Intensive Use Of Groundwater Research Articles

Application of an Integrated SWAT–MODFLOW Model to Evaluate Potential Impacts of Climate Change and Water Withdrawals on Groundwater–Surface Water Interactions in West-Central Alberta

It has become imperative that surface and groundwater resources be managed as a holistic system. This study applies a coupled groundwater–surface water (GW–SW) model, SWAT–MODFLOW, to study the hydrogeological conditions and the potential impacts of climate change and groundwater withdrawals on GW–SW interactions at a regional scale in western Canada. Model components were calibrated and validated using monthly river flow and hydraulic head data for the 1986–2007 period. Downscaled climate projections from five General Circulation Models (GCMs), under the RCP 8.5, for the 2010–2034 period, were incorporated into the calibrated model. The results demonstrated that GW–SW exchange in the upstream areas had the most pronounced fluctuation between the wet and dry months under historical conditions. While climate change was revealed to have a negligible impact in the GW–SW exchange pattern for the 2010–2034 period, the addition of pumping 21 wells at a rate of 4680 m3/d per well to support hypothetical high-volume water use by the energy sector significantly impacted the exchange pattern. The results showed that the total average discharge into the rivers was only slightly reduced from 1294 m3/d to 1174 m3/d; however, localized flowrate differences varied from under 5 m3/d to over 3000 m3/d in 320 of the 405 river cells. The combined potential impact is that intensive groundwater use may have more immediate effects on river flow than those of climate change, which has important implications for water resources management and for energy supply in the future.

Evaluation of the quality of groundwater used for irrigation in the Mina plain, Algeria

The development of agriculture in the Mina plain is hampered by the drought that has occurred in recent years. As a result, water scarcity has favoured an intensive use of groundwater of poor quality. This behaviour is one of the forerunners of soil degradation. Knowing the quality of the irrigation water used becomes imperative. In this context, water samples from 178 wells in the Mina plain were subjected to a physico-chemical analysis, mainly electrical conductivity (EC), sodium adsorption ratio (SAR), and irrigation water quality index (IWQI), were used to identify water quality classes as well as residual alkalinity (RSC) to determine salinization pathways. The thematic maps established by the two methods (EC and SAR, IWQI) showed that 73.44% of the total area could be used for irrigation and that 87.55% of the total area may be used for irrigation in soils with high permeability where additional water should be applied to prevent salt accumulation. The residual alkalinity revealed two types of salinization: one neutral and one alkaline, representing respectively 149 and 29 wells. The electrical conductivity varied between 2.24 and 16.50 dS∙m-1, divided into two classes of salinity (C4, 44.03% and C5, 55.97%). SAR values fluctuated between a low of 4.28 and a high of 94.73, with S2 dominance accounting for 49.57% of the total area. IWQI’s assessment of groundwater quality revealed that 87.55% of the Mina study area is severely restricted, which is dominant in the southeastern and southwestern parts of the area. The remaining area, 12.44% or less, is in the high restriction category. This simple index uses the most important parameters that evaluate the quality of irrigation water for management.

SAR interferometry monitoring of subsidence in a detritic basin related to water depletion in the underlying confined carbonate aquifer (Torremolinos, southern Spain)

This research underlines the need to improve water management policies for areas linked to confined karstic aquifers subjected to intensive exploitation, and to develop additional efforts towards monitoring their subsidence evolution. We analyze subsidence related to intensive use of groundwater in a confined karstic aquifer, through the use of the InSAR technique, by the southern coast of Spain (Costa del Sol). Carbonates are overlain by an unconfined detritic aquifer with interlayered high transmissivity rocks, in connection with the Mediterranean Sea, where the water level is rather stable. Despite this, an accumulated deformation in the line-of-sight (LOS) direction greater than −100 mm was observed by means of the ERS-1/2 (1992–2000) and Envisat (2003–2009) satellite SAR sensors. During this period, the Costa del Sol experienced a major population increase due to the expansion of the tourism industry, with the consequent increase in groundwater exploitation. The maximum LOS displacement rates recorded during both time spans are respectively −6 mm/yr and −11 mm/yr, respectively. During the entire period, there was an accumulated descent of the confined water level of 140 m, and several fluctuations of more than 80 m correlating with the subsidence trend observed for the whole area. Main sedimentary depocenters (up to 800 m), revealed by gravity prospecting, partly coincide with areas of subsidence maxima; yet ground deformation is also influenced by other factors, the main ones being the fine-grained facies distribution and rapid urbanization due to high touristic pressure.

