North Lake Research Articles

If There Can Only Be ?One Law?, It Must Be Treaty Law. Learning From Kanawayandan D?aaki

The paper stems from a research collaboration with the Anishini community of Kitchenuhmaykoosib Inninuwug (KI), known as the people of Big Trout Lake in the far north of Ontario. In the face of renewed threats of encroachment by extractive industries onto their homelands, our research team visited the community on the invitation of leadership in 2017. The community was engaged in strategic planning and reflection on the work that they have done in recent years to articulate and record their own laws for the territory, and to gain recognition for those laws from settler governments. Between 2008 and 2018, the community drafted a Declaration of Sovereignty, a Governance Framework, a Watershed Declaration and a Consultation Protocol, amongst other ‘operational documents’ describing their Indigenous legal order. This period of legal drafting was stimulated by a legal dispute between the community and a mining company, Platinex, that culminated in 2008 with the jailing of the Chief, 4 members of Council and another community member who became known as the “KI6”. Despite community members describing their obligation to protect the land drawn from the key legal concept of Kanawayandan D’aaki, roughly translated as “keeping the land”, the KI6 were convicted of contempt of court for disobeying a court order to provide Platinex with access for its drilling program. The message from the settler courts to the community in 2008 was essentially that only ‘one law’ could govern the land; the application of settler law on KI lands could not accommodate the community members’ obligations under Indigenous law. In this paper, we draw on the transcripts from workshops conducted in KI in 2017 to share insights into the motivations of the community in articulating their laws, and we explore the question of how to reinvigorate historic treaty interpretations so as to produce ‘one law’ inclusive of Indigenous legal orders. We conclude that if there can be only ‘one law’ on treaty territory, it must be a renewed and reinvigorated treaty law.

A local clay-varve chronology of Onega Ice Lake, NW Russia

Onega Ice Lake developed in front of the receding Late Weichselian ice margin in Russian Karelia. Glacial varves that formed in Onega Ice Lake have been earlier studied by means of varve counts, palaeomagnetism and 14C AMS dates from small lakes north of modern Lake Onega and from Lake Onega proper. Synchronous changes in magnetic parameters and similar stratigraphy of these varve records together with the existence of basin-wide marker interval of pink-coloured varves have been used for core-to-core correlation and palaeogeographic interpretations. Unfortunately, there are missing varve-to-varve correlations between these cores. We present a 1155 yr long local varve chronology based on 3 parallel overlapping cores from two small lakes in the Zaonezhsky Peninsula at the northern coast of Lake Onega. Varve counts and matching of varve series were made from digital images. Following the textural, structural, colour and thickness changes of varves within Onega Ice Lake varve series, six characteristic varve units are identified. These clay units reflect changing sedimentary conditions at the time of accumulation that in general can be interpreted as a progressively increasing distance to the retreating ice margin. Variations in varve thickness superimposed on that overall trend, namely two episodes of abrupt and consistent decrease in varve thickness, do not correspond to known lake-level changes or shifts in outflow directions. AMS chronology for deglaciation of Lake Onega basin gives some evidences for correlation of above intervals of decreased varve thickness with the GI-1c2 and GI-1B cold events in NGRIP δ 18O event stratigraphy but further age estimations are needed to confirm presented correlations. Interval of reddish-brown varves – earlier described also as the ‘pink horizon’ – was observed in all studied sequences, and according to varve correlation, at the same stratigraphical level, which proves its basin-wide synchronous appearance. Ca 100 km south of our study area, Saarnisto and Saarinen (2001) reported ca 200 more varves compared to our results. Visual correlation of varve thickness graphs places these extra varves to the proximal part of the series and indicate a rapid ice recession from the main lake basin to the northern Lake Onega area with the ice recession rate ca 500 m per year.

