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Radium isotopes have been used to trace nutrient, carbon, and trace metal fluxes inputs from ocean margins. However, these approaches require a full accounting of radium sources to the coastal ocean including rivers. Here, we aim to quantify river radium inputs into the Arctic Ocean for the first time for 226Ra and to refine the estimates for 228Ra. Using new and existing data, we find that the estimated combined (dissolved plus desorbed) annual 226Ra and 228Ra fluxes to the Arctic Ocean are [7.0–9.4] × 1014 dpm y−1 and [15–18] × 1014 dpm y−1, respectively. Of these totals, 44% and 60% of the river 226Ra and 228Ra, respectively are from suspended sediment desorption, which were estimated from laboratory incubation experiments. Using Ra isotope data from 20 major rivers around the world, we derived global annual 226Ra and 228Ra fluxes of [7.4–17] × 1015 and [15–27] × 1015 dpm y−1, respectively. As climate change spurs rapid Arctic warming, hydrological cycles are intensifying and coastal ice cover and permafrost are diminishing. These river radium inputs to the Arctic Ocean will serve as a valuable baseline as we attempt to understand the changes that warming temperatures are having on fluxes of biogeochemically important elements to the Arctic coastal zone.

This study evaluates variations in petrophysical properties within a mixed alluvial to lacustrine carbonate system (Miocene, Madrid Basin, Central Spain). The transition from alluvial environments to lake margins settings displays a shift from alluvial, siliciclastic red sandstones and mudstones to palustrine–lacustrine mudstones to packstones. Fluctuations in lake‐water level enabled land plants to occupy the lake margins during periods of low lake levels. The palustrine carbonates include features like pseudo‐microkarst, nodular and mottled limestones; the lacustrine deposits include enlarged root cavities, desiccation cracks and channel bodies. Scarce fresh water biota comprises charophytes, gastropods and ostracods. The sediments possess high natural, irregular varying, gamma‐ray values at the alluvial–lacustrine transition, and low, but constant values at full lacustrine sites. Acoustic properties agree with lithological variations within individual facies. Porosity is the most important parameter influencing P‐wave and S‐wave velocities. The scatter in the velocity–porosity relationship links to the porosity type; macro‐porosity or microporosity. The wide range of pore types and pore sizes results in a weak porosity to permeability relationship for the carbonate‐dominated rocks with low permeability for microporous and high permeability for macro‐porous carbonates. The sandstones (probably only inhibiting interparticle porosity), and to a lesser extent the sandy wackestones to packstones, show quite a strong relationship between porosity and permeability. Elastic properties of mixed alluvial–lacustrine deposits (this study) and marine deposits (literature data) overlap as variations in pore structures and porosity values are similar. Only 16% of the marine and lacustrine carbonate sediments display Equivalent Pore Aspect Ratio values above 0.2. In travertine deposits, 83% of the samples exceed Equivalent Pore Aspect Ratio values above 0.2, which highlights that travertine deposits are dominated by larger Equivalent Pore Aspect Ratios compared to lacustrine and marine carbonate deposits. Travertines display other rock frameworks with different pore types, pore distribution and amount of porosity.

Vegetation is affected by hydrological cycle components that have altered under the influence of climate change. Therefore, it is necessary to investigate the impact of hydrological cycle components on regional vegetation growth, especially in alpine regions. In this study, we employed multiple satellite observations to comprehensively investigate the spatial heterogeneity of hydrological cycle components in the Yarlung Zangbo River (YZR) basin for the period 1982–2014 and to determine the underlying mechanisms driving regional vegetation growth. Results showed that the normalized difference vegetation index (NDVI) values during May–October were high, and the NDVI values increased from the upper reaches of the YZR to its lower reaches, reflecting the enhancement of vegetation growth. Annual precipitation, precipitation-actual evapotranspiration (AET), and snow water equivalent (SWE) all affect terrestrial water storage in the YZR basin through changes in soil moisture (SM), i.e., SM is the intermediate variable. Seasonal variability of vegetation is controlled mainly by precipitation, temperature, AET, SM anomaly, and SWE. Groundwater storage anomalies (GWA) and terrestrial water storage anomalies (TWSA) were not reliable indicators of vegetation growth in the YZR basin and the midstream and downstream regions. The effects of GWA and TWSA on vegetation occurred in the upstream region. HIGHLIGHTS The spatial heterogeneity of hydroclimatological factors in the Yarlung Zangbo River basin were analyzed based on satellite observations.; The interactions of hydrological factors were discussed.; The major controlling factors of the vegetation driving forces were examined.

The Mirim and Patos Lagoons form the largest lagoon complex in South America. Wind is one of the dominant climatic elements of circulation and water levels in the basin. Therefore, we aimed to better understand the effects of wind on the Mirim–São Gonçalo watershed by applying the MGB hydrological model and to assess whether it would produce satisfactory results for modeling. Various tests were performed to determine the best representation of the processes involved and the observed levels. The best results were obtained with the inclusion of sub-daily wind data in the simulation and also the downstream boundary condition by using the observed water level data at the sluice dam of the São Gonçalo channel. The results showed that the model could successfully simulate the levels and demonstrated the importance of including the wind when modeling the hydrodynamic processes of large lake environments. HIGHLIGHTS What is the numerical effect of introducing wind influence in the inertial flux propagation method?; What are the optimal values of the coefficient of wind friction and parameterization for minibasin connections to obtain the best simulation of the lagoon?; Does the inclusion of lock level information in the SGC as a downstream boundary condition and hourly winds benefit the level representation?

Reservoir characteristics of beach-bar sandstone reservoirs in the 2nd member of the Shahejie Formation in Banqiao Sag are studied by means of well logging interpretation, thin section observation and physical property analysis. Further, the influence of deposition, diagenesis and internal architecture interface on reservoir quality are quantitatively analyzed. On this basis, the geneses of reservoir heterogeneity of beach-bar sandstone reservoirs are summarized. The following results are obtained. (1) Primary pores, secondary pores and micro-fractures are the main types of reservoir space in the study area, and the primary intergranular pore is the main pore type; the microscopic heterogeneity of reservoirs is strong, and the physical properties of beach-bar reservoirs in different regions vary widely. (2) Tectonic-deposition, diagenesis and reservoir internal architecture work in unison to cause the heterogeneity of beach-bar reservoir quality in the 2nd member of the Shahejie Formation in Banqiao Sag; the locations and scales of beach-bar sand bodies are obviously different in different fault blocks in the study area, determining the macroscopic distribution of beach-bar reservoirs; differential diagenesis intensifies the degree of reservoir heterogeneity; the fine-grained argillaceous deposits between different architecture units of beach-bar reservoirs are critical to the quality of reservoirs. (3) The differential distribution of beach-bar reservoir quality parameters in the study area affects the spatial heterogeneity of reservoirs, which not only controls the original oil/gas distribution, but also has a significant influence on the effect of waterflooding and leads to the local enrichment of remaining oil.

In high altitude, scarcely gauged basins, climate change impact assessment on river discharge is important for sustainable management of water resources. These basins are sources for irrigation and hydropower generation in the region. Expected changes in precipitation and temperature can affect the basin's hydrological regime which will have consequential impacts on the dependent sectors. For quantifying the impacts of major climatic variables on hydrological processes, this paper examined bias-corrected GCM outputs coupled with a hydrological model – HBV for Chenab basin. Trend analysis shows that precipitation would decrease after the short-term period and temperature is expected to increase throughout the century. Simulated river discharge is expected to increase throughout the 21st century under both RCP 4.5 and RCP 8.5 scenarios. It is also observed that there would be a shift in seasonal discharge patterns with increased pre- and post-monsoon contributions. Increase in snow and ice melt contribution to the overall discharge is also expected and would range between 50 and 59% until 2100. This study concluded that expected increase in discharge volume coupled with shift in seasonal discharge pattern would impact the basin water management and thus it is important to consider the impact of climate change on the hydrological regimes of basins. HIGHLIGHTS Paper deals with the ungauged basin originating from the Himalayas and assesses shifts in seasonal discharge patterns which highlights increased pre- and post- monsoon contributions in annual discharge.; Output from the study is important for the data scarce Himalayan region and for better planning and management of water resources.