Revisiting groundwater overdraft based on the experience of the Mancha Occidental Aquifer, Spain

Aquifers provide a reliable freshwater source in arid and semiarid regions, where droughts are common and irrigated crops present significant water requirements, so intensive pumping is generally needed. Over-extraction leads to dropping water tables, which in turn threatens the survival of groundwater-dependent ecosystems and water supplies. This calls for strategies to channel hydrological, environmental, agricultural, political and social change. Based on the experience of the Mancha Occidental aquifer, Spain, this paper explores some of the complexities of managing groundwater, dealing with the long-term changes that intensive groundwater use has generated in the region. The Mancha experience shows how environmental conservation may drive social and economic change at the regional scale for periods spanning several decades. What makes this case study unique, however, is the combination of social and environmental conflicts, most of which stem from the prevalence of illegal water use, and their detrimental effect on Ramsar wetlands. The situation exposed a paradox, namely that subsidies for farmers to cut down on water use were actually detrimental to the welfare of groundwater-dependent ecosystems. The unexpected (and timely) occurrence of extreme rainfall events in recent times, after 40 years of ineffective management measures and sustained environmental degradation, enabled the aquifer and its associated wetlands to recover spectacularly to a near-pristine condition. As groundwater-dependent wetlands are highly sensitive ecosystems, it is concluded that it is up to society to decide how much environmental damage can be tolerated in exchange for the social and economic benefits of groundwater-based development.

Monitoring continuous subsidence in the Costa del Sol (Málaga province, southern Spanish coast) using ERS-1/2, Envisat, and Sentinel-1A/B SAR interferometry

In this paper we analyze the subsidence behavior of a coastal area in the province of Málaga (Costa del Sol), southern Spain, in the period 1992-2018 using C-band SAR interferometry. The area comprises several zones of interest where continuous deformation has happened during the analyzed period. Using SAR data from ESA’s ERS-1/2, Envisat, and Sentinel-1A/B satellites, and Multi-Temporal InSAR methods we detect and monitor subsidence in highly populated and industrial areas, airport, harbor, as well as local instabilities over a railway line and a highway. In a previous work, we reported a subsidence due to intensive use of groundwater in some populated towns in the period 1992-2009 with maximum line-of-sight (LOS) rates of the order of –11 mm/yr. In this contribution, we confirm the subsidence trend. Furthermore, we detect an increase in the deformation rates for the most recent period (2014-2018), suggesting that the overexploitation of the aquifers has not ceased.

Prosper, survive or exit: Contrasted fortunes of farmers in the groundwater economy in the Saiss plain (Morocco)

In North Africa, the development of groundwater-based irrigation enabled agricultural intensification and market-oriented production. Groundwater use was also often said to alleviate smallholder poverty. However, there is growing evidence linking the expansion of groundwater-based agriculture with increasing socioeconomic inequalities in a context of declining water tables and rapid agrarian change. This paper analyzes the contrasted fortunes of different categories of farmers participating in the groundwater economy, depending on access to other resources including land, capital and labor. The study was conducted in a 3910ha area in the Saiss plain (Morocco), where rapid agrarian transformations took place with the arrival of investors attracted by state subsidies and the possibility to carry out intensive groundwater-based agriculture. The study began with interviews with key informants to determine the role of groundwater use in farm trajectories. Then, an inventory was undertaken of all farms and of all wells and tube-wells in the study area. Next, the groundwater use per farm type was determined on a sample of 24 farms. Finally, the socioeconomic differentiation of farms was determined, based on the inequalities in access to groundwater, land, labor and financial capital. The results revealed contrasted fortunes of farmers involved in the groundwater economy. The boom in the groundwater economy benefitted entrepreneurial and well-endowed farmers who made intensive use of groundwater, while the effects of their overexploitation of groundwater fed the marginalization of family farmers. The results show that capital has replaced landownership as the dominant production factor, thereby re-qualifying what is a ‘small’ farmer. Capital is not only required to obtain access to groundwater, but also to deal with the more risky agriculture frequently conducted in the groundwater economy. This leads to the exclusion of small family farmers who may quit the groundwater economy poorer than they entered it. The urgent need to control access to and use of groundwater in the face of declining water tables has little chance of producing results if socioeconomic inequalities remain unaddressed.

