scholarly journals An Assessment of Groundwater Recharge at A Regional Scale for Sustainable Resource Management: Province of Alicante (SE Spain)

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 862
Author(s):  
Miguel Fernández-Mejuto ◽  
José Miguel Andreu ◽  
Ernesto García-Sánchez ◽  
Rebeca Palencia

For decades, the Province of Alicante, located in the Southeast of Spain, has experienced important economic development associated with groundwater exploitation. The scarcity of superficial resources and irregular distribution in the time and space of rainfall, typical of the Mediterranean environment, together with the extensive limestone outcrops, have made groundwater a key resource for the area. However, insufficient knowledge about aquifers, especially the lack of precise recharge estimates, hinders regional water management. This study establishes updated recharge estimates and water budgets for the 200 aquifers found in Alicante, using readily usable methodologies and available data. These are soil water budget models, groundwater flow models, water table fluctuation methods, and spring flow analyses. The results show low mean annual values of recharge from precipitation (69 mm/year and a coefficient of 12%) and two main differentiated domains. The first one, in the northeast of the province, under more humid climatic conditions with larger carbonate aquifer systems, has higher recharge coefficients, ranging from 14% to 24%, and greater resources. For the rest of the province, where aquifers are smaller and annual averages of rainfall range between 250 and 400 mm, average recharge rates are low (9–12%).

2021 ◽  
Vol 80 (5) ◽  
Author(s):  
Stefan Scheidler ◽  
Peter Huggenberger ◽  
Horst Dresmann ◽  
Adrian Auckenthaler ◽  
Jannis Epting

AbstractIn regional scale aquifers in the Rhine Valley and Tabular Jura east of Basel (Switzerland), the groundwater circulation was investigated using regional-scale geological and hydraulic 3D models. The main aquifers in the area comprise the Quaternary aquifer of unconsolidated gravel deposits along the River Rhine and its tributaries, as well as the regional scale karst aquifer within the Upper Muschelkalk. Land subsidence, a process likely associated with salt solution mining, indicates further subordinate groundwater bearing segments and complex groundwater interactions along fault zones. In the aquifer systems we investigated, regional-scale groundwater circulation was simulated and visualized in relation to the geological settings. Lithostratigraphic units and fault structures were parameterized and analyzed, including the sensitivity of hydraulic properties and boundaries. Scenario calculations were used to investigate the sensitivity that the aquifer systems had to hydraulic parameter changes during Quaternary aggradation and degradation in the main valley. Those calculations were also done for base-level changes in the Rivers Rhine and Birs. For this purpose, this study considered probable historic base-levels before river regulation occurred, and before river dams and power plants were constructed. We also focused on scenarios considering increased groundwater recharge rates, e.g. due to exceptional long-lasting precipitation, or heavy rainfall events in the catchment area. Our results indicate that increased groundwater recharge rates in the catchment areas during such events (or periods) are associated with orders of magnitude increases of regional inflow into the Upper Muschelkalk karst aquifer. Furthermore, the groundwater fluctuations and groundwater saturated regions within the karst aquifer shift to places where high densities of sinkholes are documented. When the surface water base-levels adapt to probable historic levels, it leads to increased hydraulic gradients (i.e. local lowering of the groundwater level by up to 7 m). Those increased gradients are associated with increased groundwater flow within some aquifer regions that are particularly prone to karst development.


