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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 composition of the organic matter (OM) of coals of the Ulug-Khem Basin has been studied. According to Rock-Eval pyrolysis data, this OM is a type III kerogen, sometimes significantly oxidized. The coal of low-grade metamorphism has a high hydrocarbon potential. Based on the gas–liquid chromatography and chromatography–mass spectrometry data on the distribution of n-alkanes, isoprenoids, polycyclic biomarkers, and aromatic hydrocarbons, we have established the composition of the primary OM of the coals and the grade of OM metamorphism. The primary OM of the coals consists mainly of remains of aquatic vegetation and terrigenous OM. The latter includes conifer remains, which are identified from the presence of 4β(H)-19-norisopimarane in the aliphatic fraction of bitumen and from the domination of retene over cadalene and 6-isopropyl-1-isohexyl-2-methylnaphthalene in the aromatic fraction.

A quantitative estimate is given to the hypothesis, explaining the paleogeographic data on the extremely high water abundance in rivers in the Caspian Basin in the period when the Late Khvalynian Transgression was forming, by postglacial permafrost in this basin, which could contribute to a decrease of soil infiltration and evapotranspiration, and an increase of river flow. The estimate was based on numerical experiments with a physical-mathematical ECOMAG model of Volga runoff formation. Two series of experiments were carried out to simulate deep soil freezing all over the territory of the present-day Volga basin. In these experiments, the process of seasonal thawing of frozen soils was described taking into account their thawing during the warm (summer–autumn) season and the formation of annual thawed layer (1); in the cases where there was no seasonal thawing, lower values of soil heat conductance were specified (2). If we assume that the climate conditions in the territory of the present-day Volga basin during the formation of the Late Khvalynian transgression were similar to those we see now, the increase in the water abundance in rivers compared with its present-day level can be partly attributed to the occurrence of postglacial permafrost in this basin. At the same time, the increase in the normal annual runoff due to seasonal thawing of permafrost is about 20% (the runoff coefficient increases from 0.36 to 0.44) and does not agree with the huge inflow (>450 km3/year) estimated by paleogeographic data. Under the current climate conditions, an inflow 85% greater than the estimated value (an increase in the runoff coefficient up to 0.67) can be formed in the absence of seasonal thawing of the frozen catchment, i.e., at air temperature lower than its current value.

Large paleochannels, which are common in the floodplains and terraces of rivers in the Volga Basin, are indicators of an appreciable increase in river flow in the past and can be used to evaluate the paleodischarges of water using morphometric relationships. The study develops the procedure proposed earlier for evaluating the paleorunoff. An improved procedure is used to evaluate the runoff in the period when large paleochannels were forming (18–13 thousand years ago) for more than 120 small basins. Areal interpolation was used to map the annual paleorunoff depth in the Volga Basin. The reconstructed field of river runoff in the Late Glacial Period shows zonality similar to that one can see now: the maximal runoff depth (from 450–550 mm) was recorded in the Upper Volga and in the upper part of the Kama Basin, and the minimal runoff depth (100–200 mm), in the Lower Volga. In large parts of the Volga Basin, the runoff was 1.5–1.9 times greater than its present-day value. The annual runoff for the entire Volga Basin was evaluated at 420 km3. This volume is enough to keep the Caspian level at elevations of the maximum of Khvalynskaya transgression (~+48 m abs.), provided that the effective evaporation (evaporation less precipitation) in the water area was one quarter less than its present-day level (~550 mm with the possible glacier runoff not taken into account and~600 mm with it).

Pleistocene vertebrate faunas have long been known from the island of Timor but have rarely been studied. In particular, dwarf elephant-like proboscideans such as Stegodon were once widespread across the island, including to the Atambua Basin, but the cause of their extinction is unknown. Here, we document the fossil Pleistocene fauna of this basin with their palaeoenvironmental context. We also investigate the possibility of human-Stegodon chronological overlap. Our methods include field survey, excavation, pollen analysis, and U-series dating. Palaeoenvironmental data based on geomorphology and hydrological information show a transition from marine to fluvial depositional conditions in the basin during Pleistocene. Pollen data supports this interpretation and shows a clear shift from mangrove to terrestrial vegetation types. Palaeoclimatic conditions after the transition are characterized by a high humidity with high-flow water across the basin. Fossils of vertebrate faunas are restricted to fluvially-derived sandstone units. Meanwhile lithic artefacts were recorded widely across the basin, in the from of surface finds. There is so far no example of direct association of lithic artefacts with extinct Pleistocene faunas. Direct dating of the vertebrate fossils suggest they came from the Middle Pleistocene or earlier, and consequently pre-date the oldest current records of modern human existence on the island ~45,000 years ago.

The Queima Pe Stream Basin (QPSB) and Ararao River Basin (ARB) in central Brazil have had recurrent problems with water scarcity. This may get worse under anthropogenic climate change. In order to explore this, we modelled mean water flows in these two basins under two different future climate scenarios. Specifically, modelled two Representative Concentration Pathways (RCP 4.5 and RCP 8.5) to model future water availability conditions in these basins. Our results indicate that by the middle of the current century, the basins will experience significant increases in temperature and decreases in humidity and water flow, sometimes leading to periods of extremely low water availability in heavily populated parts of the basins. Given the high levels of current water demand in the region, significant action will be required to mitigate and adapt to the future hydrological regime in the region.

