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This chapter begins by examining general patterns of groundwater flow, recharge and discharge patterns, flow in layered systems, and crustal-scale flow patterns. The next topic covered is surface water hydrology and groundwater/surface water interaction, including examination of stream hydrographs and estimation of baseflow. The distribution of recharge in space and time is studied and common methods for estimating recharge are covered. The chapter has sections focused on the characteristics of groundwater flow in specific geologic environments. Case studies of many specific aquifers and hydrogeologic settings are presented: the High Plains Aquifer, New Jersey coastal plain aquifers, Western Cape Cod sand and gravel aquifers, the Dakota sandstone aquifer, karst systems near Mammoth Cave, and the Columbia Plateau basalts. The chapter closes with coverage of groundwater in permafrost environments.

A one-dimensional morphodynamic model was improved to study the unsteady flow and sediment transport processes in a tail reach of the Yellow River estuary (YRE). In this model, the modified equations for flow hydrodynamics take the effects of sediment concentration and bed evolution into consideration. The improved model was validated using measurements in the tail reach of the YRE for the years 2003 and 2015, and the model showing an excellent data fit for discharge, water level, suspended sediment concentration and the cumulative volume of channel evolution. The effect of different cross-sectional spacings was also studied using the model results in the tail reach, with various numerical tests of the 2015 flood event conducted. It was found that an appropriate cross-sectional distance of less than 3.14 km should be adopted when simulating the process of bed deformation. Moreover, the interaction between runoff and tide in 2015 was studied on the basis of the simulated water levels and an empirical relation for the location of tidal limit was established. The results show that the tidal limit in 2015 was 15.84 km downstream of Xihekou.

Es-Sbikhat- El-Mahmel, basin, located at the southeastern piedmont of Aures massif (Northeasten Algeria), is an area with a semi-arid climate. 39 samples were collected during May 2015, for physicochemical analysis. The interpretation of analysis data has shown a chemical facies evolution from bicarbonate-calcium waters into chloride-calcium waters, going through a transition facies marked by sulfate-calcium to sulfate-magnesium waters. The principal component analysis showed that the percentage of the variances expressed is 52.70% for the factor 1, 14.73% for the factor 2 and 11.44 for the factor 3. The binary diagrams and thermodynamic analysis corroborated that interaction water-rock is responsible for the mineralization through the geochemical process of mineral dissolution-precipitation, cationic exchange and anthropogenic pollution.

The concentration and sources of organic nitrogen (ON) in lake sediment significantly affect the lake nitrogen cycle. However, the influencing factors and contributors to the ON accumulation rate (ONAR) are unclear. In this study, tree sediment cores from northern, eastern, and southern Dianchi Lake (DC-N, DC-E, and DC-S, respectively), sampled in July 2014, were used to study the effects of autochthonous and allochthonous sources on ON. The results showed that ON and the ONAR increased 2.4–5.1 and 2.6–4.8 times, respectively, from1900 to2000, especially since the 1980s, at which point algal blooms occurred more frequently. The ON contents decreased in the order: DC-S > DC-N > DC-E, whereas the ONAR values followed the order: DC-N > DC-S > DC-E, suggesting that the ONAR was influenced by ON content as well as depositional environmental conditions. The total concentrations of n-alkanes (n-C12 to n-C34) ranged from 4719.4 ng g− 1 to 61,959.6 ng g− 1 in the three sediment cores, each of which exhibited different n-alkanes characteristic variation with vertical depth. The sources of ON were mainly allochthonous (soil erosion and terrestrial plants) and autochthonous (algal and aquatic plants) in DC-S and DC-N, respectively, whereas they were primarily mixed planktonic and terrestrial sources in DC-E. Using the stochastic impacts by regression on population, affluence, and technology model to further examine the ONAR values revealed that 1% increase in temperature and nitrogen fertilizer can increase the ONAR by 73.8–86.2% and 73.2–151.3% in all sediments, especially in DC-S and DC-E. However, a 1% increase in construction area could reduce the ONAR by 2.4–14.2%, especially in DC-N. Overall, climate change and human activities determine the spatial and temporal ONAR variation in Dianchi Lake.

Film cooling is used to protect turbine components from the extreme temperatures by ejecting coolant through arrays of holes to create an air buffer from the hot combustion gases. Limitations in traditional machining meant film cooling holes universally have sharp inlets which create separation regions at the hole entrance. The present study uses experimental and computational data to show that these inlet separation are a major cause of performance variation in crossflow fed film cooling holes. Three hole designs were experimentally tested by independently varying the coolant velocity ratio (VR) and the coolant channel velocitty ratio (VRc) to isolate the effects of crossflow on hole performance. Leveraging additive manufacturing technologies, the addition of a 0.25D radius fillet to the inlet of a 7-7-7 shaped hole is shown to significantly improve diffuser usage and significantly reduce variation in performance with VRc. A second AM design used a very large radius of curvature inlet to reduce biasing caused by the inlet crossflow. Experiments showed that this “swept” hole design did minimize biasing of coolant flow to one side of the shaped hole and it significantly reduced variations due to varying VRc. RANS simulations at six VR and three VRc conditions were made for each geometry to better understand how the new geometries changed the velocity field within the hole. The sharp and rounded inlets were seen to have very similar tangential velocity fields and jet biasing. Both AM inlets created more uniform, slower velocity fields entering the diffuser. The results of this paper indicate large improvements in film cooling performance can be found by leveraging AM technology.

Pollen-based vegetation, biodiversity, and biome reconstructions over the last 15,500 years from sediment core data at Mbi Crater in the Cameroon highlands (6.089273° N, 10.348549° E; 2015 m above sea level) are used to discuss the behavior of the lower edge of the Afromontane forest facing climate change. The data reveal that the post-glacial forest change gradually happened at Mbi and that the forest-wooded grassland ecotone was highly influenced by the climate variability related to the North Atlantic. The forest disruption and diversity loss intermittently occurred over the whole period, and their vegetation changes temporally match dry-cold events at the northern latitudes during the Younger Dryas, at 9.5–9.1 ka, 8.6–8.0 ka, 6.7–6.0 ka, 3.2 ka, and during the Little Ice Age (LIA). During the LIA, the mountain forest was subject to unprecedented levels of disturbance at all altitudes, unlike the seasonal lowland forests, which appears to have been only marginally affected.

Speleothem deposits in nowadays arid environments are important climate archives, as they indicate phases of enhanced precipitation and can precisely be dated by uranium-series dating. So far only very few of such archives have been found in the today hyper-arid Saharo-Arabian Desert (SAD). Therefore, the study at hand fills a gap that exists for speleothem climate archives in Northeast Africa. A new record from Saqia Cave (Central Eastern Desert, Egypt) documents for the first-time speleothem growth in Egypt for all sub-stages of MIS 5 and singular phases during MIS 6. Most important growth phases occur during periods of strong increase and maximum orbitally-forced northern hemisphere insolation, but also during phases of low insolation, which are in general attributed to aridity in North Africa. Here, at least semi-arid climate conditions are proposed for periods of low insolation during stadials of MIS 5. This suggests an impact of different possible sources of precipitation, apart from large scale shifts of the African monsoon, such as Red Sea Troughs, tropical plums and a larger spatial extent of the Mediterranean winter-rainfall zone. Concerning the spatial rainfall pattern in Egypt, we propose a considerable east to west rainfall gradient in Egypt for the Last Interglacial and suggest a stronger impact of variable moisture sources in the Eastern Desert near the Mediterranean and Red Sea in comparison to the more continental Western Desert of Egypt. This reveals more favorable pre-conditions for an enhanced land use potential in the past. Therefore, the more sustaining wetter climate in the Eastern Desert point to a recurring feasible dispersal corridor for Homo sapiens from the tropical climate into the temperate climate regime throughout MIS 5. Such a more humid climate provided an ideal basis for long-term, favorable environmental conditions east of the Nile Valley, creating a kind of contiguous landscape corridor that may have been attractive to humans and wildlife alike, linking the East African tropical climate regime with that of the temperate zone in Northeast Africa and Eurasia.

