scholarly journals Study of historical groundwater level changes in two Belgian chalk aquifers in the context of climate change impacts

2021 ◽  
pp. SP517-2020-212
Author(s):  
Pascal Goderniaux ◽  
Philippe Orban ◽  
Alain Rorive ◽  
Serge Brouyère ◽  
Alain Dassargues
Keyword(s):  
Groundwater Level ◽  
Groundwater Resources ◽  
Summer Drought ◽  
Aquifer Recharge ◽  
Groundwater Abstraction ◽  
Groundwater Levels ◽  
Future Evolution ◽  
Precipitation Decrease ◽  
Chalk Aquifer ◽  
The Impact

AbstractIn Southern Belgium, 23% of abstracted groundwater volumes are from chalk aquifers which represent strategic resources for the region. Due to their specific nature, these chalk aquifers often exhibit singular behaviour and require specific analysis. The quantitative evolution of these groundwater resources is analysed for the Mons Basin and Hesbaye chalk aquifers as a function of past evolution, in the short and long terms. Groundwater level time series exhibit decreases when analysed over different periods. This is particularly visible for the Hesbaye chalk aquifer when comparing the 1960-1990 and 1990-2020 periods. Such decreases are associated to observed temperature increase and a precipitation decrease, inducing a decrease of aquifer recharge, and a probable increase of groundwater abstraction in the adjacent catchment. Past evolution is also discussed considering recent winter and summer drought events. The aquifers exhibit long delays in response to recharge events, particularly where the thickness of the partially saturated zone plays a crucial role in observed delays. Regarding future evolution, simulations of the impact of climate changes using medium-high emission scenarios indicate a probable decrease of the groundwater levels over the Hesbaye chalk aquifer.

scholarly journals Impact of Groundwater Abstraction on Hydrological Responses during Extreme Drought Periods in the Boryeong Dam Catchment, Korea

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2132
Author(s):  
Sanghyun Park ◽  
Hyeonjun Kim ◽  
Choelhee Jang
Keyword(s):  
Surface Water ◽  
Groundwater Level ◽  
Agricultural Sector ◽  
Assessment Tool ◽  
Groundwater Resources ◽  
Groundwater Abstraction ◽  
Runoff Simulation ◽  
Groundwater Levels ◽  
Hydrological Responses ◽  
The Impact

Groundwater withdrawal results in a significant depletion of groundwater storage due to the frequency and intensity of droughts and increasing irrigation demands. To ensure the sustainable use of groundwater resources, it is necessary to accurately simulate the groundwater behavior of catchments using a surface–groundwater integrated runoff model. Most of the existing catchment runoff models have been applied to surface water management; thus, integrated runoff analysis studies that consider the interaction between surface water and groundwater are required. Due to the intensive agricultural sector in Korea and the position of rice as the staple in the Korean diet, more than 50% of groundwater abstraction is used for irrigation. Therefore, it is very important to understand the hydrological interrelationships between agricultural areas and the entire watershed. This study aimed to compare and analyze the groundwater levels in the mountainous areas and paddy field areas in the Boryeong Dam catchment through a surface–groundwater integrated runoff simulation using the Catchment Hydrologic Cycle Assessment Tool model, and to compare the hydrological responses in wet years (2010–2012) and dry years (2014–2016). The maximum difference in the monthly groundwater level in the dry years compared to the wet years was 1.07 m at the forest catchment and 0.37 m at the paddy catchment. These results indicate that the impact of drought on the groundwater level of paddy catchments is not significant compared to the forest catchments; however, drought slows the recovery of the groundwater level before the rainy season, thereby limiting the agricultural groundwater use in the catchment.

scholarly journals Depletion of groundwater resources under rapid urbanisation in Africa: recent and future trends in the Nairobi Aquifer System, Kenya

2020 ◽  
Vol 28 (8) ◽  
pp. 2635-2656
Author(s):  
Samson Oiro ◽  
Jean-Christophe Comte ◽  
Chris Soulsby ◽  
Alan MacDonald ◽  
Canute Mwakamba
Keyword(s):  
Negative Impact ◽  
Groundwater Resources ◽  
Climatic Data ◽  
Groundwater Abstraction ◽  
Management Scenarios ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Future Evolution ◽  
Level Data ◽  
Groundwater Assessment

