Sixty years of global progress in managed aquifer recharge

The last 60 years has seen unprecedented groundwater extraction and overdraft as well as development of new technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume of MAR at global scale, and to illustrate the advancement of all the major types of MAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity of climate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design of facilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance of MAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10 km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality of water supplies

A coupled groundwater-flow-modelling and vulnerability-mapping methodology for karstic terrain management

A coupled groundwater-flow-modelling and vulnerability-mapping methodology for the management of karst aquifers with spatial variability is developed. The methodology takes into consideration the duality of flow and recharge in karst and introduces a simple method to integrate the effect of temporal storage in the unsaturated zone. In order to investigate the applicability of the developed methodology, simulation results are validated against available field measurement data. The criteria maps from the PaPRIKa vulnerability-mapping method are used to document the groundwater flow model. The FEFLOW model is employed for the simulation of the saturated zone of Palaikastro-Chochlakies karst aquifer, in the island of Crete, Greece, for the hydrological years 2010–2012. The simulated water table reproduces typical karst characteristics, such as steep slopes and preferred drain axes, and is in good agreement with field observations. Selected calculated error indicators—Nash-Sutcliffe efficiency (NSE), root mean squared error (RMSE) and model efficiency (E′)—are within acceptable value ranges. Results indicate that different storage processes take place in different parts of the aquifer. The north-central part seems to be more sensitive to diffuse recharge, while the southern part is affected primarily by precipitation events. Sensitivity analysis is performed on the parameters of hydraulic conductivity and specific yield. The methodology is used to estimate the feasibility of artificial aquifer recharge (AAR) at the study area. Based on the developed methodology, guidelines were provided for the selection of the appropriate AAR scenario that has positive impact on the water table

Sixty years of global progress in managed aquifer recharge

Sessanta anni di progressi a livello globale nella ricarica delle falde acquifere in condizioni controllate Riassunto Gli ultimi 60 anni sono stati testimoni di prelievi e fenomeni di sovrasfruttamento delle falde senza precedenti, come pure dello sviluppo di nuove tecnologie per il trattamento delle acque. Questi fattori hanno guidato i progressi nelle applicazioni della ricarica intenzionale degli acquiferi, nota in lingua inglese come managed aquifer recharge – MAR (in italiano tradotto in “ricarica delle falde in condizioni controllate”). Questo articolo è il primo tentativo conosciuto dagli Autori che ha l’obiettivo di quantificare a scala globale il volume prodotto attraverso tecniche MAR, di illustrare i progressi compiuti nelle varie tipologie di MAR e di mettere questi in relazione con gli avanzamenti nella ricerca e nella regolamentazione. Di fronte al cambiamento del clima e all’aumento dell’intensità degli eventi climatici estremi, le tecniche MAR rappresentano una strategia di gestione delle acque sempre più importante, insieme alla gestione della domanda, per mantenere, migliorare e proteggere i sistemi acquiferi sotto pressione e per salvaguardare e migliorare la qualità delle acque. In questo arco di tempo, la ricerca scientifica relativa alla progettazione idraulica degli impianti, agli studi con traccianti, alla gestione dei fenomeni di intasamento, all’efficienza di recupero ed. alle modifiche della qualità delle acque sotterranee, ha supportato i miglioramenti pratici nei sistemi MAR e ha prodotto benefici in senso più ampio in idrogeologia. I pozzi di ricarica hanno largamente contribuito ad incrementare il ravvenamento degli acquiferi, in particolare nelle aree urbane e nella gestione delle acque di miniera. Negli ultimi anni sono state intraprese ricerche sulla governance, le pratiche operative, l’affidabilità, l’economicità, la valutazione del rischio e l’accettazione pubblica dei sistemi MAR. Dagli anni ‘60, la realizzazione di sistemi MAR è progredita ad un tasso del 5% all’anno, ma non sta tenendo il passo con l’aumento dei prelievi delle acque sotterranee. Attualmente si stima che i sistemi MAR forniscano circa 10 km3/anno, circa il 2.4% dei prelievi di acque sotterranee nei paesi che riportano la presenza di impianti MAR (o ~1.0% del prelievo globale di acque sotterranee). Si ritiene, sulla base dei dati provenienti dai paesi in cui l’uso di questa tecnica è avanzato, che i volumi immagazzinati attraverso i sistemi MAR potranno arrivare a superare il 10% dei prelievi globali, sostenendo la disponibilità, affidabilità e qualità delle risorse idriche.The last 60 years has seen unprecedented groundwater extraction and overdraft as well as development of new technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume of MAR at global scale, and to illustrate the advancement of all the major types of MAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity of climate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design of facilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance of MAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10 km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality of water supplies