2021 ◽  
Author(s):  
Anthony Lamur ◽  
Silvio De Angelis ◽  
Rayco Marrero ◽  
Yan Lavallée ◽  
Pablo J. Gonzalez

<p>Surface water resources on volcanic islands with moderate rainfall and relatively high permeability are usually scarce or non-existent. As such, life and local economies of these islands mostly relies on groundwater exploitation. It is therefore important to characterise the sustainability of volcanic aquifer systems. In short, an aquifer is deemed in equilibrium when the recharge rate equals or exceeds the exploitation rate. The Izaña area in Tenerife Island (Canary Islands, Spain) has been exploited since the 1900s via a series of ~30 horizontal drilling or water galleries coming from both flanks of the NE-Ridge. Since exploitation began, the water table has dropped continuously, in some area even more than 200 m. Since the 2000s, aquifer dynamics (compaction) have been observed using InSAR indicating a subsidence rate of up to 2 cm per year.</p><p>Here, we investigate a suite of rock samples collected. The samples were collected at several water galleries aiming to be representative of the aquifer materials from the Izaña area. We first characterise the basic physical properties of each samples (porosity, permeability, solid density) before quantifying the elastic parameters (Young’s modulus, Poisson ratio) and uniaxial strength of the lithologies collected. We also measure V<sub>p</sub> under dry and wet conditions (i.e. different saturation levels) to assess whether water saturation can alter the velocity of P-waves passing through those rocks.</p><p>Preliminary results show that connected porosities range from 0.16 to 45%, conferring a wide range of mechanical response to increasing effective pressure, with strength ranging from 18 – 315 MPa and Young’s moduli ranging from 3 – 57 GPa. In a similar fashion, results for V<sub>p</sub> measurements also exhibit a range of values (~1.5 – 4.5 km/s). These data show that materials present in the aquifer are extremely varied, suggesting that both fluid flow and observed deformation are likely to be controlled by the weakest, most porous lithologies.</p><p>These results will further be integrated with the lithostratigraphic record of the aquifer in order to model the mechanical response of the aquifer to changes in effective pressures, and specifically pore pressure reduction with water extraction. Additionally, chemical and textural analysis will provide insights on the evolution of the porous network at different alteration levels, here serving as a proxy for time at saturation in the aquifer. Finally, we aim to compare the experimental results from laboratory measurements to those of hydro-geophysical measurements that will be collected in the field starting in mid-2021.</p>


2020 ◽  
pp. SP494-2019-61
Author(s):  
Stuart G. Archer ◽  
Tom McKie ◽  
Steven D. Andrews ◽  
Anne D. Wilkins ◽  
Matt Hutchison ◽  
...  

AbstractThe Triassic of the Central North Sea is a continental succession that contains prolific hydrocarbon-bearing fluvial sandstone reservoirs stratigraphically partitioned by mudstones. Within the Skagerrak Formation of the UK sector, hydrocarbon accumulations in the Judy, Joanne and Josephine Sandstone members are top sealed by the Julius, Jonathan and Joshua Mudstone members, respectively. However, UK and Norwegian stratigraphic correlations have been problematical for decades, largely due to biostratigraphic challenges but also due to the non-uniqueness of the lithotypes and because the cross-border stratigraphic nomenclature differs and has yet to be rationalized. This study focuses on mudstones rather than sandstones to unify cross-border correlation efforts at a regional scale. The mudstone members have been characterized by integrating sedimentological, petrophysical and geophysical data. The facies are indicative of playa lakes that frequently desiccated and preserved minor anhydrite. These conditions alternated with periods of marshy, palustrine conditions favourable for the formation of dolostones. Regional correlations have detected lateral facies changes in the mudstones which are important for their seismically mappable extents, resulting palaeogeographies and, ultimately, their competency as intraformational top seals. Significant diachroneity is associated with the lithological transitions at sandstone–mudstone member boundaries and although lithostratigraphic surfaces can be used as timelines over short distances (e.g. within a field), they should not be assumed to represent timelines over longer correlation lengths. Palaeoclimatic trends are interpreted and compared to those of adjacent regions to test the extent and impact of climate change as a predictive allogenic forcing factor on sedimentation. Mudstone member deposition occurred as a result of the retreat of large-scale terminal fluvial systems during a return to more arid ‘background’ climatic conditions. The cause of the member-scale climatic cyclicity observed within the Skagerrak Formation may be related to volcanic activity in large igneous provinces which triggered the episodic progradation of fluvial systems.