This is an innovative study that deals with the application of continuous wavelet transform (CWT)-based seismic spectrum decomposition (SD) and static wedge modelling (SWM) to characterize the fluvial system of Indus Basin, Pakistan. The CWT better discriminates the thin and thick-bedded hydrocarbon-bearing reservoir pore-fluids compared to band-limited seismic characteristics. The hydrocarbon-bearing point bar shows higher amplitudes compared to the water-filled channel, which indicates lower amplitudes A static amalgamation of CWT attributes within the sandstone reservoirs indicates that 28 Hz can resolve the thick-bedded sandstone-filled point bar facies. The mapping of reservoir facies within the 27 Hz to 40 Hz CWT-based frequencies predicts the lateral distribution of channel sandstone, fluvial point bars, regional faults, and three-dimensional seal of shale-bearing levee deposits. The 48 Hz amplitudes can be used for predicting the regional seal for petroleum system. The SWM resolves a 25 m thick gas-bearing fluvial point bar, which is laterally distributed by head-to-head continuity of 29 km. The SWM can be used to predict the quantitative aspects of fluvial systems. The paleo-flow direction of the river was predicted in NNE-SSW orientations. The low-velocity of ∼ 3500 m/s of river flow eroded the coarse-grained sandstone facies from the eastern flanks and deposited in the western regions of the Basin. The angle of stratigraphic trap and thickness of point bar petroleum system was 20° and 25 m in the west of Basin. These observations can serve as an analogue for the development of stratigraphic plays within the Indus Basins of Pakistan and fluvial systems with similar geological settings.

In this study, the available 2D seismic lines have been interpreted to understand the basin development and petroleum potential of the Late Cretaceous–Quaternary stratigraphy of the Tanga offshore Basin in Tanzania. Conventional seismic interpretation has delineated eight sedimentary fill geometries, fault properties, stratal termination patterns and unconformities characterizing the studied stratigraphy. The Late Cretaceous was found to be characterized by tectonic quiescence and uniform subsidence where slope induced gravity flows that resulted during the Miocene block movements was the major mechanism of sediment supply into the basin. The Quaternary was dominated by extensional regime that created deep N-S to NNE-SSW trending graben. The graben accommodated thick Pleistocene and Holocene successions deposited when the rate of tectonic uplift surpasses the rate of sea level rise. Thus, the deposition of lowstand system tracts characterized by debris flow deposits, slope fan turbidites, channel fill turbidites and overbank wedge deposits, known for their excellent petroleum reservoir qualities, especially where charged by Karoo Black Shales. Subsequent tectonic quiescence and transgression lead to the emplacement of deep marine deposits with characteristic seismic reflection patterns that indicate the occurrence of Quaternary shale sealing rocks in the study area. The occurrence of all the necessary petroleum play systems confirms the hydrocarbon generation, accumulations and preservation potential in the Tanga Basin.

The runoff of glacial melt water into the river system of the Volga and farther into the Caspian Sea is evaluated for the epoch of the last glaciation. Melt water entered the Volga only from the part of the basin that was covered by the Scandinavian ice sheet. During the maximal phase (19–20 thousand years ago) the glacier occupied the farthest upstream parts of the basin, i.e., the Mologa–Sheksna depression (60 thous. km2) and the area near the Volga source and Lake Seliger (5 thous. km2). The volume of melt water runoff was calculated for deglaciation time by three models of the ice sheet. The upper estimate yielded a value of 60–70 km3 per year, and the lower estimate was 15 km3 per year, or 5–25% of the present-day Volga runoff into the Caspian Sea, where the lower value appears more plausible. In that case, even the maximal estimate is not enough to initiate the Khvalynian level rise in the Caspian Sea. In addition, the major part of the time of meltwater inflow into the Volga (~21...~16.5 thous. years ago) corresponds to a regressive state of the Caspian basin. This also does not allow us to consider the glacial factor as the cause of the Khvalynian transgression, the rise of which ~17 thousand years ago fell into the period of a decline of the glacial runoff.

Carbon sequestration activities are increasing in a global effort to mitigate the effects of greenhouse gas emissions on the climate. Injection of wastewater and oil-field fluids is known to induce seismic activity. This makes it important to understand how that risk relates to CO2injection. Injection of supercritical CO2into the Cambrian Mt. Simon sandstone in Illinois Basin induced microseismicity that was observed below the reservoir, primarily in the Precambrian crystalline basement. Geomechanical and flow properties of rock samples from the involved formations were measured in the laboratory and compared with geophysical log data and petrographic analysis. The controlling factors for induced microseismicity in the basement seem to be the hydraulic connection between the reservoir and basement rock and reactivation of pre-existing faults or fractures in the basement. Additionally, the presence of a laterally continuous low-permeability layer between reservoir and basement may have prevented downward migration of pore pressure and reactivation of critically stressed planes of weakness in the basement. Results of the geomechanical characterization of this intermediate layer indicate that it may act as an effective barrier for fluid penetration into the basement and that induced microseismicity is likely to be controlled by the pre-existing system of faults. This is because the intact material is not expected to fail under the reservoir stress conditions.