The colonization pattern of fish assemblages in streams is often studied in the context of environmental filters. On the other hand, when fish assemblages are subjected to anthropogenic effects, variables associated with environmental quality assume more importance. Therefore, this work evaluated the richness and composition of fish from streams sampled at different urbanization levels, aiming to determine any direct effects on the structure of fish assemblages. To accomplish this, samples were collected from 2003 to 2011 at 31 sites distributed among 3 microbasins in the Rio Ivinhema Basin, Alto Rio Paraná. Based on environmental variables, physicochemical of the water and analysis of the use and occupation of the soil, the microbasins were classified into different urbanization levels (low, medium and high). A total of 4,320 individuals were sampled, out of which 57 fish species were recorded. Sampled sites with medium urbanization level presented higher richness compared to sampled sites with high urbanization level which presented lower richness. Species richness in these sites was explained mainly by water temperature and water velocity. Results confirmed that urbanization does directly affect environmental integrity, which, in turn, can lead to the homogenization of stream assemblages.

Here we examine the bone histology of multiple skeletal elements of three individuals of Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa. Our histological results reveal a predominance of highly vascularized, uninterrupted fibrolamellar bone tissue, which suggests rapid periosteal bone deposition and an overall fast growth. However, in a rib, the periosteal bone deposition periodically stops abruptly, resulting in the deposition of several lines of arrested growth. The absence of bone growth marks in the limb bones (except for an annulus in a radius) suggests a young ontogenetic status for all specimens of the studied sample. All the skeletal elements are characterized by thick bone walls, extensive secondary reconstruction and the complete infilling of the medullary cavity by bony trabeculae. The latter condition is different to observations of contemporaneous graviportal terrestrial pareiasaurs, but similar to the observations in the modern semi-aquatic Hippopotamus, and suggests a possible semi-aquatic lifestyle for Jonkeria. On the basis of our histological findings, we assert that during early ontogeny Jonkeria experienced rapid sustained rates of growth, whereas later in ontogeny they experienced cyclical rates of growth.

The hyper-arid Taflilat Basin, South-East Morocco, is dominated by two ephemeral fluvial networks and several ergs with various dune forms from barchans to mega dunes. Especially the genesis of the star dunes remains an open research question. Therefore, a new multi-sheet geomorphological map describes the surface dynamics in the basin. Identification of major surface features was done with remote sensing data and on-site surveys. The analyses were used to identify all different landscape units. Additionally, aeolian features are emphasized to deduce current wind directions. The identification of two opposite wind fields was possible and a spatial correlation in the fluvial-aeolian system is detected. The border of the opposite wind fields crosses Erg Chebbi. Hence, the star dunes are under the influence of a multimodal wind system. Overall, this new geomorphological map strengthens the understanding of the fluvial-aeolian interaction in the Tafilalt Basin and sets a baseline for ongoing in-depth studies.

The optical and radar satellite data based Global Digital Elevation Models (DEMs) serve as a main data source in hydrological studies today. Open access Remote Sensing (RS) products have increasing accuracy and improved spatial resolution. The main research purposes are to study the use of AW3D30, ASTER GDEM V003 and SRTMGL1 DEMs in modeling mountainous lake basin and comparative analysis of their spatial accuracy. Topographic maps and very high resolution satellite imagery of the study area have been applied for the spatial accuracy verification and surface referencing. The relative accuracies of three different DEMs were analyzed using 1284 elevation points on the terrain surfaces. Comparison of these DEMs with 30 m spatial resolution confirms that an AW3D30 DEM has a higher vertical accuracy compared to other models and can be used for modeling river and lake basins over high mountainous terrain. The detected unreliable sections of the modeled lake basin boundary were analyzed and corrected based on the basin delineation by different DEMs. Analysis of spatial accuracy of the delineated Issyk-Kul Lake basin provide further incentive for DEM modification based on higher resolution remote sensing data, considering the applied geoid height differences as well by using satellite positioning data.

In the present study, the structure of sedimentary basins in the eastern Asia Arctic zone is analysed by employing the approach based on decompensative gravity anomalies. Two obtained models, differing in their initial conditions, provide thickness and density of sediments in the study area. They demonstrate essentially new details on the structure, shape, and density of the sedimentary basins. Significant changes in the sedimentary thickness and the depo-centre location have been found for the Anadyr Basin in its continental part. Also, new details on the sedimentary thickness distribution have been revealed for the central part of the Penzhin and Pustorets basins; for the latter, the new location of the depo-centre has been identified. The new model agrees well with the seismic data on the sedimentary thickness for the offshore part of the Chauna Basin confirming that the method is robust. The most significant lateral redistribution of the thickness has been found for the Lower Cretaceous coal-bearing strata in the northern part of the Zyryanka Basin, where the connection of two coal-bearing zones, which was not previously mapped, has been identified. Also, the new details on the sedimentary thickness distribution have been discovered for the Primorsk Basin. Therefore, the new results substantially improve our knowledge about the region, since previous geological and geophysical studies were unsystematic, sparse, and limited in depth. Thus, the implementation of the decompensative gravity anomalies approach provides a better understanding of the evolution of the sedimentary basins and the obtained results can be used for planning future detailed studies in the area.

Study region This research is carried out in the Kabompo Basin, a headwater catchment of the Zambezi Basin which has an area of 67,261 km2. Kabompo River originates in North-Western Province of Zambia between the Zambezi and Congo River Basins. Study focus This study focuses on error propagation of the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center-MORPHing (CMORPH) rainfall product on simulated streamflow. Assessments are based on automated multi-objective calibration of the Representative Elementary Watershed (REW) model (2006–2012). Parameters of the model were optimized using the ɛ-NSGAII algorithm. Assessments on error propagation targeted streamflow modelling for hydrograph shape and volume, specific hydrograph characteristics, and water balance composition. New hydrological insights for the region By use of multiple objective functions, this study shows that uncorrected CMORPH results in substantial augmentation of rainfall error to streamflow simulation mismatch whereas bias corrected estimates result in attenuation of error. This study shows that analysis for water balance composition has great potential to improve application of satellite precipitation products in water management and decision making in the Zambezi basin. This study advises optimization of model parameters for each respective rainfall input data source so to identify outcomes and effects of respective rainfall data sources on the simulated water balance. Optimization of parameter sets by ɛ -NSGAII results in optimal parameter sets that attributes to findings on the water balance composition and closure.

It was showed that the sedimentary environment of lacustrine basins is more susceptible to basin size than that of marine basins, leading to frequent changes in sedimentary environment and large differences in sediment supply and types. Based on the comprehensive analysis of clay minerals, spore pollen, major elements and trace elements, the sedimentary environment of Dongying Formation and its evolution in Bozhong Sag were studied. The results showed that during the sedimentary period of Dongying Formation, the study area was in a subtropical warm and humid climate as a whole. In addition, the vertical distribution of spore pollen and algae was divided into four zones and each one represents different sedimentary environments. Combination zone I is characterized by a large number of spore pollen and algae, including juglanspollenites verus, ulmipollemites minor, abietineaepollenites and pinuspollenites, taxodiaceaepollenites hiatus, leiosphaeridia and granodiscus, and it indicates a relatively hot and dry climatic; Combination zone II mainly contains juglanspollenites verus, ulmipollemites minor, abietineaepollenites and pinuspollenites, pediastrum and leiosphaeridia. Compared with I, the number of spore pollen and algae decreases, but the number of pediastrum increases a lot, which represents warm and humid climate. The combination zone III is dominated by abietineaepollenites and pinuspollenites and chaetosphaeridium, and the species and quantity decrease significantly. It indicates a relatively hot and humid climate at that time. Combination zone IV contains a small amount of spore pollen and algae, and it means the climate was warm and humid at that period. The frequent changes of sedimentary environment in lacustrine basins are influenceded by regional tectonic environment and basin scale. Using S/A and E-T parameters, the paleoclimate in the study area was delineated and 10 sedimentary environment interfaces were identified, which further illustrated the characteristics of frequent fluctuations of sedimentary environment in lacustrine basins.