Topical Collection: Groundwater-based agriculture in the Mediterranean

This essay introduces a collection of articles that explore the future of groundwater-based agriculture in the Mediterranean from an interdisciplinary perspective, in a context of declining water tables due to intensive groundwater use. The imminent crisis that many groundwater economies face due to very rapid and intense global change may have severe irreversible social, economic and environmental consequences, but could also be the opportunity to make a clear break with current agricultural development models and move towards more sustainable agricultural practices. The Mediterranean region is, therefore, an interesting case for the future of intensive groundwater use, as innovative ideas and practices may emerge and inspire similar groundwater-based agricultural systems around the world.

An Overview of Reclaimed Wastewater Reuse in Gold Heap Leaching

ABSTRACTThe intensive use of groundwater by the gold mining industry is an important sustainability concern, especially in arid and semiarid regions where groundwater is a scarce resource. Alternatives, such as water reuse, treatment and recycling, have been implemented to overcome this issue. The potential use of reclaimed wastewater in gold heap leaching, without decreasing the process efficiency, has not yet been considered. Hence, this review focuses on the physicochemical, biological, and chemical features (organic matter, microbial loads, metal ions, and anions) of reclaimed wastewater that may limit its use in gold heap leaching.

Intensive Use of Groundwater in Transboundary Aquifers

Transboundary aquifers are present in all parts of the world, ranging from hundreds to tens of thousands km 2 . The largest have fresh water to provide the planets drinking water needs for 200 years, e.g. the Guarani. Intensive use of most of the larger transboundary aquifers has not yet taken place. Consequently, in broad terms they are not yet severely threatened, though with conspic uous exceptions e.g. the Middle East. Some smaller, and therefore more vulnerable transboundary aquifers are intensively used. Severe overabstraction is still contained within national boundaries, but continuing demands could impact across national boundaries especially in arid zones. For the sus tainable use and sound management, plans need to be made in early stages of development, with the participation of all the riparians, to ensure equitable and fair share. This chapter outlines a multi disciplinary approach, involving the legal, institutional, economic and environmental inputs, that is needed, over and above the hydrogeological understanding. Suggestions are made about the staged process, commencing from the status quo, quasi-steady state analysis.

Groundwater intensive use and mining in south-eastern peninsular Spain: Hydrogeological, economic and social aspects

Intensive groundwater development is a common circumstance in semiarid and arid areas. Often abstraction exceeds recharge, thus continuously depleting reserves. There is groundwater mining when the recovery of aquifer reserves needs more than 50years. The MASE project has been carried out to compile what is known about Spain and specifically about the south-eastern Iberian Peninsula and the Canary Islands. The objective was the synthetic analysis of available data on the hydrological, economic, managerial, social, and ethical aspects of groundwater mining. Since the mid-20th century, intensive use of groundwater in south-eastern Spain allowed extending and securing the areas with traditional surface water irrigation of cash crops and their extension to former dry lands, taking advantage of good soils and climate. This fostered a huge economic and social development. Intensive agriculture is a main activity, although tourism plays currently an increasing economic role in the coasts. Many aquifers are relatively high yielding small carbonate units where the total groundwater level drawdown may currently exceed 300m. Groundwater storage depletion is estimated about 15km3. This volume is close to the total contribution of the Tagus-Segura water transfer, but without large investments paid for with public funds. Seawater desalination complements urban supply and part of cash crop cultivation. Reclaimed urban waste water is used for irrigation. Groundwater mining produces benefits but associated to sometimes serious economic, administrative, legal and environmental problems. The use of an exhaustible vital resource raises ethical concerns. It cannot continue under the current legal conditions. A progressive change of water use paradigm is the way out, but this is not in the mind of most water managers and politicians. The positive and negative results observed in south-eastern Spain may help to analyse other areas under similar hydrogeological conditions in a less advanced stage of water use evolution.