In India, large rivers are experiencing serious threat to aquatic biodiversity, and therefore flagship projects are being executed on freshwater biodiversity conservation using various methods and strategies. Ganga River is the largest and longest river of India supporting rich commercial and artisanal fisheries for decades. Periodical and systematic assessments of fish biodiversity of the large river ecosystem are important for effective conservation planning. Although over the years, the ichthyofaunal diversity of the river has been assessed under different programmes, however current assessment of fish diversity across different zones are not adequately studied and reported. In the present study systematic re-explorations were carried out and changing pattern of fish diversity and distribution during the period 2016–19 was recorded. We described a total of 190 fish species (182 indigenous and 8exotics) belonging to 133 genera, 62 families and 23 orders from upper Ganga (Harsil) to the river mouth of Hooghly estuary (Fraserganj). The assessment of native species revealed about 10% and 14.21% of the total species are listed under threatened status of IUCN Red List (version 2020) and CAMP (1998) threatened category respectively. Among the exotics, common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) was found dominated in upper, middle and part of lower stretch. The study showed considerable dominancy of major and minor catfish followed by small indigenous fishes. The evaluation of species richness through biodiversity matrices resulted the lower stretch to be the richest zone forming a strong cluster relationship (>0.71) among all the stations. The analysis of similarity percentage (SIMPER) of all the stations revealed an average similarity of 4.59% between all the stations. Shift in distribution pattern of few fish species was also recorded in certain sections of the river. The study indicated drastic decline of commercially important major carps and catfishes in comparison to previous records. The present paper also discussed about the potential threats and important guidelines concerning sustainable fisheries of River Ganga. The comprehensive information presented in this paper on fish diversity, distribution, abundance, production trend of major fish group of the river in different zones have highlighted relative change as compared to previous studies that will be useful for monitoring biodiversity and future conservation planning of the river basin.

The now-abandoned project for a new international airport for Mexico City was located at a site on the former Texcoco Lake, where extremely difficult subsoil conditions prevail. The behaviour of one of the trial embankments built to test foundation solutions for the runways is analysed in this paper. Observational data were gathered over 50 months at the so-called reference embankment, where no special foundation or soil improvement techniques were adopted. The performance of this embankment was investigated through finite-element simulations in which an elasto-viscoplastic constitutive model was implemented in commercial software. The model incorporates key features such as time dependence, long-term deformation and an anisotropic flow surface. The results provide an assessment of the constitutive description adopted as well as the role of anisotropy in the simulation of the case study.

Studies show that electromobility will emerge in urban areas. As urban mobility solutions are changing, electromobility is intended with a big potential of sustainable innovation. Nevertheless, changing the mobility culture depends on certain requirements. According to Urri, the automobile development lies in breaking the dominant role of cars which results in a development deadlock. In order to change the mobility culture, the mental approach to mobility options and the infrastructural conditions need to be considered as two central factors. Future mobility isn´t about less mobility, but rather a different way of being mobile and using different types of mobility solutions. This paper presents a research project that is based on the systemic-relational approach. It seeks to develop and introduce the conditions of electromobility in an urban area without a well-frequented local public transport by a networked innovation cooperation in four development areas. The central goal of this work is the integrated development of service innovation of technical and non-technical manner based on the network of project partners, the city council and the university. A change towards electromobility means changing infrastructure, market actors and business models. It signifies a change of social-cultural systems regarding mobility habits, practices and values. One of our main results show that the emotional perception by using experiences of electromobility has a positive effect on its social acceptability which raises the “flow factor” of electromobility.

Slope stability analysis and seepage analysis are two important aspects of embankment stability. Landslides are a common risk faced by many people in the world, with this risk increased in the case of an earthfill embankment or water reservoir. People living in downstream regions are always at risk if the dam is not designed to achieve full strength. In this work, a pre-defined earthfill dam was analysed to assess its strength with variations of dam width (WD), shear strength of the soil (τ) and dam slope angle (β). The factor of safety was considered as the dependent, with WD, τ and β as independent variables. A pre-defined proposed dam model was analysed using limit equilibrium (LE) methods with the help of the LE software Slide. Linear regression analysis was performed using SPSS (Statistical Package for Social Sciences) software and equations were developed. The computed equations show a very close relation of all the analysed parameters. The coefficient of determination (R2) of all the developed correlations was found to be very high and the equations can thus be used in design analysis of slopes, embankments and earthfill dams.

A temporal analysis of landscape change patterns and consequent evaluation of urban expansion has been studied for the Dera Ghazi Khan city which is developing fast since 2000 as an emerging metropolis of South Punjab. The geospatial techniques particularly remote sensing augmented with GIS are vital tools and are mostly used in studying landscape changes and decision making for sustainable urban development. Four Landsat images (1991, 2001, 2011 and 2021) obtained from the free web of GLFC have been analysed. A supervised classification algorithm was applied to all images and results have been presented in both tabular and graphic forms. Present study, focuses upon two land-use classes i.e. built up and open areas, which will be monitored by land-use patterns of Dera Ghazi Khan city during 1991 to 2021 using satellite images. The graphical depiction of all the landscape changes, which have taken place in D. G. Khan city in the form of tables and maps provides detailed information about the degree and ratio of urban expansion and the changes in land use that occurred during the stipulated period.The classification was based on four categories i.e., urban land, bare soil, vegetation, and water; while maps were prepared to present the temporal changes in D. G. Khan city. A total of 52 sq./kms areas was selected for this study designated as the Dera Ghazi Khan city. According to the results, 33% of the urban area has been expanded in Dera Ghazi Khan from 1991 to 2021 and 19% vegetation cover has been reduced. It is a very alarming situation that agricultural land is decreasing because of urban expansion. The results revealed the significance of remote sensing and GIS in evaluating landscape changes.

Knowledge of reproductive biology and life-history traits of populations exploited by fisheries is important for their sustainable management. We investigated the life-history traits of Trichiurus lepturus (largehead hairtail) in south-eastern Australia; a region of low exploitation for this otherwise heavily exploited circumglobal species, to investigate whether there were differences in the reproductive biology and life-history traits in the south-east Australian population compared with those in other regions. We also used histological sections to examine male and female gonads at a microscopic level. Trichiurus lepturus in south-eastern Australia had a greater maximum length (193 cm total length (TL)), matured at a larger length (108 cm TL at 50% mature) and had a spawning period (March to September, Austral winter) that was inconsistent with other regions. The overall sex ratio of 1:0.4 females: males was consistent with a female dominant sex ratio observed in other regions, particularly in larger length classes. However, females in the current study dominated samples from both estuarine and coastal habitats, as well as during the spawning and non-spawning periods, which is not consistent with the patterns found in other regions. Differences in south-eastern Australia may relate to limited fishing pressure, genetic variation, or differences in environmental factors that influence reproductive development, including temperature, trophic resources and habitat.