This work presents the volcanic geology of the easternmost sector of the Trans-Mexican Volcanic Belt, including the Serdán-Oriental basin and Cofre de Perote-Citlaltépetl volcanic range, two contrasting Quaternary volcanic fields. The first comprises dominant monogenetic volcanism of bimodal composition including isolated rhyolitic domes and tuff rings, basaltic andesite maar volcanoes, cinder and lava cones, and an active caldera complex (Los Humeros). The second is dominated by large composite polygenetic volcanoes of andesitic-dacitic composition, including the shield-like compound Cofre de Perote volcano, La Gloria and Las Cumbres complexes, and the active Citlaltépetl stratovolcano. Mapping units include a pre-volcanic basement made of metamorphic (Paleozoic), and sedimentary (Jurassic-Cretaceous); intrusive (Miocene) rocks; multiple basaltic-andesitic lava flows and rhyolitic domes; volcaniclastic sequences (debris avalanches and lahars; and pyroclastic deposits (block-and-ash flows, ignimbrites, fallouts, and surges) (Miocene-Holocene). This map provides a comprehensive view of the highly diverse volcanism, which may reference for future research work.

Progress in GIS technology has facilitated the topographic position index (TPI)-based auto-classification of landform units. Multispectral satellite images, when used along with terrain analysis output, provide valuable information on structure, soil, land use land cover (LULC), hazards etc. The present work makes an endeavour to classify landforms using TPI and assess its distribution pattern across different LULC segments in the Kaljani River Basin of the Sub-Himalayan region. An attempt is also made to analyse the inundation pattern during the most recent major flood (2016) across the landform and LULC units. The Kaljani Basin is occupied by upper slopes, mountain tops and gorges in its upper (northern) part, while its lower (southern) part is characterised by wide valleys and plains. The areas occupied by gorges and midslope drainages in the hills, and wide valleys in the foothills, are comparatively more exposed to fluvial erosion, as found from the topographic wetness index (TWI). LULC classification reveals that the northern and central parts of the basin have plenty of vegetation cover. Land use units like fallows, farmlands and built-up areas are more common in the southern part of the basin. During the flood of 2016, three-fourth of the total inundation occurred in the wide valleys and plains. More than 90% of the inundated areas are found in the human-modified terrain, indicating its susceptibility to the flood hazard.

Drought is defined as the amount of precipitation in a region less than the amount of evaporation. Human facts such as population growth, industrialization, deforestation, and uncontrolled irrigation in agriculture are among the factors that cause drought. Today, with the increase of human activities such as population growth and industrialization, drought has become a serious life-threatening issue. With a depth of around 450 m and a volume of over 600 km3, Lake Van (Turkey) is the world's largest soda lake and one of the world's largest closed-basin lakes. Increasing temperatures and decreasing precipitation in recent years indicate that there may be a drought in Lake Ban. It is important to analyze this drought and determine its change. Methods derived from remote sensing and geographic information systems technologies provide speed, practicality, and high accuracy in determining drought. Research to date has not yet determined the change of drought in Van Lake Basin using remote sensing and GIS methods. In this study, the drought in Van Lake Basin was examined periodically from 1989 to 2019. In this context, Land Surface Temperatures (LST) and Land Use/Land Cover (LULC) maps of the basin were obtained from Landsat-5 and Landsat-8 satellite images. In addition to remote sensing and GIS analysis, the Standard Precipitation Index (SPI) was calculated with precipitation data obtained from meteorology stations to determine the drought in the region. According to the results, it was concluded that the drought level in the basin has been increasing from 1989 to 2019. The findings of this research provide insights for drought increase in Van Lake Basin. Also, this study strengthens the idea that remote sensing and GIS methods can be used in drought studies effectively.

Lake Bardawil, similar to the other Mediterranean Egyptian lakes, is a unique wetland, separated from the Mediterranean Sea by a narrow sandbar with very restricted water exchange that allowed the development of a shallow-hypersaline lagoon. Late Pleistocene tectonics activities divided the lake into two main basins; the eastern and western basins. Twelve surface sediment samples were collected along the Lake and subjected to sediment texture and benthic foraminiferal analyses. In general, benthic foraminifera were abundant in the surface sediments of Lake Bardawil and were characterized by low diversity. The statistical analysis revealed two biotopes that distinguished between the eastern and western basins' environments. The eastern basin biotopes were characterized by fine bottom sediments with the predominance of salinity-tolerant assemblages, thus demonstrating hypersaline stressful restricted environment. The western biotope exhibited coarser bottom sediments associated with relatively narrow salinity-tolerant assemblages. This reflected sandy and less saline sediment of uncontaminated environments, as the western basin was exposed to active hydrodynamic regime that developed more magnitudes of water exchange with the Eastern Mediterranean Sea through the western inlet. Based on the results of this study, the biomonitoring of Lake Bardawil could be assessed by the analysis of its benthic foraminifera as a bioindicator tool that may help in the improvement of the Lake's conditions.

In the present study, an attempt is made to delineate groundwater potential zones in Lower Rihand River Basin using remote sensing, GIS, and Analytical Hierarchical Process (AHP). Multiple data, viz. lithology, lineament density, geomorphology, slope, soil, rainfall, drainage density, relief, landuse/landcover were considered for delineating the groundwater potential zones. All nine thematic layers were prepared using remote sensing data on GIS platform. After that, weights were assigned to different layers and the features within them using a pairwise comparison matrix through the Analytical Hierarchical Process. The weights obtained were tested for their consistency using the consistency index and consistency ratio. A final weighted map was then obtained by multiplying each thematic layer’s weights with the weights of features within them and adding them. Based on this final weighted layer, the basin was categorized into very poor, poor, moderate, good, very good groundwater potential zones. The maximum area (49.22%) is under poor groundwater potential zone followed by moderate zone (26.17%), very poor (12.53%), good (11.77%), very good (0.31%). Results obtained have been validated using pre-monsoon and post-monsoon 10 years average water depth and seasonal fluctuation of various observation wells. Sensitivity analysis using map removal method is performed to assess the most influential parameters, geology, geomorphology, lineament density are the most influential. Overall results prove the efficacy of the use of geospatial technology in combination with AHP in the delineation of underground water potential zones.

Erosion of soil in the Lake Tana basin poses a critical economic and environmental crisis due to its impacts on agriculture productivity, food security and reservoir sedimentations. This study assesses soil erosion hazards by considering changes of land use and the climate. Simulation of land use change was conducted using CA_Markov chain model while climate was downscaledusing statistical techniques from CanESM2 model. The integration of the revised universal soil loss equation (RUSLE) with a geographic information system and remote sensing were used to estimate the soil loss. To quantify soil loss, six RUSLE model parameters were used: rainfall erosivity (R), soil erodibility (K), topography (LS), cover management (C), support and conservation practices (P). The average annual loss of soil by the 2080s in the basin is projected to be 7.7, 7.5 and 8.3 tons per hectare per year for changes land use, combined changes in land use and climate, and changes in climate under RCP8.5, respectively. Furthermore, by the end of this century, the soil loss in the basin tends to increase by 10.8%, 3.4% and 2.2% by considering changes in land use pattern, combined changes in land use and climate, and changes in climate, respectively, suggesting the aggravation of soil erosion in the basin. Accordingly, the effects of climate variability on annual average loss of soil are relatively higher than the combined effects of changing climate and land use. Consequently, the integration of RUSLE model with geospatial technology is recommended for an effective soil and water conservation measures.