AbstractThe Nairobi volcano-sedimentary regional aquifer system (NAS) of Kenya hosts >6 M people, including 4.7 M people in the city of Nairobi. This work combines analysis of multi-decadal in-situ water-level data with numerical groundwater modelling to provide an assessment of the past and likely future evolution of Nairobi’s groundwater resources. Since the mid-1970s, groundwater abstraction has increased 10-fold at a rate similar to urban population growth, groundwater levels have declined at a median rate of 6 m/decade underneath Nairobi since 1950, whilst built-up areas have increased by 70% since 2000. Despite the absence of significant trends in climatic data since the 1970s, more recently, drought conditions have resulted in increased applications for borehole licences. Based on a new conceptual understanding of the NAS (including insights from geophysics and stable isotopes), numerical simulations provide further quantitative estimates of the accelerating negative impact of abstraction and capture the historical groundwater levels quite well. Analysis suggests a groundwater-level decline of 4 m on average over the entire aquifer area and up to 46 m below Nairobi, net groundwater storage loss of 1.5 billion m3 and 9% river baseflow reduction since 1950. Given current practices and trajectories, these figures are predicted to increase six-fold by 2120. Modelled future management scenarios suggest that future groundwater abstraction required to meet Nairobi projected water demand is unsustainable and that the regional anthropogenically-driven depletion trend can be partially mitigated through conjunctive water use. The presented approach can inform groundwater assessment for other major African cities undergoing similar rapid groundwater development.

scholarly journals Deep Learning based assessment of groundwater level development in Germany until 2100

2021 ◽  
Author(s):  
Andreas Wunsch ◽  
Tanja Liesch ◽  
Stefan Broda
Keyword(s):  
Climate Change ◽  
Groundwater Level ◽  
Climate Models ◽  
Groundwater Resources ◽  
Groundwater Abstraction ◽  
Water Shortages ◽  
Entire Area ◽  
Groundwater Levels ◽  
The Past ◽  
Skill Scores

<p>Clear signs of climate stress on groundwater resources have been observed in recent years even in generally water-rich regions such as Germany. Severe droughts, resulting in decreased groundwater recharge, led to declining groundwater levels in many regions and even local drinking water shortages have occurred in past summers. We investigate how climate change will directly influence the groundwater resources in Germany until the year 2100. For this purpose, we use a machine learning groundwater level forecasting framework, based on Convolutional Neural Networks, which has already proven its suitability in modelling groundwater levels. We predict groundwater levels on more than 120 wells distributed over the entire area of Germany that showed strong reactions to meteorological signals in the past. The inputs are derived from the RCP8.5 scenario of six climate models, pre-selected and pre-processed by the German Meteorological Service, thus representing large parts of the range of the expected change in the next 80 years. Our models are based on precipitation and temperature and are carefully evaluated in the past and only wells with models reaching high forecasting skill scores are included in our study. We only consider natural climate change effects based on meteorological changes, while highly uncertain human factors, such as increased groundwater abstraction or irrigation effects, remain unconsidered due to a lack of reliable input data. We can show significant (p<0.05) declining groundwater levels for a large majority of the considered wells, however, at the same time we interestingly observe the opposite behaviour for a small portion of the considered locations. Further, we show mostly strong increasing variability, thus an increasing number of extreme groundwater events. The spatial patterns of all observed changes reveal stronger decreasing groundwater levels especially in the northern and eastern part of Germany, emphasizing the already existing decreasing trends in these regions</p>

scholarly journals Development of groundwater levels as a consequense of climate change

2012 ◽  
Vol 20 (1) ◽  
pp. 29-34
Author(s):  
M. Pásztorová ◽  
J. Skalová ◽  
J. Vitková ◽  
M. Juráková
Keyword(s):  
Climate Change ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Winter Season ◽  
Water Levels ◽  
Rainfall Regime ◽  
Wetland Ecosystems ◽  
Groundwater Levels ◽  
Run Off ◽  
The Impact

