Fifteen-year experiences of the internationally shared aquifer resources management initiative (ISARM) of UNESCO at the global scale

Study region: Global scale. Study focus: This paper highlights the main outputs and outcomes of the Internationally Shared Aquifer Resources Management Initiative (ISARM, 2000–2015) of UNESCO on the global scale. We discuss the lessons learned, what is still relevant in ISARM, and what we consider irrelevant and why. We follow with discussion on the looming scenarios and the next steps following the awareness on transboundary aquifers (TBAs) as identified by ISARM. New insights for the region: This analysis emphasizes the need for more scientific data, widespread education and training, and a more clearly defined role for governments to manage groundwater at the international level. It describes the links, approach and relevance of studies on TBAs to the UN Law of Transboundary Aquifers and on how they might fit regional strategies to assess and manage TBAs. The study discusses an important lesson learned on whether groundwater science can solve transboundary issues alone. It has become clear that science should interact with policy makers and social entities to have meaningful impacts on TBAs. Bringing together science, society, law, policy making, and harmonising information, would be important drivers and the best guidance for further assessments. ISARM can still make contributions, but it could be redesigned to support resolving TBAs issues which, in addition to science (hydrogeology), require considering social, political, economic and environmental factors. ISARM can increase its international dimension in the continents that still lag behind the assessment and shared management of TBAs, such as Asia and Africa.Peer ReviewedPostprint (published version

Hydrological conceptual model characterisation of an abandoned mine site in semiarid climate : the Sierra de Cartagena-La Unión (SE Spain)

A comprehensive study at Sierra de Cartagena-La Unión (SE Spain) abandoned mine site was carried out to characterise the regime and water quality of the groundwater system after the mine closure. The system consists of five geologic fractured blocks belonging to the Alpujarride and Nevado-Filabride complexes. The aquifer units are composed of limestone and dolostone materials. Recharge is mainly controlled by the N-130 fault system, man-made induced fractures, open-pits and underground workings. Discharge is indicated from open pit lakes by the proximal dome-shaped groundwater level contours. Aquifer natural recharge, assessed by fracture density maps and chloride mass balance, provided consistent results. The water hydrochemical facies show a marked sulphate concentration and acidic pH (average pH of 2.53-6.30). A maximum concentration of 4,100 mg/L of Zn and 40,000 mg/L of sulphate was observed in open-pit lakes. Springs present the lowest residence time and are low mineralised with an average pH of 7.6. Geochemical modelling based on the PHREEQCI code indicates water undersaturation with respect to almost all related mineral species and anoxic conditions prevail in the system. Although an adequate understanding of the regional system is provided, a further detailed hydrochemical study is necessary to assess the undergoing geochemical changes

Water balance on the Central Rift Valley

Material complementari del cas estudi "Water balance on the Central Rift Valley", part component del llibre "Case studies for developing globally responsible engineers"Peer ReviewedPostprint (author's final draft

Presence of emerging contaminants priority substances and heavy metals in treated wastewater and groundwater in the Llobregat delta area (Barcelona, Spain)

Initial sampling results of emerging contaminants at the Llobregat delta deep aquifer (Barcelona, Spain) are presented. Among micro contaminants selected are 82 pharmaceuticals (antibiotics, lipid regulation agents, analgesic/anti-inflammatory drugs, etc), 18 personal care products (sunscreen agents, preservatives and disinfectants/antiseptics), 4 metals, 44 pesticides, 6 volatile priority pollutants, 16 PAHS and dioxins. Monitoring programme consisted on periodical water sampling from municipal wastewater tertiary treatment plant (WWTP), tertiary water with additional treatment being injected in the aquifer and from the aquifer. With regard to the emerging contaminants, the applied treatment has demonstrated its effectiveness for the removal of this type of microcontaminantsPostprint (published version

Water resources management at the University of Alicante for landscape irrigation from groundwater desalination

The southeastern part of the Iberian Peninsula is an area of water resources scarcity and important seasonal demand. Moreover, aquifers with low quality water for consumption due to salinity also exist precluding its further use. However, since the important concern of water shortage has been growing, possible exploitation of low quality groundwater has been taken into consideration. An example of sustainable use of the treated saline water developed by University of Alicante (UA) is presented, where pumped groundwater from the in campus existing aquifer is applied for landscape irrigation after RO desalination by the existing plant.Postprint (published version

Economic evaluation of small desalination plants from brackish aquifers. Application to Campo de Cartagena (SE Spain)