We study the influence of bank competition on U.S. public borrowers’ accounting conservatism by exploiting the staggered adoption of the Riegle-Neal Interstate Banking and Branching Efficiency Act (IBBEA) of 1994, which increased the threats of new bank entrants and actual bank entry. We find that borrowers’ conditional conservatism fell after IBBEA. Conservatism fell more for firms located in states with weak incumbent banks and states with more out-of-state entrants, especially entrants with better monitoring technologies. The decrease in conservatism partially stems from borrowers’ increased investment and risk-taking incentives. Conservatism fell more for firms relying more on bank loans, especially those that borrowed loans for the first time after IBBEA and for firms having lower dedicated institutional ownership and board independence. We also find that loans included fewer covenants and that bank loan borrowers became less likely to choose Big N auditors and industry specialist auditors after IBBEA. Data Availability: Data are available from the public sources cited in the text. JEL Classifications: G21; G28; K23; M41.

Pollen and carbon isotope data from Natural Trap Cave provides insights into the environmental conditions of the Bighorn Basin, in north-central Wyoming, USA during the time intervals 151.1 to 132.2 cal ka BP, 51.8 to 17.4 cal ka BP, and 10.4 cal ka BP to present. Similarities between the buildup of the penultimate and last glacial maxima include abundant Artemisia, Amaranthaceae, Asteraceae, and Poaceae pollen, which, when combined with high δ13C values (>−25.0‰) and low plant discrimination values (18.0–19.0‰) from sedimentary organic matter, indicate steppe-like, cold-dry conditions. Between 151 and 142.5 cal ka BP, abundant Poaceae associated with much lower δ13C values (−28.0‰ to −26.0‰) and higher plant discrimination values (19.0‰–21.0‰) could be indicative of relatively wet summers. Similarly, after 25 cal ka BP increases in Poaceae may indicate wet conditions during the growing season. Holocene conditions differ from the earlier sections of the record, with greater arboreal pollen abundance (i.e., Pinus), consistent with woodland expansion in the region. Carbon isotope data from sedimentary organic matter show the Holocene was more humid than the glacial conditions of the late Pleistocene. This is especially clear at the start of the Holocene when a large negative carbon isotope excursion (CIE

The paper studies strike-slip fault rupture propagation through dense sand and its interaction with surface foundations, combining physical and numerical modelling. A series of centrifuge tests is conducted using a three-section split-box, which allows the modelling of two strike-slip faults per test. A free-field test is initially conducted, followed by four interaction tests. Eight different foundation configurations are studied, varying the foundation location, surcharge load, aspect ratio and rigidity. The experiments are numerically simulated employing three-dimensional finite-element modelling, combining periodic boundaries and a relatively simple yet efficient constitutive model, developed as part of this study. Based on a Mohr–Coulomb yield criterion, the model incorporates post-yield isotropic frictional hardening and softening (MC–HS). Carefully calibrated on the basis of triaxial tests, the model is validated against the centrifuge model tests, and exploited to derive further insights. The MC–HS model covers the entire range from elastic to fully softened response, capturing the deviatoric and volumetric behaviour of dense sand, and especially its pre-softening volumetric response, which is proven to be crucial for the simulation of the complex mechanisms of strike-slip faulting. Both physical and numerical modelling reveal the formation of diagonal shear ruptures at the ground surface (Riedel shears). These are complex helicoidal structures, formed due to the spatial variation of shear stresses. Foundation response is mainly governed by the kinematic constraint offered by its presence. Fault rupture locations close to its sides typically lead to a translational mechanism, whereas locations close to its centreline lead to a rotational one. Foundation rigidity is proven to be a prerequisite for the development of both mechanisms, which rely on the ability of the foundation to resist the developing normal and shear stresses.

An analytical solution for contaminant transport through a vertical cut-off wall and aquifer system is developed, which can consider the advection, dispersion and degradation processes. The uniqueness of the solution is that it includes hyperbolic eigenfunctions, considers the degradation process and is suitable for an aquifer with finite thickness due to the existence of a river or lake. The solution is first verified against an existing analytical solution and a numerical model using the Comsol software program. The three important aspects are then investigated and some important conclusions are obtained. In some scenarios, the hyperbolic eigenfunctions must be considered; otherwise, the obtained results are unreasonable. When the aquifer thickness is more than a critical value (approximately ten times the cut-off wall thickness in this study), it is reasonable to regard the aquifer as semi-infinite. Contaminant degradation has significant influence on contaminant transport. A higher degradation intensity leads to a lower contaminant concentration but a larger mass flux in the cut-off wall. Therefore, the present solution is suitable for an aquifer with arbitrary thickness and has better applicability than the existing analytical solutions. It is promising to be used as an applicable tool for the design of vertical slurry cut-off walls.

Numerous incidents and failures of earth slopes, dykes, levees and embankment dams are caused by internal erosion. At a time of global climate change, rapid pore-water pressure changes in soil masses are frequently induced by extreme rainfall, storm surges, waves, flash floods and so on. Under such complex cyclic hydraulic conditions, the soil erodibility, hydraulic conductivity and subsequent stress–strain behaviour may differ from those under the monotonic seepage condition, and are still poorly understood. In this study, preliminary laboratory tests have been conducted to investigate the development of internal erosion and changes in hydraulic conductivity under one-way cyclic seepage, and the post-erosion stress–strain behaviour. Representative internally stable and unstable soils were tested. The effects of mean hydraulic gradient and cyclic gradient amplitude were investigated in detail. Results show that the erosion development is significantly influenced by both the initial grain size distribution and the pattern of imposed cyclic hydraulic gradient. The cyclic seepage promotes the loss of fine particles and leads to larger hydraulic conductivity. For the internally unstable soil, the eroded soil mass and hydraulic conductivity increased significantly with increasing cyclic gradient amplitude. Nevertheless, the internally stable soil experienced a small amount of particle loss, even under large cyclic gradients. For both types of soil, a larger cyclic gradient amplitude corresponds to a stronger post-erosion contractive shearing behaviour and a smaller critical friction angle.

The Salish Sea is a marginal inland sea of the NE Pacific (NW North America) that includes the Georgia Strait-Gulf Islands Archipelago of British Columbia, Canada and the San Juan Archipelago, Strait of Juan de Fuca, and the Lower Puget Sound of Washington State, USA. This marginal seafloor has been extensively mapped and according to criteria presented and discussed at GeoHab conferences critical marine benthic habitat types are identified. One such habitat that is the focus of this paper is the deep-water sub-tidal habitat of Pacific sand lance (PSL). The PSL (Ammodytes personatus) is a critical forage fish for a variety of mammals, birds and fish including minke whales and salmon as it preys upon zooplankton and acts as an energy transfer species from the lower to higher trophic levels. Pacific sand lance seeks refuge and overwinters in sand-wave fields consisting of dynamic bedforms. The species prefers loosely packed, well-aerated, well-sorted, medium- to coarse-grain (~1 phi [φ], 500 µm) sand that it can burrow into easily. Such geomorphic features as active dynamic bedforms provide preferable habitats for PSL and depends on specific and unique oceanographic processes that can maintain the habitat's morphology and grain sizes. Understanding these processes is essential in forecasting alteration or destruction of such features, including changes that may be brought about by sea level rise. Using the five-person submersible Cyclops 1, we recently examined a well-studied sand-wave field in the San Juan Archipelago of Washington State, USA, which has been reported to harbor up to 12 million PSL. Observations, video recordings, and photography from this vehicle allowed us to assess modern seafloor processes of the central Salish Sea that can be used along with fish and sediment sample data to determine physical preferences this fish needs to sustain its population. Changes in the seafloor current regime, sediment source, and anthropogenic disturbances can critically alter these dynamic bedforms. This research provides insight into the structure of these bedforms, their composition, their persistence, their resilience to disturbance, and the susceptibility as an impact and becoming impacted.