The previous studies on the petrophysical and volumetric analysis of Habiganj gas field were based on limited well data. As the accuracy of volumetric analysis relies greatly on petrophysical parameters, it is important to estimate them accurately. In this study we analyzed all eleven wells drilled in the Habiganj field to determine the petrophysical parameters. Analysis of the well logs revealed two distinct reservoir zones in this field termed as upper reservoir zone and lower reservoir zone. Stratigraphically, these two reservoir zones are in the Bokabil and Bhuban Formation of Surma Group. Petrophysical analysis shows significant differences between the two zones in terms of petrophysical parameters. Porosity in the upper reservoir zone ranges from 12% to 36%, with an average of 28%. This zone is highly permeable, as indicated by the average permeability of 500 mili Darcy (mD). The average water saturation in this zone is around 18% suggesting high gas saturation. The lower reservoir zone has an average porosity, permeability, and water saturation of 12%, 60mD, and 43%, respectively, indicating poor reservoir quality. An analysis of log motifs indicates that the upper reservoir zone is composed of stacked sands of blocky pattern. The sands in this interval are clean, as indicated by the lower shale volume of 12-15%. The average thickness of this zone is 230m, and the presence of this zone in all the drilled wells suggests high lateral continuity. The lower reservoir zone consists of sand bodies of serrated pattern. The sands have high shale volume and are laterally discontinuous. Overall, the upper reservoir zone has superior petrophysical properties to the lower reservoir zone. Although the reservoir quality of the lower reservoir zone is poorer than that of the upper zone, this zone can be considered as the secondary target for hydrocarbon production. Petrophysical parameters of this study were estimated from all the eleven wells drilled in this field; hence the values are more accurate. The reported values of the petrophysical parameters in this study are recommended to use to re-estimate the reserves in Habiganj field. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 10(1), 2021, P 1-10

Fine-grained mixed rocks in saline lacustrine basins are important targets for shale oil exploration. However, the controls on shale oil accumulation are complex due to the multi-source mixed deposition. This is a challenging issue in the study of shale oil. Here, we present a case study in the Middle Permian Lucaogou Formation in the Jimusar Sag, Junggar Basin, northwestern China. Results show that the Lucaogou Formation consists mainly of carbonate rocks, dolomitic or calcareous mudstones, tuffaceous or silty mudstones, and siltstones. The dolomitic/calcareous mudstones ( TO C average = 6.44 wt . % ) and tuffaceous/silty mudstones ( TO C average = 4.83 wt . % ) have the best hydrocarbon generation potential and contain type I–II1 kerogens that are in the peak oil generation stage. However, the shale oil potential is highest for the carbonate rocks and siltstones with average oil saturation index (OSI) values of 315.03 mg HC/g TOC and 343.27 mg HC/g TOC, respectively. This indicates that hydrocarbon generation potential is not the main factor controlling shale oil potential. Micro-nanoscale pores are the main control. Abundant dissolution pores provide excellent reservoir space for near-source migration and accumulation of shale oil. Different mixing processes between lithofacies control the accumulation of shale oil, and shale oil productivity is the best when multi-facies deposition in transitional zones formed the mixed rocks (facies mixing). In addition, local accumulations of calcareous organisms and adjacent carbonate components on terrigenous sediments (in situ mixing) are also conducive to shale oil enrichment. This is an unusual and special feature of saline lacustrine shale oils, which is different from freshwater lacustrine and marine shale oils. Comprehensive assessment of source rock and reservoir is needed to robustly establish a widely applicable method to determine the shale oil potential in such basins.

The groundwater vulnerability assessment is an effective tool for protecting groundwater from pollution. The objective of this study is to determine the groundwater vulnerability of the Plio-Quaternary aquifer to pollution in the Saiss basin of Morocco using the DRASTI-LU framework. As validation of groundwater vulnerability map using the Pearson correlation between nitrate (NO3−) concentrations observed at 51 wells and corresponding vulnerability indices calculated showed a poor correlation coefficient (r = 0.35, p

Sand mining from the catchment basin for building is a worldwide issue. The increasing demand for sand in the construction industry has led sand suppliers to look for alternative methods by which they can obtain source of sand from the riverbed. Floodplain and river slabs can be used as new sources of sand mining. In Sungai Kemaman, during September until March a high precipitation can cause high flow in river. This high flow can cause riverbank erosion which leads to instability of river. Therefore, river erosion can probably be reduced by identifying the potential area for sand mining. This research was conducted to analyse sand capability on floodplain and riverbed by integrating resistivity method and sediment transport loads using Acoustic Doppler Current Profiler (ADCP). Resistivity survey is used in determining the availability of potential soil at the study area and the equipment could measure subsurface profile up to 80 meters depth. Meanwhile, ADCP survey is utilized to make river profiler in term of velocity meshes and riverbed depth. The primary data collected was from 20 January 2014 to 19 February 2014. The findings found that the samples trapped in the Helly-Smith grabber were majority of the samples consisted more than 93% of gravel and sand materials and from the resistivity analysis, it is verified that the surrounding materials along the Sungai Kemaman is sandy material and high potential of the sand mining site.

The network of streams continuously changes its location based on time, environmental factors and human interventions. It is very important to study the stream changes in order to provide the manag...

High resolution aero-radiometric data of Sokoto basin Northwestern, Nigeria were used in this research work. The location of the basin is between latitude 11o30Ito 13o30IE and longitude 4o30Ito 6o30IN. Sixteen (16) sheets of high resolution of airborne radiometric data were used to obtain the concentration of Potassium (K), Uranium (U) and Thorium (Th) respectively in the area of interest. The data were gridded and analyzed using Geosoft software. The result of the analysis revealed that potassium concentration is between -0.577935% to 7.34347% with an average of 3.3827%. The Thorium concentration values ranged from -3.81541ppm to 91.9404ppm with an average of 44.0624ppm. The Uranium concentration revealed values from -4.44524ppm to 46.1767ppm with an average of 20.86572ppm. The ratio of potassium and equivalent thorium (K/eTh) indicated values between -8.69847%/ppm to 39.567%/ppm and ratio of equivalent uranium and equivalent thorium (eU/eTh) revealed values between -412.181ppm to 99.4613ppm. The ternary diagram of the radiometric data showed that the south and southeastern regions of the study area have high radioactive mineral concentration above the average normal value of radioactive minerals in a natural environment and radioactive minerals are good source of geothermal energy. The results obtained has shown that the basin has geothermal potential which can cause non productivity of hydrocarbon in the area of interest and the research area can be recommended for geothermal energy resource to compliment the electric power supply in the nation.