Development of groundwater levels as a consequense of climate changeClimate change poses a significant threat to many wetland ecosystems. Wetlands exist in a transition zone between aquatic and terrestrial environments and can be affected by slight alterations in regional hydrology, which can influence climate change through air temperature changes, regional changes in a rainfall regime, surface run-off, snow, duration of the winter season, groundwater resources and evapotranspiration.Climate change in wetland areas is most significantly reflected in water levels and adjacent groundwater levels, and it can significantly change the hydroecological proportions of wetland ecosystems and endanger rare wetland fauna and flora communities. The focus of this paper is the impact of climate change on the groundwater level in the Záhorie Protected Landscape area in the Zelienka national nature reservation. The impact of the climate change was solved through the meteorological characteristic changes adapted by the GISS98 and CCCM2000 climatic scenarios. The groundwater level was determined by the HYDRUS-ET model for the time frames 2010, 2030 and 2075 in 20-year time intervals and consequently compared to the reference period of 1971-1990.

scholarly journals The impact of urbanization and rapid population growth on the groundwater regime in Dhaka city, Bangladesh

2021 ◽  
Author(s):  
Mazeda Islam ◽  
Marc Van Camp ◽  
Delwar Hossain ◽  
Md. Mizanur Rahman Sarker ◽  
Shahina Khatun ◽  
...  
Keyword(s):  
Groundwater Level ◽  
Average Rate ◽  
Groundwater Resources ◽  
Dhaka City ◽  
Groundwater Abstraction ◽  
Aquifer System ◽  
Depression Cone ◽  
The Impact ◽  
The City

<p>Dhaka city with an area of about 306 Km<sup>2</sup> and a population of more than 20 million is located in the central part of Bangladesh. Immense and prolonged groundwater abstraction due to rapid unplanned urbanization and population blast in this city have led to significant decline in groundwater level in the last three decades. 78% of the supplied water comprises groundwater from the Dupi Tila Sandstone aquifer system. Hydrogeological and geophysical data aided to the delineation of three different aquifers (based on lithology): Upper Dupi Tila aquifer (UDA), Middle Dupi Tila aquifer (MDA) and Lower Dupi Tila aquifer (LDA).  The evaluation of long-term hydrographs, piezometric maps and synthetic graphical overviews of piezometric trends in both the UDA and MDA depicts that the rate of dropping of groundwater level (GWL) is very substantial. Massive pumping in the city has altered its natural hydrologic system. The groundwater level has dropped on average 2.25 m/year and 2.8 m/year in UDA and MDA, respectively, in the whole city in 2018, whereas the average rate of decline in the center of the depression cone during this time was 4.0 m/year and 5.74 m/year respectively. Presently, the groundwater level elevation has declined to levels lower than -85 and -65 m PWD in UDA and MDA, respectively. The changes in pattern and magnitude of depression cones in UDA and MDA are directly associated with the city expansion and number of deep tube wells installed over a certain period in particular parts of the city. The depletion of GWL from 1980 to 2018 is very notable. There is only limited vertical recharge possible in the UDA and MDA as they are semi-confined aquifers, and only lateral flow mostly in the UDA and MDA from the surroundings is to be expected. In this regard the long-term management of groundwater resources in Dhaka city is urgently needed, otherwise the condition may go beyond control.</p><p> </p><p><strong>Key words:</strong> Groundwater abstraction, city expansion, hydrographs, piezometric maps, GWL decline, depression cone.</p>

scholarly journals Seismically induced changes in groundwater levels and temperatures following the ML5.8 (ML5.1) Gyeongju earthquake in South Korea

2021 ◽  
Author(s):  
Soo-Hyoung Lee ◽  
Jae Min Lee ◽  
Sang-Ho Moon ◽  
Kyoochul Ha ◽  
Yongcheol Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Groundwater Level ◽  
Seismic Waves ◽  
Groundwater Resources ◽  
Fluid Pressure ◽  
Water Levels ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Gyeongju Earthquake

AbstractHydrogeological responses to earthquakes such as changes in groundwater level, temperature, and chemistry, have been observed for several decades. This study examines behavior associated with ML 5.8 and ML 5.1 earthquakes that occurred on 12 September 2016 near Gyeongju, a city located on the southeast coast of the Korean peninsula. The ML 5.8 event stands as the largest recorded earthquake in South Korea since the advent of modern recording systems. There was considerable damage associated with the earthquakes and many aftershocks. Records from monitoring wells located about 135 km west of the epicenter displayed various patterns of change in both water level and temperature. There were transient-type, step-like-type (up and down), and persistent-type (rise and fall) changes in water levels. The water temperature changes were of transient, shift-change, and tendency-change types. Transient changes in the groundwater level and temperature were particularly well developed in monitoring wells installed along a major boundary fault that bisected the study area. These changes were interpreted as representing an aquifer system deformed by seismic waves. The various patterns in groundwater level and temperature, therefore, suggested that seismic waves impacted the fractured units through the reactivation of fractures, joints, and microcracks, which resulted from a pulse in fluid pressure. This study points to the value of long-term monitoring efforts, which in this case were able to provide detailed information needed to manage the groundwater resources in areas potentially affected by further earthquakes.