The high-resolution biochemical records (SRXRF, ICP-MS and FTIR analyses) of bottom sediments were used for the reconstruction of clastic flux into Lake Baikal via the Barguzin River as moisture and glacier indexes from 1631 ka BP. According to the obtained data, proxies of a high supply of clastic flux by the river are high: the content of feldspar and LREE/HREE, Rb/Sr and Th/Mo ratios. We sampled a sediment core extremely close to the estuary of the Barguzin River. It seems that the water budget of the Baikal tributaries dramatically reduced ca. 34–30 ka BP, and the lake water level was minimum (less than 35–40 m compared to the present) for the last 34 ka. The lake water level has gradually increased from ca. 30 to 25–23 ka BP, and it was likely linked with the activity of the East Asia Monsoon. The very contrasting changes in chemical and mineralogical records were ca. 29.5 ka BP, and these changes were very likely associated with the Heinrich-3; however, there were no significant changes in the records around the Heinrich-2. Our records revealed some intensification of the clastic flux of the Barguzin River into the Barguzin Bay ca. 25–23 ka BP. The Baikal event ca. 21.5–22.5 ka BP was characterized by a sharp reduction of the influx of clastic material into the Barguzin Bay. The time span of 19.5–18 ka BP was the last time that the Barguzin River inflow increased during the Late Pleistocene. This increase in the water budget was at arid regional conditions, and we assumed it could occur due to the contribution of meltwater from glaciers of the Barguzin Ridge. It is most likely that at the regional Late Pleistocene/Holocene transition (around 12–13 ka BP), a rapid rise of the water budget of the Barguzin River occurred, while the lake level was not high, and the sediments deposited from 12(13)–16.5 ka BP could be directly eroded by a kill of the Barguzin River. In general, the obtained records show that an increase in the water budget of the Barguzin River was gradual. The duration of high inflow into the Barguzin Bay was ca. 1.5 ka, while the reductions of this inflow were dramatic.

This paper discusses the results of siliceous microfossils studies performed in a “staircase” of four isolation basins (33.7 m–2.9 m a.s.l.) on Big Solovetskiy Island (Solovki Archipelago, the White Sea). Diatoms were used as a primary group for paleoinferences, while chrysophyte cysts and sponge spicules also demonstrated high indicative potential. In all study lakes, the siliceous microfossils stratigraphy revealed three main stages of their evolution, i.e. large-basin, transitional and small-lake stages, each characterized by certain composition of the diatom assemblages and floristic diversity, relative abundances of chrysophyte cysts and sponge spicules, and siliceous microfossils concentrations. In the uppermost lake, glaciolacustrine environments unfavorable for aquatic biota existed during the large-basin stage. The proglacial lake stage terminated prior to ca. 10.4 cal ka BP, followed by a (semi)terrestrial episode before the transition to small-lake environments. In the other three lakes, marine environments were inferred at the earlier stage, characterized by the predominance of marine and brackish-marine diatoms, increased proportions of sponge spicules and low “cysts to diatoms” ratio. At the transitional marine-freshwater stage, mass growth of small fragilarioid diatoms and decreased abundances of spicules indicated unstable environments, while increased proportions of cysts pointed to progressive freshening of the basins. The duration of the marine-freshwater transition expectedly prolonged from ca. 200 yr in the upper basin (16.6 m a.s.l) to ca. 500 yr in the lowermost lake (2.9 m a.s.l.). The isolation from the sea took place between ca. 6.3 and 1.4 cal ka BP. At the small-lake stage, siliceous microfossils stratigraphies reflected local specifics of the basins and their catchments. We argue that besides traditionally used diatom data, relative and absolute abundances of siliceous microfossils also possess high indicative value for isolation basin studies. Our study demonstrated that marine waters on Big Solovetskiy Island never reached ca. 34 m a.s.l. during the Holocene, unlike the western coast of the Onega Bay where the Preboreal marine intrusion was recorded even at higher elevated localities. Different rates and amplitudes of shoreline displacement are thus suggested for the inner and outer parts of the Onega Bay. During the mid-Holocene Tapes transgression, before ca. 6.3 cal ka BP, the relative sea level on Big Solovetskiy Island exceeded 17 m a.s.l. The average estimated rates of the shoreline retreat during the second half of the Holocene gradually decreased from 0.28 cm year−1 to 0.2 cm year−1, indicating slowed isostatic uplift.

The vicinity of the Rozprza archaeological site (central Poland) has been the area of a series of palaeoecological studies tracking the environmental history of the Luciąża River valley up to ca. 13,200 cal. BP. Numerous subfossil palaeomeanders of different sizes have been discovered in the valley floor. Here, we present the first results of multiproxy research on the paleo-oxbow lake fill, one of the oldest in the region. The wide range of palaeoecological analyses resulted in reconstructions of vegetation history, climatic, hydrological and habitat changes. The studied oxbow was an aquatic ecosystem with diverse invertebrate fauna until the end of Younger Dryas when it transformed into a limno-telmatic habitat. The sediment composition indicates active denudation processes and several episodes of turbulent hydrological conditions. Such an increased river activity could have caused flooding, resulting in an allochthonous matter supply to the oxbow lake in Late Vistulian. Environmental changes were strictly related to the regional features of the catchment, the transformation of soils, and the hydrogeological conditions. The chironomid- and pollen-inferred climatic reconstructions indicate periods of high and low continentality. The chironomid record indicates relatively cool summer conditions in the Allerød, especially ca. 13,000 cal. BP, possibly related to the Gerzensee Oscillation. On the other hand, a distinct increase of summer temperatures in Younger Dryas (up to 16 °C) was recorded. Such a situation was also confirmed in some other studies from the region, suggesting that it might be the effect of some specific, local palaeoclimatic conditions. Fundator badań: Fundator badań: Optional.empty

Data on the mineralogy and geochemistry of rare earth elements (REE + Y) in water, suspended matter and stratified sediment cores from different parts of Lake Onego are presented. The study finds that the dissolved REE + Y in the water from different areas of Lake Onego have common features: (1) a maximum in the area of middle rare earth elements (MREE), (2) a distinct negative Ce anomaly and (3) a positive Eu anomaly. Comparison of the average concentration of elements in the stratified core of the bottom sediments and particulate matter (from the filters and sedimentation traps) from different parts of Lake Onego and the distribution of REE + Y do not reveal any significant differences. The trend of the REE + Y distribution for samples from the South Onego completely coincide the REE + Y distribution in siltstones and sandstones of the Russian Platform Scale Composite (RPSC). In the water area of Lake Onego from south to north, a well-defined trend of changes in REE + Y patterns relative to the RPSC is revealed, with depletion by heavy REE + Y and gradual enrichment by light rare earth elements (LREE). Geochemical and mineralogical data confirm our hypothesis of a significant reformatting of the catchment basin of the Onego Ice Lake in the Late Pleistocene. During the formation of the preglacial lake, a significant part of the catchment area was located south of Lake Onego and is mainly represented by Russian Platform sedimentary rocks. Due to the degradation of the Last Glacier from the Lake Onego depression and the nearby territories, the catchment area changed of its southern and south-eastern sections. Today the composition of the modern sedimentary matter entering Lake Onego is determined by mixing clusters from two geochemically contrasting feeding areas: loose sediments formed by the repeatedly re-deposited products of the weathering of the Fennoscandian Shield's crystalline rock massifs, including Phanerozoic sediments; and to a lesser extent the sediments of the sedimentary cover of the Russian Platform, except the bottom sediments of the South Onego, in which Phanerozoic sedimentary formations have completely predominated throughout the lake's development.