SUMMARYThe numerical simulation of seismic wave propagation in realistic heterogeneous media, as sedimentary basins, is a key element of seismic hazard estimation. Many numerical methods in two dimensions are based on unstructured triangular meshes and explicit time schemes. However, the presence of thin layers and tangential stratigraphic contacts in sedimentary basins entails poorly shaped mesh elements: some triangle heights are extremely small compared to the edge lengths, which requires small time steps in the simulations and thus leads to prohibitive computation times. We compare manual and automatic geological model simplification techniques to modify problematic areas of the domain, so as to improve the quality of the triangulated mesh. We modify the shape and the connectivity between rock units in the basin, with the objective to reduce the computation time without significantly changing the physical response of the geological medium. These simplification techniques are applied in an investigation of site effects in the lower Var valley, a densely urbanized area located near the city of Nice (southeast of France). Numerical simulations of plane wave propagation in a heterogeneous 2-D profile are carried out with a discontinuous Galerkin finite element method. Five simplified meshes are generated and the impacts of the simplifications are analysed in comparison to the reference model. We compare the time solutions and the transfer functions obtained on the surface of the basin. The results show that the simplification procedures, in particular automatic modifications of the model, yield a significant performance gain, with a ratio higher than 55, while having a negligible impact on the ground motion response.

The Asian westerly region is one of the regions sensitive to global hydrological and climatic changes. In this study, the annual runoff for 1796–2016 in the lower reaches of the Heihe River basin w...

The Indus Waters Treaty (IWT) and the Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin are two of the most important transboundary water treaties signed between member states that have a history of disputes and wars. In the case of India and Pakistan, voices to scrap the IWT in both countries are made chiefly because of their day-to-day bitter relationships. The treaty nevertheless remains in effect. The Mekong River Basin countries have had sour relationships in the past, and even after the agreement was signed in 1995 some political differences and disputes between them have remained. In both the Indus and Mekong basins, China is an important upper riparian. This article discusses the IWT and Agreement among the Mekong basin countries and examines the convergences and divergences between the two. It then analyses the role of China, as an upper basin to Indus and Mekong.

Countries adjoining the North Indian Ocean (NIO) region are among the world's worst affected areas by tropical cyclones (TCs). An increase in frequency and intensity of TCs affecting this basin is noticed in recent years. Timely and accurate prediction of a TC can lead to a decrease in damages to life and property caused by the cyclone. In recent times, the forecasts of TC tracks and intensity have improved due to advancements in the resolution, data assimilation techniques and physics of Numerical Weather Prediction (NWP) models and improvements in the model's initial condition. In this study, we have analysed the forecasts of Super Cyclone (SuCS) 'Amphan' that occurred over the Bay of Bengal during 16-21 May, 2020 obtained from the Global and Regional version of the NCMRWF Unified Model, i.e., NCUM-G and NCUM-R, respectively. The analysis of the track error shows that the initial position and 24-hour forecast errors in both the models are very close. However, the 48 to 72-hour forecast errors are much lower in the NCUM-R compared to NCUM-G. The percentage decrease in the track errors from global to regional model is about 12% in the 48-hour forecasts and 17% in the 72-hour forecasts. The landfall position error is less than 50 km in the predictions after 18th May, 2020 in NCUM-G. However, NCUM-R shows a lower landfall location error as compared to NCUM-G. Comparing the intensity forecasts from NCUM-G and NCUM-R shows that the 48 hrs forecast of minimum sea level pressure (SLP) based on initial conditions of 16th May, 2020 are very close to the observed intensity. The rapid intensification of Amphan is also well predicted by both the models, although with a delay. The cyclone structure shows that the 850 hPa vorticity core is much stronger in NCUM-R forecasts than NCUM-G. The warm-core system in the NCUM-R forecasts is also more organized than in NCUM-G. On the other hand, the maximum wind radius is greater in NCUM-G forecasts than NCUM-R.

Study of rainfall pattern and trend in the long term is essential from climatic change and socioeconomic perspectives. In the present study, monthly, seasonal and annual rainfall of semi-arid regions (Madhya Maharashtra, Marahwada and Vidarbha) of the Godavari basin is evaluated for the period of 1871–2016. The innovative trend analysis (ITA), Mann–Kendall test (MK) and Sen's slope estimator methods are used to check gradual change. A significant increasing or decreasing trend is not detected in the seasonal and annual rainfall series for any of the regions. The rainfall variability index indicates Madhya Maharashtra has received normal rainfall for 40% of the time, Marathwada for 36% of the time and Vidarbha region for 41% of the time. Very dry and very wet conditions are experienced by all three regions for 15% of the time. The spatial and temporal variation in the seasonal and annual rainfall is not significant in these regions. The results obtained from the study will be useful for water resource management of the Godavari basin. HIGHLIGHTS Increasing trend in rainfall of August and decreasing trend in September is observed for all the regions.; Significant upward or downward trend is not found for any season and for annual rainfall.; All the regions receives the normal rainfall for 39% of the time.; All the regions experiences very dry and very wet situation for 15% of time.; The results are matching with the rainfall trend for all India.

