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Mekuria, W., & Tegegne, D. (2023). Water harvesting. In M. J. Goss, & M. Oliver (Eds.), Encyclopedia of Soils in the Environment (Second Edition) (pp. 593–607). Oxford: Academic Press.
Abstract: Water harvesting is the intentional collection and concentration of rainwater and runoff to offset irrigation demands. Secondary benefits include decreased flood and erosion risk. Water harvesting techniques include micro- and macro-catchment systems, floodwater harvesting, and rooftop and groundwater harvesting. The techniques vary with catchment type and size, and the method of water storage. Micro-catchment water harvesting, for example, requires the development of small structures and targets increased water delivery and storage to the root zone whereas macro-catchment systems collect runoff water from large areas. The sustainability of water harvesting techniques at the local level are usually constrained by several factors such as labor, construction costs, loss of productive land, and maintenance, suggesting that multiple solutions are required to sustain the benefits of water harvesting techniques.
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Rubin, R. (1988). Water conservation methods in Israel’s Negev desert in late antiquity. Journal of Historical Geography, 14(3), 229–244.
Abstract: Settlement in Israel’s Negev desert historically has been dependent on water conservation techniques. Fieldwork carried out on settlement sites constructed during the Byzantine period, when agriculture and trade flourished, revealed a variety of water installations some of which are in use today. Perennial springs in the Negev are generally small and difficult of access. Cisterns were the most common conservation devices and came in both large, enclosed and single, open forms. Cisterns were common particularly in the towns, where they were usually built as part of house foundations. Dams were discovered at several sites but proved to be inefficient and easily abandoned because of evaporation and siltation problems. Public reservoirs were part of the structure of the largest towns and were open and among the larges structures uncovered at settlement sites. Wells were distributed widely throughout the desert and were part of the only conservation system that did not depend directly on surface rainfall. A qanat system was located in the eastern Negev dating from the late settlement period before the area was abandoned at the turn of the eighth century. These various water systems raise questions about their builders and their origins, and suggests that builders originating in more humid Mediterranean environments tended to produce less adaptable installations than builders derived from the south or the east.
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Kharaka, Y., Harmon, R., & Darling, G. (2015). W. Mike Edmunds (1941–2015). Applied Geochemistry, 59, 225–226.
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Gardiner, J., Thomas, R. B., Phan, T. T., Stuckman, M., Wang, J., Small, M., et al. (2020). Utilization of produced water baseline as a groundwater monitoring tool at a CO2-EOR site in the Permian Basin, Texas, USA. Applied Geochemistry, 121, 104688.
Abstract: Carbon dioxide (CO2) enhanced oil recovery (EOR) provides a pathway for economic reuse and storage of CO2, a greenhouse gas. One challenge with this practice is ensuring CO2 injection does not result in target reservoir fluids migrating into overlying shallow (\textless1000 m) groundwater formations. Effective monitoring for leakage from storage formations could involve measuring sensitive chemical indicators in overlying groundwater units and within the producing formation itself for evidence of deviation from an initial state. In this study, produced waters and overlying groundwaters were monitored over a five-year period to evaluate which geochemical signals may be useful to ensure that oilfield produced waters did not impact overlying groundwaters. During this five-year period, a mature carbonate oil reservoir in the Permian Basin transitioned from a waterflooding operation to a water-alternating-gas injection (WAG), in which the formation was flooded with CO2 and various mixtures of produced water. Significant increases in dissolved inorganic constituents [alkalinity, TDS, Na+, Cl−, SO42−] were observed in produced waters following CO2 injection; however, carbonate reservoir dissolution-precipitation reactions appear to be minimal and injected CO2 appears to be stored via solubility trapping. Although there are statistically significant geochemical variations following CO2 injection, applying isometric log-ratios to certain parameters establishes a narrow range for post-CO2 injection produced waters. This narrow range can be considered a baseline for post-CO2 injection produced waters; this baseline can be utilized to monitor overlying local groundwaters for produced water intrusion. Additionally, certain parameters [Na+, Ca2+, K+, Cl−, alkalinity, and TDS] display large concentration disparities between produced water and overlying groundwaters; these parameters would be sensitive indicators of produced water intrusion into overlying groundwaters.
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Rooyen, J. D. van, Watson, A. W., & Miller, J. A. (2022). Using tritium and radiocarbon activities to constrain regional modern and fossil groundwater mixing in Southern Africa. Journal of Hydrology, 614, 128570.
Abstract: This study combines historical records of 14C and 3H in the atmosphere and soil with renewal rate and groundwater lumped parameter models to predict the abundance of 14C and 3H in groundwater over time. 624 groundwater samples from numerous studies, over four decades (1978–2019), in South Africa, Namibia, Botswana and Mozambique were collated to compare with predicted groundwater activities of 14C and 3H within the South African Development Community (SADC) region. Spatial datasets of carbonate bearing lithology, C3/C4 vegetation, summer/winter rainfall and coastal proximity were used to apply corrections to 14C and 3H data. Corrected values of 14C and 3H were compared with the theoretical abundance of these tracers, derived from the lumped parameter models, to estimate the general mean residence times and presence of groundwater mixing between modern recharge and older groundwaters. This study found that corrected values produced varying mean residence times derived from 14C ages (∼500–28500 years) and a wide range of potentially mixed waters within each aquifer system (0–100 % of tested wells) across the study area. The largest proportions of mixed groundwater, as well as the youngest mean residence times, were found in alluvial and primary fractured rock aquifers (e.g., western coast of South Africa and southern Mozambique). The smallest proportions of mixed groundwater were predicted in deep confined clay-rich aquifers as well as layered coal bearing carbonate sequences (e.g., Orapa, Malwewe and Serowe, Botswana). Insights into the proportions of mixed groundwater and mean residence times can help assess hydrological resilience on a regional scale. Such information is pertinent in promoting socio-economic development and increased water/food security in the SADC region. By understanding the resilience of groundwater resources, robust and informed strategies for water equality and GDP growth in the SADC region can be envisioned and implemented.
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