2019 ◽  
Vol 59 (2) ◽  
pp. 940
Author(s):  
Mark Reilly ◽  
Suzanne Hurter ◽  
Zsolt Hamerli ◽  
Claudio L. de Andrade Vieira Filho ◽  
Andrew LaCroix ◽  
...  

The stratigraphy of the Surat Basin, Queensland, has historically been sub-divided by formation and unit nomenclature with a few attempts by other authors to apply sequence stratigraphy to existing formation boundaries. At a local- to field-scale, lithostratigraphy may be able to represent stratigraphy well, but at regional-scale, lithostratigraphic units are likely to be diachronous. To date, this lithology-driven framework does not accurately reflect time relationships in the sub-surface. An entirely new integrated methodological approach, involving well tied seismic data and sequence stratigraphic well-to-well correlations compared with published zircon age dates, has been applied to hundreds of deep wells and shallower coal seam gas wells. This method sub-divides the Surat Basin stratigraphy into defendable 2nd order to 3rd order sequence stratigraphic cycles and has required the use of an alpha-numeric sequence stratigraphic nomenclature to adequately and systematically label potential time equivalent surfaces basin-wide. Correlation of wells is the first step in building models of aquifers and coal seam gas fields for numerical simulation of fluid flow, which is necessary for responsible resource management. Lithostratigraphic correlations will overestimate the extent and hydraulic connectedness of the strata of interest. The result may be fluid flow models that do not represent a realistic pressure footprint of the flow. The present sequence stratigraphic method more accurately reflects the disconnectedness of sub-surface coals and sandstones (aquifers) on a field-to-field scale, adjacent field-scale, and basin-wide scale. It forms the basis for improved and more representative modelling of the sub-surface.


Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 203 ◽  
Author(s):  
W. Timms ◽  
R. I. Acworth ◽  
D. Berhane

Dynamic shallow (<5 m) groundwater levels are an important indicator of water and salt fluxes in smectite-dominated clay on the Liverpool Plains in north-eastern New South Wales. Previous hydrogeological assessments of shallow groundwater related salinity risk have focused on regional scale distribution and interaction with rising pressure levels in confined aquifer systems. In this study, groundwater levels over a 7-year period for the saline Yarramanbah subcatchment are presented, along with data from 60 new and existing shallow piezometers and precise elevation surveying and intensive automated monitoring at selected sites. The shallow groundwater system is shown to respond to recharge; however, over the medium-term it is in hydrologic balance, with no evidence of increased water storage. A proportion of recharge is lost by discharge into deeply incised surface channels. Groundwater salinity in the banks of Warrah Creek indicate that flushing of salts from clay is related to increased flux of fresh water. Concern exists that there may be increased salt export from the catchment. If this is in fact occurring while the plains are in hydrologic equilibrium, then increased salt fluxes must be related to factors other than rising groundwater levels.


2020 ◽  
Author(s):  
Natasha Roy ◽  
Bianca Fréchette ◽  
Anne de Vernal

&lt;p&gt;The rapid ongoing warming recorded across northern regions is unprecedented. This warming is however not uniform across the territory and large regional discrepancies exist. It is therefore relevant to document the variations of climate in the past in both time and space in order to understand the regional climate dynamics. However, in Labrador, instrumental and historical data are rare and only cover a short period of time. Our knowledge of the natural evolution of the climate is therefore limited, which hampers our capacity to evaluate the natural modes of variability and simulate changes at regional scales. From this viewpoint, quantitative climate reconstructions from pollen assemblages are useful because they allow the development of time series covering long periods of time. Here, we report on pollen data from peat and lake sediments collected in the area of Okak, Nain and Dog Island along the Labrador coast. &amp;#160;These data are used for climate reconstruction over the last millennia, thus allowing to document natural climate variability at regional scale. The climate parameters we reconstruct by the means of the modern analogue technique include the summer temperature, sunshine and precipitation. The results provide new insights about the climate of Labrador at local to regional scale, illustrating notably the importance of the Labrador Current on climatic conditions at nearshore locations. In fact, our climate reconstructions demonstrate a disparity with the regional climate curve which may testify of the east-west climatic gradient between islands and the land.&lt;/p&gt;


