scholarly journals Hydrochemical, Isotopic, and Geophysical Studies Applied to the Evaluation of Groundwater Salinization Processes in Quaternary Beach Ridges in a Semiarid Coastal Area of Northern Patagonia, Argentina

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3509
Author(s):  
Eleonora Carol ◽  
Santiago Perdomo ◽  
María del Pilar Álvarez ◽  
Carolina Tanjal ◽  
Pablo Bouza

Quaternary sea level fluctuations have led to the development of beach ridges on many South Atlantic coasts. The objective of this paper was to asses from lithological, hydrochemical, isotopic, and geophysical studies the salinization processes affecting groundwater stored in Pleistocene and Holocene beach ridges of the northern Patagonian coast. A hydrogeomorphological characterization of the area was performed using digital elevation models, the interpretation of satellite images, and field studies. Vertical electrical soundings were performed on transects running perpendicular to beach ridges in order to define variations in the freshwater-saltwater interface position. The salinity, chemistry, and stable isotopes of the groundwater were analyzed. The results demonstrated that the groundwater salinization of Pleistocene ridges responds to processes associated with the geological-geomorphological evolution of the area. The cementation of these surface sediments limits rainwater infiltration, which consequently prevents the development of freshwater lenses. This suggests that saline water is the result of ancient marine ingressions. Freshwater lenses develop in Holocene beach ridges; however, slight water salinization is detectable in the most populated areas as a result of intensive exploitation. The data provided are useful for freshwater resource prospection along the arid coast of Patagonia, where beach ridge deposits abound and populations experience serious drinking water supply problems.

2019 ◽  
Vol 98 ◽  
pp. 07034
Author(s):  
Qi Zhao ◽  
Xiaosi Su ◽  
Yiqun Gan

The deep confined water of coastal plain of northern Yangtze River suffers salinization. That results from overexploitation. This work aims to investigate the geochemical processes that lead to the salinization for this aquifer. Multiple environmental tracers of major ions, minor ions and isotopes (18O, 87Sr, 13C) were used to yield reasonable conclusions. The TDS of the aquifer ranges from 387 to 2600 mg/L. The aquifer is mainly composed of fresh water. Brackish water is distributed in the eastern and southern coastal areas, and is scattered in some inland areas. The water chemical type evolves from HCO3-Na to Cl-Na as TDS increases. Groundwater salinization is caused by mixing with saline water of marine origin. The aquifer is also affected by other hydrochemical processes. Silicate weathering and carbonate dissolution add Na+, K+, Ca2+, Mg2+ and HCO3- to groundwater. Sulfate reduction makes sulfate be deficient and HCO3- be enriched. Carbonate minerals equilibrium limits the increase in the concentrations of Ca2+, Mg2+ and HCO3-. Cation exchange reduces the concentration of Ca2++Mg2+ and increases the concentration of Na++K+. The aforementioned processes have a combined influence on the formation of fresh water with HCO3-Na type.


2017 ◽  
Vol 5 (3) ◽  
pp. 529-556 ◽  
Author(s):  
Kees Nooren ◽  
Wim Z. Hoek ◽  
Tim Winkels ◽  
Annika Huizinga ◽  
Hans Van der Plicht ◽  
...  

Abstract. The beach-ridge sequence of the Usumacinta–Grijalva delta borders a 300 km long section of the southern Gulf of Mexico coast. With around 500 beach ridges formed in the last 6500 years, the sequence is unsurpassed in the world in terms of numbers of individual ridges preserved, continuity of the record, and temporal resolution. We mapped and dated the most extensively accreted part of the sequence, linking six phases of accretion to river mouth reconfigurations and constraining their ages with 14C and OSL dating. The geomorphological and sedimentological reconstruction relied on lidar data, coring transects, GPR measurements, grain-size analyses, and chemical fingerprinting of volcanic glass and pumice encountered within the beach and dune deposits. We demonstrate that the beach-ridge complex was formed under ample long-term fluvial sediment supply and shorter-term wave- and aeolian-modulated sediment reworking. The abundance of fluvially supplied sand is explained by the presence of easily weatherable Los Chocoyos ignimbrites from the ca. 84 ka eruption of the Atitlán volcano (Guatemala) in the catchment of the Usumacinta River. Autocyclic processes seem responsible for the formation of ridge–swale couplets. Fluctuations in their periodicity (ranging from 6–19 years) are governed by progradation rate, and are therefore not indicative of sea level fluctuations or variability in storm activity. The fine sandy beach ridges are mainly swash built. Ridge elevation, however, is strongly influenced by aeolian accretion during the time the ridge is located next to the beach. Beach-ridge elevation is negatively correlated with progradation rate, which we relate to the variability in sediment supply to the coastal zone, reflecting decadal-scale precipitation changes within the river catchment. In the southern Mexican delta plain, the coastal beach ridges therefore appear to be excellent recorders of hinterland precipitation.


