Arabian Journal of Geosciences最新文献

A combined detailed palynofacies and lithofacies analysis was carried out on the Nsukka Formation outcropping Danian (Palaeocene) lithostratigraphic units in the Ikpankwu domain (SE Nigeria) for the first time. Lithological characteristics of grain size textural attributes, sedimentary structure and microflora palynofacies elements were instrumental in deciphering eight lithofacies: carbonaceous shale facies (Shfc), claystone facies (Csf), mudstone facies (Mfm), cross-bedded sandstone facies (Spt), siltstone facies (Fmt), heterolith facies (Fls), structureless sandstone facies (Smc), plane parallel laminated sandstones facies (Pls) and seven sub-facies deposited within low- to high-energy environment. These lithofacies and palynofacies-induced sedimentary attributes were grouped into three facies association (FA1, FA2 and FA3) and palynofacies types to delineate the principle palaeoenvironments, palynofacies provenance and depositional mechanisms triggered by hydrodynamic antics of the Nsukka Formation. The palynomaceral elements display superiority of large to medium-sized well-preserved brown to dark brown Palynomaceral 2 phytoclasts and terrestrial sporomorphs, Palynomaceral 4 and limited number of Palynomaceral 1 and Palynomaceral 3. The lithofacies and palynomaceral hydrodynamic array indicate that the mudrock facies of shale, mudstone and siltstone are deposits of lower deltaic plains or Lagoon with high terrestrial microflora input, while the sandstone facies depicts sediment of the upper deltaic plain (upper shoreface) or coastal tidal settings with overall effective oscillation tendency from tidal flat, lagoon to nearshore with open marine-influenced setting. The lithofacies and palynomaceral provenance prototype suggest terrestrially dominated shallow marine and tidally influenced outer neritic environment signalled from the quality and quantity of land-derived palynofacies components in association with few AOM and Kenleyia spp. and Spiniferites ramosus dinocysts, foraminifera test lining along with Laevigatosporites sp., Longerpertites group and other pollen and spore microflora. Lithofacies and palynomaceral organic matter in fluvial and inner neritic deep marine-influenced paralic strata of the study exhibit a perfect model for appreciating the lithological changes associated with a larger diversity of palynomaceral elements in marine and non-marine settings along with those of fluctuating salinity in the water realm.

The health risk to the population from consuming vegetables contaminated with potentially toxic elements is a matter of great concern. Therefore, contamination of potentially toxic elements in the vegetables and associated health risks from their consumption were quantified in the current study. For this purpose, wastewater, soil, and vegetable samples were collected from the suburban areas of Sargodha. The outcomes perceived that the contents of potentially toxic elements in wastewater ranged from 0.43 to 1.10, 0.13 to 0.28, and 0.96 to 3.04 mg L⁻¹ for Pb, Ni, and Zn, respectively. The highest averaged contents of Pb (15.5 mg Kg⁻¹), Ni (8.60 mg Kg⁻¹), and Zn (59.1 mg Kg⁻¹) were observed in spinach, while lower contents of potentially toxic elements were recorded in tomato. The order of vegetables regarding potentially toxic elements contents was spinach > cabbage > coriander > onion > tomato. Moreover, it was found that consuming contaminated vegetables may pose a potential health risk to the population. Based on the findings, it is concluded that regular monitoring of wastewater-irrigated vegetables is necessary. Moreover, to mitigate health risks associated with contaminated vegetables, it is essential to avoid using untreated irrigation water. Instead, proper treatment of wastewater should be adopted before employing it in agricultural practices.

Graphical Abstract

The present study examines two important and dominant phenomena that influence human life on Earth. The first is increasing urbanization, while the second is climate change. The trends of both of them pose challenges to present and future human generations. The city of Aligarh, which lies in North India’s Gangetic Plain, is the study area. It is immensely affected by urbanization and climate change. The main objective of this study is to highlight demographic transformations, which induce physical, economic, and social change and to examine the impact on micro-climatic elements by analyzing 30 years of data for temperature, precipitation, humidity, and wind speed drawn from MERRA-2, NASA’s global atmospheric product. The MK test is used to find trends among selected meteorological parameters and investigate their relationship with land use change. Lastly, the study also assesses the spatial vulnerability among the city population in different city wards. The analysis reveals that the population of Aligarh City has increased along with greater and more intense activities during the study period. This, in some way, has some bearing on meteorological parameters, confirming global climate change at the local level. However, the vulnerability to climate change is not uniform across the entire city. It has great physical, socio-economic, and spatial variations. Thus, the present study suggests that climate change and urbanization are the realities of the modern world, but human response to them would determine the degree of vulnerability.