To build an environment facility of a large-scale ocean basin, various detailed reviews are required, but it is difficult to find data that introduces the related research or construction processes on the environment facility. The current generator facility for offshore structure safety evaluation tests should be implemented by rotating the water of the basin. However, when the water in the large basin rotates, relatively large flow irregularities may occur and the uniformity may not be adequate. In this paper, design and review were conducted to satisfy the performance goals of the DOEB through computational numerical analysis on the shape of the waterway and the flow straightening devices to form the current in the large tank. Based on this, the head loss, which decreases the flow rate when the large tank water rotates through the water channel, was estimated and used as the pump capacity (impeller) design data. The impeller of the DOEB current generator was designed through computational numerical analysis (CFD) based on the lift surface theory from the axial-type impeller shape for satisfying the head loss of the waterway and maximum current velocity. In order to confirm the performance of the designed impeller system, the flow rate and flow velocity performance were checked through factory test operation. And, after installing DOEB, the current flow rate and velocity performance were reviewed compare with the original design target values.Finally, by measuring the current velocity of the test area in DOEB formed through the current generator, the spatial current distribution characteristics in the test area were analyzed. Through the analysis of the current distribution characteristics of the DOEB test area, it was confirmed that the realization of the maximum current velocity and the average flow velocity distribution, the main performance goals in the waterway design process, were satisfied.

The Indus River System is a major source of life in Pakistan. A vast array of Pakistan's agricultural and domestic consumption needs are critically dependent on the Indus River System. The Indus River contributes towards 25% of the country's gross domestic product, providing water for almost 90% of the food production in Pakistan. Linked to the water security issues, Pakistan is potentially at risk of facing a severe food shortage in the near future. The World Bank report of 2020–2021 estimates that the water shortage will increase to 32% by 2025, which will result in a food shortage of almost 70 million tons. Water shortage could also result in confrontation between the provinces as river sharing has always been a source of problem for Pakistan. According to recent estimates, siltation and climate change will reduce the water storage capacity by 2025 to almost 30%. As for the per capita water storage capacity in Pakistan, it is about 150 m3, which is quite meagre in comparison with that in other countries. Irrigated agriculture will soon be adversely affected due to the reduced surface water supplies and the consequent increase in groundwater abstraction. To make matters worse, over the past decades, a great deal of distrust has developed among the provinces of Pakistan regarding the water distribution issue, and the successive federal governments have failed to formulate a cohesive inter-provincial National Water Policy. Along with the shortages and increasing demand for water, administrative corruption also plagues the water sector and is quite common. The beneficiaries of this water reallocation system are not only the rural elite, for example the large and politically influential landlords, but also the small and medium capitalist farmers. If not properly addressed, these complications of decreasing water resources could result in serious political and economic hostility among the provinces. If it wants to harness its potential to increase storage capacity, Pakistan must improve its water-use efficiency and manage its groundwater and surface water resources in a sustainable way. Strengthening the institutions and removing mistrust among the provinces are the key elements for maintaining a sustainable irrigated agriculture in the Indus Basin. HIGHLIGHTS Indus River, a major source of life in Pakistan.; River sharing has always been a source of problem and confrontation between the provinces of Pakistan.; The paper highlights various problems in Pakistan's Indus Basin.; It also gives several recommendations for improving sustainability in Pakistan's Indus Basin.

The Ordovician system of the Ordos Basin is rich in oil and gas resources, but the tectonic evolution of Ordovician strata and controls on natural gas generation and accumulation are poorly understood. In this study, we integrate field observations, seismic and drill core interpretation, and geochemical data analysis [total organic carbon (TOC) and vitrinite reflectance (Ro)] to address this issue. Results show a clear depositional axis, with thick (>2500 m) Ordovician sediments in the southern half of the basin, and thinner strata in the central and northern parts. Ro values range from 2.04% to 3.45%, and 55 of 73 samples have TOC > 0.23 wt%. Our novel findings made as below: (i) Ordovician strata have high contents of organic matter and that thermal evolution reached the dry gas stage, favorable for natural gas generation. (ii) Ordovician strata have recorded multiple tectonic events and experienced erosion that resulted in the formation of a karst type residuum in the central and northeastern parts of the basin. (iii) An Early Cretaceous tectono-thermal event controlled the generation and accumulation of natural gas, and this was the peak period of gas generation of Ordovician strata. (iv) Natural gas accumulation and adjustment occurred during the Cretaceous and Cenozoic, respectively. The Ordos Basin has experienced strong deformation and denudation since the Late Cretaceous. Collectively, the deformation was more intense in the south and weaker in the north, preventing hydrocarbon preservation in the southern part of the basin. These findings provide new insights to guide oil and gas exploration of the Ordos Basin.

Identifying hydro-meteorological trends is critical for assessing climate change and variability both at a basin and regional level. This study examined the long- and short-term trends from stream discharge, temperature, and rainfall data around the Rietspruit sub-basin in South Africa. The data were subjected to homogeneity testing before performing the trend tests. Inhomogeneity was widely detected in discharge data, hence no further analyses were performed on such data. Temperature and rainfall trends and their magnitudes at yearly, seasonal, and monthly time steps were identified after applying the non-parametric Mann-Kendall and Sen's slope estimator. The possible starting point of a trend was determined by performing the sequential Mann-Kendall test. This study revealed a combination of upward and downward trends in both temperature and rainfall data for the time steps under observation. For rainfall on an annual basis, there were no statistically significant monotonic trends detected, although non-significant downward trends were dominant. However, significant decreasing rainfall trends were observed in dry and low rainfall months, which were April, August, September, and November. In contrast, significant upward temperature trends were detected at the Vereeniging climate station at an annual scale and in October, November, spring, and winter. The findings are critical for climate risk management and reduction decisions for both near- and long-term timescales. HIGHLIGHTS The need to perform homogeneity tests to avoid erroneous conclusions is emphasised.; The study cautions the direct use of stream discharge data for climate analyses in urban areas.; Long-term data show no significant changes in rainfall while temperature is rising.; Findings will improve the understanding of hydro-meteorological trends specific to the Rietspruit sub-basin mainly due to temperature spatial variability.

Microfractures can obviously improve physical properties and connectivity of tight reservoir, which is an important factor to control the exploration and development of tight oil and gas. However, there is little quantitative research on microfracture, thus, its reservoir mechanism is not clear. Taking the Cretaceous tight reservoir in the Liuhe Basin as an example, the microstructure characteristics of fractures were discussed on micron and nanometer scale respectively, and their contribution to physical properties was revealed in this paper. The results show that a small number of intercrystalline pores, intergranular pores and dissolution pores are developed in the Cretaceous tight reservoirs, and microfractures are the main reservoir space. The width of nano-sized fracture is mainly in the range from 2 nm to 300 nm, in which the proportion of fractures with larger width increases obviously with the increase of buried depth, and its contribution to pore volume is also greater. The width of micron-sized fracture is mainly in the range from 2.95 μ m to 114 μ m, and micron-sized fracture is much more developed with the increase of burial depth. Although the distribution frequency of micron-sized fracture is much smaller than that of nano-sized microfracture, it makes a greater contribution to permeability.

