficas. Objetivou-se analisar a morfometria da bacia do ribeirão da Laje, uma das principais fontes fornecedoras de água para o abastecimento público da população urbana de Rio Verde (GO), apoiado em geotecnologias e obras de autores consagrados. A área de estudo apresenta variáveis morfométricas, geologia, solos e precipitação pluviométrica predominantemente favoráveis à sua conservação e à recarga de água. Entretanto, a forma alongada e possíveis ocorrências de chuvas intensas na cabeceira sujeitam a bacia hidrográfica às torrentes eventuais, podendo causar prejuízos ambientais e econômicos; a amplitude altimétrica máxima, as maiores declividades, a densidade hidrográfica, densidade de drenagem, Nitossolo Vermelho, Neossolo Litólico e a predominância de agricultura intensiva são favoráveis à perda de solos. Este estudo irá subsidiar o planejamento e a gestão ambiental dessa bacia hidrográfica, além de servir de base para outros trabalhos locais e de outras regiões, contribuindo para a disponibilidade hídrica em quantidade e qualidade adequadas aos usos múltiplos.

Heavy Metals Pollution Influence the Community Structure of Cyanobacteria in Nutrient Rich Tropical Estuary

Anthropogenic inputs influence the community structure and activities of microorganisms, which may impinge the functioning of estuarine and coastal ecosystem. The aim of the present study was to understand the influence of dissolved heavy metals (Cr, Mn, Fe, Ni, Cu and Zn) on community structure of cyanobacteria in a nutrient rich tropical estuary, Cochin Estuary (CE), across the southwest coast of India. Dissolved heavy metals were higher in CE during dry season, with Zn as major pollutant. The level of dissolved Zn was higher in stations near river head during dry (130 μg L-1) and wet seasons (105 μg L-1). The community structure of cyanobacteria was higher in CE during wet season (H’ index: 1.4 to 3.1) compared to that in dry season (H’ index: 1.1 to 2.2). The 16S rRNA gene sequence analysis showed the prevalence of Synechococcus sp in CE. PCA analysis indicated the positive influence of Zn and nutrients on community structure of cyanobacteria. We postulate that the Zn pollution may be a critical factor to be monitored and controlled in nutrient rich estuaries, otherwise it may accelerate the eutrophication and associated ecological constraints.

Determinação do gradiente hidráulico médio em aquífero costeiro influenciado pela variação constante de carga hidráulica em ambiente estuarino

Na determinação dos gradientes hidráulicos das águas subterrâneas em aquíferos estuarinos, as ondas de pressão decorrentes das flutuações das marés e corpos de água devem ser consideradas. Para este estudo, monitorou-se por 45 dias as variações de nível de água do Rio Cubatão e carga hidráulica do aquífero raso (em 3 níveis de profundidade) numa área industrial adjacente ao rio, em Cubatão, SP, a fim de se determinar as cargas hidráulicas médias e gradientes médios pelo método conforme proposto por Serfes (1991). Este monitoramento foi contínuo e realizado em dois cenários: com o sistema de remediação (“Air Sparging”) ativado e desativado. Os resultados mostraram a interferência do sistema de remediação e da variação da maré nas cargas hidráulicas dos poços monitorados nos poços próximos ao rio Cubatão, e somente a variação da maré nos poços mais distantes. No entanto, na porção superior do aquífero monitorado mostrou a condição de influência do rio Cubatão nos dois cenários. Condições de efluência e influência na porção intermediária e efluência predominante desse rio na porção mais profunda foram observadas. Nas porções intermediária e profunda, os gradientes hidráulicos calculados apresentam valores baixos (-0,0027 a 0,0030), de modo que a análise sobre o sentido de fluxo deve ser criteriosa.