Endocrine disrupting compounds and in particular estrogenic substances have the ability to interact with the hormone system of organisms. Among them are not only synthetic but also natural substances that potentially stress the aquatic ecosystem. High human population densities such as around the Pearl River Estuary (PRE) are suspected of exerting significant anthropogenic pressure onto coastal areas. In this study, natural and synthetic estrogens as well as estrogen-like substances derived from plants and fungi were investigated in the PRE and at the adjacent northern shelf of the South China Sea. Maximum concentration of 3.6 ng L−1 for estrone (E1), 0.7 ng L−1 for 17α-ethinylestradiol (EE2), 12.9 ng L−1 for genistein (GEN), 11.9 ng L−1 for daidzein (DAI) and 1.9 ng L−1 for zearalenone (ZEN) were observed. While E1 and EE2 were detected in fresh and saltwater samples, GEN, DAI and ZEN were observed only at freshwater sampling sites. During the investigations, the analysis of 17β-estradiol (E2) and EE2 indicated a strong matrix dependence. Additionally, an estrogen screen observation showed estrogenic activity in form of estradiol equivalent quotients up to 0.18 ng L−1.

To study the morphological characteristics of the largest canyons in the Southern and Central Basins of Lake Baikal, we analysed a digital relief model based on high-resolution multibeam bathymetric surveying. We evaluate the role of tectonic, lithological and climatic controlling factors in the formation and evolution of canyons. Tectonic activity and seismicity act as a catalyst for canyon formation and for the development of sublacustrine gravity flows and turbidity currents, and alter the morphological appearance of already existing canyons. The influence of tectonics on the formation of the Baikal canyons is particularly noticeable on the western slope of Lake Baikal, where canyons are mainly located along faults and follow their directions. Gravity flows and turbidity currents become more important during earthquakes and periods of lower lake level. When canyon heads are located close to river mouths, riverine processes have a significant impact on the evolution of the canyon. The topography of the original surface and the lithology of the substrate also play a significant role in the evolution of canyons and in shaping the canyon morphology. During periods of lower lake level (during Pleistocene glacial periods) riverine processes were responsible for initiating the formation of many canyons in Lake Baikal. The canyons developed under the complex influence of the factors considered. One or another factor could be dominant at different stages of their evolution, while the role of the other factors became secondary. These roles could interchange over time. The Baikal canyons show a great deal of resemblance to canyons in marine environments, in terms of morphological characteristics as well as of canyon-forming processes. We propose a morphogenetic classification of the underwater valleys and canyons of Lake Baikal.

The stock of shale gas in the Shahezi shale reservoir in the Changling fault depression, Songliao Basin, is believed to be worth exploring. In-depth study on the pore structure and fractal characterization of organic matter (OM) can help better understand the pore system of shale reservoir, which has implications for the exploration of lacustrine shale. To demonstrate the nanoscale pore structure and irregularity of the isolated OM, we collected a large number of samples and then conducted a series of laboratory experiments, such as X-ray diffraction, scanning electron microscopy, and [Formula: see text] and [Formula: see text] adsorption experiments to determine the pore structure parameters and reveal their heterogeneity according to Frenkel-Halsey-Hill theory. As suggested by the experimental results, the pore size distribution curve of the [Formula: see text] and [Formula: see text] exhibits similar pore peaks, whereas the trends of change in bulk shale and isolated OM samples are basically paralleled. The pore volume of the isolated OM ranges between 0.034 and [Formula: see text], which is approximately 0.90–3.06 times that of bulk shale samples. As for the fractal dimensions [Formula: see text] (2.594 on average) and [Formula: see text] (2.657 on average) of bulk shale, they are larger as compared with isolated OM, indicating that inorganic minerals can make a significant difference in the heterogeneity of shale pores. The fractal dimensions ([Formula: see text] and [Formula: see text]) of bulk shales indicate a close correlation with the parameters of pore structure, whereas there is no significant correlation observed between the dimensions of isolated OM and its parameters. In addition, thermal maturity and solid bitumen have only limited impact on the OM pore structure of isolated OM samples. Then, we conducted further research to reveal that the insoluble OM macerals derived from terrestrial higher plants can be used to explain the difference in pore structure and heterogeneity between isolated OM samples. Therefore, we arrived at the conclusion that the composition of macerals depends on the exact pore structure and fractal characteristics of isolated OM samples with similarity in thermal maturity.

Background The present study was aimed at genetic characterization and diversity analysis of indigenous swamp buffalo population ‘Bhangor’ from Tripura, India using the Food and Agriculture Organization (FAO) recommended bovine microsatellite markers. So far buffaloes of the north-eastern states of India have been studied except for Tripura. Results Buffalo blood samples were collected from Tripura. Of the 24 microsatellite markers studied only 15 markers (CSSM33, BM1818, CSRM60, HEL13, ILSTS019, ILSTS025, ILSTS028, ILSTS029, ILSTS030, ILSTS033, ILSTS036, ILSTS056, ILSTS058, ILSTS061, ILSTS089 and ETH003) were found to be highly polymorphic in the population. A total of 114 alleles were secured, with an overall average of 7.60 alleles per locus. The number of alleles ranged from 3 (CSRM60 and ILSTS025) to 12 (ILSTS056 and ILSTS061). The mean effective number of alleles across all polymorphic loci was found to be 3.76. The overall mean expected heterozygosity and unbiased expected heterozygosity values were 0.67 and 0.68, ranging from 0.067 (ILSTS025) to 0.85 (ILSTS058) and 0.068 (ILSTS025) to 0.86 (ILSTS058), respectively. Within-population inbreeding estimates (FIS) for bhangor buffalo ranged between − 0.4352 and 0.804 with an average FIS of 0.114 ± 0.033. Conclusions The outcome for IAM, TPM and test for mode shift revealed the absence of any recent bottleneck in Bhangor buffalo population. The population was found to be in optimum diversity based on polymorphic microsatellite markers. This is the newly characterized buffalo population from north-east India.

México está considerado como uno de los países megadiversos y en su territorio se encuentran entre 4 y 8% del número de total de especies de plantas del mundo, de las cuales 51% son endémicas. Existe una gran preocupación sobre la conservación de la flora mexicana, ya que se han detectado varias actividades y factores que la amenazan. En este trabajo se identifican áreas de endemismo para las angiospermas de México con el objetivo de priorizar regiones para conservación. Para categorizar estas zonas se sigue el enfoque que toma en cuenta la biodiversidad, el índice de endemismo ponderado y la historia evolutiva. Se identificaron los linajes de angiospermas, ya sean familias, géneros, o grupos infragenéricos con o sin estatus taxonómico que previamente se habían determinado como monofiléticos para representar la historia evolutiva en unidades espaciales equivalentes. Se construyó una base de datos de 9416 registros de especies de 259 grupos monofiléticos de angiospermas restringidas a México y se registró su presencia en estas áreas. Para cada una se calculó la riqueza de taxones y el índice de endemismo ponderado. Los resultados muestran que la mayoría de las zonas de más alto endemismo están en climas secos, con vegetación xérica, con dos excepciones de vegetación tropical y templada. Los índices de endemismo ponderado más altos se localizaron en: el área norte de matorral rosetófilo en Nuevo León y Coahuila, matorrales gipsófilos en San Luis Potosí, la Sierra Gorda en Querérato, Tolantongo en Hidalgo, el Valle de Tehuacán-Cuicatlán en Puebla y Oaxaca, El Salto en Durango, la Sierra de Quila en Jalisco, la zona oeste de la Depresión del Balsas en Michoacán, Guerrero, Morelos y el Estado de México, la zona de Tehuantepec en Oaxaca y El Triunfo en Chiapas. Algunas áreas de endemismo en el Desierto Chihuahuense, en la Cuenca del Balsas y en la Depresión de Chiapas, así como del sur de Oaxaca no están suficientemente protegidas. Se registraron aproximadamente 340 especies con distribución restringida a un solo cuadrante y de éstas la mayoría de las que se incluyen en la lista de taxones amenazados de México pertenecen a las Cactaceae.