The influence of road salt on seasonal mixing, redox stratification and methane concentrations in urban kettle lakes

Influxes of saline water from roads treated with deicers can alter the density structure of urban lakes. This can diminish or halt turnover events, such that lakes may transition from dimixis to monomixis or meromixis. In nutrient-rich lakes, this lack of turnover can produce persistent hypolimnetic anoxia. We hypothesized that diminished turnover in urban lakes impacted by road salt inputs would lead to increased accumulation of methane in the hypolimnia, with the potential for greater release of methane to the atmosphere via ebullition and from larger storage fluxes of methane when turnover events do occur. The lake water columns of two urban lakes (Woods Lake and Asylum Lake), previously suggested to have transitioned to meromixis and monomixis because of road salt deicer inputs, were sampled monthly from March 2016 to June 2017. A nearby rural lake (North Lake) less likely to be impacted by road salt and maintaining seasonal mixing, was also sampled for comparison. Lake column water was analyzed for conductivity, temperature, dissolved oxygen, ferrous iron, manganese, sulfide, calcium, magnesium, sodium, chloride and methane concentrations as a function of depth. All three lakes are eutrophic with at least seasonally anoxic hypolimnia. Our data are consistent with prior studies suggesting that Woods Lake has transitioned to meromixis and Asylum Lake to monomixis due to an influx of dense saline water from roads treated with deicers. In contrast, rural North Lake, which had much lower chloride, sodium and conductivity levels, was dimictic. The diminished or absent turnover in the two urban lakes during fall and spring resulted in persistently anoxic, redox-stratified hypolimnia, with much larger accumulations of methane compared to the rural lake. This study demonstrates that road salt deicers impact lake mixing and biogeochemistry, especially methane concentrations, with the potential for significant increases in greenhouse gas emissions from urban lakes.

Diversity, distribution and community composition of fish in the archipelago of large and deep lakes north and south of the European Alps

Event Abstract Back to Event Diversity, distribution and community composition of fish in the archipelago of large and deep lakes north and south of the European Alps Ole Seehausen1, 2* 1 Institute of Ecology and Evolution, Department of Biology, Faculty of Science, University of Bern, Switzerland 2 Center for Ecology, Evolution & Biogeochemistry (CEEB), Fish Ecology & Evolution, EAWAG Swiss Federal Institute of Aquatic Science and Technology, Switzerland Archipelagic habitats are classical model systems in ecology, evolution and biogeography because the existence of multiple contained and partly isolated ecosystems, colonized by similar biota and exposed to similar environmental conditions, provides researchers with replicated natural experiments in evolution and community ecology. Such systems are also of primary conservation concern because they are frequently home to endemic species and species radiations, which have come under pressure by a multitude of factors, including invasive species that arrive in the wake of globalisation. One of the most extensive archipelagos of freshwater lakes are the deep postglacial lakes of the European Alps in the old glacier valleys, incised fjord-like into the mountains from the North and the South. After the glaciers retreated 15000 years ago, the lakes north of the Alpine ridge, and those south of it, were independently colonized from different refugial species pools. Most of the larger and deeper among these lakes contain endemic fish species or small radiations of several species. Unfortunately, many have gone extinct in recent decades. Yet, the knowledge of diversity, distribution and endemism among the fish in these systems is surprisingly incomplete. I will present results and key insights that we obtained in the course of a multi-year quantitative survey of fish diversity and distribution that we conducted between 2009 and 2017, the first of its kind in the region, but hopefully the basis for more in-depth research on these unique lake biota. Acknowledgements I thank Pascal Vonlanthen, Guy Periat, Tim Alexander for working together on Projet Lac for many years. I thank Eawag, the Institute of Ecology & Evolution of Uni Bern, the Federal Office for the Environment (FOEN), fisheries authorities of many Swiss kantons, fisheries authorities in France, Italy and Germany for their support Keywords: endemism, Endangered Species, extinction, adaptive radiation, speciation, conservation, salmonids Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Plenary Invited Presentation Topic: TAXONOMY, PHYLOGENY AND ZOOGEOGRAPHY Citation: Seehausen O (2019). Diversity, distribution and community composition of fish in the archipelago of large and deep lakes north and south of the European Alps. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00160 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Jul 2019; Published Online: 14 Aug 2019. * Correspondence: Prof. Ole Seehausen, Institute of Ecology and Evolution, Department of Biology, Faculty of Science, University of Bern, Bern, Bern, 3012 Berne, Switzerland, ole.seehausen@eawag.ch Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Ole Seehausen Google Ole Seehausen Google Scholar Ole Seehausen PubMed Ole Seehausen Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