2016 ◽  
Vol 64 (8) ◽  
pp. 609 ◽  
Author(s):  
Ian R. K. Sluiter ◽  
David T. Blackburn ◽  
Guy R. Holdgate

The Late Oligocene to Mid-Miocene (25–13 million years ago) brown coals of the Gippsland Basin in southern Victoria, Australia, were deposited in peat mega-swamps, unlike any in the world at the present day. The swamps preserve a rich botanical suite of macro- and microfossils, many of which can be identified with plant genera and families present today in Australia, New Caledonia, New Zealand and New Guinea. The peat-forming environments also preserve evidence of past burning in the form of micro-charcoal as well as macro-charcoal, the latter being evident as regional lenses or layers of fusinite, generally in coals of the darkest colour termed dark lithotypes. The presence of micro-charcoal in dark and some other lighter lithotypes indicated that fires also burnt locally, although they may have been extinguished before regional-scale burning occurred. It is also feasible that some peat mega-swamp plant communities dominated by rainforest angiosperm plants may have been fire excluders and prevented widespread fires from developing. Pollen and macrofossil evidence is presented of a distinctive southern conifer and angiosperm flora with an open canopy, primarily associated with the darkest coals that formed in the wettest parts of the peat-forming environment. Elsewhere, swamp forests with a large rainforest component grew on swamps raised appreciably above the regional groundwater table in a structural context akin to the ombrogenous peats of tropical coastal Sumatra and Sarawak. These vegetation types were not fire prone, but may have occasionally burnt at a local scale or at forest margins. Evidence is presented for the existence of seasonal climatic conditions that would appear to have facilitated a drying-out of the peat swamps in the warmest months of the year. A mesothermal climate was invoked where mean annual precipitation was at least 1500 mm, and possibly as much as 2000 mm, and mean annual temperatures were ~19°C.


2000 ◽  
Vol 31 ◽  
pp. 281-286 ◽  
Author(s):  
Regula Frauenfelder ◽  
Andreas Kääb

AbstractClimate and its long-term variability govern ground thermal conditions, and for this reason represent one of the most important impacts on creeping mountain permafrost. The decoding and better understanding of the present-day morphology and distribution of rock glaciers opens up a variety of insights into past and present environmental, especially climatic, conditions on a local to regional scale. The present study was carried out in the Swiss Alps using two different approaches: (1) kinematic analysis of specific active rock glaciers, and (2) description of the altitudinal distribution of relict rock glaciers. Two theoretical shape concepts of active rock-glacier morphology were derived’ a"monomorphic" type, representing presumably undisturbed, continuous development over several millennia and a ˚polymorphic" type, reflecting a system of (possibly climatically affected) individual creep streams several centuries old. The topoclimatic-based inventory analysis indicated an average temperature increase at relict rock-glacier fronts of approximately +2°C since the time of their decay, which is a sign of rock-glacier ages reaching back to the Alpine Late Glacial. The temperature difference of some tenths of a degree Celsius found for active/inactive rock glaciers is typical for the bandwidth of Holocene climate variations. These results confirm the importance of Alpine rock glaciers as highly sensitive indicators of past temperature evolution.


