scholarly journals Development of monthly seawater intrusion vulnerability assessment method using GALDIT

2021 ◽  
Author(s):  
Il hwan Kim ◽  
IL-Moon Chung ◽  
Sun Woo Chang
Keyword(s):  
Sea Level ◽  
Seawater Intrusion ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Assessment Method ◽  
Coastal Areas ◽  
Dynamic Parameters ◽  
Groundwater Occurrence ◽  
Monthly Changes ◽  
Galdit Method

Accurate diagnoses of vulnerability of seawater intrusion (SWI) into aquifers are required to ensure sustainable utilization of groundwater resources in coastal areas. GALDIT was selected to assess the SWI vulnerability on western coastal areas of South Korea. Climate change trends are updated every year. The existing GALDIT method has various scores to express the changing observed values. However, they are limited because of their sensitivity in the assessment of regional characteristics or climatic change due to low weight flexibility. Therefore, this study assessed vulnerability to SWI by classifying the existing GALDIT into static and dynamic parameters. The static parameters include groundwater occurrence (G), aquifer hydraulic conductivity (A), and distance from the shore (D), whereas the dynamic parameters include height to groundwater level above sea level (L), impact of existing status of seawater intrusion (I), and aquifer thickness (T). The monthly mean was used as the dynamic index to reflect monthly variations. To indicate the temporal trend of parameter L was calculated based on the data observed at the sea level station adjacent to the groundwater level station. To sensitively reflect the monthly changes in values, the range of scores was divided into 10 parts. The calculated GALDIT index showed that the most vulnerable month was September. In the progress of SWI, vulnerability was assessed monthly to highlight the differences in parameters that fluctuate seasonally. The proposed method can be used to apply intensive countermeasures to vulnerable sites and build an operation plan considering the vulnerability period.

scholarly journals Development of Seawater Intrusion Vulnerability Assessment for Averaged Seasonality of Using Modified GALDIT Method

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1820
Author(s):  
Il Hwan Kim ◽  
Il-Moon Chung ◽  
Sun Woo Chang
Keyword(s):  
Sea Level ◽  
Seawater Intrusion ◽  
Groundwater Level ◽  
Anthropogenic Activities ◽  
Groundwater Resources ◽  
Dynamic Parameter ◽  
Management Plan ◽  
Coastal Areas ◽  
Seasonal Characteristics ◽  
Galdit Method

Climate change and anthropogenic activities are necessitating accurate diagnoses of seawater intrusion (SWI) to ensure the sustainable utilization of groundwater resources in coastal areas. Here, vulnerability to SWI was assessed by classifying the existing GALDIT into static parameters (groundwater occurrence (G), aquifer hydraulic conductivity (A), and distance from shore (D)) and dynamic parameters (height to groundwater-level above sea-level (L), impact of existing status of seawater intrusion (I), and aquifer thickness (T)). When assessing the vulnerability of SWI based on observational data (2010–2019), 10-year-averaged data of each month is used for GALDIT dynamic parameter for representing the seasonal characteristics of local water cycles. In addition, the parameter L is indicated by the data observed at the sea-level station adjacent to the groundwater level station. The existing GALDIT method has a range of scores that can be divided into quartiles to express the observed values. To sensitively reflect monthly changes in values, the range of scores is divided into deciles. The calculated GALDIT index showed that the most vulnerable month is September, due to relatively low groundwater level. The proposed method can be used to apply countermeasures to vulnerable coastal areas and build water resources management plan considering vulnerable seasons.

scholarly journals GROUNDWATER VULNERABILITY ASSESSMENT TO SEAWATER INTRUSION THROUGH GIS - BASED GALDIT METHOD. CASE STUDY: ATALANTI COASTAL AQUIFER, CENTRAL GREECE

2017 ◽  
Vol 50 (2) ◽  
pp. 798 ◽  
Author(s):  
I. Lappas ◽  
A. Kallioras ◽  
F. Pliakas ◽  
Th. Rondogianni
Keyword(s):  
Seawater Intrusion ◽  
Coastal Aquifer ◽  
Groundwater Resources ◽  
Groundwater Vulnerability ◽  
Aquifer Vulnerability ◽  
Hydrogeological Parameters ◽  
Groundwater Occurrence ◽  
Boundary Parameter ◽  
Groundwater Vulnerability Assessment ◽  
Galdit Method