An Engraved Bulbous-Necked Caddo Bottle from 41OR33 at the mouth of the Sabine River, Orange County, Texas

41OR33 is a large prehistoric shell midden deposit in Orange County, Texas, about 8.5 miles southwest of the city of Orange, at the mouth of the Sabine River and just north of Sabine Lake in Southeast Texas. Before the site was destroyed for road fill in October 1956, limited archaeological investigations had been done there by avocational archaeologists and then by E. Mott Davis of The University of Texas at Austin. During that work, a number of Native American burials were exposed and excavated, including one burial with an engraved bulbous-necked ancestral Caddo ceramic bottle. The bottle was donated by Edgar W. Brown, Jr. to UT in October 1956. I recently documented this vessel, which is a far-flung companion to bulbous-necked and spool-necked Caddo bottles from post-A.D. 1600 sites in the Red River and Ouachita River basins in East Texas and Southwest Arkansas as well as several post-A.D. 1600 sites in East Texas such as the Taylor site (41HS3) in the Big Cypress Creek basin.

The 234U/238U variations in groundwater from the Mondy area in response to earthquakes at the termination of the Tunka Valley in the Baikal Rift System

High 234U/238U activity ratio (AR4/8), identified in groundwater from the Elovka-Kultuk and Nilovka-Mondy inversion sections of the Tunka Valley, coincide with areas of earthquake concentrations. In order to substantiate an approach to earthquake prediction, spatial variations of this parameter were determined in natural water at the western termination of the valley and its temporal variations were monitored in water from the Mon-D well in the Mondy basin in 2013–2017. A recorded gradual decrease of AR4/8 values in water of this well, coeval with preparation and implementation of an earthquake with the energy class K=13.9 in the north of lake Khövsgöl, reflected crack closure that prevented deep water penetration in the Tumelik-Mondy aseismic zone. At the eastern termination of the valley, near the Kultuk village, decreasing AR4/8 values in groundwater were followed with their sharp increasing and transition to low-amplitude variations. Accordingly, crack closing was followed with their opening that facilitated the circulation of deep water and provided seismic events. Leveling of the Mondy anomaly in the Tumelik-Mondy aseismic zone, accompanied by a continuous activity of the Turan and Nilovka anomalies within the Nilovka-Mondy section, emphasized a specific role of the latter as an intermediate chain between the Khövsgöl segment of radial rifts, originated in front of the Hangay orogen, and the largest central basin of the Tunka Valley. The Kultuk, Zaktuy, and North-Tory AR4/8 and earthquake anomalies denoted boundaries of the Elovka-Kultuk section in the Khamardaban lithospheric block flattened at the edge of the Siberian platform basement.

Arsenic survey in Dried Sediments of Maharlu Saline Lake

Being on the steep slope of Shiraz city and getting the main drainages, Maharlu Lake is always home to extensive levels of urban pollution. Prolonged droughts and drying of surface sediments of the lake happen usually in warm seasons of the year, and with the continuation of the droughts particles spread out from the surface into the surroundings of the lake. Arsenic and its compound are well known for its toxicity and carcinogenicity. Industrial and farming waste in upstream of the lake are the main sources of arsenic and may disperse in Maharlu Lake. In this study, by meshing the lake’s surface and by sampling 15 points 3 kilometers away there determined the Arsenic amount. Then, the toxicity indexes and Mueller index together with its risks were studied before zoning of the lake through GIS and verification. The results showed that the average concentration of arsenic was 3.5 mg/ kg of surface sediment. The concentration has gone in most parts of the lake below normal as shown by Mueller index so that its contamination and lower-than-usual toxicity is deemed anthropogenic. Interpolations by GPI, LPI, and IDW methods demonstrated the north part of the lake more concentrated, likely due to the north lake farming and being the entrance of River Soltanabad. The verification of data has recognized the IDW method as the most accurate as regards interpolation. According to the importance of heavy metals in the dust, samples should be taken from winds coming from the lakeside as dust hotspot to control the metals concentration.