Distressed Elephants: Policy Initiatives for Sustainable Groundwater Management in India

This article reviews the dominant arguments which shaped public policies in the agricultural groundwater sector in India. It also examines the initiatives to arrest groundwater depletion. It is a synthesis of the research carried out by the author over the last two decades and review of the work by others. Following were the arguments that shaped public policies in the agricultural groundwater sector in India, as per the review: high density of farm wells in remote areas increases the transaction cost of metering and charging for electricity on a pro-rata basis, as a tool to control groundwater draft; groundwater economy is controlled by small and marginal farmers, and attempts to regulate it are politically sensitive; and raising power tariff would adversely affect farmers who buy water. Furthermore, the regions with high density of wells do not experience intensive groundwater use; groundwater economy is mainly controlled by large farmers. In water-abundant regions, subsidized power does not reduce the monopoly of water sellers; in water-scarce regions, an increase in power tariff would have only marginal effect on it; and, in semi-arid regions, raising farm power tariff would result in improved efficiency, equity and sustainability in groundwater use and would be socio-economically viable. In water-scarce regions, the large public funds spent for watershed management, dug well recharging and community-based water harvesting produce no positive outcomes. Attempts to introduce electricity pricing or groundwater taxes or water rights are absent. Schemes promoting the use of micro irrigation do raise farm productivity, but leave no incentive among farmers to reduce water use.

Legal Challenges in Government Imposition of Water Conservation: The Kansas Example

This article deals with legal challenges in conserving water in the United States, using Kansas as an example. The focus is on one aspect of American water allocation law—the extent to which a state can force reductions in pumping by holders of water rights. It explains the hybrid nature of water rights, which on the one hand are “real property rights,” and yet on the other hand they are viewed as rights only to use water and not to own the water itself. Because they are a kind of property right, they are protected by the fifth amendment to the U.S. Constitution against “takings” by the government without compensation. The question becomes: to what extent, then, can states demand reductions in pumping without having to pay compensation? The answer is difficult for both water right holders and government officials to predict. The law of groundwater rights in Kansas illustrates the problem. The article describes the Kansas law in the context of other states on this issue, including the historic changes in Kansas' water law doctrines, water management under the appropriation doctrine, the public trust doctrine, groundwater management districts, and intensive groundwater use control areas, as well as recent attempts to foster voluntary actions by water right holders that avoid government imposition of restrictions. Questions remain in Kansas and elsewhere about where the line can be drawn, between acceptable government restrictions and unacceptable takings of property. Future drought caused by climate change will focus even more attention on this question.

Metodologia para estudos da qualidade das águas subterrâneas e sua aplicação para caracterização hidrogeoquímica do Aquífero Guarani

O Aquífero Guarani é um dos maiores reservatórios de águas subterrâneas do planeta e representa uma reserva estratégica para os quatro países da América do Sul – Argentina, Brasil, Paraguai e Uruguai – onde ele ocorre. O município de Ribeirão Preto, localizado na região Nordeste do Estado de São Paulo, com uma população de mais 600 mil habitantes, é suprido inteiramente pelas águas do aquífero. Nesse município e região vem ocorrendo o uso intensivo de água subterrânea e uma numerosa quantidade de poços em atividade já evidenciam problemas de interferência entre eles. Ao mesmo tempo, percebe-se o aumento do risco de contaminação das águas subterrâneas por incremento de fontes instaladas sobre as partes aflorantes do aquífero (principalmente as relacionadas ao uso de agrotóxicos na agricultura), que são de alta vulnerabilidade. Este trabalho apresenta metodologia para investigação de dados de qualidade química de águas subterrâneas e sua aplicação para a caracterização hidrogeoquímica do Aquífero Guarani, no âmbito do território ribeirão-pretano e região.