Abstract In agriculture, the characterization of dry spells is essential whether it is to calibrate the water needs of crops or the flow rates of rivers. This study seeks to develop a discretization of dry and wet spells on a monthly scale while evaluating the risk of extremes using the renewal wet-dry spell model. This model consists of defining the wet spell according a negligible precipitation threshold. The structure of the model is that all parameters of the climate cycle, including its length, are random variables. To study the trend of the parameters we use the Mann–Kendall test, while the magnitude is evaluated by the Sen’s estimation method. The approach is applied to Ichkeul Lake basin in northern Tunisia to demonstrate its capacity. This region is of great agricultural and water importance, although it holds six large dams. The results show that the duration of the dry and wet spells reach’s, respectively, 49 days and 17 days. The maximum dry spell was 49 days in 1982. The Mann–Kendall test revealed three stations with significant positive trend of the monthly extreme dry spell length (at March) located in south and east of the basin. The trend analysis of the seasonal rainfall number showed one station with significant negative trend in east and one station with significant negative trend in the center of the basin. Results indicated that no significant changes in the start and end of rainy season have occurred over the past years. But a great relation with a subsequent length exists. The results of this research assist farmers and managers in establishing drought management plans. It allow, among other things, to calibrate simulation models for a more realistic management of water reservoirs. It also makes it possible to plan irrigations on a more different basis from that of observations made at regular time intervals. Highlights We analyze the trends of the drought in Ichkeul lake basin, Northern Tunisia, characterized from the daily rainfall data of five stations. The alternating wet-dry spell model and a precipitation threshold value are used to define the rainfall/dry event. The Mann–Kendall test and the Sen’s estimation method were used to analyze the possible trends and the magnitude of variables analyzed, respectively. The results show an increasing trend of maximum monthly dry spells. No significant changes in the start and end of rainy season have occurred over the past years. These analyses provide useful information for science and society and make it possible to minimize unexpected damage due to long dry spells and to have effective and efficient planning for various stakeholders.

application/pdf, Nonlinear Dynamics. 2021, 106 (3), P.2363-2376

Methane, a potent greenhouse gas, is the main component of natural gas. Previous research has identified considerable methane emissions associated with oil and gas production, but estimates of emission trends have been inconsistent, in part due to limited in-situ methane observations spanning multiple years in oil/gas production regions. Here we present a unique analysis of one of the longest-running datasets of in-situ methane observations from an oil/gas production region in Utah’s Uinta Basin. The observations indicate Uinta methane emissions approximately halved between 2015 and 2020, along with declining gas production. As a percentage of gas production, however, emissions remained steady over the same years, at ~ 6–8%, among the highest in the U.S. Addressing methane leaks and recovering more of the economically valuable natural gas is critical, as the U.S. seeks to address climate change through aggressive greenhouse emission reductions.

The proposal of the Quilmes Tectonic Trough (Fosa tectónica de Quilmes – FQ) as the extension of the southern end of the Santa Lucía basin in Uruguay and its connection to the Salado basin in Argentina suggest the existence of a large sedimentary volume capable of housing a new aquifer on the La Plata River coast. However, the sedimentary volumes that form the FQ are hidden under a thick, recently deposited cover, and thus, there is a lack of studies on the nature of this formation. Nevertheless, the Uruguayan section of the Meso-Cenozoic depocenter of the Santa Lucía basin has been more thoroughly studied for hydrocarbon exploration, which enabled us to estimate the equivalent tectosedimentary characteristics in the FQ. In the Uruguayan territory, three aquifer systems of the Santa Lucía basin are exploited: the Raigón (Plio-Pleistocene) aquifer, which is the most important source of groundwater for various uses in the south-central region of Uruguay, and the Mercedes (Upper Cretaceous) and Migues (Lower Cretaceous) aquifers, which are also used, albeit to a lesser extent, for drinking water, irrigation, and industrial purposes. The Migues aquifer, the least known of the three, shows a variable depth ranging from 100 to 1500 m and considerable stratigraphic sequences of porous and permeable sandstones. These sandstones provide the aquifer with very good qualities as a reservoir rock; as such, the Migues aquifer has been studied for its potential natural gas reserves and geothermal and water resources. Accordingly, if the same sequences with equivalent sedimentary and hydrogeological qualities are present in the FQ, similar aquifers with interesting properties may remain unidentified along the Buenos Aires coast beneath the intensely explored Puelches, Pampeano and Paraná aquifers. In conclusion, specific exploratory activities may prove the existence and quality of these hydrogeological resources, the regional slope toward the southwest from the Uruguayan outcrops, upwelling or semiupwelling conditions and even geothermal energy associated with the deepest cretaceous aquifers.

Laguna de Bay, having a surface area of about 900 km2 is the largest freshwater lake in the Philippines, and is the most important water body in Metro Manila with its variety of uses ranging from aquaculture, irrigation, water supply and flood control. Due to its available resources and strategic location, over extraction, land conversion, and urbanization, have resulted in massive changes in the lake's watershed. The objective of this study is to simulate the impact of land cover change, particularly urbanization, on the hydrology of Laguna de Bay watershed. By hypothetically converting brushland to urban areas and using ArcSWAT to simulate the effects of urbanization, discharges and water balances were assessed. The long-term hydrologic simulations showed an annual increase of 20.6 m3/s (68%) in surface runoff and a 12.8 m3/s (26%) decrease in groundwater recharge for the entire watershed as urban areas increase. The mean seasonal flows were 75. m3/s during the dry season and 149.4 m3/s during the wet season for the original land cover, and 70.2 m3/s and 154.1 m3/s for the urbanized land cover, during the dry and wet seasons, respectively. Water percolating into the aquifers beneath the ground were also lessened by 13.6 m3/s (23%). The calibration of Marikina subbasin resulted to a satisfactory percent bias (PBIAS), Nash-Sutcliffe (NSE), and the ratio of the root-mean-square error to the standard deviation of measured data (RSR). Other subbasins resulted in a relatively lower performance rating due to limited available monitoring stations within the basin.

The features of source rock hydrocarbon generation, expulsion, and retention are essential factors in petroleum resource potential evaluation. In this study, the improved hydrocarbon generation potential evaluation method was used to quantify the characteristics of the source rocks of the first member of the Paleogene Shahejie Formation (Es1) in the Nanpu Sag, Bohai Bay Basin, NE China. Based on the geological and geochemical data for the source rocks, the favorable exploration areas were predicted and the resource potential was evaluated. Our results show that Es1 is a set of high-quality source rocks with desirable geological (maximum thickness > 600 m) and geochemical (average total organic carbon content of 1.44%; dominantly type II kerogen; mature stage) characteristics. The improved hydrocarbon generation potential model shows that the hydrocarbon expulsion threshold is located at Ro=1.0%. The maximum hydrocarbon generation potential (Qg), hydrocarbon expulsion potential (Qe), hydrocarbon retention potential (Qs), and efficient hydrocarbon retention potential (Qse) are 549.31, 162.20, 387.11, and 287.11 mg HC/g TOC, respectively. The maximum hydrocarbon generation, expulsion, retention, and effective retention intensities are 250 × 104, 70 × 104, 180 × 104, and 150 × 104 t/km2, respectively. These parameters reach the highest value in the Linque and Caofeidian Sub-sag. The resource potential of the retention shale oil, the movable shale oil, and the conventional and the tight petroleum resources are 1.99 × 108, 4.38 × 108, and 1.37 × 108 t oil equivalent, respectively. This study offers a fresh and plain but operable workflow for resource evaluation, which can be applied in other petroliferous basins with low degree of exploration.

The Cambrian weathered crust formed in the Early Paleozoic central paleouplift of the Ordos Basin and its periphery has always been a key target for oil and gas exploration, and important breakthroughs in oil and gas exploration have been made there. In order to further accelerate the process of natural gas exploration in this area, this paper based on systematic analysis of source-reservoir assemblage and trap type in the Cambrian weathered crust in southwestern Ordos Basin, and then evaluates its natural gas exploration potentials and favorable exploration zones. The following research results are obtained. First, the Upper Paleozoic coal-measure source rocks in the basin is the main gas source rocks, forming a source-reservoir assemblage of “upper source and lower reservoir” with Cambrian reservoir. Second, the types of the reservoir in the Cambrian weathered crust are mainly dolomite intercrystalline (dissolution) pores and karst fractures and vugs, whose development is controlled by grain shoal microfacies and karstification in the weathered crust stage, respectively. Third, the traps in the Cambrian weathered crust are mainly lithologic-stratigraphic traps, which were formed in the tectonic uplifting setting of the eastern Ordos Basin during the Yanshanian. There are geological conditions of lithologic and stratigraphic barriers in the updip direction, which is beneficial to the short-distance natural gas migration and accumulation. In conclusion, Huanxian-Zhengning area on the east margin of the central paleouplift in southwestern Ordos Basin is a favorable exploration zone of Cambrian weathered crust gas reservoirs, and the Middle Cambrian Zhangxia Formation and Upper Cambrian Sanshanzi Formation are favorable intervals of oil and gas exploration.

