Volume 1 Issue 1 (2025)

Understanding how large-scale climate circulation influences hydroclimatic factors in both tropical and extratropical regions is crucial. This study employed empirical methods to identify areas with consistent hydroclimatic signals associated with the El Niño/Southern Oscillation (ENSO). We examined the climatic linkages between the warm and cold phases of ENSO and precipitation patterns across South Carolina. Spatial coherence values were calculated using monthly precipitation composites over a 2-year ENSO cycle, and candidate regions were identified using the first harmonic fit. Temporal consistency rates were determined through aggregate composites and index time series (ITS) to pinpoint core regions. This study identified three core regions: the Upstate Region (USR), the Pee-Dee Region (PDR), and the Lowcountry Region (LCR), with the LCR showing the most significant response to both warm and cold ENSO forcings. During ENSO warm (cold) years, precipitation composites showed above (below) normal levels in these regions from winter to spring. Spatial coherence rates for El Niño (La Niña) in USR, PDR, and LCR were between 0.96 and 0.98 (0.95 and 0.97), and temporal consistency rates ranged from 0.72 to 0.83 (0.73 to 0.77). Composite-harmonic analysis revealed that precipitation anomalies tend to reverse signs between opposite ENSO phases, with positive anomalies in warm years showing more coherence and stronger responses compared to negative anomalies in cold years. The findings indicate that South Carolina's precipitation patterns are significantly influenced by ENSO, highlighting a climatic teleconnection between large-scale climate circulation and middle latitude precipitation.

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Ballast water (BW) to maintain a ship’s stability carries multitude of aquatic invasive species and poses serious threat to the ecosystems at destination ports. To minimize transfer of harmful aquatic organisms and pathogens at the global level, Ballast Water Treatment Systems (BWTS) were introduced along with the recommendation of IMO standards (Regulation D-2), where indicators are in ratios. However, observations across samples from the same ballast tank are not additive like average speed of cars. The paper describes an index of overall quality of treated BW by multiplicative aggregation of the indicators of viable organisms and specific microbes. The index value  indicates compliance of D-2 standard across all the indicators. The index satisfies desirable properties, including statistical test of the equality of means of two sample GMs (SGMs). Identification of critical indicators and confidence interval around mean SGM, giving a range of index values indicating compliance, are novelties of the paper. The proposed index can be decomposed into the Index of Viable Organisms and the Index of Specific Microbes, facilitating the computation of relative importance. A separate index of physical and chemical factors can be computed by multiplicative aggregation. Empirical linear relationships can be fitted with each proposed index as dependent variable and ratio of value of variables in a year ( and base year ( as independent variables. Empirical verifications are planned to highlight salient features of the proposed indices along with the efficiency of different filtration units associated with BWTS.

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Coastal land erosion and accretion (EA) are highly dynamic processes influenced by local climatic variability, often resulting in land loss and population displacement in Bangladesh. This study examines the linkages between climatic variables and coastal land transformations by analyzing 33 years of daily precipitation and temperature data from multiple meteorological stations. Following a moving average smoothing process, three statistical approaches—Spearman’s rank, Pearson’s, and Kendall’s tau correlations—were applied to identify robust associations. Results demonstrate a strong rainfall–temperature relationship (0.78–0.85), exhibiting consistent spatial patterns with minor regional variations. Annual correlation analyses were calibrated against observed erosion and accretion rates, indicating that Kutubdia loses approximately 0.29 km² of land annually, while Sandwip, Teknaf, and Sitakund gain 0.59, 7.6, and 7.3 km² per year, respectively. Mangrove ecosystems substantially enhance shoreline stability, with trunk densities of 30–40 per m² and inland coverage extending about 200 m from creek margins. Mangrove-dominated zones such as Cox’s Bazar show net land gains of around 0.6 km² annually. Overall, spatial heterogeneity in southeastern coastal dynamics reflects both erosional vulnerability and accretional resilience. The study proposes an integrated, scalable framework that couples climatic and ecological indicators for sustainable coastal land management and climate resilience planning.

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Research on sediment transport has focused on large dams, whose impacts are more visibly dramatic. The impacts of low-head dams, which are smaller and more numerous, have received less attention. It is partly due to the challenges of modeling sediment transport in these environments, which requires high-resolution data on flow dynamics and sediment properties. This work shows that there are tools allowing the acquisition of these hydrometric data and that the hydro-morphodynamic models can integrate it. The study site is the Clain river flowing through the Grand Poitiers municipality in the Vienne department (France), where low-head dams are installed at two key sites, Îlot Tison and Saint-Benoît, which pose potential barriers to sediment continuity. The hydro-morphodynamics of the Clain river are studied by means of the software HEC-RAS. The numerical simulations, performed in this work, show that the software HEC-RAS uses water flow and sediment transport equations tailored to specific conditions of the Clain river, a plain river with low-head dams. The robustness of the turbulent model and sediment transport laws present in the software HEC-RAS was checked for this river type. These numerical simulations allowed us to elucidate the hydro-morphodynamic impacts of two low-head dams present at the Saint-Benoît and Îlot Tison sites, on the Grand Poitiers municipality. For specific discharges exceeding the mean specific discharge of the Clain river, the low-head dams are bypassed. For specific discharges below the mean specific discharge of the Clain river, disturbances in water flow and sediment transport occur locally around these low-head dams. The occurrence of two phenomena, erosional narrowing and widening, depends on the height of the removal dam, the specific discharge, and the volume of stored sediments upstream of the removal dam. Removing these two low-head dams doesn’t disturb the hydro-morphodynamics of the Clain river at the large scale.

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Rising trends in global population have resulted in increased urbanization, industrialization, and food demands. This has resulted in the rapidly increasing water demands for domestic, agricultural and industrial sectors; which have severely depleted groundwater resources in Pakistan. The urban centres like Lahore city—the capital of Punjab province and the 2^nd largest city of Pakistan. To address this challenge, a field-scale Managed Aquifer Recharge (MAR) system integrated with Rainwater Harvesting (RWH) was developed and tested to evaluate its feasibility and efficiency for urban groundwater recovery. In this system, rainwater collected from paved surfaces was filtered and injected into a Pleistocene sand aquifer through recharge wells. Double filtration mechanism has been introduced in the model to ensure good quality rainwater is recharged into the aquifer. Field monitoring during multiple rainfall events demonstrated successful infiltration and aquifer-storage, with recharge volumes of 150,700, 281,097, and 89,887 L of rainwater corresponding to potential domestic water supplies for 132, 246, and 79 days for an average household respectively. The results confirm that decentralized RWH–MAR systems can significantly enhance aquifer replenishment in overexploited urban aquifers. The study underscores the viability of such systems for broader implementation in Punjab and other similar semi-arid regions, contributing to sustainable groundwater management and urban water resilience in Pakistan.

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