The city of Joinville, in the northern region of the state of Santa Catarina, has a history of damages caused by floods, caused both by rainfall and by the impact of tides. This paper analyzes the most recent flood control measures in the three main hydrographic basins areas of Joinville, Hydrographic Basin of Cachoeira river (BHRC), Hydrographic Basin of Cubatão do Norte river (BHRCN) and Hydrographic Basin of Piraí River (BHRP). In the BHRC, in recent years there have been interventions in two sub-basins of the BHRC, contrution of macrodrainage has been made in the Morro Alto River and in the Mathias River it has been through recent works of alteration of its bed. In one of the sub-basins of the Piraí River, the Vermelho river basin, rainwater drainage galleries were built. Still in the Piraí Basin, there is a project to build micro drainage networks in the Vila Nova neighborhood (basin and paving of their respective roads as a goal of flood risk reduction). In the BHRCN one of the main works was the construction of an extravasation channel, dam and pourers for flow control. As non-structural measures, the hydro-meteorological monitoring of the Joinville Civil Defense (DCJ) and CEMADEN (National Center for Monitoring and Alerting Natural Disasters), the Evacuation Plan and Contingency Plan for Civil Protection and Defense for extreme natural events of the city developed by DCJ, the flood warning service of Joinville, included in the project of warning of the possible disasters of the Secretariat of Public Security of the State of Santa Catarina, implantation in Joinville of the Regional Center of Management of Risks and Disasters (CIGERD) and the zoning of areas subject to flooding or flooding available on the site of the Municipal Information System Georeferenced (SIMGeo). These actions are the result of the development of public policies that are demanded by a set of laws - municipal, state and federal - in force from time to time, and a historical series of laws and decrees related to flood control is found in the appendix of this work.

Tight-gas sandstone reservoirs of the Ordos Basin in China are characterized by high rock-fragment content, dissimilar pore types, and a random distribution of fluids, leading to strong local heterogeneity. We model the seismic properties of these sandstones with the double-double porosity theory, which considers water saturation, porosity, and the frame characteristics. A generalized seismic wavelet is used to fit the real wavelet, and the peak frequency-shift method is combined with the generalized S-transform to estimate attenuation. Then, we establish rock-physics templates (RPTs) based on P-wave attenuation and impedance. We use the log data and related seismic traces to calibrate the RPTs and generate a 3D volume of rock-physics attributes for the quantitative prediction of saturation and porosity. The predicted values are in good agreement with the actual gas production reports, indicating that the method can be effectively applied to heterogeneous tight-gas sandstone reservoirs.

Eucalyptus (Myrtaceae) trees are ubiquitous in riparian–floodplain zones of Australia’s south-eastern river catchments, where natural ecosystems continue to be affected. In the Murray–Darling Basin (MDB), provision of environmental flows to mitigate tree decline is informed by past field studies. However, broadscale empirical field data on tree nutrition and response to external changes remain scarce. This is the first study to gather soil and plant data across a large area of catchment lowlands to generate a low-resolution regional snapshot of tree nutrition and soil chemistry. Leaves and soils were sampled across and adjacent to the MDB; from and beneath mature trees of three key riverine eucalypts, Eucalyptus largiflorens, E. camaldulensis, and E. coolabah. Foliar sodium concentrations ranged from ∼500 mg kg−1 for E. coolabah up to ∼4500 mg kg−1 for E. largiflorens, with highest values at the River Murray sites. The results suggest E. largiflorens is highly salt tolerant by foliage accumulation given all trees sampled were in good condition. Further research into these species is needed to determine toxicity thresholds for elements such as sodium to aid early diagnosis of potential tree stress, which could provide an additional line of evidence for when environmental water is required to mitigate decline.

Within the North Indian Ocean basin, tropical cyclone (TC) activity over the Bay of Bengal (BoB) is substantially greater than over the Arabian Sea (AS). The authors attempt to quantify the roles of specific environmental factors in order to understand the reasons for this difference between the two basins. Environmental variables are considered in the basin as a whole and in the immediate times and places at which cyclognesis and storm intensification occur. The results for the two sub-basins are compared to determine which environmental variables differed significantly between the sub-basins. A tropical cyclone genesis index (TCGI) is also examined to determine whether the AS-BoB difference can be explained in terms of the environment using this index. Though the overall level of activity in both is under-predicted by the index by about a factor of two, the index shows a relative diffrence between the basins that is approximately consistent with that in observations. Based on that partial success, climatologies of the individual factors that comprise the index are examined to determine which ones are most important in the AS-BoB diffrence. Column relative humidity and vertical wind shear emerge as the most likely candidates. A closer examination suggests that column relative humidity is the more important factor and thus that the AS has fewer cyclones than the BoB primarily because it has a drier lower troposphere.

We provide a short overview of the bottom-up, non-governmental organisation (NGO)-driven conservation efforts that go a long way towards implementing the Ramsar Convention on the ground in the Prespa basin in the Balkans. Encompassing two lakes, the transboundary Prespa basin is covered by three Ramsar sites. The lakes host significant endemism and internationally important breeding and wintering waterbirds. For over 30 years, the Society for the Protection of Prespa (SPP), a locally based NGO representing an international constituency, has successfully used the obligations, goals and objectives laid out by the Ramsar Convention. The SPP has led broader alliances, implementing and coordinating conservation action, initially on the Greek side and later at basin level, through an integrated ecosystem approach, multiparticipatory decision-making processes and transboundary collaboration. It has achieved substantial benefits for waterbird populations, especially pelicans, engaged in community-based resource management approaches and drawn support, mainly from international donors, to achieve progress in the wise use of the wetland. The established decision-making mechanisms in Greek Prespa, the long-term monitoring data on the wetland ecosystem and the operation of transboundary collaboration networks are also expected to contribute towards addressing ongoing challenges, such as eutrophication and adaptation to climate change.