The Influence of Community Behaviour on the Quality of Tourism Services at Toba Lake North Sumatera

This research aim as analyzing the influence of community behaviour on the quality of tourism services at Toba Lake North Sumatera. The method of research used mixed between quantitative and the qualitative research. Research sample were taken from 120 head of family at Toba Lake North Sumatera. The technique of data collection of research used documentation study, questionnaires, interviews and observations. The technique data analysis used Simple and Multiple Regression Analysis. The research results showed that there was positive and significant influence between community behavior on the quality of tourism services at Toba Lake North Sumatera. The recommendations of the research stated that it was important to enhance the quality of tourism services by enhancing knowledge, attitude and action about the quality of tourism services so that the quality of tourism services will be increased, and it need to establish tourism school at the Toba Lake North Sumatera

Distribution and accumulation of trace elements in El-Brullus lake islands

El-Brullus Lake is one of three coastal lakes north of Delta. It covered with shallow water. The main objective of this research is to investigate the relationship between contents of some trace elements and major oxides of the Quaternary sediments of El-Brullus lake islands and the correlation coefficient factor between them. For sampling, a total number of 17 samples were collected from 17 boreholes of Quaternary sediments of El-Brullus lake islands. The results indicated that Cu, Zn, and Pb having no correlation with any of these major oxides might be due to their low contents. It concluded contamination of lake water by toxic substances, excess nutrients, and fertilizers, considered the most dangerous manufactured environmental hazards, received from the agricultural drainage system besides the drainage water of private farms.

How useful are geochemical and mineralogical indicators in assessing trace metal contamination and bioavailability in a post-restoration Mediterranean lagoon?

Tunis's Lake North (LNT), located on the Mediterranean Sea, and Tunisia's most important lagoon due to its economic value and its strategic position within the city, has recently undergone a vast sanitation project. To study the lagoon's level of metal pollution, three sediment cores were taken and the sediments were analyzed for trace and major elements, acid volatile sulfides (AVS), total organic carbon (TOC), and minerals. Results showed that TOC concentrations (0.2-3.1%) decreased following the lagoon's restoration. In addition, in comparison to historical data, concentrations of Cu (16-69.5μgg-1), Zn (60.6-191.4μgg-1), and Pb (13-100.9μgg-1) also decreased. Enrichment factor calculation with respect to the crust and local background showed that the sediment had long been contaminated by human pollution and especially by Pb, Zn, and Cu. The AVS to simultaneously extracted metal (SEM) ratio revealed values generally less than 1 indicating no sediment toxicity risks. Statistics revealed a detrital origin for certain metals and a diagenetic origin for FeS2 and carbonate minerals.

STONES, SEA AND BARROWS: SCYTHIAN TIME SITES IN THE LANDSCAPE OF NORTHERN AZOV COAST

Herodotus described the land to the north of the Maeotian lake as a place where the royal Scythian tribes lived. Today, the northern coast of the Azov sea is most commonly associated with this land. However, even though nomadic barrows have been excavated there for more than a century, this region remains the blind spot on the archaeological map of European Scythia, in the comparison to the neighboring sites in the Dnieper and Don basins. Only the «elite» Scythian burial sites, such as Melitopol kurgan, Bierdiansk kurgan and Dvohorba mohyla have been analyzed in the broader context of nomadic burial practices. To address this gap, I have made a closer examination of 117 barrows with 160 burials of Scythian time in this region. In particular, I focused on whether the distinctive features of the local landscape correlate to the burial construction patterns. The sites, included in this research, are located within the 60 km area to the north of coastline. The latitudinal extend of this area is approximately 380 km. In addition, several sites, such as Tokmak barrows and Perederieva mohyla, which are not located in the Azov littoral, but in the upstream basins of coastal rivers are surveyed as well. This territory is divided in several geographic zones, though the high-cliffed Donets ridge and Azov Upland along with flat lowlands of Black Sea and Azov sea occupy the largest part of it. Considering the size and diversity of the territory, the claim of studying some common landscape characteristics seems to be problematic. However, this study shows that land use strategies have reflected in (1) the pattern and frequency of stone constructions, (2) the use of marine eelgrass as architectural material and (3) the arrangement of sites in regard to the bronze age barrows. This analysis contributes to the understanding of regional differentiation of burial sites and land use characteristics in Scythian time.

