Seawater Intrusion Research Articles (Page 1)

This study evaluated the decadal trends and spatial distribution of four irrigation suitability indices—Electrical Conductivity (EC), Sodium Adsorption Ratio (SAR), Magnesium Hazard (MH), and Kelley’s Ratio (KR)—using agricultural groundwater data collected from 157 monitoring sites across Korea between 2015 and 2024. Internationally recognized classification criteria were applied, long-term trends were analyzed using the Mann–Kendall test and Sen’s slope estimator, and spatial distributions for 2015, 2020, and 2024 were visualized using Inverse Distance Weighting (IDW). The results showed that EC and SAR remained at generally low absolute levels but exhibited statistically significant increasing trends with Sen’s slopes of +0.0038 and +0.0053/year, respectively, indicating the necessity of long-term salinization management. KR remained largely stable throughout the study period. In contrast, MH displayed a distinct pattern, with unsuitable levels concentrated in Jeju Island—approximately 15% of monitoring sites were classified as unsuitable for irrigation. This was interpreted as the combined effect of the basaltic aquifer’s geological and hydrological characteristics, seawater intrusion, and the relatively high mobility of Mg compared with Ca. This study uniquely integrates temporal trend tests with spatial mapping at a national scale and offers a mechanistic interpretation of MH vulnerability in Jeju’s volcanic aquifers. These findings emphasize the need for tailored regional management centered on groundwater abstraction control and continuous monitoring to ensure the sustainable use of agricultural groundwater.

ABSTRACT The relocation process and exposure to climatic extremes directly influence the resilience of climate migrants. This study assessed the impact of a government-led relocation program on migrant resilience in Khurushkul Ashrayan Prokolpo, Cox’s Bazar, using data from 251 randomly selected households. Household resilience was measured with the ARC-D toolkit, and findings were validated through focus group discussions and field observations. Resilience scores decreased from 76.37 to 70.99 after relocation, indicating reduced adaptive capacity against cyclones, coastal flooding, and salinity intrusion. Qualitative data revealed unequal aid distribution, limited volunteerism, and weak community cohesion. Quantitative analyses showed resilience was higher among males (M = 2.44, SD = 0.40), adults aged 26–40 (M = 2.42, SD = 0.40), and tourism workers (M = 2.58, SD = 0.36), and lower among females and fishermen. Regression results confirmed that gender (β = –0.164, p = 0.006), occupation (β = 0.148, p = 0.015), and water access (β = 0.196, p = 0.001) significantly influenced resilience. The findings highlight that physical relocation alone cannot ensure resilience without essential services, inclusive governance, and sustainable livelihoods, emphasizing the need for integrated and equitable relocation planning in climate-vulnerable coastal region.

Numerical simulation of density-dependent saltwater intrusion in sandbox model

This study aims to analyze the potential utilization and economic valuation of mangrove forest ecosystems. This study was conducted in Manyampa Village, Ujung Loe District, Bulukumba Regency, South Sulawesi Province. Samples were selected using a purposive sampling method, involving 20 pond fish farmers, 20 crab catchers, and 20 tourists. The study employed both descriptive quantitative and qualitative data analysis methods. This study indicates that the mangrove forest in Manyampa Village covers 27 hectares; however, only 7 hectares are currently utilized. Direct benefits such as mangrove fruits, wood products, and protective functions against abrasion, storm surges, and saltwater intrusion. Indirect benefits such as fish-shrimp-crab habitat, nutrient sources, environmental education, and ecotourism. The direct benefit value of the economic valuation of the mangrove ecosystem is IDR 4,562,963,185.00 per hectare per year. The indirect benefit value from milkfish (bandeng) cultivation in ponds is estimated at IDR 741,925,000.00 per hectare per year, and the value of coastal fishermen's catch is IDR 11,910,000.00 per hectare per year. The economic value of ecotourism in the mangrove forest ecosystem is estimated at IDR 89,250,000 per hectare per year. The mangrove forest ecosystem in Manyampa Village has an estimated economic value of IDR 5,406,048,185 per hectare per year. Given the total area of 27 hectares, the overall annual economic value of the mangrove forest is approximately IDR 145,963,300,995.