The Guamá River basin, in the northeastern state of Pará, eastern Amazon, Brazil, encompasses approximately 1,200,000 hectares. It presents great economic and social importance and is under significantly changes in land use and land cover. The objective of this work was to analyze and characterize the landscape structure of this basin through landscape ecology indexes (density, size, metric variability, shape, core area, proximity indexes, and patch area index). Land use and land cover maps were developed using images from the RapidEye system through supervised digital classification. The vegetation and landscape structure were quantified in patches, classes, and land cover. The forest patches were associated with partial conservation of some areas where production sectors had not yet directly affected, or those from natural regeneration of abandoned areas, mainly pastures. The class vegetated area was the second class most representative of the Guamá River basin covered about 37% considering the total area. The basin landscape presented more than 34,000 vegetated area patches It showing that this class are very fragmented by the presence of a large number of small patches, with this the basin landscape is compromised regarding its ecological integrity, since more than half of its forest patches are in edge environments. The indexes enabled a good joint analysis of the sub-basins of the Guamá River basin, resulting in a more detailed overview of the forest fragmentation process.

Population, salinity, and increasing water consumption have caused high pressure on groundwater resources in Iran. The study reported here investigates the change of groundwater quality in Zrebar lake basin and the relationship between it with land-use change and precipitation rate from 1992 to 2018. To achieve the intended goal, chemical parameters of water from wells around the lake, bicarbonate (HCO3−), sulfate (SO4), sodium absorption ratio (SAR), and electrical conductivity (EC) were analyzed. Then, four methods including interpolation in the ArcGIS environment, Wilcox and Schoeller Diagram in Aq.QA software and Ground Water Quality Index (GWQI) were used to indicate the trend of water quality from 1992 to 2018. To detect land-use changes from 1992 to 2018, three Landsat satellite images covering the study area were used to identify land uses and their changes during the period that shows a significant area of forests that has been replaced by agricultural use, the dominant cover in 2018, while the area of forest has declined sharply. In this study, the precipitation patterns over the past years were showed to assess the relationship between rainy and low rainfall years with water quality. The results showed that forest area in 1992, 2003 and 2018 was 70.6, 62.5 and 50.2 hectares, respectively, which shows a significant reduction, 22%, during this study period. On the other hand, the area of farmlands and human-made constructions has increased by 20% and 200%, respectively. This study additionally revealed that although there was a decreasing trend in the rate of rainfall and the agricultural lands have increased, the quality of water was still suitable for drinking and agriculture consumptions. Changes in groundwater quality were not justifiable by rainfall rate and land-use change because there was no significant relationship between them with all the groundwater quality parameters.

Estimating monthly runoff variation, especially in ungauged basins, is inevitable for water resource planning and management. The present study aimed to evaluate the regionalization methods for determining regional parameters of the rainfall-runoff model (i.e., GR2M model). Two regionalization methods (i.e., regression-based methods and distance-based methods) were investigated in this study. Three regression-based methods were selected including Multiple Linear Regression (MLR), Random Forest (RF), and M5 Model Tree (M5), and two distance-based methods included Spatial Proximity Approach and Physical Similarity Approach (PSA). Hydrological data and the basin's physical attributes were analyzed from 37 runoff stations in Thailand's southern basin. The results showed that using hydrological data for estimating the GR2M model parameters is better than using the basin's physical attributes. RF had the most accuracy in estimating regional GR2M model’s parameters by giving the lowest error, followed by M5, MLR, SPA, and PSA. Such regional parameters were then applied in estimating monthly runoff using the GR2M model. Then, their performance was evaluated using three performance criteria, i.e., Nash–Sutcliffe Efficiency (NSE), Correlation Coefficient (r), and Overall Index (OI). The regionalized monthly runoff with RF performed the best, followed by SPA, M5, MLR, and PSA. The Taylor diagram was also used to graphically evaluate the obtained results, which indicated that RF provided the products closest to GR2M's results, followed by SPA, M5, PSA, and MLR. Our finding revealed the applicability of machine learning for estimating monthly runoff in the ungauged basins. However, the SPA would be recommended in areas where lacking the basin's physical attributes and hydrological information.

The drainage gates have been controlled for desalination under normal conditions and flood defense in Saemangeum basin, Korea. Recently, it became an issue that the gates have been opened not to deteriorate water quality in the lake. It is, thus, necessary to precisely estimate the changes of water quality characteristics, especially DO, phosphate and nitrate, in the lake according to various gate operations. In this study, Semi-implicit Cross-scale Hydroscience Integrated System Model and Carbon, Silicate, Nitrogen Ecosystem model (SCHISM-CoSiNE) which is cable to simulate dynamic exchange such as gate operation conditions was utilized to obtain reliable and reasonable results including hydrodyanamic and environmental variables. For the verification, the measured data at 6 locations in Saemangeum basin was used to compare incluidng temperatue and salintiy from 2016 and each relative error became small enough to show high accurary. Also, under various scenarios by changing the designated water surface elevation on flood seasons, this model has been applied to present the best designated water surface elevation in terms of both water quality and water supply in the Saemangeum basin. It becomes possbile to show reliable guidance for dynamic operations and environmental changes with this model as requested in near future.

An inorganic geochemical investigation of mudrocks and sandstone from the southern Bredasdorp Basin, off the south coast of South Africa was carried out to unravel the provenance, paleoweathering, and tectonic setting of the basin. Seventy-seven representative samples from exploration wells E-AH1, E-AJ1, E-BA1, E-BB1, and E-D3 underwent geochemical analysis involving major and trace elements. The major oxide compositions show that the sandstones could be classified as sub-arkose and sub-lithic arenite. The provenance discrimination diagrams based on major oxide geochemistry revealed that the sandstones are mainly of quartzose sedimentary provenance, while the mudrocks are of quartzose sedimentary and intermediate igneous provenances. The discrimination diagrams indicate that the Bredasdorp sediments were mostly derived from a cratonic interior or recycled orogen. The bivariate plots of TiO2 versus Ni, TiO2 against Zr, and La/Th versus Hf as well as the ternary diagrams of V–Ni–Th∗10 suggest that the mudrocks and sandstones were derived from felsic igneous rocks. The tectonic setting discrimination diagrams support passive-active continental margin setting of the provenance. Also, the closely similar compositions of the analysed samples and recent sedimentary rocks of the East African Rift System perhaps suggest a rifted basin tectonic setting for the Bredasdorp Basin. Chemical index of alteration (CIA) indices observed in the sandstones suggest that their source area underwent low to moderate degree of chemical weathering. However, the mudrocks have high CIA indices suggesting that the source area underwent more intense chemical weathering, possibly due to climatic and/or tectonic variations.

A study on the risk of Cretaceous water inrush in the Ordos Basin in China is of great significance to the safe production and environmental protection of the western coal seam. This paper selects the following five key influencing factors for Cretaceous water inrush: the coal seam mining thickness, rock quality designation, distance between the top boundary of the water-conducting fracture zone and the bottom boundary of the Cretaceous system, the thickness of the Cretaceous aquifer, and the height of the water head. Furthermore, based on an analysis of geological and hydrogeological conditions of the Yingpanhao coal mine, the comprehensive weights of these factors were found using a fuzzy analytic hierarchy process and the entropy method (FAHP-EM) to be 0.27, 0.25, 0.22, 0.08, and 0.18, respectively. This paper describes the use of ArcGIS's spatial overlay analysis to create a risk assessment zoning map using these weightings. By comparing the evaluation results of the FAHP-EM and the water inrush coefficient method, it is shown that the FAHP-EM provides additional insight in assessing the risk of coal seam roof water inrush. The research results of this paper provide a theoretical basis for coal mining safety in western China to assess water inrush. HIGHLIGHTS Based on the fuzzy analytic hierarchy process and the entropy method (FAHP-EM), a method for evaluating the risk of water inrush from coal roof is proposed.; This paper selects the following five key influencing factors for Cretaceous water inrush: the coal seam mining thickness, rock quality designation, distance between the top boundary of the water-conducting fracture zone and the bottom boundary of the Cretaceous system, the thickness of the Cretaceous aquifer, and the height of the water head, established the Cretaceous water disaster evaluation system.; Based on an analysis of geological and hydrogeological conditions of the Yingpanhao coal mine, this paper uses the FAHP-EM to create a risk assessment zoning map.

