scholarly journals Usage of environmental isotopes in characterizing groundwater recharge sources

2012 ◽  
Author(s):  
H. Bhandary ◽  
K. Al-Fahad ◽  
M. Al-Senafy ◽  
A. Al-Khalid
Keyword(s):  
Groundwater Recharge ◽  
Environmental Isotopes ◽  
Recharge Sources

scholarly journals Geochemical and isotopic evidence of groundwater salinization processes in the Essaouira region, north-west coast, Morocco

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Otman EL Mountassir ◽  
Mohammed Bahir ◽  
Driss Ouazar ◽  
Abdelghani Chehbouni ◽  
Paula M. Carreira
Keyword(s):  
Groundwater Recharge ◽  
West Coast ◽  
Exchange Process ◽  
Environmental Isotopes ◽  
Annual Rainfall ◽  
Groundwater Salinization ◽  
Rock Interaction ◽  
North West ◽  
The North ◽  
Water Rock Interaction

AbstractThe city of Essaouira is located along the north-west coast of Morocco, where groundwater is the main source of drinking, domestic and agricultural water. In recent decades, the salinity of groundwater has increased, which is why geochemical techniques and environmental isotopes have been used to determine the main sources of groundwater recharge and salinization. The hydrochemical study shows that for the years 1995, 2007, 2016 and 2019, the chemical composition of groundwater in the study area consists of HCO3–Ca–Mg, Cl–Ca–Mg, SO4–Ca and Cl–Na chemical facies. The results show that from 1995 to 2019, electrical conductivity increased and that could be explained by a decrease in annual rainfall in relation to climate change and water–rock interaction processes. Geochemical and environmental isotope data show that the main geochemical mechanisms controlling the hydrochemical evolution of groundwater in the Cenomanian–Turonian aquifer are the water–rock interaction and the cation exchange process. The diagram of δ2H = 8 * δ18O + 10 shows that the isotopic contents are close or above to the Global Meteoric Water Line, which suggests that the aquifer is recharged by precipitation of Atlantic origin. In conclusion, groundwater withdrawal should be well controlled to prevent groundwater salinization and further intrusion of seawater due to the lack of annual groundwater recharge in the Essaouira region.

Groundwater age from multi-level bores: What it can tell about the aquifers

2021 ◽  
Author(s):  
Uwe Morgenstern ◽  
Zara Rawlinson
Keyword(s):  
Groundwater Flow ◽  
Groundwater Recharge ◽  
Sea Level ◽  
Preferential Flow ◽  
Groundwater Age ◽  
Geological Processes ◽  
Recharge Sources ◽  
Transient Electromagnetic ◽  
Geophysical Surveys ◽  
Multi Level

<p>Geologic data to provide information on the functioning of aquifers is often scars. For the aquifers underlying the Heretaunga Plains, Hawkes Bay, one of New Zealand’s most important groundwater systems, we used groundwater age (tritium, SF6, 14C) to inform the geologic model and to provide information on groundwater flow through alternating strata of permeable river gravel beds and fine impermeable beds that form an interconnected unconfined–confined aquifer system with complex groundwater flow processes.</p><p>The aquifers are a result of geological processes responding to climate change cycles from cold glacial when sea level was more than 100m below present sea level, to warm interglacial periods with sea level similar to present day. Glacial climate strata are river gravel, sand and silt deposits and include the artesian aquifers. The interglacial strata form the aquicludes and are marine sand, silt, and clay deposits with interbedded estuarine, swamp and coastal fluvial silt, clay, peat and gravel deposits.</p><p>We have re-visited tracer data sampled during the drilling of multi-level observation well in the early 1990s, and collected new samples from these multi-level bores in order to understand in 3D the groundwater recharge sources, groundwater recharge and flow rates, connection to the rivers, and potential groundwater discharge out to sea. Consistently young water (c. 25 years) at depth greater than 100m indicates preferential flow paths, likely related to paleo-river channels. The flow pattern obtained from the water tracer data improves the geologic information from the drill-holes, and fits with information from recent airborne transient electromagnetic (SkyTEM) geophysical surveys.</p>

scholarly journals Application of a Self-Organizing Map of Isotopic and Chemical Data for the Identification of Groundwater Recharge Sources in Nasunogahara Alluvial Fan, Japan