On the Salt Water Intrusion into the Durusu Lake, Istanbul: A Joint Central Loop TEM And Multi-Electrode ERT Field Survey

Durusu Lake is the biggest and most important freshwater source supplying drinking water to the European side of Istanbul. In this study, electrical resistivity tomography (ERT) and transient electromagnetic (TEM) measurements were applied to detect a possible salt water intrusion into the lake and to delineate the subsurface structure in the north of Durusu Lake. The ERT and TEM measurements were carried out along six parallel profiles extending from the sea coast to the lake shore on the dune barrier. TEM data were interpreted using different 1-D inversion methods such as Occam, Marquardt, and laterally constrained inversion (LCI). ERT data were interpreted using 2-D inversion techniques. The inversion results of ERT and TEM data were shown as resistivity depth sections including topography. The sand layer spreading over the basin has a resistivity of 150–400 Ωm with a thickness of 5–10 m. The sandy layer with clay, silt, and gravel has a resistivity of 15–100 Ωm and a thickness of 10–40 m followed by a clay layer of a resistivity below 10 Ωm. When the inversion of these data is interpreted along with the hydrogeology of the area, it is concluded that the salt water intrusion along the dune barrier is not common and occurs at a particular area where the distance between lake and sea is very close. Using information from boreholes around the lake, it was verified that the common conductive region at depths of 30 m or more consists of clay layers and clay lenses.

Repositórios para tecnologias sociais de área rural em Brasília

O objetivo deste estudo é o demonstrar a indicação de um projeto de aplicação das técnicas e ferramentas da área da Ciência da Informação no apoio a disseminação e utilização da informação de Tecnologias Sociais desenvolvidas no âmbito dos núcleos rurais do Lago Norte, Brasília, Distrito Federal. Assim, a metodologia indicada é uma pesquisa aplicada com utilização de pesquisa de campo com abordagem qualitativa e quantitativa. Como resultados um site da instituição proponente com DSpace e AtoM. Podemos concluir que a utilização dos repositórios disponibilizará e propiciará o acesso as informações sobre as Tecnologias Sociais desenvolvidas pela comunidade de moradores dos núcleos rurais da Serrinha do Paranoá, possibilitando a replicação e a aprendizagem ampliando a sustentabilidade da região.

Spatial Distribution, Chemical Fraction and Fuzzy Comprehensive Risk Assessment of Heavy Metals in Surface Sediments from the Honghu Lake, China.

Spatial concentrations and chemical fractions of heavy metals (Cr, Cu, Pb, Zn and Cd) in 16 sampling sites from the Honghu Lake were investigated using an atomic absorption spectrophotometer and optimized BCR (the European Community Bureau of Reference) three-stage extraction procedure. Compared with the corresponding probable effect levels (PELs), adverse biological effects of the studied five sediment metals decreased in the sequence of Cr > Cu > Zn > Pb > Cd. Geo-accumulation index (Igeo) values for Cr, Cu, Pb and Zn in each sampling site were at un-contamination level, while the values for Cd varied from un-contamination level to moderate contamination level. Spatially, the enrichment degree of Cd in lower part of the South Lake, the west part of the North Lake and the outlet were higher than the other parts of Honghu Lake. For metal chemical fractions, the proportions of the acid-extractable fraction of five metal contents were in the descending order: Cd, Cu, Zn, Pb and Cr. Cd had the highest bioaccessibility. Being the above indexes focused always on heavy metals’ total content or chemical fraction in deterministic assessment system, which may confuse decision makers, the fuzzy comprehensive risk assessment method was established based on PEI (Potential ecological risk index), RAC (Risk assessment code) and fuzzy theory. Average comprehensive risks of heavy metals in sediments revealed the following orders: Cd (considerable risk) > Cu (moderate risk) > Zn (low risk) > Pb > Cr. Thus, Cd and Cu were determined as the pollutants of most concern. The central part of South Honghu Lake (S4, S5, S6, S9, S12 and S14), east part of the North Honghu Lake (S1) and outlet of outlet of the Honghu Lake (S10) were recommended as the priority control areas. Specifically, it is necessary to pay more attention to S1, S4, S5, S6, S9 and S16 when decision making for their calculated membership values (probabilities) of adjacent risk levels quite close.