The Features of Dismantling Works of the Former Ishikari River Head Works

The Features of Dismantling Works of the Former Ishikari River Head Works

Morphosculpture of the river Mashey valley (Central Altai)

Complexes of exogenous processes and morphosculptures in the mountain valley of the Mashey river (North Chuya Ridge, Central Altai) are described. 5 cites with different geomorphic structure were distinguished: two – in the river head occupied by glacier, two – in the high mountain part, where Pleistocene trough is transformed intensely by slope, cryogenic and fluvial processes, one – in the low mountain part, where the relics of glacial forms are predominant. On the base of paleo-trough and associate landforms morphometry the reconstruction of paleoglacier Mashey was fulfilled. We ascertain that no Pleistocene moraines exist in the upper part of the valley, and that in Holocene a sharp change of geomorphologic situation took place, which led to accumulation renewal.

Calibration process for groundwater flow model of a river influenced shallow aquifer

Understanding and simulating the interaction of groundwater and surface water is essential to hydrologists. Water supply and water quality aspects are a few examples of common water-resource issues where understanding the interconnections of groundwater and surface water is fundamental to develop an effective water-resource management and policy. In our study a detailed investigation of a riverbank aquifer was performed to be able to simulate and predict the behavior of the flow system. The continuous hydraulic head measurements in the area of interest showed strong influence on the hydraulic head field caused by intensively changing river head at a distance from the river up to 3,500 m. Based on the results steady state and transient flow calculations were compared, and a great effort has been made to ensure that the model more precisely describe the time and space variable flow field. Beside fulfilling the standard calibration requirements, a multi-step calibration process was performed.

Flow‐Through Stream Modeling with MODFLOW and MT3D: Certainties and Limitations

This paper aims to assess MODFLOW and MT3D capabilities for simulating the spread of contaminants from a river exhibiting an unusual relationship with an alluvial aquifer, with the groundwater head higher than the river head on one side and lower on the other (flow-through stream). A series of simulation tests is conducted using a simple hypothetical model so as to characterize and quantify these limitations. Simulation results show that the expected contaminant spread could be achieved with a specific configuration composed of two sets of parameters: (1) modeled object parameters (hydraulic groundwater gradient, hydraulic conductivity values of aquifer and streambed), and (2) modeling parameters (vertical discretization of aquifer, horizontal refinement of stream modeled with River [RIV] package). The influence of these various parameters on simulation results is investigated, and potential complications and errors are identified. Contaminant spread from stream to aquifer is not always reproduced by MT3D due to the RIV package's inability to simulate lateral exchange fluxes between stream and aquifer. This paper identifies the need for a MODFLOW streamflow package allowing lateral stream-aquifer interactions and streamflow routine calculations. Such developments could be of particular interest for modeling contaminated flow-through streams.

Potential Sites Screening for Mini Hydro Power Plant Development in Kapuas Hulu, West Kalimantan: A GIS Approach

Mini Hydro Power Plant (MHPP) is characterized by river discharge and head profile. However, the lack of discharge data and river head information becomes barriers in developing MHPP. In this research, GIS approach is used to assess MHPP potential by analysing spatial data. Head calculation was conducted using neighborhood statistical method while river discharge was approached using SCS-CN equation. Potential sites were determined using potential energy formula. The results showed that study area has 18 potential sites from 100 kW to 5.2 MW. This method is suitable for initial screening only. Further in-depth feasibility study is needed to develop MHPP.

Олойский флористический комплекс из меловых отложений верховьев р. Ильгувеем, Северо-Восток России