2005 ◽  
Vol 47 (2) ◽  
pp. 235-251 ◽  
Author(s):  
Nobuyuki OHASHI ◽  
Yoshinari HIROSHIRO ◽  
Atsushi TSUTSUMI ◽  
Kenji JINNO ◽  
Hiroshi NIIDA

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1780
Author(s):  
Elad Ben-Zur ◽  
Haim Gvirtzman ◽  
Eyal Shalev

Sea-tide effects on the fresh-saline water interface (FSI) in a stratified coastal aquifer are examined through laboratory experiments. The physical model, a two-dimensional rectangular flow tank, is filled with layered aquifers and aquitards. The aquifers serve as the main entrances/exits of water to/from the system through significant horizontal flows, creating unstable conditions of heavier saline water above lighter freshwater for short periods of time. Several processes create mixing; this instability results in haline convection, creating downward fingering, stable rising of horizontal saltwater front, and unstable upward fingerings of flushing freshwater. The time lag between the sea tide fluctuations and the emergence of adequate fresh- and saltwater is higher in a stratified system compared to a homogeneous system. Furthermore, longer tide cycles lead to the enlargement of the FSI’s toe horizontal movement range. The combination of tidal forcing with a layering aquifer structure leads to a wider FSI by creating a significant salt- and freshwater mixing inside each layer, vertical flows between the layers, and saltwater bodies at isolated areas. Haline convection within the FSI might be the reason for the wider fresh-saline interfaces that are found in field studies.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 838B-838
Author(s):  
J.P. Mitchell ◽  
D.M. May ◽  
C. Shennan

Field studies were conducted in 1992 and 1993 to assess the effects of irrigation with saline drainage water on processing-tomato fruit yields and quality constituents. Saline water (ECiw = 7 dS/m) was used for 66% of the seasonal irrigation requirements in 1992 and 82% in 1993. Yields of tomatoes irrigated with saline water were maintained relative to nonsaline irrigation in 1992, but were decreased by 33% in 1993. Juice Brix and Bostwick consistency were generally improved by irrigation with saline water. pH was unaffected by irrigation treatment, and titratable acidity, an estimate of citric acid content, was increased only in 1993. Calculated quantities for various marketable processed product yields reflect the dominant influence of fresh fruit yield that masked, to a large extent, whatever quality enhancements that may have derived from saline irrigation. The substantial tomato yield reduction that occurred in the second year of this study in plots irrigated with saline drainage water, the gradual surface accumulation of boron, as well as the significant salt buildup in lower portions of the crop root zone following drainage water irrigations demonstrate definitive limitations to the reuse approach and restrict options for the crops that can be grown in this system and the frequency of saline drainage reuse.


2021 ◽  
Author(s):  
Xianzhang Dang ◽  
Maosheng Gao ◽  
Zhang Wen ◽  
Guohua Hou ◽  
Daniel Ayejoto ◽  
...  