Hydrochemical changes due to intensive use of groundwater in the carbonate aquifers of Sierra de Estepa (Seville, Southern Spain)

Summary The carbonate aquifers of Sierra de Estepa, situated in southern Spain, are undergoing intensive groundwater exploitation. Consequently, the volume of pumping surpasses the average recharge for periods of several consecutive years. Under such conditions, nearby springs have either dried up or only function during short time periods, after very rainy episodes followed by long droughts. During the brief periods when the springs are active, their water and the water extracted by pumping are calcium bicarbonates, with a spatial–temporal variability of their physico-chemical characteristics that is mainly conditioned by the degree of functional karstification of each system. When the springs are inactive, the pumping water gradually increases in salinity and becomes HCO3ClCaNa, ClHCO3NaCa and ClNa. Under the new conditions caused by so much pumping, the main factors determining the hydrochemical changes are the mixing of waters and the subsequent reactions of dissolution–precipitation between (1) the recharge coming from rainwater, (2) the hypersaline inputs from the clay-evaporite aquitards situated on the edges and at the base of the aquifer, and (3) the water stored in each aquifer. The hydrochemical information acquired allowed us to characterize and model the groundwater of these aquifers, to study the causes of its great spatial and temporal variability, and explain the influence of exploitation. This research shows that making sustainable use of water resources associated with carbonate aquifers calls for sound knowledge of the relationship between the aquifer and other bodies of groundwater or surface water, the hydrochemical quality of these possible inputs, and the vulnerability of the aquifer to exploitation, which in turn is conditioned by the ratio between water reserves and recharge.

Intensive groundwater use and (in)equity: Processes and governance challenges

Groundwater forms the basis for millions of rural and urban livelihoods around the world. Building on insights from the theory of access, in this article we present how groundwater development has brought much well-fare in many parts of the world; and how resulting intensive groundwater use is leading to ill-fare through aquifer overexploitation and processes of water accumulation and dispossession. We show the difficulty of state regulation and the modest achievements of other governance approaches that aim to solve existing groundwater problems. To study these processes we propose a framework of analysis that is based on the study of hydrosocial-networks, the political economy of groundwater and the domains and discourses that define groundwater access. Such analysis highlights the challenges of devising policies and modes of governance that contribute to social and environmental sustainability in intensively used aquifers. These we argue should build on an analysis of equity that scrutinizes the discourses, actors, powers and procedures that define groundwater access. By inciting debates on equity a first and fundamental step can be made toward advancing more inclusive groundwater governance that crucially engages the marginalized and addresses their groundwater problems, concerns and needs.

Desalination for securing water productivity in an intensively used coastal aquifer (Campo de Dalías, Spain)

The Campo de Dalias aquifer is a coastal aquifer located in the southeast Spain (Andalucia). Since the 1960s, the area has experienced a spectacular economic development based on the intensive use of groundwater for the irrigation of greenhouse crops, becoming one of the world’s largest areas under greenhouses. This development, however, coincided with a rising groundwater demand from cities and tourism. The resulting fall in groundwater levels and seawater intrusion jeopardizes water security for the local economy based on intensive groundwater use. To remediate this situation, it is expected that from 2014–2015, part of the supply will be obtained from desalinated seawater, so as to reduce withdrawals. The main aims of this study are: first, to detail the water footprint in Campo de Dalias, and its productivity, with a particular focus on agriculture; second, review the process of seawater intrusion; and, finally, analyse the role of desalination as a solution to ensure water security for the multiple water uses and implications for cost recovery in the context of the European Union Water Framework Directive (WFD).

Contribution of the multi-attribute value theory to conflict resolution in groundwater management – application to the Mancha Oriental groundwater system, Spain