Ephemeral fluvial systems in the dryland region of Kachchh are susceptible to climatic fluctuations. An increase in Indian Summer Monsoon Intensity (ISM) is responsible for the aggradation of sediments as valley-fill deposits in the river basins. In the present study sedimentological, chronometric, and geochemical analysis on the fluvial terrace sequences of Nirona and Bhukhi river basins are being used to interpret southwest summer monsoon variability from MIS 5D-5C along with the fluvial response to local tectonics. The sediment record indicates increased ISM precipitation from ∼110ka to ∼90ka, which corresponds to the MIS 5D to MIS 5C (Interstadial stage). The ISM became progressively weaker during the MIS-5B (stadial stage), leading to present-day arid conditions. The climatic factors weakened along with an interplay of local tectonics, leading to present-day conditions of bedrock incision.

Fires, explosions, and spills at petrochemical industry facilities create air pollution exposure risks for surrounding residences, which are disproportionately communities of color and low-income c...

Urban expansions into natural habitats have forced many carnivores to adapt to the modified areas; however, our understanding of their ecology in such areas is limited. The Indian fox (Vulpes bengalensis) is a small carnivore species that can adapt and exploit urban areas due to its generalist nature, but there is a paucity of data on Indian foxes in these human-modified areas. To understand the resource requirement of Indian foxes in urban habitats, we conducted a diet analysis by examining 119 scats of Indian foxes in a peri-urban habitat of Baripada town, Odisha, eastern India. To determine the diet composition of Indian foxes, we analyzed scat contents by their frequency occurrence (%FO), the relative frequency of occurrence (%RF) and mean percent volume (%Vm). Indian foxes consumed a wide range of food categories, including arthropods, rodents, reptiles, birds, plant parts and anthropogenic resources. In %Vm, rodents showed the highest volume, followed by polythene, Spondias pinnata fruit and Coleoptera. We found anthropogenic foods in considerable quantities, including polythene and paper. The diet of Indian foxes indicates that the species has opportunistic and generalist feeding habits consisting primarily of easily accessible foods. Furthermore, management efforts should focus on the proper management of waste and control of anthropogenic food sources in urban habitats.

Recognizing the risk of fluvial bank erosion is an important challenge to ensure the early warning and prevention or control of bank collapse in river catchments, including in the Yangtze River. This study introduces a geomorphons-based algorithm to extract river bank erosion information by adjusting the flatness from multibeam echo-sounding data. The algorithm maps 10 subaqueous morphological elements, including the slope, footslope, flat, ridge, peak, valley, pit, spur, hollow, and shoulder. Twenty-one flatness values were used to build an interpretation strategy for the subaqueous features of riverbank erosion. The results show that the bank scarp, which is the erosion carrier, is covered by slope cells when the flatness is 10°. The scour pits and bank scars are indicated by pit cells near the bank and hollow cells in the bank slope at a flatness of 0°. Fluvial subaqueous dunes are considered an important factor accelerating bank erosion, particularly those near the bank toe; the critical flatness of the dunes was evaluated as 3°. The distribution of subaqueous morphological elements was analyzed and used to map the bank erosion inventory. The analysis results revealed that the near-bank zone, with a relatively large water depth, is prone to form large scour pits and a long bank scarp. Arc collapse tends to occur at the long bank scarp to shorten its length. The varied assignment of flatness values among terrestrial, marine, and fluvial environments is discussed, concluding that diversified flatness values significantly enable fluvial subaqueous morphology recognition. Consequently, this study provides a reference for the flatness-based recognition of fluvial morphological elements and enhances the targeting of subaqueous signs and risks of bank failure with a range of multibeam bathymetric data.

This review tries to explain the effects of river infiltration and the interaction between groundwater and surface water on nitrogen (N) and phosphorus (P) distribution in riparian zones. On the basis of previous studies, this review summarized the distribution characteristics of N and P of 7 different riparian zones in China, compared the water quality of water bodies adjoining these riparian zones, proposed the distribution regularity of N and P in diverse riparian zones. The concentrations of N and P in the riparian zones with better water quality have increasing trend from riverside to upland. And those rivers with poorer water quality have decreasing trend. If the infiltrated concentration of runoff pollutant is more than river pollutant infiltration, the upland soil may obtain higher contaminants. On the contrary, if the concentration of river infiltration is more than that of the runoff, the riverside soil will show higher concentration. Similarly, if those two effects are equivalent, the concentration of N and P in the riparian zone will be low on riverside and upland, and somewhere in the middle will be higher than elsewhere. Clean rivers and polluted rivers taken with different quantity of contaminants will infiltrate diverse concentrations of N and P. It is expected that this review can provide a new theoretical basis for revealing the environmental effects of riparian zones and managing, protecting and restoring the riparian ecosystems.

This paper reports on the performance analysis of an embankment over a soft soil deposit during construction. The study section is part of the duplication of the Brazilian federal highway, BR 470, a major infrastructure project that crosses several soft clay deposits in the state of Santa Catarina, Brazil. To guarantee stability and accelerate the landfill consolidation, the project provided geotechnical solutions as follows: basal reinforcement with geogrids, equilibrium berms, stage constructions of the landfill (slow construction), preloading and prefabricated vertical drains. The performance during field construction was mostly evaluated through instrumentation considering the evolution of horizontal displacements (distortion and distortion rates) and the Asaoka method to evaluate the stabilisation of settlements. Given the limitations of the methods used for control during construction, and a discrepancy between field settlements and original project predictions, the soil profile and geotechnical parameters were revaluated during construction and used in a revised performance analysis. Some important considerations were observed from this back-analysis that could have been used to modify the construction process during execution. In addition, to analyse the effects of the inherited variability, a sensitivity analysis to determine levels of possible settlements and time of consolidation was performed.

Mixed or intermediate soils are widely used in the construction of embankment dams. Unfavourable climate conditions and poor quality control may result in the use of mixed soils as under-compacted dam cores, with moisture content highly in excess of the optimum. It is thus essential to design safe filters to prevent internal erosion and piping from wet, under-compacted mixed-soil cores in embankment dams. In this study, 87 no-erosion filter tests were performed on seven mixed core soils having dissimilar geotechnical specifications with diverse moisture contents and compaction ratios. The experimental findings showed that the filter performance (success or failure at preventing erosion) depends on moisture in excess of optimum, the filter D15 (particle size with 15% finer in filter gradation) and the fines content of the core soil. An increase in excess moisture necessitates a smaller D15 to inhibit erosion, to the extent that filters respecting accepted criteria may fail to hinder erosion in the case of excessively wet and under-compacted cores. Overall, for group II, cores the criterion of D15 15

The hydrological process in the dry–warm valley of the mountainous area of southwestern China has unique characteristics and has attracted scientific attention worldwide. Given that this is an area with fragile ecosystems and intensive water resource conflicts in the upper reaches of the Yangtze River, a systematic identification of its hydrological responses to climate and land use variations needs to be performed. In this study, MIKE SHE was employed and calibrated for the Anning River Basin in the dry–warm valley. Subsequently, a deep learning neural network model of the long short-term memory (LSTM) and a traditional multi-model ensemble mean (MMEM) method were used for an ensemble of 31 global climate models (GCMs) for climate projection. The cellular automata–Markov model was implemented to project the spatial pattern of land use considering climatic, social, and economic conditions. Four sets of climate projections and three sets of land use projections were generated and fed into the MIKE SHE to project hydrologic responses from 2021 to 2050. For the calibration and first validation periods of the daily simulation, the coefficients of determination (R) were 0.85 and 0.87 and the Nash–Sutcliffe efficiency values were 0.72 and 0.73, respectively. The advanced LSTM performed better than the traditional MMEM method for daily temperature and monthly precipitation. The average monthly temperature projection under representative concentration pathway 8.5 (RCP8.5) was expected to be slightly higher than that under RCP4.5; this is contrary to the average monthly precipitation from June to October. The variations in streamflow and actual evapotranspiration (ET) were both more sensitive to climate change than to land use change. There was no significant relationship between the variations in streamflow and the ET in the study area. This work could provide general variation conditions and a range of hydrologic responses to complex and changing environments, thereby assisting with stochastic uncertainty and optimizing water resource management in critical regions.

