portant factor for (i) capture zone modification, (ii) wa- ter table depletion and (iii) water balance changes of in- take in karsticaquifer areas. The anisotropy of hydraulic conductivity is not easy to assess by way of simple hy- draulic tests or laboratory investigation. In the case of field investigation, pumping tests with several obser- vation wells are necessary. Laboratory analysis pro- vides only local-scale data. Both methods in large flow systems are limited by efficiency and costs.
The dam is located in the tectonically folded belt of the Zagros Mountains within a canyon that is located in the southwestern flank of the Kuh-Sefid anticline which has a NW-SE trend. Most of the reservoir is situated on Cretaceous to Miocene limestone and marly limestone (Haghnejad et al., 2014). The geologi- cal formations around the dam site consist of carbonate layers of the Asmari formation (As) which can be divided into lower (As1), middle (As2) and upper (As3) units and marlstone and marly limestone of im- pervious Pabdeh formation (Pd) on upstream of dam site (see Figs.2 and 3). The lower unit (As1) com- prises limestone, porous limestone and some marly limestone with some marlstone, generally thick to very thickly bedded and highly karstic. The measured mean RQD (rock-quality designation) index (Deere, 1964) ranges between 55% and 83%. The middle unit (As2) is located downstream of the dam and comprises alternating limestone, dolomitic, marly limestone and marl. Karstification is limited and the RQD is between 53% and 84%. The upper part (As3) consists of alternating layers of limestone, marly limestone and marl with slight karstification and an RQD between 45% and 78%. These RQD- values indicate a fair to good quality rock in all three units (Koleini, 2012). As1 outcrops in the dam val- ley abutments are highlighted in the cliff around the site. The strike of the beddings is northwest to south- east, and southern limb slopes to the south with a dip of 70-80 degrees. The AS1 unit, with an apparent thickness of about 200 m in normal direction to the bedding, constitutes the foundation rock of the dam. The geology of the dam site is affected by many faults, 122 major joints and 4 discontinuities sets. The strongly dipping reverse Monj fault, with a length of 14 km, is located at a distance of about 500 m down- stream of the dam. The joint openings along the bedding at the ground surface range from 1 to 100 mm and decrease with increasing depth.
movement of water (and sediment and agricultural chemicals) in complex watersheds with varying soils, land use and management conditions over long periods of time. It includes surface run-off, return flow, percolation, crop growth, irrigation, groundwater flow, and reach routing among other features. Surface run-off is calculated by an improved SCS (Soil Conservation Service) Curve Number approach (Arnold et al., 1998). The percolation component consists of a linear storage with up to ten layers, with the flow rate governed by the hydraulic conductivity and the available water capacity of each layer. For lateral subsurface flow, a kinematic storage model is used. Percolation from the root zone recharges a shallow aquifer (Neitsch et al., 2005), which is also connected to stream flow. The model calculates evaporation from soil and transpiration from plants separately, as described by Ritchie (1972). The actual evaporation is a function of soil water content, plant type and soil depth. Transpiration is computed as a linear function of potential plant evapotranspiration and leaf area index. Canopy storage for each crop is also included. SWAT also contains a plant growth model, which is a simplified version of the plant growth approach of the EPIC model (Williams et al., 1983). It is based on accumulating heat units, harvest index for the partitioning of grain yield, the Monteith approach for potential biomass (Monteith, 1977) and water, nutrient and temperature stress concepts. Tillage systems and agricultural management can be specified for each crop.