The Oloy floristic assemblage comes from volcanic-sedimentary deposits of the Teleneut Unit, distributed in the Il’guveem river head, at the Oloy, Great Anuy and Yablon Rivers interfluve area. This area belongs to the Anadyr segment of the Okchotsk-Chukotka volcanic belt (Belyi, 1977). The Oloy floristic assemblage consists of 15 species. Equisetopsida: Equisetum sp. Polypodiopsida: Cladophlebis sp., Coniopteris sp., Tchaunia tchaunensis Samyl. et Philipp. Czekanowskiopsida: Phoenicopsis ex gr. angustifolia Heer. Cycadophytes: Heilungia oloensis Samyl. et Philipp., Taeniopteris sp., Pterophyllum sp. Ginkgoopsida: Ginkgo sp., Sphenobaiera sp. Pinopsida: Pagiophyllum zhuravlevii Golovn., Araucarites sp., Taxodium sp., Sequoia sp., Pityophyllum sp. Among them gymnosperms predominate. Angiosperms are not revealed. Cycadophytes are represented by three genera (Heilungia, Taeniopteris and Pterophyllum). Taxonomic composition of the Oloy floristic assemblage most closely resembles the composition of the Chaun flora, which comes from the Coniacian deposits of the Chaun Group of Central Chukotka. From 15 species of the Oloy assemblage 13 species are common with the Chaun ones (besides Taeniopteris иPterophyllum). Among common taxa there are the characteristic endemic plants of the Chaun flora: Tchaunia tchaunensis and Pagiophyllum zhuravlevii. The great systematic similarity of these floras indicate that they were even-aged and belonged to the single phytogeographic area – the Chukotka subprovince of the Mountain Okchotsk-Chukotka province (Golovneva, 2014b).

Adapting Water Allocation to Irrigation Demands to Constraints in Water Availability Imposed by Climate Change

Climate change projections predict a rise in temperatures which may result in a reduction in water resource availability. Irrigation is both the most demanding water use and that which is the lowest priority. Consequently, adaptation measures regarding irrigation demands are required in coping with such a resource decrease. As improvement in water efficiency use could not be enough to counteract strong stream flow reductions, management actions regarding demands may be implemented. This paper proposes a methodology for identifying the required reductions and sequence in which water allocation is to be reduced in order to meet satisfactory system behaviour. Such a methodology could help basin managers in decision making in meeting irrigation demands which, accordingly, could offer better performance in terms of both reliability and productivity. The methodology is applied at the Guadalquivir Basin in Spain, under eight hydrological projections which represent future climate change scenarios. The results show that it is possible to reduce future water scarcity problems and, hence, improve system performance. In addition to this, it is found that optimal reduction sequence is not only affected by water productivity, but also by the system topology which influences reliability. In the case study, the most sensitive demands are those located at the river head. As such demands have no alternative sources, they typically offer the lowest degree of reliability.

The riverbank filtration plant in S. Alessio (Lucca): monitoring and modeling activity within EU the FP7 MARSOL project

The riverbank filtration (RBF) scheme along the Serchio River, Lucca (Tuscany – Italy) allows abstraction of an overall amount of about 1 m3/s groundwater providing drinking water for about 300000 people of the coastal Tuscany (town of Lucca, Pisa and Livorno). Water is derived by means of an RBF scheme by a set of ten vertical wells inducing riverbank filtration into a high yield (10-2 m2/s transmissivity) sand and gravel aquifer including a downstream weir to raise river head and increasing water storage in the aquifer along the river reach. Within the framework of the MARSOL FPVII-ENV-2013 project, the Sant’Alessio well field will be used to demonstrate the sustainability, by a technical, social and market point of view, and the benefits of RBF managing versus the unmanaged option. The Serchio experimental site will involve merging existing and proved technologies, including continuous monitoring of several parameters and analytes and the development of dedicated software tools, to produce a Decision Support System (DSS) based on remote data acquisition and transmission and GIS physically-based fully distributed numerical modeling to continuously monitor and manage the well field, reducing also, prone to error, human operated activities. A set of sensors will be installed to monitor by a quantitative and qualitative point of view hydrologic variables in the river water, in the aquifer, the unsaturated zone and the wells. Data will be continuously acquired and remotely transmitted to a server where they will first be checked for consistency and then sent to a database for processing in a dedicated modelling environment included in the DSS and equipped with an alert system to inform water managers about the scheme performance and reaching limits of infiltration rates or water quality indices. The DSS along with the installed sensors, data transmission and storage tools will constitute a prototype whose potential market exploitation will be tested.