We describe the history of studying the current crustal movements by various methods and discuss technogenic effects recorded at large water-reservoir zones and mineral deposits in Siberia. Initially, classical surveying techniques aimed to obtain high-accuracy ground-based measurements of height, tilt and direction. Modern geodesy techniques and methods for measuring absolute gravity are now available to investigate displacement, deformation, tilt and other phenomena taking place on the Earth’s surface. These methods are used to estimate kinematic parameters of the crust areas (e.g. rates of subsidence and horizontal movements) and to monitor fluid motions in mineral deposits. Such data are critical for ensuring a proper management of the mineral deposits. In this article, we analyse technogenic processes observed in the Ust Balyk oil-gas field, the Zapolyarny gas deposit, the water-reservoir zone at the Sayano-Shushenskaya hydroelectric power station (SSHPS) on the Yenisei river, and large open-pit mines in the Kuzbass basin. Our analysis is based on surface displacement rates estimated from the data collected in different periods of observations at large man-made facilities. In the study of the hydro technical objects, we estimated the displacement rates at 5.0 mm per year. In the northern areas of the West Siberian petroleum basin, subsidence rates amounted to 20–25 mm per year in the early 2000s. These estimates were supported by the high-accuracy gravity measurements showing an increase up to 6–7 microGal per year in the oil-gas field development areas. We assess a possibility of triggering effects related to weak seismicity due to a high stress accumulation rate (1 KPa per hour) in the SSHPS area. A connection between earth tides and catastrophic events, such as gas emissions in high amounts on mining sites, is discussed. Having analysed the surface monitoring records taken in South Primorye in September 2017, we conclude that underground nuclear explosions in North Korea in this period did not cause any significant displacement of the surface in this most southerly region of the Russian Far East territories.

Transition to the Early Iron Age was marked by the appearance of innovations such as iron technology and changes in the lifestyle of local societies on the territory of the North-Western Pontic Sea region. One of the most interesting sites of this period is the Glinjeni II-La Șanț fortified settlement, located in the Middle Dniester basin (Republic of Moldova). Materials of different cultural traditions belonged to the Cozia-Saharna culture (10th–9th cc. BC) and the Basarabi-Șoldănești culture (8th–beginning of 7th cc. BC) were found on this site. The article presents the results of a multidisciplinary approach to the study of ceramic sherds from these archaeological complexes and cultural layers as well as raw clay sources from this area. The archaeometry analysis, such as the XRF-WD, the thin section analysis, SEM-EDX of ceramics, m-CT of pottery were carried out. The study of ancient pottery through a set of mineralogical and geochemical analytic methods allowed us to obtain new results about ceramic technology in different chronological periods, ceramic paste recipes and firing conditions. Correlation of archaeological and archaeometry data of ceramics from the Glinjeni II-La Șanț site gives us the possibility to differ earlier and later chronological markers in the paste recipes of pottery of 10th–beginning of 7th cc. BC in the region of the Middle Dniester basin.

The Rashrashiyah Formation of the Sirhan Basin in northern Saudi Arabia contains diverse assemblages of planktonic foraminifera. We examined the biostratigraphy, stratigraphic range and preservation of upper Eocene planktonic foraminifera. Assemblages are well-preserved and diverse, with 40 species and 11 genera. All samples are assigned to the Priabonian Globigerinatheka semiinvoluta Highest Occurrence Zone (E14), consistent with calcareous nannofossil biostratigraphy indicating Zone CNE17. Well-preserved planktonic foraminifera assemblages from the lower part of the upper Eocene are rare worldwide. Our study provides new insights into the stratigraphic ranges of many species. We find older (Zone E14) stratigraphic occurrences of several species of Globoturborotalita previously thought to have evolved in the latest Eocene (Zone E15, E16) or Oligocene; these include G. barbula, G. cancellata, G. gnaucki, G. pseudopraebulloides, and G. paracancellata. Older stratigraphic occurrences for Dentoglobigerina taci and Subbotina projecta are also found, and Globigerinatheka kugleri occurs at a younger stratigraphic level than previously proposed. Our revisions to stratigraphic ranges indicate that the late Eocene had a higher tropical–subtropical diversity of planktonic foraminifera than hitherto reported.

Widespread catastrophic fog episodes in polluted northern India have been attributed to tropical cyclone activity in the Bay of Bengal & Arabian Sea; however, limited studies have been conducted on the effect of tropical cyclone intensity (‘T’ Numbers) on different fog characteristics in Indo Gangetic Basin, Northern India. In this study, different characteristics, including persistence, intensity, and areal extension, were analyzed at the Indira Gandhi International Airport, New Delhi during 1998–99, 2013–14, and 2016–17. A high-intensity tropical cyclone (Severe to Very Severe Cyclonic Storm) has been found to significantly increase the persistence, intensity, and areal extension of fog by inducing strong subsidence over the IGI Airport/Indo-Gangetic Basin. This knowledge is vital for improving the short-term forecasting of fog in the Indo-Gangetic Basin of Northern India and will further support the Government agencies to take preventive safety measures and planning well in advance time.

The prioritisation of catchments, particularly in the context of catchment plans and management programmes, is part of water resources development. In fact, morphometric analysis assisted by geospatial technology is carried out by prioritising sub-catchments according to their natural resource availability characteristics. Information on the geomorphology and erosion factors of the study area is used in the area in the preparation of local models of ungauged sub-catchments, which otherwise lack an adequate hydrological database. The objective of this paper is to use geographic information systems (GISs) in morphometric analysis to prioritise sub-catchments of the Soungrougrou (a tributary of the Casamance River). In this respect, the integrated methodology involving morphometric aspects from geospatial technology is used. To carry out the geospatial research, basic mathematical equations used in a GIS environment were used to measure a series of aspects of hydrology such as flow length, flow length ratio, bifurcation ratio, drainage density, drainage texture, flow frequency, elongation rate, circularity ratio, form factor, relief and relief ratio. The results divided the whole catchment into three priority areas, namely high, medium and low. The results are relevant for establishing soil and water conservation plans in the Soungrougrou basin, as well as adequate groundwater production and management. The high category (sub-basins 6, 8, 14, 17 and 18) is subject to maximum soil erosion, which requires immediate intervention to avoid possible natural hazards.

Distributed hydrological models rely on hydrography data such as flow direction, river length, slope and width. For large-scale applications, many of these models still rely on a few flow direction datasets, which are often manually derived. We propose the Iterative Hydrography Upscaling (IHU) method to upscale high-resolution flow direction data to the typically coarser resolutions of distributed hydrological models. The IHU aims to preserve the upstream–downstream relationship of river structure, including basin boundaries, river meanders and confluences, in the D8 format, which is commonly used to describe river networks in models. Additionally, it derives representative sub-grid river length and slope parameters, which are required for resolution-independent model results. We derived the multi-resolution MERIT Hydro IHU dataset at resolutions of 30 arcsec (∼ 1 km), 5 arcmin (∼ 10 km) and 15 arcmin (∼ 30 km) by applying IHU to the recently published 3 arcsec MERIT Hydro data. Results indicate improved accuracy of IHU at all resolutions studied compared to other often-applied upscaling methods. Furthermore, we show that MERIT Hydro IHU minimizes the errors made in the timing and magnitude of simulated peak discharge throughout the Rhine basin compared to simulations at the native data resolutions. As the method is open source and fully automated, it can be applied to other high-resolution hydrography datasets to increase the accuracy and enhance the uptake of new datasets in distributed hydrological models in the future.