Plant Community Structure and Forage Nutritive Value of Reed Canarygrass‐Invaded Wetlands

Core Ideas Frequently harvesting reed canarygrass best maintains species richness in wetlands.Frequently harvesting reed canarygrass reduces its cover, a benefit to waterfowl.Reed canarygrass has nutritive value that exceeds needs of spring‐calving beef cows. Many wetlands across the United States have been threatened by reed canarygrass (Phalaris arundinacea L.) invasion. The use of reed canarygrass as forage may provide a revenue stream for agricultural producers while improving wetland ecosystem services. This study was conducted to evaluate the effects of forage harvest frequency (zero, one, two, and three times per year) on plant community structure and nutritive value in reed canarygrass–invaded wetlands. The research was conducted in two wetlands (North Lake Basin [NLB] and Straight Water [SW]), with frequently ponded soils in Seward County, NE, from 2011 to 2013. Harvesting three times per year best maintained plant species richness at NLB but had no effect at SW. Reed canarygrass cover was 14 and 12% greater in unharvested compared with harvested stands at NLB and SW, respectively, but forb cover was unaffected by harvest frequency at either location. Forage harvested increased with harvest frequency during the cooler and wetter years of 2011 and 2013 but was limited by drought during 2012. Crude protein (CP) and total digestible nutrients (TDN) in reed canarygrass and forbs did not show consistent responses to harvest frequency. Across locations and years, reed canarygrass had 88 to 159 g CP kg−1 and 534 to 680 g TDN kg−1. Harvesting wetlands more frequently decreases reed canarygrass cover and increases forage harvested, which are outcomes that could improve waterfowl habitat by increasing access to ponded water. The nutritive value of reed canarygrass at most times throughout the growing season exceeds nutritional requirements of mature, spring‐calving beef cows.

Response of Zooplankton to Climate Variability: Droughts Create a Perfect Storm for Cladocerans in Shallow Eutrophic Lakes

A major attribute of the Earth’s climate that may be affected by global warming is the amplitude of variability in teleconnections. These global-scale processes involve links between oceanic conditions in one locale and weather in another, often distant, locale. An example is the El Niño Southern Oscillation (ENSO), which can affect rainfall and then the properties of lakes in Europe, Africa, North and South America. It affects rainfall, droughts and the depth of lakes in Florida, USA. It is predicted that the amplitude of variation in the ENSO will increase with global warming and, therefore, droughts will become more severe and periods of rain more intense. We investigated possible effects of climate on the zooplankton in shallow subtropical lakes by studying 16 years of monthly data from six shallow eutrophic lakes located north of Orlando, Florida. Results indicate that water depth and lake volume are tightly coupled with rainfall, as expected. During droughts, when lake depth and volume were greatly reduced, there were intensified cyanobacterial blooms, and the zooplankton shifted towards greater relative biomass of copepods compared to cladocerans. The change of zooplankton was likely due to the intensified selective fish predation in the reduced water volume, and/or selective adverse effects of cyanobacteria on cladocerans. The greatly reduced volume might lead to a ‘perfect storm’ of top-down and bottom-up factors that favor copepods over cladocerans. The mechanism needs further study. Regardless, this study documents a direct link between climate variability and zooplankton composition, and suggests how future changes in climate might affect plankton communities.