This review synthesizes recent evidence on groundwater security in Vietnam’s Mekong Delta under the twin pressures of climate change and sustained over-abstraction. Advancing prior work, we (i) integrate disparate findings into an extraction–subsidence–salinization systems frame and (ii) align post-2015 scientific evidence with the latest regulatory reforms to distill implementable pathways. Using a selective but transparent literature strategy focused on peer-reviewed studies (2015–2025) indexed in Scopus/Web of Science and authoritative governmental/international reports, we prioritized sources with explicit methods, georeferenced observations, and reported uncertainties; grey literature without methodological disclosure was screened out. The Delta’s multi-aquifer endowment is heavily stressed: recorded withdrawals from centralized wells are approximately 2.0 million m³ d⁻¹, groundwater heads decline by 0.3–0.5 m y⁻¹ across many localities, and land subsidence averages about 1.07 cm y⁻¹ with urban hotspots exceeding these values; earlier and deeper saltwater intrusion further jeopardizes domestic supply and agriculture. Water-quality risks—including widespread microbial contamination and geogenic arsenic above WHO guidelines—compound exposure. While recent legal instruments establish clearer mandates for restricted zones, licensing, and extraction charges, implementation is hindered by fragmented monitoring networks, limited metering of household wells, and transition costs for small users. We propose a four-pillar strategy: legally binding, risk-zoned extraction thresholds; phased substitution by interprovincial surface-water conveyance; managed aquifer recharge (e.g., riverbank filtration) in suitable formations; and digital metering coupled with economic instruments and integrated forecasting that co-simulates extraction, subsidence, and salinity. The review also identifies critical evidence gaps—household abstraction inventories, in-situ deformation–pumping linkages, and cost-effectiveness of recharge options—that should anchor near-term research. Collectively, these measures are necessary to arrest the subsidence–salinity feedback loop and restore groundwater resilience in the Mekong Delta.

Towards smart water monitoring: IoT-driven LSTM modelling for multi-step-ahead forecasting of river salinity dynamics.

Blue carbon loss driven by the accelerating rate of sea level rise during the Anthropocene Marine Transgression, Southeast Saline Everglades, Florida.

Hydrogeochemical characterization and human health risk assessment for heavy metal contamination in coastal aquifers: A case study in Satkhira District, Bangladesh.

Seawater intrusion and mud volcanism impact the groundwater geochemistry of small Bornean islands

Seawater intrusion in river delta systems. Inter-annual dynamics and drivers of salinity variations in the southern Mekong Delta, Vietnam

Assessment of the role of estuarine barrage operational management in enhancing glass eel (Anguilla japonica) migration in a closed estuary.

Abstract We demonstrate the effectiveness of long‐term continuous interferometric Synthetic Aperture Radar (InSAR) monitoring for local resource management. Sustainable yield is a key concept in groundwater management to ensure sustainable, low‐impact groundwater extraction. This study proposes to estimate sustainable yield using InSAR, combined with local groundwater production data. We apply this method to the Hollywood Basin in Los Angeles, California, leveraging nearly 30 years of InSAR data (1992–2023) to investigate ground deformation linked to groundwater extraction. High spatial InSAR measurements reveal deforming regions linked to anthropogenic activities previously not well‐characterized by in situ observation networks. By integrating InSAR data with production records, we estimate the sustainable yield for the basin to be 1.44 to 1.67 million cubic meters per year, significantly lower than the current operating safe yield of 3.70 million cubic meters per year. Utilizing Independent Component Analysis, we are able to distinguish hydrological signals originating from the deep and shallow aquifers in the Hollywood Basin. Our findings demonstrate the effectiveness of InSAR for long‐term monitoring of anthropogenic deformation and for supporting urban planning and resource management.

Spatial distribution pattern of heavy metals in sediments of seasonal ice-covered lakes.

Risk quantification of saltwater intrusion in Modaomen Estuary of the Pearl river Delta, South China

Implications of waterfowl impoundments as a response to sea-level driven saltwater intrusion.

Preferential seawater intrusion in a heterogeneous alluvial aquifer that extends offshore: Insights from numerical modeling

Controlling seawater intrusion in unconfined coastal aquifers through aquifer storage and recovery (ASR): Insights from sandbox experiments

Source apportionment of groundwater contamination and spatial variability in the Bohai Sea region (China).

Impact of groundwater extraction intensity on the monitoring design for seawater intrusion in heterogeneous coastal aquifers

Abstract Land subsidence driven by groundwater exploitation poses a critical threat under future water stress from population growth, urbanization, and economic expansion. While the relationship between groundwater level (GWL) fluctuations and land subsidence has been studied, limited research has explored their co‐evolution under future development, climate change, and groundwater management aimed at stabilizing or reversing GWL decline. The long‐term effects of large‐scale water transfer projects, such as China's South‐to‐North Water Diversion (SNWD) project, on subsidence remain unclear despite their role in reducing extraction pressures and recovering groundwater level. This study develops a coupled groundwater flow and land subsidence model for a key city in the SNWD's middle route, incorporating water demand projections (from Shared Socioeconomic Pathways, SSPs), climate change scenarios (from CMIP6), and water diversion strategies. Results indicate that future (until 2050) GWL changes and subsidence are primarily driven by water demand (over 50%) and water diversion (up to 45.3%), with climate change having a minor effect (under 18.6%). Over the period extending from 2020 to 2050, subsidence recovery could reach 56.8 mm (averagely 1.9 mm/yr) with reduced demand and increased diversion. However, in a worst‐case scenario characterized by rising demand and absence of diversion optimization, subsidence could worsen by up to 439.9 mm (averagely 14.7 mm/yr). Water diversion could be 15 times more effective in mitigating subsidence under higher water‐stress conditions, while prohibiting deep groundwater extraction for agriculture could lead to a 4.4‐fold improvement in GWL recovery and subsidence mitigation. This study highlights the role of technology, policy, and optimized water diversion in managing GWL and mitigating subsidence under future uncertainties.