Indian summer monsoon (ISM) variability in the late Holocene (last 4000 years) is of great interest as the arid phase of ISM and cultivation of kharif (rainy season) crops started in this period. The present study aims to revisit the available speleothem records to study ISM rainfall variations and possible controlling factors in different Indian regions viz., core monsoon zone (CMZ), peninsular, the Himalaya, and the Bay of Bengal in the last 4000 years. The late Holocene encompasses notable global warm periods viz., Medieval Climate Anomaly, Roman Warm Period (RWP) & Minoan Warm Period, and cold periods viz., Dark Age cold period and Little Ice Age (LIA). ISM rainfall declines until the middle of RWP in all the regions. The decline is linked with the southward migration of the Intertropical convergence zone caused by the northern Hemisphere summer insolation. Though the Solar insolation follows the same trend, all the records show large variability with the disappearance of the declining trend around the middle of RWP. This change coincided with the reversal in the north Atlantic Sea surface temperature (SST) trend, northern hemisphere temperature, and abrupt changes in the southeastern Indian Ocean SST. This period also witnessed high El-Nino Southern Oscillation activities. This synergy of ISM variations in the characterized zones falls apart during the pre-LIA with a slight increasing (decreasing) trend in CMZ and Bay of Bengal (peninsular and Himalayan). The spatially variable response of ISM rainfall in recent centuries might be caused by the interaction between internal variability and external forcing and also by anthropogenic-induced warming and aerosol forcing.

Based on the results of our analysis, a classification of bird species of the Kyrgyz mountain ridge (Northern Tien Shan) was compiled according to their preference for habitats and occurrence throughout the year. The program of factorial classification used for this unites species according to the maximum similarity in their distribution and stay in an unspecified number of clusters. In total, 4 supertypes and 12 types of preferences have been identified along the Kyrgyz ridge. In the supertype of birds that prefer undeveloped areas, 6 types were distinguished, namely, the species choosing: 1 – high mountains, 2 – high and medium mountains, 3 – medium mountains, 4 – medium mountains and foothills, 5 – foothills, and 6 – found at all heights. The supertype of birds preferring built-up areas is represented by one type only: the species preferring foothill sheaths and villages, and the supertype of birds preferring rivers and their banks is represented by four types, namely, the species preferring: high-mountain rivers in the summer and autumn; high-altitude and mid-mountain rivers in the spring and summer; mid-mountain rivers in the autumn; and foothill rivers in the first half of the summer. The supertype uniting species found in all habitats is represented by one type of preference, namely, found throughout the whole year. It is shown that of the 154 recorded bird species, most were found in undeveloped habitats, and 6 and 12 times less were in built-up areas and rivers, including their banks. In undeveloped areas, most bird species prefer high- and mid-mountainous landscapes and half as many prefer foothill landscapes. In residential landscapes, most species tend to the foothills, and among rivers, they prefer high-altitude and mid-mountain areas. At to the seasons, the maximum number of species was recorded in the spring-summer and summer periods.

Paleoclimatic constraints from mountain ranges separating major climate systems are important in understanding past climatic changes. Using the present-day glacial geomorphology combined with the GlaRe model, the last glacial maximum (LGM) of seven representative valley glaciers of the Pir Panjal Range (PPR), Kashmir Himalaya was reconstructed. The Range lies at the interface of the tropical and temperate climates in the NW Himalayas. The glacier reconstructions showed that the glaciers in the Range advanced ~10 km down the present-day cirque margins and attained a thickness of more than 200 m during the LGM. Using six different methods, the equilibrium line altitude (ELA) changes in the selected valleys of the PPR were estimated for which the LGM was reconstructed. ELA depressions calculated for the LGM vary from 374 m to 416 m with a mean of 395 m. The weighted average ELA of the Range lies at an altitude of 3922 m a.s.l showing a general increasing trend from SE to NW of the Range. The published chronology of the loess deposits, a proxy for glacial aridity, shows the evidence of significant glacial advances starting around 350 kya in the valley, which is consistent with the evidence of both the pre- and post-LGM advances observed in this study. The presence of extensive glacier features all across the PPR and the presence of a few small heavily debris-covered glaciers in the Range points towards the rapid deglaciation in the area.

Late Quaternary carbonate dissolution was evaluated by using planktonic foraminifera indices perfect test ratio (PTR) of Goborotalia menardii, G. menardii fragmentation index (MFI), percentage of total resistant species (RSP) and sediment calcium carbonate (CaCO3) content in five sediment cores collected from two diverse oceanographic settings of the Indian Ocean. The cores collected from a depth range of 2000 and 4250 m of the Andaman Sea, a marginal sea in the Northern Indian Ocean and a seamount rise in the Central Indian Basin (CIB) in the abyssal Indian Ocean depict the intensity of selective carbonate dissolution in the glacial-interglacial cycles of the late Quaternary period. The assemblages from the Andaman Sea show little or no dissolution (deepest core AAS 11, water depth: ~3000 m), whereas cores collected from the CIB shows moderate to very high dissolution (SVBC 37, water depth of ~4000 m and core BC 37, water depth of ~4250 m). Excellent carbonate preservation in the Andaman Sea is reflected in the high order of species diversity consisting of thirty-five species. In contrast, selective dissolution in the CIB resulted in poor diversity with just about twenty-three species. The well-preserved planktonic foraminifera assemblages provide a better paleoceanographic record in the Andaman Sea. The carbonate dissolution proxies in the Andaman Sea point towards excellent preservation during Marine Isotope Stage 2 (MIS 2), especially during the deglacial period (Heinrich event 1) attributed to enhanced ventilation and deepening of carbonate compensation depth (CCD). Cores from the CIB demonstrate that the dissolution does not uniformly modify an assemblage due to the differential susceptibility of each species. Selective dissolution is an important issue in interpreting foraminiferal assemblages for climatic and environmental changes. The study reveals that the relationship between G. menardii abundances and its fragments in a single core is an effective parameter to understand the dissolution as its ratio is not affected by climatic or related environmental changes. Utmost care should be taken while using species variation as an evidence for climatic or related environment change from the CIB. The present investigation observes that the MFI can trace deep-sea carbonate dissolution quantitatively at both CIB and the Andaman Sea locations.

This paper presents field observations of the riprap slope of a dam regarding the slope damage due to adherence of the ice floe to the slope protection when the water level fluctuates. Analysis of field observation data has made it possible to identify the nature of the slope failure, including the scope of failure, as well as the steepness of a slope resistant to ice impact. To repair the slope of the toe rock, which is pervious fill, and the drainage of the dam, a rational solution has been proposed which, on the one hand, does not lead to a rise of the phreatic surface in the body of the dam, and on the other, its entire mass resists fluctuations of the ice floe. The design concept of the slope protection can be used for both rivers and marine structures, because the geometry of the concrete beams that are the basis of the proposed solution can be modified easily, thus adapting them to specific conditions associated with both ice impacts and the geometry of the slopes to be protected.