The area covered by the four lakes in the Zhuonai Lake–Salt Lake Basin in Hoh Xil (Zhuonai Lake, Kusai Lake, Heidinor Lake, and Salt Lake) has changed significantly over the past 30 years. In this study, remote sensing image data gathered via the Landsat thematic mapper, enhanced thematic mapper plus, and operational land imager from 1989 to 2018 were used to extract the areal parameters of four lakes. The total area of the four lakes had increased by 18% in the past 30 years due to climate change. Interpolated results based on the meteorological data from 28 meteorological stations in the basin were used for trend analysis. A single-layer lake evaporation model was utilized to study the changes in the annual lake evaporation in the basin. The annual lake evaporation slightly increased from 1989 to 1995, followed by a sharp decrease from 1995 to 2018. From 1989 to 2018, the annual evaporation in the basin ranged between 615.37 and 921.66 mm, with a mean of 769.73 mm. A mass balance model was developed to estimate the changes in the lake volumes due to precipitation and evaporation. The increase in precipitation and the decrease in the annual lake evaporation promote the expansion of the four lakes. Lake evaporation is the main factor inducing changes in the lake areas. HIGHLIGHTS A study of the evolution of ecological environment in the Tibetan Plateau was proposed.; Meteorological data from 28 meteorological stations were subjected to trend analysis.; A lake evaporation model was used to study the changes in annual lake evaporation.; Precipitation and evaporation were the main factors resulting in lake area changes.

The estimation of seismic reservoir properties faces difficulties such as delineating deceptive fluid contacts, over-estimating reserves and drilling dry holes. To overcome these problems, sequence stratigraphic and rock physics analyses that were constrained by the compaction trend were implemented in the Sigma Field. Sigma field is located in the Coastal Swamp depobelt, in the distal part. Seismic data from the field and a total of three wells, Sigma-30, 26, and 25 were provided for the analyses. Biostratigraphic data was also given for the field and dated to shale marker Cassidulina-7. The stratigraphic sequence analysis of the wells in field indicate they were deposited in a regressive, transgressive and aggradational episodes, whereas the entire depositional history shows predominantly regressive episode. Three field reservoirs, SM-14 (LST), SM-04 (TST), and SM-02 (HST) were delineated. Depositional analysis of the landscape from sequence stratigraphic analyses of the field indicates that Sigma field reservoirs were deposited in a front region of the delta. Trend to compaction has been generated for the well. Sigma wells showed a normal trend toward compaction. Rock physics analysis of the reservoirs of interest reveals that LST and TST reservoirs have been difficult to distinguish against HST reservoirs which are easy to classify regardless of their depth for fluids in a Vp/Vs crossplot versus acoustic impedance. In the analysis, a pattern is suggested for TST reservoirs. Therefore, this research work shows that fluid discrimination becomes simpler as we go basin ward as the sorting of the reservoir rocks increases with finer grain sand sizes.

The catchment area of Oued Larbaâ is located in the eastern prerif at the very eastern end of the large Innaouene basin, a stream of Oued Sebou (Lahrach. A et al, 1994)[1]. The objective of the study is to establish a quality comparison of the watershed during the dry and wet seasons. Eight water and sediment samples were taken during the two seasons, all along the main channel of Larbaa river, taking into account anthropogenic activities and the areas of confluence with its tributaries: Tarmasst, Taza, Larouireg, Defali and Jaouna. Physicochemical parameters in summer studied (pH, EC, TDS, nitrates, sulphates, chlorides), as well as metal contamination (Al, Zn, Ni, Pb, Ag, Fe, Cd, Cr, Cu, Mg, Mn). The results revealed on alkaline pH higher than 7, a significant electrical conductivity in several stations, but still conform to Moroccan standards. Laboratory analyses reflect that the waters of the basin have generally a good quality, except for a few peaks that indicate metallic contamination in Fe and Al. In order to better assess whether there is an anthropogenic effect influencing these results, and to remove the relationships between the different parameters studied, a statistical analysis with the PCA tool was carried out. This analysis made it possible to indicate Cr, Ni and Al as indices of pollution in certain areas. Although the results obtained are tolerant until now, but it is necessary to put in place an action plan to control the areas at risk of contamination during the years.

Sedimentation in Lake Baikal is significantly affected by continuous seismic activity in the Baikal Rift Zone. Our study shows that historical earthquakes, as well as recent seismic events, considerably influenced sedimentation in this deep tectonic basin. Here we present some of the results of extensive international research activities during the period of 1996–2019. To identify traces of seismic events in the uppermost sediments (

Total suspended solids are an indicator of material constituted by sedimentable solids, suspended solids, and colloidal, whose origin is erosion, wastewater discharges, and agricultural waste. The objective of this research was to determine territorial water erosion, its relation with total suspended solids, and the water quality in the lower basin of the Usumacinta River in Tabasco. Three sampling points were established, located in the municipalities of Tenosique, Emiliano Zapata, and Jonuta, in the state of Tabasco. Water samples were collected during 12 monthly sampling campaigns in an annual cycle, and the total suspended solids were determined according to the provisions of the NMX-AA-034-SCFI-2015 standard. Water erosion was calculated based on the Universal Soil Loss Equation (USLE) and with the use of geographic information systems (GIS). The results obtained were statistically analyzed, finding that the measured maximum TSS concentrations are 130.92 mg.L-1 in Boca del Cerro, 165.28 mg.L-1 in Chablé, and 113.91 mg.L-1 in Jonuta which are within the permissible concentrations for protection of freshwater aquatic life and agricultural irrigation according to ecological criteria of water quality (CE-CCA-001/89), in Mexico. The lower basin of the Usumacinta River has areas with extreme erosion (990 tons.ha-1yr-1), with conditions that accelerate the erosion process, such as annual rainfall between 1805 mm and 2250 mm, clay soils located on slopes greater than 16%, and agricultural soils. These events cause loss of the soil fertile layer where agriculture is developed, also giving rise to the accelerated transport of suspended solids; which negatively alter the quality of the water of the Usumacinta River.

Most of the existing studies on meteorological drought suggest more intense and frequent drought events due to changing climate. However, basin-scale assessment of future agricultural drought is lacking due to many reasons. In this study, the intensity and frequency of future agricultural drought (characterized by the Standardized Soil Moisture Index, SSMI) for 226 sub-basins across India are analyzed, and vulnerable basins are identified. The prediction of the future agricultural drought status is achieved using the wavelet-based drought temporal consequence modeling of meteorological drought with the best performing bias-corrected Coordinated Regional Downscaling Experiment (CORDEX) simulations, selected by Multi-Criteria Decision-Making frameworks. This study reveals a geographically contrasting change in future agricultural drought that indicates more intense agricultural drought in north, north-east, and central India as compared with south India. The area under drought is also expected to increase, and about 20 and 50% of the Indian mainland is expected to suffer from extreme (SSMI ≤ −2) and moderate (SSMI ≤ −1) agricultural drought conditions by the end of this century. Sub-basins lying in north and central India are expected to have a longer time under drought conditions. Thus, the findings of this study will be useful for future planning and preparedness against agricultural productivity. HIGHLIGHTS Future agricultural drought status reveals new insights into its spatial variation.; The concept of drought translation is a useful one for making use of the best potential of climate model simulations.; More intense droughts in north, north-east and central India are expected as compared with south India.; In future, about 20 and 50% of the area in India is expected to face extreme and moderate agricultural droughts, respectively.

Knowledge about the taxonomy and fish composition from the upper rio Paraúna (rio São Francisco basin) and upper rio Santo Antônio (rio Doce basin) in the middle portion of the Southern Espinhaço mountain range, state of Minas Gerais, Brazil is still incipient. Only few studies focusing on ichthyofaunistic diagnostic and species descriptions in the lower stretches of the rio Santo Antônio are available. Herein the aim was to provide a species list of the freshwater ichthyofauna from the headwaters of both basins in such region, and to verify the occurrence of threatened, exotic, and potentially new species. Sixty species were registered, with 34 associated to the upper rio Paraúna, and 40 to the upper rio Santo Antônio. Two species are included in some threatened category, three are exotics, and 14 represent potentially new species. An identification key of the fish species recorded in the area is also provided.