Abstract. Since the Quaternary Period, palaeo-seawater intrusions have been suggested to explain the observed saline groundwater that extends far inland in coastal zones. The Luanhe River Delta (northwest coast of Bohai Sea, China) is characterized by the distribution of saline, brine, brackish and fresh groundwater, from coastline to inland, with a wide range of total dissolved solids (TDS) between 0.38–125.9 g L−1. Meanwhile, previous studies have revealed that this area was significantly affected by Holocene marine transgression. In this study, we used hydrochemical, isotopic, and sedimentological methods to investigate groundwater salinization processes in the Luanhe River Delta and its links to the palaeo-environmental settings. The isotopic results (2H, 18O, 14C) show that deep confined groundwater was recharged during the Late Pleistocene cold period, shallow saline and brine groundwater was recharged during the warm Holocene period, and shallow brackish and fresh groundwater was mainly recharged by surface water. The results of hydro-geochemical modeling (PHREEQC) suggest that the salty sources of salinization are seawater and concentrated saline water (formed after evaporation of seawater). The 18O–Cl relationship diagram shows that saline and brine groundwater are formed by three end-member mixings (seawater, concentrated saline water and, fresh groundwater). In contrast, brackish groundwater is formed after the wash-out of saline groundwater by surface water. Using palaeo-environmental data from sediments, we found that palaeo-seawater intrusion during the Holocene marine transgression was the primary cause of groundwater salinization in the study region. Seawater was found to evaporate in the lagoon area during the progradation of the Luanhe River Delta; the resulting concentrated saline water infiltrated into the aquifer, eventually forming brine groundwater due to salinity accumulation. Surface water recharge and irrigation, on the other side, would gradually flush the delta plain's saline groundwater. This study provides a better understanding of saline groundwater evolution in other similar coastal zones.


2015 ◽  
Vol 48 (3) ◽  
pp. 5-12
Author(s):  
A. Sadeghi ◽  
Gh. Zehtabian ◽  
N. Moradi ◽  
A. Nohegar ◽  
H. Khosravi

Abstract Approximately 34% of soils in Asia are influenced by salts. With about 25 million ha of saline and alkaline lands, about 15% of the country, Iran has the most saline lands in Asia after China, India, and Pakistan due to its geographical position, climate and human activities. This research was done due to determine the effective factors on soil and water salinization. At the first the boundaries of this region were characterized using GIS, then landuses were determined for field survey and also soil sampling in nine landuses were done according to both factors of planting pattern and water resources in each unit. The soil profile was prepared and soil samples were obtained from surface depths of (0 - 50 cm) and some factors such as soil texture EC, SAR, pH, CaCO3, Cl and potassium were measured. For study of water resources some samples were obtained from 30 wells and also from upland runoff, then soil and water sample were analyzed and some parameters such as EC, SAR, Cl− and pH were measured. Finally, according to data base, geological map, topography map, landuse map, soil and water measured data and also field studies, soil and water salinization schedule and region status were investigated. The results showed that important factors influencing water salinization in Ghaleh Ghazi region (Iran) are geological formations located in aquifer recharge and climate condition. Important factors of soil salinization in region are irrigation with saline water, improper irrigation method, unsuitable planting method, climate condition and landform.


2018 ◽  
Vol 69 (4) ◽  
pp. 542 ◽  
Author(s):  
E. Carol ◽  
S. Richiano ◽  
C. Tanjal

A study of hydrological and lithological characteristics that allow the development of freshwater lenses in littoral ridges underneath clay sediments of the coastal plain was undertaken, considering as a case of study the freshwater lenses located in the coastal sector of Samborombón Bay (Argentina). Geological characteristics were studied at a regional scale, as well as detailed sedimentological and ichnological aspects. Thickness of the lens and the freshwater–saline water interface were determined by salinity measurements in exploration wells located at different depths. Results obtained suggest that the infiltration of rainwater into the littoral ridges causes the formation of freshwater lenses that deepen below the clayey layers of the coastal-plain deposits. The key to answering this question are the crustacean burrows, which regionally occur in the fine sediments of the coastal plain. The burrows create an interconnected system of galleries and tunnels filled with sandy-silt material that favours seepage. Because the alternation of coastal-plain deposits and littoral ridges is a frequent situation throughout the world, the data provided by the present work do not represent just a simple case study; on the contrary, they show that biological structures promote bigger freshwater lenses in coastland environments, thus increasing water reserves.


Sign in / Sign up

Export Citation Format

Share Document