Investigating the effects of climate and land-use changes on surface runoff is critical for water resources management. The majority of studies focused on projected climate change effects on surface runoff, while neglecting future land-use change. Therefore, the main aim of this article is to discriminate the impacts of projected climate and land-use changes on surface runoff using the Soil and Water Assessment Tool (SWAT) through the lens of the Upper Indus Basin, Pakistan. Future scenarios of the land-use and climate changes are predicted using cellular automata artificial neural network and four bias-corrected general circulation models, respectively. The historical record (2000–2013) was divided into the calibration period (2000–2008) and the validation period (2009–2013). The simulated results demonstrated that the SWAT model performed well. The results obtained from 2000 to 2013 show that climate change (61.61%) has a higher influence on river runoff than land-use change (38.39%). Both climate and land-use changes are predicted to increase future runoff depth in this basin. The influence of climate change (12.76–25.92%) is greater than land-use change (0.37–1.1%). Global weather data has good applicability for simulating hydrological responses in the region where conventional gauges are unavailable. The study discusses that both climate and land-use changes impact runoff depth and concludes with some suggestions for water resources managers to bring water environment sustainability.

Inter-basin water transfer (IBWT) has been widely applied to solve the water resource crisis in water shortage areas, and its impact on the ecological environment of water-recipient areas has gained increasing attention in recent years. In this study, based on the Soil and Water Assessment Tool (SWAT) model, the average monthly channel flow and water environmental capacity (WEC) with or without IBWT projects were simulated and quantified in the Fenhe River basin of China. The results showed that the IBWT projects significantly improved the flow of 63% of channels, and the increase in the dry season (80%) was much higher than that in the wet season (20%). The changes in the ideal WEC were positively correlated with the channel flow, while the remnant WEC showed different change trends in different channels and seasons. Spatially, the remnant WEC decreased in a few upstream channels and increased in the downstream channels. Seasonally, IBWT projects had different seasonal effects on the remnant WECs of total nitrogen (TN) and total phosphorus (TP). In the dry season, the remnant WEC of TN decreased by 2% after IBWT, while the remnant WEC of TP increased by 140%. In the wet season, the remnant WEC of TN increased by 4%, while the remnant WEC of TP decreased by 80%. Through a long-term simulation of IBWT projects, this study reduced the uncertainties caused by random changes in the hydrological environment. These results could provide effective guidance for management after the construction of IBWT projects.

Fractures in Cretaceous and early Tertiary strata record several deformation events that were imposed on the formations that fill the Raton Basin in Colorado and New Mexico. A regional, generally WNW-ESE striking extension-fracture set is present across much of the basin, but fracturing also includes both dip-slip and strike-slip conjugate shear-fracture sets as well as irregular deformation-band shear fractures. In some areas of the basin, the extension fractures are dynamically-compatible with associated conjugate shear fractures, both recording a maximum compressive stress that was horizontal, trending predominantly WNW-ESE. Fracture strikes vary from NW-SE to ENE-WSW but are approximately normal to the front of the Laramide thrust-fault system that forms the western edge of the basin, implying that fracturing was the result of a horizontal compressive stress anisotropy created by indentation of the thrust system into the basin margin. Fracture anomalies occur over local structures including a N-S basement wrench-fault system that connects two large anticlines within the basin, the Tercio and Vermejo Park anticlines, where N-S strike-slip offset along the basement wrench faults caused folding and fracturing in the overlying strata. The Laramide stress system in the basin changed from thrust-related WNW-ESE horizontal compression to the present-day N-S maximum horizontal compressive stress in mid-Tertiary time as the thrust system became inactive and was replaced by regional E-W extension. No new fracture sets were formed by the re-oriented stress system, although stress-release fractures normal to the regional set formed in outcrops as overlying strata were eroded. Fracture datasets were derived from three sources during this study: outcrops, image logs, and cores. Each source provides a somewhat different perspective on the fractures that enhance permeability in Raton Basin reservoirs. Taken together, the three datasets provide the basis for a relatively complete conceptual model of the Raton fracture system. Fracture-controlled permeability anisotropy will be greatest in the WNW-ESE direction, parallel to the strike of the dominant set of Laramide-age natural fractures, but hydraulic stimulation fractures will propagate N-S, across the strike of those fractures under the influence of the present-day stress system. The apertures of the WNW-ESE fractures will be susceptible to closure under that stress system since the maximum horizontal compressive stress is approximately normal to fracture strike.

The identity of the earliest inhabitants of Xinjiang, in the heart of Inner Asia, and the languages that they spoke have long been debated and remain contentious1. Here we present genomic data from 5 individuals dating to around 3000–2800 bc from the Dzungarian Basin and 13 individuals dating to around 2100–1700 bc from the Tarim Basin, representing the earliest yet discovered human remains from North and South Xinjiang, respectively. We find that the Early Bronze Age Dzungarian individuals exhibit a predominantly Afanasievo ancestry with an additional local contribution, and the Early–Middle Bronze Age Tarim individuals contain only a local ancestry. The Tarim individuals from the site of Xiaohe further exhibit strong evidence of milk proteins in their dental calculus, indicating a reliance on dairy pastoralism at the site since its founding. Our results do not support previous hypotheses for the origin of the Tarim mummies, who were argued to be Proto-Tocharian-speaking pastoralists descended from the Afanasievo1,2 or to have originated among the Bactria–Margiana Archaeological Complex3 or Inner Asian Mountain Corridor cultures4. Instead, although Tocharian may have been plausibly introduced to the Dzungarian Basin by Afanasievo migrants during the Early Bronze Age, we find that the earliest Tarim Basin cultures appear to have arisen from a genetically isolated local population that adopted neighbouring pastoralist and agriculturalist practices, which allowed them to settle and thrive along the shifting riverine oases of the Taklamakan Desert., A genomic analysis of human remains from the Bronze Age provides insights into the origin of the Tarim Basin mummies from the Xinjiang region.

