| 1. |
- Mushtaq, S., et al.
(författare)
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An innovative systematic approach to internalize external costs of salinization in major irrigated systems
- 2016
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Ingår i: Groundwater for Sustainable Development. - : Elsevier. - 2352-801X. ; 2-3, s. 16-26
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural production has external costs embedded in different forms. These externalities have not yet been internalized in the market's prices. The study applied a basin-wide systematic approach to manage river salinity, which is one of the most vexatious of these externalities, and needs urgent remediation. The application of the approach is exemplarily demonstrated for the Murray Darling Basin (MDB) in Australia. An in-depth economic analysis indicates that in the upper areas, plant-based options are suitable and economically viable, while in middle and downstream parts of the MDB, more options are suitable such as irrigation management, subsurface drainage and effluent reuse, and salt interception systems and Sequential Biological Concentration (SBC). The SBC differs from most other options since it provides direct economic benefits to the operators and is profitable. We adopt Pigouvian recommendations as polluters pay principle to internalize externality. Charging salinity credits in terms of polluters pay principle (e.g. in this case of about A$53 t-1) would result in attractive economic returns even at higher level of salinity, thus offering sufficient incentives to invest in relevant salinity management strategy. We recommended that potential salinity mitigation technique should consider regional characteristics and that it should be focused on high impact salinity zones to increase the effectiveness of the effort.
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| 2. |
- Ormachea Muñoz, Mauricio, et al.
(författare)
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Geochemistry of naturally occurring arsenic in groundwater and surface-water in the southern part of the Poopó Lake basin, Bolivian Altiplano
- 2016
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Ingår i: Groundwater for Sustainable Development. - : Elsevier. - 2352-801X. ; 2-3, s. 104-116
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Tidskriftsartikel (refereegranskat)abstract
- Groundwaters from shallow aquifers and surface water from rivers of the southern part of Poopó Lake basin within the Bolivian Altiplano have significant quality problems such as high salinity and high concentrations of arsenic (As). The extent of As contamination is observed in the studied groundwater over large parts of the study area. Surface-waters are generally alkaline (pH 8.2–8.7) and oxidizing with dissolved oxygen (DO) concentrations in a range of 2.5–6.6 mg/L The water chemistry is predominantly of Na–Cl–HCO3–type, with concentrations of dissolved As in the range of 8.6–117 µg/L with As(V) as the main aqueous species. The concentration of Li varies in the range of 1.1–4.4 mg/L, while other trace elements occur in low concentrations. Groundwaters have a very large range of chemical compositions and the spatial variability of As concentrations is considerable over distances of a few km; dissolved As in groundwater spans over 4 orders of magnitude (3–3497 µg/L), while concentrations of Li have a range of 0.05–31.6 mg/L. Among the investigated drinking-water wells, 90% exceed the WHO guideline value of 10 µg As/L. Electrical conductivity ranges between 295 and 20,900 µS/cm; high salinity is resulting from evaporation under ambient semi-arid climatic conditions. The pH values of the groundwaters are generally slightly alkaline (5.5–8.7) and universally oxidizing, under these conditions As(V) is the prevalent specie. Groundwater As correlates positively with pH, electrical conductivity, Cl−, Na+, HCO3 −, Ca2+ and SO4 2−. Weathering/dissolution of carbonates, evaporites, halite and plagioclase minerals incorporate Na+ and HCO3 − in solution with consequent pH and alkalinity increase; these are favorable conditions for high mobility of As species. Stable isotopic signatures indicate recharge at the Altiplano with seasonal effects. All surface water and some groundwater samples are enriched due to evaporation, which probably increased concentration of dissolved As.
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