coincided with lower discharge rates and therefore they concluded that SGD was not a significant source of DOC to the bay. This trend was found in other study locations (e.g. Maher et al., 2013). However, in this current study SGD had the highest DOC concentrations in the summer campaigns. During the winter campaigns, the DOC levels were lower and similar to oceanic values (Table 3.1; Figure 3.1). This pattern has also been reported previously: for example, groundwater was found to be a significant source of DOC and DIC to the Baltic Sea during summer and autumn (Szymczycha et al., 2014). Bacterial and chemical breakdown of organic matter within the aquifer or in surface streams may lead to a continuous production of DOC in summer due to higher temperatures (Cadée 1982). Significantly higher water fluxes coincided with the January 2015 sampling campaign (Chapter 2) and therefore corresponding DOC fluxes were higher during this period. During all other periods, SGD-borne DOC fluxes into the bay were similar. SGD was considered a significant source of DOC to the coastal region of Kinvara Bay at all sampling time points. DOC concentration at Parkmore Pier showed a negative trend with salinity during January 2015, which is consistent with the findings of Smith and Cave, (2012). At the other sampling time points, the DOC concentrations had high variability and DOC-salinity relationships could not be established. SGD- borne DIC was larger in both winter campaigns compared to samples taken in June 2015. The relatively low SGD DOC:N ratios of this study (2 – 5) were consistent with those found by Smith and Cave, (2012) previously. Smith and Cave, (2012) also showed that Kinvara Bay had lower C:N ratios observed during winter compared to summer in their study.
Abstract. Karstic aquifers are well known for their vulnera- bility to groundwater contamination. This is due to character- istics such as thin soils and point recharge in dolines, shafts, and swallow holes. In karstic areas, groundwater is often the only freshwater source. This is the case of the Apulia re- gion (south-eastern Italy), where a large and deep carbonate aquifer, affected by karstic and fracturing phenomena, is lo- cated. Several methods (GOD, DRASTIC, SINTACS, EPIK, PI, and COP) for the assessment of the intrinsic vulnerabil- ity (Iv) were selected and applied to an Apulian test site, for which a complete data set was set up. The intrinsic vulnera- bility maps, produced using a GIS approach, show vulnera- bility from low to very high. The maximum vulnerability is always due to karstic features. A comparison approach of the maps is proposed.
E. Nicolini et al. / Journal of Hydrology: Regional Studies 5 (2016) 114–130 115 Karst aquifers are important water resources that supply fresh water to about 25% of the world’s population ( Ford and Williams, 1989 ) and are found mainly in large sedimentary basins and mountain ridges although they also cover many uplifted reef islands. Both continental and island karstic aquifers have the same vertical structure: the epikarst, or “skin” of the karst ( Williams, 2008 ) is the weathered zone of enhanced porosity on, or near, the surface ( Jones et al., 2004 ). Water percolates down through the vadose zone which, in turn, recharges the saturated or phreatic zone. Large island karstic aquifers (e.g. Puerto Rico, Jamaica) are indistinguishable from tropical continental karstic aquifers as they have no freshwater/seawater mixing and therefore are not affected by sea-level change. In contrast, small carbonates islands affected by tectonic uplift and subsidence overprinted by glacio-eustasy display speciﬁc characteristics which inﬂuence the circulation of groundwaters.
The groundwater does not solely occurring in Maas- trichtian geological formation. Indeed, lower aquifer lay- ers are Campanian formations, particularly in Dias horst area. Similarly, in the eastern edge of the basin, the upper aquifer layers may be Paleocene ones . The aquifer is confined in the whole territory of Senegal, except in the Dias horst where it is unconfined and maintaining lateral hydraulic contact with Paleocene karsticaquifer. Its con- fining bed is made of marl or clay belonging to Paleo- cene. It is overlaid by a set of geological formations en- countering several aquifers, with a more or less limited extension. These minor aquifers are observed in the Pa- leocene (karstic limestone around Mbour), in the Eocene (Lutetian limestone near Louga and Kébémer), in the Oligo-Miocene (clayey sands in Kaffrine area, in the central-eastern Basin), in the Quaternary (coastal sands of the north-west and alluvium of major rivers).
First, Linc’s application does not demonstrate that the formation contains commercially producible minerals. During cross-examination at the hearing, Linc and DEQ testified that the mineral they are considering to be commercially producible is coal. However, at the depth and location, coal is not commercial producible. Instead, Linc proposes to turn coal into a syngas. Unlike aquifer exemptions granted for uranium mining – where uranium is the product that is extracted from the aquifer – here, the mineral in question is admitted to be non-producible. Linc will not be producing coal through its project.
