Hydrogeochemical and Isotopic (δ2H-δ18O) Investigations of Hydrologic Dynamics of the Southern Urucuia Aquifer System, Brazil

The integration of hydrogeochemical and isotopic data (δ2H-δ18O) allowed the reconstruction of the hydrological dynamics of Southern Urucuia Aquifer System. This system is a combination of aquifers that are responsible for the perennity of the rivers during the rainy recession. In this study, water samples were collected from three sources: rainfall, rivers and pumping wells. The hydrogeochemical data lead to subdivide the aquifers in three main types: regional unconfined, confined, and unconfined with deep water level. The unconfined aquifer with deep water level originates from an groundwater flow deflection in the westernmost portion of the study area. The occurrence of silicified and fractured levels divide the aquifer types and represents a mixing and interfaced zone, allowing a leakage between aquifers and a great variability of hydrogeochemical facies. The hydrogeochemical evolution occurs by local, intermediate and regional flow systems. The buildup of dissolved solids is the major controlling mechanism of the groundwater composition represented by the systematic changes of anion species from HCO3 to SO4 to Cl, and cationic exchange between Ca and Na. The discharge occurs through the baseflow of rivers, which have hybrid composition between regional unconfined and confined aquifer from Na-Ca-Cl to Na-Cl. The analysis of stable isotopes shows that the surface water and groundwater are located in the same range of values, which indicates a connection between the reservoirs. During the rainy season, the regional unconfined isotopic composition becomes similar to the precipitation isotopic composition, with the main recharge occurring mostly by direct infiltration of rainwater. However, there is a modification of this composition in the dry season due to strong isotopic enrichment caused by the evaporation process. The seasonal variation in the isotopic composition represents a continuous cycle. In other words, as the rainy season approaches, the atmospheric air column becomes increasingly saturated with water vapor, what results in a considerably diminishment of evaporation.

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Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

Academic Journal of Nawroz University ◽

10.25007/ajnu.v7n4a289 ◽

2018 ◽

Vol 7 (4) ◽

pp. 191

Author(s):

Sherwan Sh. Qurtas

Keyword(s):

Unconfined Aquifer ◽

Middle Part ◽

Water Levels ◽

Specific Yield ◽

Aquifer System ◽

Groundwater Levels ◽

Monitoring Wells ◽

Water Table Fluctuation Method ◽

Recharge Estimation ◽

Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

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Estimated water-level declines in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico, predevelopment to 2002

10.3133/wri024233 ◽

2002 ◽

Cited By ~ 2

Keyword(s):

New Mexico ◽

Water Level ◽

Santa Fe ◽

Aquifer System

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Louisiana ground-water map no. 14 : potentiometric surface, January 2001, and water-level changes, June 2000 to January 2001, of the Chicot Aquifer system in southwestern Louisiana

10.3133/wri024088 ◽

2002 ◽

Keyword(s):

Ground Water ◽

Water Level ◽

Aquifer System ◽

Water Level Changes ◽

Potentiometric Surface

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Louisiana ground-water map no. 7: Potentiometric surface, 1991, and water-level changes, 1969-91, of the Chicot equivalent aquifer system in southeastern Louisiana

10.3133/wri944202 ◽

1995 ◽

Keyword(s):

Ground Water ◽

Water Level ◽

Aquifer System ◽

Water Level Changes ◽

Potentiometric Surface ◽

Southeastern Louisiana

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The Distribution of Volatile Organics in a Leachate Plume, Gloucester, Ontario

Water Quality Research Journal ◽

10.2166/wqrj.1987.004 ◽

1987 ◽

Vol 22 (1) ◽

pp. 49-64 ◽

Cited By ~ 1

Author(s):

J.F. Devlin ◽

W.A. Gorman

Keyword(s):

Organic Contaminants ◽

Source Area ◽

Unconfined Aquifer ◽

High Concentration ◽

Organic Contamination ◽

Aquifer System ◽

Aquifer Systems ◽

Volatile Organic ◽

Volatile Organic Contaminants ◽

Aquifer Sediments

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.

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HYDROCHEMICAL ASSESSMENT OF UNCONFINED AQUIFER SYSTEM IN BAYAT MELANGE COMPLEX, KLATEN, INDONESIA

International Journal of Geomate ◽

10.21660/2017.39.17336 ◽

2017 ◽

Vol 13 (39) ◽

Keyword(s):

Unconfined Aquifer ◽

Aquifer System

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The implication of tectonic structures compartment in the hydrochemical distribution in the Merapi unconfined aquifer system

International Journal of Hydrology Science and Technology ◽

10.1504/ijhst.2021.116665 ◽

2021 ◽

Vol 12 (2) ◽

pp. 116

Author(s):

Herry Riswandi ◽

Emi Sukiyah ◽

Boy Yoseph C.S.S. Syah Alam ◽

Mohamad Sapari Dwi Hadian

Keyword(s):

Unconfined Aquifer ◽

Tectonic Structures ◽

Aquifer System

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Temporal partitioning of reproductive activity in a neotropical anuran community

Journal of Tropical Ecology ◽

10.1017/s0266467403001172 ◽

2004 ◽

Vol 20 (3) ◽

pp. 271-280 ◽

Cited By ~ 75

Author(s):

Brigitte Gottsberger ◽

Edith Gruber

Keyword(s):

Water Level ◽

Rainy Season ◽

Abiotic Factors ◽

Reproductive Mode ◽

Reproductive Activity ◽

Active Species ◽

South American ◽

Wet Season ◽

Breeding Sites ◽

Calling Activity

The phenology of calling activity and reproduction of a neotropical anuran community in French Guiana was studied during one rainy season. We investigated the correlation between calling activity, rainfall, temperature and water level in two ponds and recorded the occurrence of tadpoles of pond-breeding species. The study site contained 31 calling frog species, which were divided into groups according to reproductive mode. Increased rainfall was associated with increased reproductive activity in all groups, but temporal patterns in calling activity varied significantly between groups. Species with aquatic oviposition exhibited sporadic acoustic activity, aggregating into explosive breeding events following heavy rainfall. Species laying eggs in foam nests had the peak of calling activity at the start of the rainy season. Taxa with embryonic development on vegetation called mainly from middle to late wet season, being the only group which showed a significant correlation of calling with increasing water level. Dendrobatids with terrestrial oviposition and subsequent parental tadpole transportation were continuously active. Species with direct development or with non-feeding larvae were mainly active at the beginning of the rainy season. It is concluded that phenologies of calling activity in South American tropical anuran species are strongly influenced by abiotic factors like rainfall and availability of breeding sites. The temporal limitation of the rainy season forces species to adjust calling and reproductive activity according to their reproductive modes.

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