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 278 ◽  
Author(s):  
Takeo Tsuchihara ◽  
Katsushi Shirahata ◽  
Satoshi Ishida ◽  
Shuhei Yoshimoto
Keyword(s):  
Groundwater Recharge ◽  
Groundwater Resources ◽  
Paddy Rice ◽  
Alluvial Fan ◽  
Rice Fields ◽  
Isotopic Ratios ◽  
Self Organizing Map ◽  
Recharge Sources ◽  
Different Origins ◽  
Self Organizing

Paddy rice fields on an alluvial fan not only use groundwater for irrigation but also play an important role as groundwater recharge sources. In this study, we investigated the spatial distribution of isotopic and hydrochemical compositions of groundwater in the Nasunogahara alluvial fan in Japan and applied a self-organizing map (SOM) to characterize the groundwater. The SOM assisted with the hydrochemical and isotopic interpretation of the groundwater in the fan, and clearly classified the groundwater into four groups reflecting the different origins. Two groundwater groups with lower isotopic ratios of water than the mean precipitation values in the fan were influenced by the infiltration of river water flowing from higher areas in the catchments and were differentiated from each other by their Na+ and Cl− concentrations. A groundwater group with higher isotopic ratios was influenced by the infiltration of paddy irrigation water that had experienced evaporative isotopic enrichment. Groundwater in the fourth group, which was distributed in the upstream area of the fan where dairy farms dominated, showed little influence of recharge waters from paddy rice fields. The findings of this study will contribute to proper management of the groundwater resources in the fan.

scholarly journals Non-Negligible Lag of Groundwater Infiltration Recharge: A Case in Mu Us Sandy Land, China

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 561 ◽  
Author(s):  
Ze-Yuan Yang ◽  
Kai Wang ◽  
Yue Yuan ◽  
Jinting Huang ◽  
Zhi-Jun Chen ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Heavy Rain ◽  
Observation Data ◽  
Sandy Land ◽  
Mu Us Sandy Land ◽  
Recharge Sources ◽  
Matrix Flow ◽  
Lag Times ◽  
Rain Events ◽  
Storm Rainfall

Groundwater is often the main source of available water, and precipitation is one of the main recharge sources of groundwater in arid and semi-arid regions. This paper studies a fixed dune in Mu Us Sandy Land in China, establishes a numerical model, acquires hydraulic parameters and heat parameters of the vadose zone, and calculates the recharge coefficient based on field observation data and numerical modelling. These measurement results show that the response depths of storm rain are more than 90 cm, while those of small rain events are less than 10 cm. The numerical results show that infiltration depths are 10 cm for small rain and more than 90 cm for middle rain respectively. The lag time of the water content at 90 cm below the surface was 25 h following a middle rain, 18–19 h following a heavy rain, and 16–18 h following a storm rainfall. Groundwater recharge lag times (matrix flow) varied from 11 h to 48 h. Excluded precipitation for groundwater recharge was 11.25–11.75 mm in 1 h when groundwater depth was 120 cm and 15–15.5 mm when 140 cm, showing significant influence in groundwater resource evaluation.

Distinct groundwater recharge sources and geochemical evolution of two adjacent sub-basins in the lower Shule River Basin, northwest China

2016 ◽  
Vol 24 (8) ◽  
pp. 1967-1979 ◽  
Author(s):  
Liheng Wang ◽  
Yanhui Dong ◽  
Yueqing Xie ◽  
Fan Song ◽  
Yaqiang Wei ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
River Basin ◽  
Northwest China ◽  
Geochemical Evolution ◽  
Recharge Sources
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