The Reno metropolitan area (located within the Truckee Meadows in northern Nevada) is subjected to significant seismic risk, primarily resulting from the region’s proximity to the Mount Rose fault system and the urban area’s presence within a large, thin (

This study evaluates the geochemical maturity and paleo weathering indices of X well JV-Field, Greater UghelliDepo belt Niger Delta Basin, using reflected light microscope and geochemical proxies. The data obtained identified three lithofacies units as Sand, Shale, and Shaly sand facies .The application of source area weathering using Chemical index of alteration (CIA) and Chemical index of weathering (CIW) values for the sampled intervals ranges from (48.6-94.9%) and (60.6-96.7%), and have median values of (83.2 and 90.3) % respectively which is an indication of high weathering at the source. The values are variable and it may be as a result of multiple provenances of the sediments which have variable proportions of source area weathering and related processes or may be due to low concentrations of the alkalis and alkaline earth elements. However, all the samples excluding one with depth (12430ft) show CIA and CIW values greater than 70% indicating high (intensive) weathering either at the source or during transportation before deposition .From the high alteration indices value recorded from the sampled intervals, it can be inferred that the sediments are geochemically and texturally mature.

The accumulation of oxygen is one of the most important characteristics that distinguish Earth from other planets in the solar system, which is also considered to be the key factor influencing the birth and evolution of complex life forms. The oxygenation process of the Earth surface has long been viewed to be episodic with two critical intervals occurring in the early Paleoproterozoic (2.45–2.10 Ga) and the late Neoproterozoic (0.80–0.54 Ga), with a 1.3-billion-year-long low oxygen period in between. Recently, increasing independent works carried out by different scientific teams in the Yanliao Basin, North China are demonstrating that the atmospheric oxygen concentrations had reached >4% PAL (present atmospheric levels) at least during 1.59–1.56, 1.44–1.43, and 1.40–1.36 Ga. These estimated values are higher than the previously recommended values of

The Chang 7 oil group in the Ordos Basin has the characteristics of a tight lithology, a low formation pressure coefficient and strong reservoir heterogeneity. To better determine reasonable developmental technical countermeasures, oiliness, seepage capacity, and compressibility evaluations are combined. Using a combination of field practice and laboratory experiments, six types of sweetness classification evaluation parameters are screened: oil saturation, longitudinal oil layer structure coefficient, average pore throat radius, gas-oil ratio, brittleness index, and minimum horizontal principal stress. By combining the relationships among variables with the initial production from directional wells, the gray correlation method is used to quantify the weights of the contributions of evaluation parameters to production. On this basis, using the difference method for the curve slope, a sweetness evaluation and classification method for the Chang 7 oil group is constructed, and it solves the difficult problem of quality difference classification for the Chang 7 oil group and provides a reference basis for the optimal design of well patterns and fracturing reconstruction parameters.

The Nu-Salween River (NSR), the longest free-flow river in Southeast Asia, plays an irreplaceable role in social development and ecological protection. The lower NSR region is particularly valuable as it is inhabited by approximately 6.7 million people. The basin has limited hydraulic conservancy infrastructure and insufficient ability to cope with climate change risks. Studying the hydrological characteristics and changes in the basin provides the scientific basis for rational protection and development of the basin. However, owing to the limitation of observation data, previous studies have focused on the local area and neglected the study of the lower reaches, which is not enough to reflect the spatial characteristics of the entire basin. In this study, the ECMWF 5th generation reanalysis data (ERA5) and Multi-Source Weighted-Ensemble Precipitation (MSWEP) were applied to develop a geomorphology-based hydrological model (GBHM) for reconstructing hydrological datasets (i.e. GBHM-ERA5 and GBHM-MSWEP). The reconstructed datasets covering the complete basin were verified against the gauge observation and compared with other commonly used streamflow products, including Global Flood Awareness System v2.1, GloFAS-Reanalysis dataset v3.0, and linear optimal runoff aggregate (LORA). The comparison results revealed that GBHM-ERA5 is significantly better than the other four datasets and provides a good reproduction of the hydrological characteristics and trends of the NSR. Detailed analysis of GBHM-ERA5 revealed that: (1) A multi-year mean surface runoff represented 39% of precipitation over the basin during 1980–2018, which had low surface runoff in the upstream, while areas around the Three Parallel Rivers Area and the estuary had abundant surface runoff. (2) The surface runoff and discharge coefficient of variations in spring were larger than those in other seasons, and the inter-annual variation in the downstream was smaller than that in the upstream and midstream regions. (3) More than 70% of the basin areas showed a decreasing trend in the surface runoff, except for parts of Nagqu, south of Shan State in Myanmar, and Thailand, where surface runoff has an increasing trend. (4) The downstream discharge has dropped significantly at a rate of approximately 680 million cubic metres per year, and the decline rate is greater than that of upstream and midstream, especially in summer. This study provides a data basis for subsequent studies in the NSR basin and further elucidates the impact of climate change on the basin, which is beneficial to river planning and promotes international cooperation on the water- and eco-security of the basin.

Glaciers in the central Qilian Mountains provide important water resources for the arid Hexi corridor and Qaidam Basin; however, changes in these glaciers interact with climate change. Twenty-four bi-static image pairs of TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X) data, in addition to a Shuttle Radar Topography Mission-C/X band digital elevation model, and the technology of iterative differential synthetic aperture radar interferometry were used to carry out glacier elevation change analysis in the central Qilian Mountains in China during 2000–2014. Glacier elevation changed with an average rate of (−0.47±0.06) m yr−1, while changes in elevation of (−0.51±0.06) m yr−1 and (−0.44±0.06) m yr−1 were found in the northern (including the Zoulangnan, Tuolai, and Tuolainan mountains) and southern (including the Shulenan and Hark mountains) regions, respectively. Summer mean temperature has risen by 0.51°C (10 yr)−1 in the northern region and 0.48°C (10 yr)−1 in the southern region during 1989–2014; however, the change in amplitude of annual precipitation was 2.69 mm yr−1 in the northern region and 4.77 mm yr−1 in the southern region for the same period. These changes can be ascribed as major driving factors for the differences in the changes in glacial elevation in the northern and southern regions. Four types of glaciers existed in the region when considering the change in elevation of the glacial tongue and variation in the position of the glacial terminus: surging, advancing, intensively retreating, and slightly retreating glaciers. If elevation decreased more than 20 m on the part of glacier tongue, the glacier terminus position had commonly retreated more than 100 m.