2006 ◽  
Vol 54 (2) ◽  
pp. 231 ◽  
Author(s):  
Heather MacKay

The protection of ecosystems associated with groundwater, and thus potentially vulnerable to groundwater exploitation, is only now being recognised as an important aspect of water management. Although there has been a gradual increase in scientific understanding of the links between groundwater availability and ecosystem health, a significant challenge remains in the development and implementation of policy that adequately addresses the protection of groundwater-dependent ecosystems. There is no single right way to solve the problem of protecting groundwater-dependent ecosystems, while still allowing the use of groundwater to support social and economic development, poverty alleviation and improved food and water security. This paper provides a global perspective in examining the potential impacts of the lack of policy, or poor implementation of policy, related to groundwater-dependent ecosystems, and discusses emerging approaches in this field. The following two important factors are considered in the paper: first, the difficulty of managing typically local- and regional-scale problems associated with groundwater exploitation, by using national-scale policy interventions and regulation; second, the need to shorten the cycle from science to policy and regulation, and thence to management activities on the ground, in order to encourage policy shifts in the short to medium term that better reflect the available scientific knowledge of groundwater-dependent ecosystems.


2021 ◽  
Author(s):  
◽  
Pablo Iribarren Anacona

<p>This study examines hazardous processes and events originating from glacier and permafrost areas in the extratropical Andes (Andes of Chile and Argentina) in order to document their frequency, magnitude, dynamics and their geomorphic and societal impacts. Ice-avalanches and rock-falls from permafrost areas, lahars from ice-capped volcanoes and glacial lake outburst floods (GLOFs) have occurred in the extratropical Andes causing ~200 human deaths in the Twentieth Century. However, data about these events is scarce and has not been studied systematically. Thus, a better knowledge of glacier and permafrost hazards in the extratropical Andes is required to better prepare for threats emerging from a rapidly evolving cryosphere.  I carried out a regional-scale review of hazardous processes and events originating in glacier and permafrost areas in the extratropical Andes. This review, developed by means of a bibliographic analysis and the interpretation of satellite images, shows that multi-phase mass movements involving glaciers and permafrost and lahars have caused damage to communities in the extratropical Andes. However, it is noted that GLOFs are one the most common and far reaching hazards and that GLOFs in this region include some of the most voluminous GLOFs in historical time on Earth. Furthermore, GLOF hazard is likely to increase in the future in response to glacier retreat and lake development. To gain insight into the dynamics of GLOFs I create a regional-scale inventory of glacier lakes and associated hazards in the Baker Basin, a 20500 km2 glaciated basin in the Chilean Patagonia. I also simulate and reconstruct moraine- and ice- dammed lake failures in the extratropical Andes using numerical and empirical models.  More than 100 GLOFs have occurred in the extratropical Andes since the Eighteenth Century and at least 16 moraine-dammed lakes have produced GLOFs. In the extratropical Andes most of the failed moraine-dammed lakes were in contact with retreating glaciers and had moderate (> 8°) to steep (>15°) outlet slopes. Ice-dammed lakes also produced GLOFs in the extratropical Andes, damaging communities and highlighting the need for a better understanding of the GLOF dynamics and hazards. Thus, I reconstruct and model GLOFs that occurred in maritime western Patagonia (Engaño Valley) and the high-arid Andes (Manflas Valley) to characterise the GLOF dynamics in these contrasting environments.  Hydraulic modelling and geomorphologic analysis shows that the Engaño River GLOF (46º S) behaved as a Newtonian flow and incorporated tree trunks, from the gently sloping and heavily-forested valley, which increased the GLOF damaging capacity. In contrast, the Manflas GLOF (28º S) descended from a steep valley behaving as a sediment-laden flow, which was capable of moving boulder-size rocks dozens of kilometres from the GLOF source. In both events lack of awareness of the GLOF hazard and a lack of territorial planning accentuated the GLOF damage. These GLOF reconstructions highlight both the difficulties in modelling sediment-laden flows over long distances, and the utility of empirical debris-flow models for regional-scale hazard analysis.  This thesis synthesises and increases our knowledge about the distribution, frequency, magnitude and dynamics of hazardous processes that have occurred in glacier and permafrost areas in the extratropical Andes. This knowledge forms a basis for future assessments of glacier and permafrost related hazards in the Chilean and Argentinean Andes and helps inform strategies and policies to face hazardous geomorphologic and hydrological processes emerging from a rapidly evolving cryosphere.</p>


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