scholarly journals The use of groundwater crustacean communities as indicators for aquifers quality in the semi-arid region of north-central Chile

2018 ◽  
Vol 1 ◽  
Author(s):  
Sanda Iepure ◽  
Nicolas Gouin ◽  
Angeline Bertin ◽  
Ana Camacho ◽  
Antonio González-Ramón ◽  
...  
Keyword(s):  
Negative Impact ◽  
Groundwater Resources ◽  
Economic Benefits ◽  
Nutrient Loads ◽  
Groundwater Temperature ◽  
Groundwater Levels ◽  
Water Abstraction ◽  
Over Exploitation ◽  
The Impact ◽  
Semi Arid

Chile has large extensions of arid and semi-arid regions throughout the whole country, where the intensive demands and use of water resources, especially groundwater for irrigations and mining activities, increased dramatically over the last decades. The aquifer depletions due to water abstraction for irrigation and nutrient loads, exert major alterations of water quality, groundwater recharge and the natural renewal rate. All these factors diminish the aquifer value for the users and contribute to the degradation of groundwater as environment and habitat for fauna. This intensive use of groundwater resources in Chile brought to significant social and economic benefits, but their inadequate management resulted in negative environmental, legal and socioeconomic consequences. In this study, we aimed at providing a first assessment of environmental alterations of groundwater ecosystems from agricultural watersheds in northern Chile by specifically evaluating the effects of nitrogen and pesticide loads on groundwater communities and identifing the ecosystem service alterations due to agricultural activities. The study has been performed in a glacial aquifer from Coquimbo region; 250 km north of Santiago de Chile, the floodplain of which is dominated by agriculture (fruits tress, vineyards). Due to low regional precipitations (100-240 mm/year) the aquifer is primarily recharged by snowmelt from the Andean chain and surface runoff. The relative groundwater levels, groundwater temperature, chemical analysis of nitrogen and total phosphorus and pesticide concentrations were examined, along with the evaluation of crustacean biodiversity and spatial distribution pattern. Stygofauna taxonomic richness and the presence of stygobites have been related more to groundwater level stability than to chemical water parameters indicating that over-exploitation has a negative impact on habitat suitability for groundwater invertebrates. Groundwater biota assessment is essential in understanding the impact produced by agriculture activities on groundwater as a resource and as ecosystem, a nexus that becomes more and more widely recognized. The rationale and the preliminary results of this study are summarized in the Suppl. material 1.

scholarly journals Analysis of Groundwater Level Variations Caused by the Changes in Groundwater Withdrawals Using Long Short-Term Memory Network

Hydrology ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 64 ◽  
Author(s):  
Mun-Ju Shin ◽  
Soo-Hyoung Moon ◽  
Kyung Goo Kang ◽  
Duk-Chul Moon ◽  
Hyuk-Joon Koh
Keyword(s):  
Groundwater Level ◽  
Short Term Memory ◽  
Groundwater Resources ◽  
Prediction Performance ◽  
Groundwater Withdrawal ◽  
Short Term ◽  
Maximum Increase ◽  
Term Memory ◽  
Long Short Term Memory ◽  
The Impact

To properly manage the groundwater resources, it is necessary to analyze the impact of groundwater withdrawal on the groundwater level. In this study, a Long Short-Term Memory (LSTM) network was used to evaluate the groundwater level prediction performance and analyze the impact of the change in the amount of groundwater withdrawal from the pumping wells on the change in the groundwater level in the nearby monitoring wells located in Jeju Island, Korea. The Nash–Sutcliffe efficiency between the observed and simulated groundwater level was over 0.97. Therefore, the groundwater prediction performance of LSTM was remarkably high. If the groundwater level is simulated on the assumption that the future withdrawal amount is reduced by 1/3 of the current groundwater withdrawal, the range of the maximum rise of the groundwater level would be 0.06–0.13 m compared to the current condition. In addition, assuming that no groundwater is taken, the range of the maximum increase in the groundwater level would be 0.11–0.38 m more than the current condition. Therefore, the effect of groundwater withdrawal on the groundwater level in this area was exceedingly small. The method and results can be used to develop new groundwater withdrawal sources for the redistribution of groundwater withdrawals.