Groundwater resources assessment has resulted in development of models that help identify the vulnerable zones. This paper presents a GIS-based hydrogeological index, named GALDIT, aiming at the assessment of aquifer vulnerability to seawater intrusion in Atalanti coastal aquifer, Central-Eastern Greece. The above acronym is formed from the most important factors controlling seawater intrusion, that is, four intrinsic hydrogeological parameters, one spatial parameter and one boundary parameter including Groundwater occurrence (aquifer type), Aquifer hydraulic conductivity, depth to groundwater Level above the sea (hydraulic head), Distance from the shore, Impact of seawater intrusion and aquifer’s Thickness. These factors nclude the basic requirements needed to assess the general salinization potential of each hydrogeological setting. Each parameter is evaluated with respect to the other to determine the relative importance of each factor. GALDIT model is described to assess and quantify the significance of vulnerability to seawater intrusion due to excessive groundwater withdrawals. Different thematic maps are prepared for seawater intrusion indicators and overlaid to develop the final vulnerability map. The derived map can be used as a tool for coastal groundwater resources management and areas’ determination of potential saltwater intrusion since the result of GALDIT ndex is classified based on vulnerability rate.

Estimating regional to global fresh-brackish-salt groundwater occurrence to support future projections

2020 ◽  
Author(s):  
Marc F.P. Bierkens ◽  
Jude A. King ◽  
Joeri van Engelen ◽  
Jarno Verkaik ◽  
Daniel Zamrsky ◽  
...  
Keyword(s):  
Sea Level ◽  
Nile Delta ◽  
Initial Conditions ◽  
Groundwater Resources ◽  
Variable Density ◽  
Coastal Areas ◽  
Estimation Methods ◽  
Fresh Groundwater ◽  
Surface Sealing ◽  
Groundwater Occurrence

<p>Coastal areas, including deltas, are hotspots for population growth and economic development. The rising demand for fresh water that results from these developments has resulted in increased rates of groundwater pumping and an associated enhanced risk of groundwater salinization. Future sea-level rise, climate change and surface sealing due to urbanisation are likely to further increase salinization risk in the near future. In order to correctly project the future fate of fresh groundwater resources in coastal areas under climate and socio-economic change, a correct estimate of the current fresh-brackish-salt groundwater occurrence is imperative. The reason for this is that future salinity projections are very sensitive to initial conditions, due to the large inertia of variable-density groundwater systems. Here, we make a case that estimating the current fresh-brackish-salt groundwater distribution by itself is a major challenge. The presence of conductivity contrasts in coastal areas, the past occurrence of sea-level transgressions and the aforementioned system inertia makes that traditional estimation methods such as interpolations between in-situ salinity observations or equilibrium (steady-state) modelling approaches are incapable of producing sufficiently realistic fresh-brackish-salt groundwater distributions. Using examples from the Rhine-Meuse delta, the Nile delta and the global coast, we show that advancements in airborne geophysics and high-resolution paleo-groundwater modelling may be key to providing distributions that are both realistic and accurate.</p>

scholarly journals Assessing groundwater vulnerability to sea water intrusion in the coastline of the inner Puck Bay using GALDIT method

2018 ◽  
Vol 54 ◽  
pp. 00023 ◽  
Author(s):  
Dawid Potrykus ◽  
Anna Gumuła-Kawęcka ◽  
Beata Jaworska-Szulc ◽  
Małgorzata Pruszkowska-Caceres ◽  
Adam Szymkiewicz ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Seawater Intrusion ◽  
Sea Water ◽  
Groundwater Vulnerability ◽  
Aquifer Vulnerability ◽  
Galdit Method ◽  
The Impact ◽  
Simulated Scenario ◽  
Puck Bay

In this research, GALDIT method was used to assess seawater intrusion in the coastal aquifer of the inner Puck Bay (Southern Baltic Sea). The impact of potential sea-level rise on groundwater vulnerability for years 2081-2100 was also considered. The study area was categorized into three classes of vulnerability: low, moderate and high. The most vulnerable area is the Hel Peninsula with northern part of the Kashubian Coastland. Increased class of aquifer vulnerability is also adopted to glacial valleys. The results of this research revealed that about 18.9% of the analyzed area is highly vulnerable to seawater intrusion, 25.3% is moderately vulnerable and 55.8% is potentially at low risk. The simulated scenario of predicted sea level rise shows enlargement of high vulnerability areas.

scholarly journals Geological processes and the management of groundwater resources in coastal areas

2003 ◽  
Vol 82 (1) ◽  
pp. 31-40 ◽  
Author(s):  
H. Kooi ◽  
J. Groen
Keyword(s):  
Sea Level ◽  
Groundwater Resources ◽  
Sea Level Change ◽  
Coastal Areas ◽  
Shallow Aquifer ◽  
Sediment Loading ◽  
Level Change ◽  
Geological Processes ◽  
And Sea Level