The present study focuses on the mechanism, climate, and sea-level implications of the coastal dune building activity in the eastern coast of Kori Creek (Gulf of Kachchh). Around 10 m thick dune is investigated using sedimentology, geochemistry, and optical chronology. This study suggests that the dune sediment that overlies the Tertiary Oyster Bed is dated to ∼4 ka. The grain size analysis and correlation of textural parameters of the inland dunes and coastal dunes showed no stark difference, revealing they were deposited during the same time. Further, the geochemical data generated from the samples of the coastal dune site represent semi-arid to semi-humid climate with increasing chemical maturity and weakening monsoon during the time of deposition. Based on the current erosion dune face and optical ages of the samples, it can be related that the Kachchh coastline was exposed due to the lowering of the sea level at the time of the deposition of coastal dunes. The sea must be at a lower level to attain a preferable condition for the deposition of dunal landforms. The lowering of the sea exposed the beach with sandy material, which got blown away in strong wind, leading to dunes deposition. The cold phase at ∼4.2ka became the most conducive environment of coastal dune formation.

A decision rule based classification algorithm is developed to classify the transient glacial zones of Bara Shigri glacier during the end of the ablation periods. The method helps to identify the highest snowlines and mean altitudes which further used to estimate mass balances of the glacier. The mass balance values of the Bara Shigri glacier are -1.37, -1.7, -0.77 and -1.07 m w.e.a-1 for the years 2017 – 2020 respectively. These values are compared with past mass balance values available for last four decades. A steady rise of mass loss is prominent and the current derived values are falling in that trend. The data of precipitation and land surface temperature during the study period are also studied to understand the controlling force of mass balance and it shows that a heavy precipitation during end of the ablation season has an indirect relation with mass loss amount. Deriving mass balance of the glacier is not a complete analysis until it can be relate with prevailing weather conditions and climatic variability in long term.

The region around the coastal Chennai area, India, is drained by three major rivers that rise from the remnants of the Eastern Ghats and receive dominantly the northeast rains. These rivers meander short distances, deposit sediments into the Bay of Bengal and preserve signatures of past phases of sedimentation and incision. In this study, detailed mapping using satellite imageries and extensive field work, logging of the river cliff bank sections was supported by sediment texture and structure and optically stimulated luminescence (OSL) dates. The main objective of this study was to infer the major periods of aggradation and incision in coastal drainage basins receiving dominantly the northeast rains. Integration of all the earlier available dated alluvial sequences (14C ages) and the present study OSL dates reveal that a major period of sedimentation occurred during the early Holocene (9 to 8.3 ka), mid Holocene (7.6–5.5 ka) and late Holocene to recent (2.4 and 1.6 ka, 0.9–0.6 ka and around 0.2 ka) periods. The Koratallaiyar river has preserved older middle Holocene terraces. Younger ages of the south easterly and east flowing rivers such as the Palar and the Coovum signify that they have incised and eroded to the present riverbed levels by catastrophic floods during the late Holocene period. This has resulted in an imbalance between sediment supply and sediment transporting power thus laterally stacking sediments rather than vertically.

Spirulina is a filamentous, multi-cellular and autotrophic cyanobacterium having distinct features of helical shape filaments (i.e. trichomes). An investigation is to isolate a marine, Spirulina subsalsa from Vellar estuary, South East Coast zone of India. The isolated strain sub-cultured in Zarrouk medium with optimum conditions for sustaining growth. Pure cultures were examined in a research microscope for morphometric studies through 16S rRNA sequencing and the sequence was submitted to NCBI-GENBANK, the accession number is MW037197 which displays the maximum similarity as 100% with a diverse sequence in databank i.e. LC 215280. The investigation is the first record for the existence of Spirulina subsalsa in Vellar Estuary, South East Coast, Tamil Nadu (India) as affirmed by a molecular nucleotide sequence.

The Blanes submarine canyon (BC) deeply incises the Catalan continental shelf in the NW Mediterranean Sea. As a consequence of the closeness (only 4 km) of its head to the coastline and the mouth of the Tordera River, the canyon has a direct influence on the shelf dispersal system as it collects large amounts of sediment, mainly during high-energy events. Multibeam bathymetry, backscatter imagery and very-high resolution seismic reflection profiles have allowed characterizing the morphology of the continental shelf around the canyon head, also identifying sediment sources and transport pathways into the canyon. The morphological data have also been used to reconstruct the evolution of the continental shelf during the last sea-level transgression so that the current understanding of shelf-to-canyon sediment exchanges through time could be improved. The continental shelf surrounding the BC consists of both depositional and erosional or non-depositional areas. Depositional areas display prominent sediment bodies, a generally smooth bathymetry and variable backscatter. These include: (i) an area of modern coarse-grained sediment accumulation that comprises the inner shelf; (ii) a modern fine-grained sedimentation area on the middle shelf offshore Tossa de Mar; and (iii) a modern sediment depleted area that covers most of the middle and outer shelf to the west of the canyon head. Erosional and non-depositional areas display a rough topography and high backscatter, and occur primarily to the east of the canyon head, where the arrival of river-fed inputs is very small. In agreement with this pattern, the continental shelf north and west of the canyon head likely is the main source of shelf sediment into the canyon. To the north, a pattern of very high backscatter extends from the coastline to the canyon head, suggesting the remobilization and off-shelf export of fines. Additionally, relict near-shore sand bodies developed over the Barcelona shelf that extend to the canyon head rim constitute a source of coarse sediment. High-energy processes, namely river floods and coastal storms, are the main controls over the river-shelf-canyon sediment exchange. River floods increase the delivery of terrigenous particles to the coastal system. Storms, mainly from the east, remobilize the sediment temporarily accumulated on the shelf towards the canyon head, so that the finer fractions are preferentially removed and a coarse lag is normally left on the shelf floor. Exceptionally, very strong storms also remove the coarse fractions from the shelf drive them into the canyon. Processes like dense shelf water cascading, which is much more intense in canyons to the north of BC, and the Northern Current also contribute to the transport of suspended sediment from far distant northern sources. During the last post-glacial transgression the BC had a strong influence on the evolution of the inner continental margin, as it interrupted the shelf sediment dispersal system by isolating the shelves to its north and south, named La Planassa and Barcelona shelves, respectively.

Columnar-jointed tuffs (bentonites) are located below the Lower Carboniferous Tideswell Dale Sill, Derbyshire, in an abandoned quarry. There are three zones of prismatic joints, columnar joints (∼60 cm thick and mean column width of 4.1 cm) and massive, conchoidally fractured rock sequentially from the dolerite contact downwards. The rocks are very fine-grained (1–10 µm) and consist mainly of sanidine, interlayered illite/smectite, and hematite, with minor quartz, apatite, montmorillonite, anatase and detrital minerals. High K2O and Fe2O3, low Na2O and low MgO are interpreted as due to alteration of felsic volcanic ash. The bentonite was contact-metamorphosed by the sill to temperatures of c. 300 °C. The progression of fracture geometries, thermal considerations and application of theories of column formation indicate that columns formed downwards away from the sill, due to prograde contact metamorphism of the originally clay-rich bentonite. The formation of columnar fracture networks by shrinkage due to igneous heating may have implications for the effectiveness of bentonite as a barrier for disposal of high-level radioactive waste. Regional dimensions include documenting widespread felsic explosive volcanism and inferring a Triassic oxidation event from palaeomagnetic data.