Integrated hydrologic and hydrodynamic modeling to assess water exchange in a data-scarce reservoir

Integrated hydrologic and hydrodynamic modeling is useful in evaluating hydrodynamic characteristics (e.g. water exchange processes) in data-scarce water bodies, however, most studies lack verification of the hydrologic model. Here, water exchange (represented by water age) was investigated through integrated hydrologic and hydrodynamic modeling of the Hongfeng Reservoir, a poorly gauged reservoir in southwest China. The performance of the hydrologic model and parameter replacement among sub-basins with hydrological similarity was verified by historical data. Results showed that hydrological similarity based on the hierarchical cluster analysis and topographic index probability density distribution was reliable with satisfactory performance of parameter replacement. The hydrodynamic model was verified using daily water levels and water temperatures from 2009 and 2010. The water exchange processes in the Hongfeng Reservoir are very complex with temporal, vertical, and spatial variations. The temporal water age was primarily controlled by the variable inflow and outflow, and the maximum and minimum ages for the site near the dam were 406.10 d (15th June) and 90.74 d (3rd August), respectively, in 2010. Distinct vertical differences in water age showed that surface flow, interflow, and underflow appeared alternately, depending on the season and water depth. The worst water exchange situation was found in the central areas of the North Lake with the highest water ages in the bottom on both 15th June and 3rd August, in 2010. Comparison of the spatial water ages revealed that the more favorable hydraulic conditions on 3rd August mainly improved the water exchange in the dam areas and most areas of the South Lake, but had little effect on the bottom layers of the other deepest areas in the South and North Lakes. The presented framework can be applied in other data-scarce waterbodies worldwide to provide better understanding of water exchange processes.

Suspended sediment distribution under varied currents in the largest river-connected lake of China

Abstract Poyang Lake was selected as the research area. Based on laboratory experiment, field investigation and numerical simulation, the spatial distributions of suspended sediment (SS) under the gravity-flow, jacking-flow and back-flow patterns were quantitatively analysed. An annular flume experiment was conducted to determine the critical starting shear stresses of the sediments in the flood and dry seasons. By numerical experiment, the SS transport under different flow patterns was explored. Several results stand out. (1) The critical starting shear stresses of the sediments in the flood and dry seasons were 0.35 N·m−2 and 0.29 N·m−2, respectively. (2) Due to the strongest flow disturbance and scouring effect, SS under the gravity-flow pattern was characterized by the highest loads. The lowest SS was observed during the jacking-flow pattern, which could be attributed to the lowest water level gap between the lake and external rivers. The loads ranged from 0.053 kg·m−3 to 0.068 kg·m−3. (3) Under the back-flow pattern, SS in the north lake was evidently influenced by the Yangtze River, and the mean value was approximately 0.12 kg·m−3. With the gradually weakened back-flow impact, the SS load was decreased from the north to the middle of the lake.

The contextualization of divergent outlooks in a Greenfield master-planned community: a pathway towards reflexivity

ABSTRACTComprehensive design schemes and specifications have progressively shaped Master-Planned Communities (MPCs). The market largely predetermines these outcomes, with background input from communities. Therefore, this paper endeavours to define the fundamental structures that generate differences between market actors and residents within the North Lakes MPC. This study employs ‘habitus theory’, which is a sociological phenomenon describing the divergence of personal outlooks and expertise. The application of this theory is thus illustrative of the evolution of distinct observations within MPCs. Contemporary studies have under-researched these inherent gaps between communities, authorities, and critics, and these frictions could be exacerbated within restrictive developmental contexts. Epistemic and objectified content analyses collated over many years and sources will uncover the underlying differences between the relevant groups. These analyses will enable the progression of a framework for understanding power relation biases and how reflexivity can enhance current consultative methods.

Persistent organic pollutants in subarctic lakes in the extreme North of European Russia

The paper presents data on the concentrations of persistent organic pollutants in bottom sediments of subarctic lakes on Vaygach Isl. and in the Polar Cis-Urals in the Northern European Russia. Dioxin pollution is estimated at the background level, and the recorded levels of hexachlorobenzene fall within the concentration range identified in the bottom sediments of small lakes in the southwestern Arkhangelsk region. The specific character of the congener profile of polychlorinated dibenzo-p-dioxins and dibenzofurans in bottom sediments is demonstrated, suggesting a relationship between the pollution that forms under the effect of atmospheric transport of persistent organic pollutants from low latitudes in the past and present and the application of dioxin-containing organochlorine chemicals in timber industry.