The Campo de Cartagena (Eastern Spain) is one of Europe’s driest areas with a mean precipitation of around 300 mm. One of the main challengesin the region is to secure a reliable water supply in both quantity and quality terms, to provide a water supply and agricultural irrigation, while water desalination has become an extensively applied solution, and one of the most sustainable solutions to the water scarcity problem. As water availability is lacking and groundwater quality is poor, the agricultural sector in Campo de Cartagena has developed small private brackish groundwater desalination plants (15-20 m3/h) through already existing agricultural wells. Costs and benefits (C-B) for citrus cultivation (1 ha) in three such plants have been assessed. The results indicate that for the studied cases, current agricultural management is feasible and costs outweigh benefits, with a positive NPV and a cost/benefit ratio higher than 1. The internal rate of return is also positive and higher than 11%. The results evidence practical and theoretical implications as to how to increase water resources in areas where water is scarce by closing the loop, ensuring farmers’ profitability and encouraging private sector investments.Peer ReviewedPostprint (author's final draft

Drainage estimation to aquifer and water use irrigation efficiency in semi-arid zone for a long period of time

Water requirements for different crop types according to soil type and climate conditions play not only an important role in agricultural efficiency production, though also for water resources management and control of pollutants in drainage water. The key issue to attain these objectives is the irrigation efficiency. Application of computer codes for irrigation simulation constitutes a fast and inexpensive approach to study optimal agricultural management practices. To simulate daily water balance in the soil, vadose zone and aquifer the VisualBALAN V. 2.0 code was applied to an experimental area under irrigation characterized by its aridity. The test was carried out in three experimental plots for annual row crops (lettuce and melon), perennial vegetables (artichoke), and fruit trees (citrus) under common agricultural practices in open air for October 1999-September 2008. Drip irrigation was applied to crops production due to the scarcity of water resources and the need for water conservation. Water level change was monitored in the top unconfined aquifer for each experimental plot. Results of water balance modelling show a good agreement between observed and estimated water level values. For the study period, mean drainage obtained values were 343 mm, 261 mm and 205 mm for lettuce and melon, artichoke and citrus respectively. Assessment of water use efficiency was based on the IE indicator proposed by the ASCE Task Committee. For the modelled period, water use efficiency was estimated as 73, 71 and 78 % of the applied dose (irrigation + precipitation) for lettuce and melon, artichoke and citrus, respectively.Peer ReviewedPostprint (published version

Drainage estimation to aquifer and water use irrigation efficiency in semi-arid zone for a long period of time

Water requirements for different crop types according to soil type and climate conditions play not only an important role in agricultural efficiency production, though also for water resources management and control of pollutants in drainage water. The key issue to attain these objectives is the irrigation efficiency. Application of computer codes for irrigation simulation constitutes a fast and inexpensive approach to study optimal agricultural management practices. To simulate daily water balance in the soil, vadose zone and aquifer the VisualBALAN V. 2.0 code was applied to an experimental area under irrigation characterized by its aridity. The test was carried out in three experimental plots for annual row crops (lettuce and melon), perennial vegetables (artichoke), and fruit trees (citrus) under common agricultural practices in open air for October 1999-September 2008. Drip irrigation was applied to crops production due to the scarcity of water resources and the need for water conservation. Water level change was monitored in the top unconfined aquifer for each experimental plot. Results of water balance modelling show a good agreement between observed and estimated water level values. For the study period, mean drainage obtained values were 343 mm, 261 mm and 205 mm for lettuce and melon, artichoke and citrus respectively. Assessment of water use efficiency was based on the IE indicator proposed by the ASCE Task Committee. For the modelled period, water use efficiency was estimated as 73, 71 and 78 % of the applied dose (irrigation + precipitation) for lettuce and melon, artichoke and citrus, respectively.Peer ReviewedPostprint (published version

Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, ¿, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control ¿ and h in the vadose zone: i) non-automatic and more timeconsuming; ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of ¿ and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, ¿s, and the n and a van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher.Peer ReviewedPostprint (author's final draft

Water resources management in the Central Rift Valley: modelling for the water poor

Achieving a sustainable development is crucial, but is even more important in developing countries, where a wide number of people does not have a safe and secure access to water and relay on the environment to sustain their lives. The Ethiopian Central Rift Valley basin is already a degraded basin from the environmental point of view: ecosystems are endangered due to human activities there developed. Moreover, poverty is widespread all over the basin, with population is mainly living from agriculture on a subsistence economy. In order to achieve sustainable development to increase population incomes without affecting lives of those who are highly dependent on the environment and Integrated Water Resources Management approach shall be applied. First step has been to model the basin water resources, using the Soil and Water Assessment Tool (SWAT), which, after calibration and validation of the model, has given correct results. In order to follow deepening in the IWRM approach, more information on actual and future water demand and specifically water applied to agriculture will be needed.Postprint (published version