Dams cause loss of habitat due to the interception of sediment transport downstream. The impact of the Wadi Ma’awil watershed dam in Oman on the distribution and pattern of plant communities has not been fully investigated. Identifying and prioritizing critical erosion and trapped sediment areas are important aspects for policymakers. The aim of this study was to assess the impact of the Wadi Ma’awil watershed dam on sediment transport across the watershed and its consequences on the pattern and distribution of plant communities. This study used the integrated valuation of environmental services and the tradeoffs sediment delivery ratio (InVEST-SDR) model to provide spatially explicit estimates of soil loss and sediment yield. The results showed that Sub-watershed 10 after the dam area exhibited the lowest sediment export, with a value of 0.36 ton/ha, while Sub-watershed 2 at the dam area had sediment retention of 1.02 ton/ha among the top five sub-watersheds. Around 1.51 ton/ha of sediments was trapped inside the dam at Sub-watershed 2 and did not reach the downstream area at Sub-watershed 10. The dam had a significant effect on the distribution, density, and communities of the small plant. The area downstream of the dam Sub-watershed 10 showed the lowest mean plant density (3.15) compared to the area upstream of the dam Sub-watershed s 3, 4, and 5 (19.65) or the dam area Sub-watershed 2 (42.9). These findings suggest a need to evaluate dam capacity, as sediment traps could hold risks that could decrease dam functionality and life span, jeopardizing dam storage and flood protection capacity.

Malachite green (MG) is extensively used in various industries including the food sector, despite having carcinogenic, mutagenic, and teratogenic effects. In the present study, sodium alginate/bentonite (SA/Bnt) nanocomposite was synthesized and characterized to evaluate its potential as an adsorbent to remove MG dye from aqueous solution. The response surface method (RSM) was utilized to optimize the process, and the kinetics of adsorption were evaluated based on experiments carried out thereon. The first-order model was shown to have a decent connection between some parameters and the outcome in this experimental situation. ANOVA results showed that only three of the five parameters (MG dye concentration, contact time, and adsorbent dosage) were important in the removal of the dye. The process parameters such as dye concentration (10–50 mg L⁻¹), contact time (10–60 min), adsorbent dosage (0.5–1.5 g L⁻¹), pH (3–8), and temperature (25–55 °C) were optimized to achieve maximum dye removal, which was around 96%. The correlation of pseudo-second-order kinetic was found to be best fitted with adsorption data with an R² value of 1.00. The synthesized nanocomposites were found to be effective as bio-adsorbent agents.

The impact of climate change on the hydrological cycle has spurred extensive research, particularly regarding potential evapotranspiration (PET), a crucial variable linking water, energy, carbon cycles, and ecosystem services. PET estimation usually relies on in situ weather station data, but data scarcity in regions like Nigeria’s Ogun-Osun Basin poses challenges. With few in situ ET monitoring stations, researchers have turned to alternative PET sources, such as satellite and reanalysis products. In this study, we evaluated four PET products in the Ogun-Osun Basin: Global Land Evaporation Amsterdam Model (GLEAM), hourly potential evapotranspiration (hPET), amine early warning systems network (NET) Land Data Assimilation System (FLDAS), and Global Land Data Assimilation System (GLDAS). We assessed monthly and annual timescales using statistical indicators such as the Pearson correlation coefficient (PCC/r), mean absolute error (M.A.E.), root mean square error (RMSE), Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS). The results showed that hPET outperformed other PET datasets at the monthly scale, with the highest correlation, lowest errors, and minimal bias values (P.C.C. = 0.80, RMSE = 25.55, PBIAS = 13.62%). GLDAS dataset showed closer performance to the hPET dataset (P.C.C. = 0.61, RMSE = 94.76, PBIAS = 71.1%) and GLEAM (P.C.C. = 0.12, RMSE = 64.67, PBIAS = 73.52%). Moreover, the FLDAS dataset performed least compared to other assessed PET datasets. hPET’s overall better performance was further certified at the annual scale, again outperforming the other products across all performance indicators (PCC = 0.34, M.A.E. = 258.10, RMSE = 263.05). The performance of the other products was quite poor, but the GLEAM product came closest to hPET compared to the other assessed products (P.C.C. = − 0.20, M.A.E. – 711.57, RMSE = 716.97). Overall, the hPET dominated all statistical indicators at both timescales, making it the best PET product among the ones evaluated by this study. The findings indicate that hPET is a reliable alternative source of PET data, which can greatly support future hydrological research and modelling in the Ogun-Osun Basin.