AbstractIn this contribution, a case is made for the significance of sedimentation and sea-level change for groundwater management of coastal areas. In groundwater practice these geological processes are rarely considered. The role of sediment loading in causing anomalous fluid pressures and flow fields in relatively shallow aquifer systems is discussed and illustrated via both case studies and generic modelling studies. The role of sea-level changes in controlling current salinity distributions is discussed likewise. Central in the discussion is the concept of memory of groundwater systems, which provides the basic reason why processes that were operative in the geological past are still of relevance today. It is argued and shown that awareness and knowledge of the influence of sediment loading and sea level change on current hydrological conditions can lead to improved characterization of the distribution of hydraulic parameters and of the distribution of water quality in coastal areas. This improved characterization, in turn, serves to enhance the validity of impact assessment studies for the long-term development and management of those areas.

scholarly journals Investigation and control of seawater intrusion in the Eastern Nile Delta aquifer considering climate change

2016 ◽  
Vol 17 (2) ◽  
pp. 311-323 ◽  
Author(s):  
Hany F. Abd-Elhamid
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Seawater Intrusion ◽  
Brackish Water ◽  
Agricultural Production ◽  
Saltwater Intrusion ◽  
Nile Delta ◽  
Groundwater Resources ◽  
And Control

Seawater intrusion is considered one of the main processes that degrade water quality by raising salinity. Over-pumping and decreasing recharge are considered the main causes of saltwater intrusion. Moreover, climate change and sea-level rise accelerate saltwater intrusion. In this paper SEAWAT code was used to study groundwater flow and seawater intrusion in the Eastern Nile Delta aquifer considering four scenarios of climate change including sea-level rise, increasing abstraction, decreasing recharge and the combination of these scenarios. The results showed that decreasing recharge has a significant effect on seawater intrusion. However, the combinations of these scenarios resulted in harmful intrusion and loss of groundwater. The soil salinity increased, which decreased agricultural production. The control of seawater intrusion and protection of groundwater resources and soil is very important. Different scenarios were implemented to protect the aquifer from seawater intrusion including decreasing abstraction, increasing recharge, abstracting brackish water and the combination of these three scenarios. The abstraction of brackish water gave a higher reduction of seawater intrusion and decreased groundwater table in the aquifer near the shore line, which protected the soil from salinity and increased agricultural production. However, the combination of these three scenarios gave the highest reduction of seawater intrusion.

scholarly journals Modelling seawater intrusion in the Pingtung coastal aquifer in Taiwan, under the influence of sea-level rise and changing abstraction regime

2020 ◽  
Vol 28 (6) ◽  
pp. 2085-2103 ◽  
Author(s):  
Mahdieh Dibaj ◽  
Akbar A. Javadi ◽  
Mohammad Akrami ◽  
Kai-Yuan Ke ◽  
Raziyeh Farmani ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sea Level Rise ◽  
Sea Level ◽  
Seawater Intrusion ◽  
Coastal Aquifer ◽  
Groundwater Resources ◽  
Element Model ◽  
Aquifer System ◽  
Pingtung Plain

Abstract A three-dimensional variable-density finite element model was developed to study the combined effects of overabstraction and seawater intrusion in the Pingtung Plain coastal aquifer system in Taiwan. The model was generated in different layers to represent the three aquifers and two aquitards. Twenty-five multilayer pumping wells were assigned to abstract the groundwater, in addition to 95 observation wells to monitor the groundwater level. The analysis was carried out for a period of 8 years (2008–2015 inclusive). Hydraulic head, soil permeability, and precipitation were assigned as input data together with the pumping records in different layers of the aquifer. The developed numerical model was calibrated against the observed head archives and the calibrated model was used to predict the inland encroachment of seawater in different layers of the aquifer. The effects of pumping rate, sea-level rise, and relocation of wells on seawater intrusion were examined. The results show that all layers of the aquifer system are affected by seawater intrusion; however, the lengths of inland encroachment in the top and bottom aquifers are greater compared with the middle layer. This is the first large-scale finite-element model of the Pingtung Plain, which can be used by decision-makers for sustainable management of groundwater resources and cognizance of seawater intrusion in coastal aquifers.

scholarly journals Effects of Aquifer Bed Slope and Sea Level on Saltwater Intrusion in Coastal Aquifers

Hydrology ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 5 ◽  
Author(s):  
Hany F. Abd-Elhamid ◽  
Ismail Abd-Elaty ◽  
Mohsen M. Sherif
Keyword(s):  
Sea Level ◽  
Groundwater Level ◽  
Coastal Aquifers ◽  
Saltwater Intrusion ◽  
Groundwater Resources ◽  
The Other ◽  
Henry Problem ◽  
Dispersion Zone ◽  
Bed Slope