Abstract. The implementation of the EU Water Framework Directive demands participatory water resource management approaches. Decision making in groundwater quantity and quality management is complex because of the existence of many independent actors, heterogeneous stakeholder interests, multiple objectives, different potential policies, and uncertain outcomes. Conflicting stakeholder interests have often been identified as an impediment to the realisation and success of water regulations and policies. The management of complex groundwater systems requires the clarification of stakeholders' positions (identifying stakeholder preferences and values), improving transparency with respect to outcomes of alternatives, and moving the discussion from the selection of alternatives towards the definition of fundamental objectives (value-thinking approach), which facilitates negotiation. The aims of the study are to analyse the potential of the multi-attribute value theory for conflict resolution in groundwater management and to evaluate the benefit of stakeholder incorporation into the different stages of the planning process, to find an overall satisfying solution for groundwater management. The research was conducted in the Mancha Oriental groundwater system (Spain), subject to intensive use of groundwater for irrigation. A complex set of objectives and attributes was defined, and the management alternatives were created by a combination of different fundamental actions, considering different implementation stages and future changes in water resource availability. Interviews were conducted with representative stakeholder groups using an interactive platform, showing simultaneously the consequences of changes in preferences to the alternative ranking. Results show that the approval of alternatives depends strongly on the combination of measures and the implementation stages. Uncertainties in the results were notable, but did not influence the alternative ranking heavily. The expected reduction in future groundwater resources by climate change increases the conflict potential. The implementation of the method in a very complex case study, with many conflicting objectives and alternatives and uncertain outcomes, including future scenarios under water limiting conditions, illustrates the potential of the method for supporting management decisions.

Study of the ground subsidences in the Sibari Plain (Southern Italy) detected by InSAR data analysis

We investigated surface ground deformations in the Sibari Plain (SP - Calabria, Southern Italy) by means of Small Baseline Subset multi-temporal InSAR technique (SBAS), applied to two SAR datasets acquired from 2003 up to 2013 by Envisat (ESA, European Space Agency) and COSMO-SkyMed (ASI, Italian Space Agency) satellites. The retrieved InSAR data show the existence of ground subsidence phenomena up to ~ -20 mm/yr. Our investigation is based on integration between InSAR data and geological, well-logs, land use and hydrogeological information. The results show a direct correlation among subsidence, the thickness of Plio-Pleistocene succession and thickness and lithology of the late Holocene deposits. We identified the fast urbanization of the coastal area during the last ~50 yr and the water table drop as incremental factors of subsidence phenomena. The second factor, due to intensive use of ground water for agriculture, is not the triggering cause of subsidence processes on contrary to the assumption of some previous publications. No evidence of tectonic contribution in the ground deformation pattern is observed.

Hydrogeological research on intensively exploited deep aquifers in the ‘Loma de Úbeda’ area (Jaén, southern Spain)

The intensive use of groundwater for irrigation in the area of Ubeda (‘Loma de Ubeda’, Jaen, southern Spain) has transformed an area of traditionally rain-fed dry farmland into fields with some of the highest olive oil productivity in the world. Early hydrogeological research studies, initiated just after the beginning of the groundwater exploitation, revealed that the water was collected from three different overlapping aquifers occupying an area of over 1,100 km2, with the lower aquifers located at depths from 300 to over 700 m in an area of 440 km2. Multidisciplinary research, based on geological characterization, and piezometric, hydrochemical and isotopic data, has led to a conceptual model of functioning in this complex hydrogeological system. The proposed model allows for the identification of the recharge areas, and the discharge, which is at present mainly associated with the groundwater pumping. Areas of mixing of waters from the different aquifers and the main hydrogeochemical processes affecting groundwater quality are described.

Groundwater recharge in semi-arid carbonate aquifers under intensive use: the Estepa Range aquifers (Seville, southern Spain)

Quantifying groundwater recharge in carbonate aquifers located in semi-arid regions and subjected to intensive groundwater use is no easy task. One reason is that there are very few available methods suitable for application under such climatic conditions, and moreover, some of the methods that might be applied were originally designed with reference to non-carbonate aquifers. In addition, it is necessary to take into account the fact that, in any given aquifer, groundwater recharge is modified by the groundwater exploitation. Here we focus on four methods selected to assess their suitability for estimating groundwater recharge in carbonate aquifers affected by intensive exploitation. The methods were applied to the Estepa Range aquifers of Seville, southern Spain, which are subjected to different degrees of exploitation. Two conventional methods were used: chloride mass balance and daily soil–water balance. These results were compared with the results obtained by means of two non-conventional methods, designed for application to the carbonate aquifers of southern Spain: the APLIS and ERAS methods. The results of the different methods are analogous, comparable to those obtained in nearby non-exploited carbonate aquifers, confirming their suitability for use with carbonate aquifers in either natural or exploited regimes in a semi-arid climate.