Hydrological studies of river basins are necessary for sustainable planning and management of drinking and irrigation water supplies. Continuous rainfall-runoff HEC-HMS models require the selection of loss and transform methods. The soil moisture accounting (SMA) loss approach is more prevalent since it can reflect water movement in wet and dry conditions. However, the transform method for a basin should be chosen based on the model’s accuracy in replicating observed flows. The present study is aimed at developing the continuous rainfall-runoff HEC-HMS model for the Sarada river basin in India using SMA as the loss method and to suggest the best transform method by assessing the performance of three distinct unit hydrograph (UH) transform methods (SCS-UH, Clark-UH, and Snyder-UH). The SMA parameters for each transform method were optimized using the built-in optimization trail manager and observed river flow data from the three existing reservoirs (Raiwad, Konam, and Pedderu). Each model reach was routed using the Muskingum method, and the linear reservoir approach was used to compute percolation losses. The Hargreaves method was used to estimate evapotranspiration. Model calibration and validation were performed for the years 2009–18 and 2019–20, respectively, using observed river flow data and Mandal-level meteorological data. Sensitivity analysis conducted on SMA loss parameters showed that the maximum infiltration rate and maximum impervious parameters were the most sensitive. Results indicate that the performances of the SCS-UH transform method are superior to other methods for all three reservoirs. During model validation, when compared to the Snyder-UH and Clark-UH techniques, the SCS-UH method reduced root mean square error by 59% and 26% for the Raiwada, 12% and 10% for the Konam, and 19% and 19% for the Pedderu reservoirs, respectively. The model can be used to predict floods in the river basin’s downstream region and plan water conservation infrastructure.

Most research studies on the behavior of footings on geocell-reinforced slopes were conducted using experimental model tests on small-scale slopes. Very few studies can be found in relation to 3D analyses using detailed geocell structures. It is, therefore, the aim of the present study to investigate this problem by using a 3D finite element analysis. The study begins with verifying the accuracy of the applied finite element method using the results of the experimental model tests on the unreinforced and geocell-reinforced footings on slopes. It continues with studying the effects of main design factors such as the slope angle (β), the depth of the geocell mattress (u), the soil internal friction angle (ϕ), and the footing setback (a) on the bearing capacity of the geocell-reinforced footings. Numerical results suggest that an increase in soil internal friction angle and a decrease in slope angle would both enhance the bearing capacity of unreinforced and reinforced footings. The geocell reinforcement proves to be more effective in improving the bearing capacity of steeper slopes with small friction angles. In addition, the optimum depth of the geocell placement was found to be 0.1 times the footing width (0.1B) regardless of the β and ϕ. Irrespective of the β, the optimum footing setback ratio (a/B) was obtained at 0.5. As a/B ˃ 2, the effect on bearing capacity vanishes. At a constant footing setback ratio (a/B < 2), the use of geocell reinforcement is more effective for steeper slopes. The findings in this numerical study are of practical significance to the geotechnical engineering community.

The present study investigates the chemical weathering characteristics of an amphibolite enclave within granite from Bundelkhand region, central India. The mineral composition varies from core to rind with depletion of hornblende and plagioclase and enrichment of clay minerals and oxyhydroxides. The chemical index of weathering (CIA) indicates an incipient stage of weathering, within the enclave (CIA = 52.22 – 54.74). A-CN-K (Al₂O₃-CaO + Na₂O-K₂O) plot reveal samples plot along the A-CN line, indicating the removal of Ca and Na, due to plagioclase destruction. The weathering trend progresses towards the formation of smectite, a significant component within the clay composition of the enclave. The results of mass balance calculation reveal a substantial mass decrease of approximately 50% to 82% in the amphibolite. Furthermore, major oxides in the amphibolite enclave, experience significant losses. Trace elements display general losses in the enclave. This study provides valuable insights into the complex dynamics of elemental behavior during weathering by shedding light on the processes shaping the geochemical evolution of these rock types and their response to weathering conditions.

Studies on the effect of biochar, manure and manure ash on soil nutrient kinetics are rare. Therefore, an incubation study was conducted to investigate nitrogen (N), phosphorus (P), and sulphur (S) kinetics in soils amended with biochar (B), B + cattle manure (BCM), B + goat and sheep manure (BGSM), B + poultry manure (BPM), farm yard manure (FYM), CM ash (CMA), GSMA, PMA, and wood ash (WA). Manure and manure ash were applied at 120 kg N ha⁻¹; B was applied at 5 tha⁻¹.Total mineral nitrogen (TMN), available P and S were determined at 2 weeks interval. Results revealed that soils treated with WA and PMA had the highest liming (pH 9.88) and salinity (820 μS m⁻¹), respectively. The overall cumulative release of TMN, P and S in soil treated with PMA was 1, 7 and 16% higher than BPM amended soils, respectively. The least percentage of TMN, P and S mineralized was in soil treated with BCM (13.5%), BPM (12.3%) and WA (9.3%), respectively. The first order and power functions were able to capture the kinetic release of N, P and S in the soil and amendments. TMN had significant correlation with nitrate–N (r = 0.925, p ≤ 0.001) ammonium-N (r = 0.737, p ≤ 0.01), sulphate (r = 0.823, p ≤ 0.01) and phosphate (r = 0.702, p ≤ 0.01). The study concluded that the application of manure ash or manure with biochar encourages the timely release of TMN, P and S as well as improving the salinity and pH of the soil.