Furthermore pumping test might provide additional information. A great variety of equations and procedures are known for pumping tests with observations wells. However, if as in the case of this study no observation wells are available the evaluation of such pumping test data is awkward. Analytical and numerical models may offer a viable approach. In this study the analytical model MLU was used for drawdown calculations and inverse modeling of transient well flow. MLU estimates selected aquifer parameters based on a best fit analytical solution to measured time-distance-drawdown data. The software includes an automatic curve-fitting algorithm computing optimized aquifer parameters and fitted drawdown re- sults .
The phrase Managed Aquifer Recharge (MAR) describes the deliberate refilling (and storage) of water into an aquifer for future retrieval or for habitat benefits. MAR is utilized to store and treat water in a suitable aquifer from an assortment of sources, including rivers, recycled water, desalinated seawater, rainwater or groundwater from other aquifers. Hence, there's a necessity for scientific designing in development of H2O below totally different hydrogeological things and to evolve effective management practices with involvement of community for higher ground water governance. India’s water security is roosted in a dubious position. Indeed even by moderate evaluations, 40% of individuals in India will not have drinking water by 2030. As per a United Nations office report, in any event 21 Indian urban areas are heading towards zero groundwater level by 2020. Tamil Nadu is experiencing the worst drought in a hundred and forty years. All districts of Tamil Nadu had been pronounced as dry regions in 2017. Chennai, specifically, confronted a water dearth, basically due to the bombed North
The hydrogeology of the Yucatan Penin- sula, in the Southeastern Mexico, is controlled by a karst system, where secondary porosity and high permeability promotes the formation of large caverns, dissolution cavities, sinkholes and channels conducting substantial quantities of water (Reddell 1981). Lakes can be formed when the superficial cavities in the limesto- ne are filled permanently by the water table. These aquatic systems are called dissolution lakes according to Hutchinson (1957), or coas- tal lakes (Cole 1979). The karstic lakes occur
It is a common practice to use the REV in modeling groundwater flow and transport in porous media. This type of simulation intentionally disregards the natural pore scale variability over an entire aquifer. While this technique may capture the general flow of groundwater, it may not be detailed enough to accurately describe microbial rates. I suggest that the groundwater flow greatly affects microbial kinetics, and that using the REV in biogeochemical models will inaccurately predict microbial activities in groundwater.
The aim of this work is to recreate the heterogeneity conditions of depositional systems of the CPQA sedimentary complex by means of stochastic simulations to both simulate and quantify the aquifer groundwater flow. The CPQA consists of geological units that are formed by heterogeneous assemblages from highly to lowly permeable lithofa- cies, which are generally characterized by large contrasts of hydraulic conductivity. The lithological and spatial he- terogeneity at the hydrofacies scale of the alluvial sediments that constitute the CPQA (clay, clay and sand, fine sand, coarse sand, sand and gravel, gravel), as well as other sedimentary deposits studied by several authors, significantly affects groundwater flow, transport and groundwater-surface interactions due to the high variability of the hydraulic conductivity values -. Thus, the uncertainty accompanying the qualitative-quantitative description of lithofacies tends to preclude the possibility for deterministic modeling of subsurface heterogeneity.
silty clay sediments belonging to the Pleistocenic Formation. The general geology of the area essentially reflects the influence of movements of rivers, in the Niger delta. In broad terms, the area may be considered Dry flat Country. (short and Stauble, 1967). The Niger Delta consists of three distinct Lithological Formation , the Akata formation , Agbada formation and the Benin formation. The Akata Formation consist of Marine shale . The Agbada formation consists of alternate Layers of Sand Stone and Shale. The Benin formation consists of sands, clay , Peat and some Granular materials. The Coastal Plain slopes gradually from an elevation of 240m to 15m above mean sea level and is largely caused by rain forest. The aquifer has a south west gradient towards the Delta and is thickened seawards in the same direction of ground water movement. The Study area is situated in the Coastal Plain region, quaternary in Age. The Zone is made of Coarse to Medium sand, with Silty and Clay Lenses. Within the Project area , groundwater is abstracted from the Benin formation , mainly in its upper section. (<300m).The aquifer at shallow depth(>10m) are unconfined while the deeper aquifers are confined and isolated from the ground surface and the natural recharge comes Northern high Coastal Plain..