scholarly journals Contribution to the hydrogeology of Six Hills sandstone aquifer in East El-Oweinat area, south Western desert, Egypt

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Saad Younes Ghoubachi
Keyword(s):  
Cross Sections ◽  
Land Reclamation ◽  
Groundwater Resources ◽  
Western Desert ◽  
Pumping Rate ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Sandstone Aquifer ◽  
Domestic Livestock ◽  
The Impact

El-Oweinat area is located in southwestern Egypt and is considered to be one of the new land reclamation projects in the Western Desert. The Nubian Sandstone aquifer has high potentiality and good groundwater quality. The results of geologic and hydrogeologic studies reveal that the Six Hills sandstone aquifer represents the sole groundwater resource used for all purposes (agriculture, drinking, domestic, livestock and poultry) in East El-Oweinat area. The Six Hills sandstone aquifer overlies directly the Precambrian basement rocks. The concerned aquifer exists under unconfined conditions as it is exposed on the surface. The hydrogeological cross sections show that the fully saturated thickness of the Six Hills sandstone aquifer ranges between 150.2 m and 651 m and increases towards the west. The groundwater generally flows towards the northeast direction with an average hydraulic gradient of 0.6 ‰. The calculated groundwater volume of the Six Hills sandstone aquifer in East El-Oweinat area (4,340 km2) reaches 350 bcm of fresh water. The comparison of the depth to water in the same monitoring wells during 14 years (2003 and 2016) reveals that the head decline rate in groundwater depths were ranging between 5 cm/year and 80 cm/year. The pumping rate increased from 600,000 m3/day in year 2003 to 3,600,000 m3/day in 2016. The average transmissivity attains 2,060 m2/day reflecting the high potential of the Six Hills sandstone aquifer in East El-Oweinat area. The groundwater flow model (MODFLOW) has been used to investigate the impact of groundwater withdrawal on groundwater levels for sustainable groundwater management. Four scenarios were applied to predict the probable head changes in the Six Hills sandstone aquifer and their impact on the availability of groundwater. The fourth scenario is recommended in order to sustain the groundwater resources in the study area and keep the drawdown rates in the range of 0.66 m/year through reducing the present discharging rates (10,000 m3/day/well) by about 40%.

scholarly journals Assessing the suitability of extreme learning machines (ELM) for groundwater level prediction

2017 ◽  
Vol 32 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Basant Yadav ◽  
Sudheer Ch ◽  
Shashi Mathur ◽  
Jan Adamowski
Keyword(s):  
Soft Computing ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Support Vector ◽  
Complex Nature ◽  
Data Set ◽  
Groundwater Levels ◽  
Soft Computing Techniques ◽  
Learning Machine ◽  
The Comparative Study

Abstract Fluctuation of groundwater levels around the world is an important theme in hydrological research. Rising water demand, faulty irrigation practices, mismanagement of soil and uncontrolled exploitation of aquifers are some of the reasons why groundwater levels are fluctuating. In order to effectively manage groundwater resources, it is important to have accurate readings and forecasts of groundwater levels. Due to the uncertain and complex nature of groundwater systems, the development of soft computing techniques (data-driven models) in the field of hydrology has significant potential. This study employs two soft computing techniques, namely, extreme learning machine (ELM) and support vector machine (SVM) to forecast groundwater levels at two observation wells located in Canada. A monthly data set of eight years from 2006 to 2014 consisting of both hydrological and meteorological parameters (rainfall, temperature, evapotranspiration and groundwater level) was used for the comparative study of the models. These variables were used in various combinations for univariate and multivariate analysis of the models. The study demonstrates that the proposed ELM model has better forecasting ability compared to the SVM model for monthly groundwater level forecasting.

Sign in / Sign up

Export Citation Format

Share Document