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 km 3 /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. Keywords Managed aquifer recharge. Artificial recharge. Review. Water banking. History of hydrogeology This article is one of a series developed by the International Association of Hydrogeologists (IAH) Commission on Managing Aquifer Recharge

Different types of managed aquifer recharge (MAR) schemes are widely distributed and applied on various scales and for various purposes in the European countries, but a systematic categorization and compilation of data has been missing up to now. The European MAR catalogue presented herein contains various key parameters collected from the available literature. The catalogue includes 224 currently active MAR sites found in 23 European countries. Large quantities of drinking water are produced by MAR sites in Hungary,

No abstract

No abstract

In this paper we study induction in the context of the firstorder µ-calculus with explicit approximations. We present and compare two Gentzen-style proof systems each using a different type of induction. The first is based on finite proof trees and uses a local well-founded induction rule, while the second is based on (finitely represented) ω-regular proof trees and uses a global induction discharge condition to ensure externally that all inductive reasoning is well-founded. We give effective procedures for the translation of proofs between the two systems, thus establishing their equivalence.