The quality of groundwater resources in coastal aquifers is affected by saltwater intrusion. Over-abstraction of groundwater and seawater level rise due to climate change accelerate the intrusion process. This paper investigates the effects of aquifer bed slope and seaside slope on saltwater intrusion. The possible impacts of increasing seawater head due to sea level rise and decreasing groundwater level due to over-pumping and reduction in recharge are also investigated. A numerical model (SEAWAT) is applied to well-known Henry problem to assess the movement of the dispersion zone under different settings of bed and seaside slopes. The results showed that increasing seaside slope increased the intrusion of saltwater by 53.2% and 117% for slopes of 1:1 and 2:1, respectively. Increasing the bed slope toward the land decreased the intrusion length by 2% and 4.8%, respectively. On the other hand, increasing the bed slope toward the seaside increased the intrusion length by 3.6% and 6.4% for bed slopes of 20:1 and 10:1, respectively. The impacts of reducing the groundwater level at the land side and increasing the seawater level at the shoreline by 5% and 10% considering different slopes are studied. The intrusion length increased under both conditions. Unlike Henry problem, the current investigation considers inclined beds and sea boundaries and, hence, provides a better representation of the field conditions.

scholarly journals Application of GALDIT in Assessing the Seawater Intrusion Vulnerability of Jeju Island, South Korea

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1824 ◽  
Author(s):  
Sun Woo Chang ◽  
Il-Moon Chung ◽  
Min-Gyu Kim ◽  
Mesfin Tolera ◽  
Gi-Won Koh
Keyword(s):  
Seawater Intrusion ◽  
Vulnerability Assessment ◽  
Groundwater Resources ◽  
Assessment Method ◽  
Jeju Island ◽  
Quantitative Index ◽  
Rational Decision Making ◽  
Environmental Threat ◽  
Level Data ◽  
Vulnerability Model

Seawater intrusion (SWI) is a major environmental threat to groundwater resources in coastal regions. GALDIT is an index-based SWI vulnerability model that is increasingly being used in many parts of the world to identify regions that are vulnerable to various types of SWI based on six major parameters. In this study, we conducted a vulnerability assessment of Jeju Island to SWI based on several years of collected groundwater level data and hydrogeological values where the objectives of the study were to visualize the distribution of recent SWI, to increase the reliability of the GALDIT assessment method by improving current GALDIT techniques, and to respond effectively to diagnoses of SWI on Jeju. To improve the GALDIT assessment method to fit the Jeju model, the possibility of electrical conductivity was explored instead of standard GALDIT parameters that represented the existing impact of SWI. Improvements to the GALDIT vulnerability assessment method made it clear that groundwater became increasingly vulnerable to SWI in the existing high-vulnerability group. The results of this research may be used to develop a quantitative index for rational decision-making on policies and suggest the need for further improvements in groundwater management, with a stronger focus on easing groundwater use.

scholarly journals Modeling and Mapping of coastal aquifer vulnerability to seawater intrusion using SEAWAT code and GALDIT index technique: the case of the Rmel aquifer – Larache, Morocco

2021 ◽  
Vol 298 ◽  
pp. 05002
Author(s):  
Mohamed Jalal El Hamidi ◽  
Abdelkader Larabi ◽  
Mohamed Faouzi
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Sea Level Rise ◽  
Sea Level ◽  
Seawater Intrusion ◽  
Climate Models ◽  
Groundwater Resources ◽  
Climate Projections ◽  
The North ◽  
And Sea Level

The study area of Rmel-O. Ogbane aquifer, located in the north of Morocco, currently faces major water challenges related to the sustainable management of water resources. Climate change and Sea-Level-Rise can increase the risks and costs of water resources management and impact water resources' quantity and quality. Hence, for planning and management, an integrated approach is developed for linking climate models and groundwater models to investigate future impacts of climate change on groundwater resources. Climate projections show an increase in temperature of about 0.45 °C and a reduction in precipitation of 16.7% for 2016-2050. Simulations of seawater intrusion corresponding to various combinations of groundwater extraction predicted climate change and sea-level-rise show that the area will be contaminated on the NW sector of the coastal part. The toe would reach about 5.2 km inland and intrude on high salinity (15–25g/l). Beyond these zones, the contamination of the aquifer will be limited. Moreover, these results were confirmed by the application of the GALDIT method. They reveal that the fringe littoral areas of the aquifer are the most affected by seawater intrusion, with a high risk in the north-western part of the study area.

Sign in / Sign up

Export Citation Format

Share Document