Even though some deviations occur among the individual karst landscapes, the general simulations of the VarKarst-R model follow well the observations of mean annual recharge rates over Europe and the Mediterranean (Fig. 9). On the other hand, the widely used large-scale simulation models PCR-GLOBWB (Wada et al., 2010, 2014) and WaterGAP (Döll and Fiedler, 2008; Döll et al., 2003) generally under- estimate groundwater recharge (Table 6). The reason for this is the representation of karstic subsurface heterogene- ity within the VarKarst-R model, i.e. the inclusion of pref- erential flow paths and of subsurface heterogeneity. Based on the conceptual understanding of soil and epikarst stor- age behaviour (Fig. 1c) it allows (1) for more recharge dur- ing wet conditions because surface runoff is not generated, and (2) for more recharge during dry conditions because the thin soil compartments will always allow for some water to percolate downwards before it is consumed by evapotran- spiration. During wet conditions, both PCR-GLOBWB and WaterGAP will instead produce surface runoff that is subse- quently lost from groundwater recharge. During dry condi- tions, due to its non-variable soil storage capacity, the PCR- GLOBWB model will not produce any recharge when the soil water is below its minimum storage. Separating surface runoff and groundwater recharge by a constant factor, the WaterGAP model will produce recharge during dry condi- tions, but a constant fraction of effective precipitation will always become fast surface/subsurface runoff resulting in re- duced recharge volumes.
Monitoring of the western area, where the railway tun- nel heights are close to the aquifer level, has been possible thanks to several natural observation points and to some ad- hoc positioned piezometers. Preliminary monitoring high- lighted that the water circulation in this area features long- lasting but limited fluctuations, with homogeneous factors due to the presence of both karst and fissured network with more frequent and limited drains (Fig. 6). On the hydro- graph of the flood curves, the contribution of infiltration me- teoric waters is not visible because it is hidden by the mixing with supply waters or waters coming from a long distance. In this particular case, geochemical monitoring permitted to distinguish water contributions to the aquifer coming from the outside of the karst infiltration basin, induced by sub- river seepage of the Isonzo river, which flows in an alluvial plain bordering the limestone landforms located to the North (Doctor et al., 2000; Flora et al., 1990). The homogeneity of the data pertaining the water level in this area permits to extrapolate a maximum and a minimum level water table. In the region close to the water catchment areas of Brestovica’s water supply system (Slovenia), however, feeding contribu- tions and local discharge directions – important parameters for the aquifer protection – have not been defined yet. 7 piezometers have therefore been installed to perform con- tinuous chemical-physical monitoring of the waters and to complement the data that can be taken from the 4 natural ob- servation points.
Climate change projections of glacier runoff only account for the glacierized area (Fig. 9b). Accordingly, it cannot be directly compared to observed discharge in downstream rivers. A complete hydrological model to calculate basin runoff including all linkages with the karstic system is be- yond the scope of this paper. Nevertheless, the long-term projections until the end of the 21st century indicate that the glacier is expected to disappear almost completely by the end of the century (Fig. 10). If this is the case, the drainage of snow and ice melt through open channels in the glacier will not be possible anymore, making drainage of snowmelt to the northern surface runoff impossible. Accordingly, down- stream water resources will be affected by the loss of glacial meltwater runoff. Furthermore, it can be expected that, in the absence of flow channels in the glacier, meltwater will pri- marily infiltrate into the local karst and reappear at the nu- merous karst springs. The tracer experiments indicate that the karst system drains large parts of infiltrating water to the Loquesse spring near Lac Tseuzier. Accordingly, it can be as- sumed that future meltwater infiltrating into the karst system may be dominantly drained to the Loquesse spring.