A new genus and species of middle size bunodont artiodactyl (Mammalia), Erlianhyus primitivus, is established based on a partial maxilla with P3–M3 from the lower middle Eocene Irdin Manha Formatio...

The availability of water resources is under stress due to its unsustainable exploitation. The Chambal basin is located in the water-scarce region in India with average annual rainfall varying between 687.1 mm in the Rajasthan (RJ) region and 938.2 mm in the Madhya Pradesh (MP) region. On average, there are 48 rainy days in the MP region and 39 rainy days in the RJ region of the Chambal basin. Fourteen drought years have been identified during the period spanning 34 years (1985–2018). 44% of basin area located in the MP region and 54% of basin area located in the RJ are found to be drought-prone. The Standardized Precipitation Index-based evaluation of drought characteristics indicated higher drought frequency in the RJ region varying between 1 in 3 years and 1 in 4 years and between 1 in 3 years and 1 in 5 years in the MP region, which has also been substantiated by the Relative Departure Index (RDI), namely average RDI for RJ (0.69) and MP (0.58). The understanding of the contrasts in rainfall and drought characteristics in upper reaches (MP region) and lower reaches (RJ region) of the Chambal basin will help in holistic management and sharing of water resources based on these contrasts and constraints. HIGHLIGHTS Drought indicator-based investigation of drought characteristics in a major tributary of the Ganga river system.; Evaluation of the contrasts in the two different regions (Madhya Pradesh and Rajasthan) of the Chambal basin.; Standardized Precipitation Index-based evaluation of meteorological droughts.; Prioritization of drought-prone districts for effecting mitigation activities during periods of drought.

SUMMARY The Jeokjung-Chogye Basin (JCB) is the first impact crater discovered in the Korean peninsula. The geometric centre of the exterior crater rim is demarcated by an elevation high surrounding the JCB, exceeding 200 m. The diameter of the exterior ring is approximately 6500 m, and its centre is located about 1000 m southwest of the basin centre. Using terrestrial measured gravity field interpretations such as dip curvature and Z-derivative analysis of the residual anomaly field, we calculated the diameters of the peak ring and uplift ring to be about 4000 and 1500 m, respectively. The centre of the peak ring is located approximately 350 m to the west of the centre of the exterior ring; meanwhile, the centre of the uplift ring is located about 300 m to the east from the exterior ring's centre. Application of the Euler deconvolution method indicates that the depth discrepancy between the peak and uplift rings is approximately 200 m. This discrepancy indicates that the bedrock under the uplift ring has risen about 200 m following the meteorite impact. The offsets of the peak and the uplift ring's centres, relative to the diameter of the crater centre, allow us to conclude that the JCB was formed by steeply inclined impact (∼50–60° to the horizontal) from the eastern direction.

Sichuan Basin (SCB) is a typical basin in southwest China and a traditional smog-prone area. Control of air pollution in this area is particularly critical in achieving China’s carbon emission peak and carbon neutral goals. It is characterized by high population density, heavy transportation, rapid industrialization, complex topography, and meteorological conditions. However, the air pollution studies of SCB remain the sparse and in-depth studies are still warranted. None of the previous research has synthetically reviewed the status of air pollution in this region. This paper comprehensively overviewed the air pollution of SCB from five aspects: air pollution characteristics, sources of air pollutants, driving factors of air pollution, air pollution episodes and health risks. A comparison on the air pollution of typical megacities in the basin was also discussed. The findings and shortcomings of the existing studies were also summarized. Recommendations for future research directions were also proposed.

In this present study, Soil and Water Assessment Tool (SWAT) embedded with ArcGIS interface has been used to simulate the surface runoff from the un-gauged sub-catchments in the upper catchment of Subarnarekha basin. Model calibration and validation were performed with the help of Sequential Uncertainty Fitting (SUFI-2) in-built in the SWAT-CUP package (SWAT Calibration Uncertainty Programs). The model was calibrated for a period from 1996 to 2008 with 3 years warm up period (1996-1998) and validated for a period of 5 years from 2009 to 2013. The model evaluation was performed by Nash - Sutcliffe coefficient (NSE), Coefficient of determination (R2) and Percentage Bias (PBIAS). The degree of uncertainty was evaluated by P and R factors. Basing upon the R2, NSE and PBIAS values respectively, of the order of 0.90, 0.90 and -12%, during calibration and 0.85, 0.83 and -15% during validation, substantiate performance of the model. All uncertainties of model parameters have been well taken by the P and R factors respectively, of the order of 0.95 and 0.77 during calibration and 0.82 and 0.87 during validation. The runoff generation from 19 sub-catchments of Adityapur catchment varies from 29.2-44.1% of the annual rainfall and average surface runoff simulated for the entire catchment is 545 mm. As the surface runoff generated in most of the sub-catchments amounts to above 30% of rainfall, it is recommended for adequate number of structural interventions at appropriate locations in the catchment to store the rainfall excess for providing irrigation, recharging groundwater and restricting the sediment and nutrient loss.