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Constantinou, C., & Udluft, P. (2000). Mapping the availability and dynamics of groundwater recharge. Part 2: Case studies from Mediterranean Basins. In Proceedings of Third Congress on Regional Geological Cartography and Information Systems (pp. 163–168).
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Külls, C. (2000). Resolving patterns of groundwater flow by inverse hydrochemical modelling in a semiarid Kalahari. In Tracers and Modelling in Hydrogeology: TraM’2000: Proceedings of TraM’2000, the International Conference on Tracers and Modelling in Hydrogeology Held at Liège, Belgium, in May 2000 (447).
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Udluft, P., & Külls, C. (2000). Mapping the availability and dynamics of groundwater recharge. Part 1: modelling techniques. In Proceedings of the Third Congress on Regional Geological Cartography and Information Systems (pp. 337–340).
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Külls, C., Jobin, J., & Weiler, M. (2015). Environmental analytics for water carbon management: enable WCM: Schlussbericht. Albert Ludwigs Universität, Professur für Hydrologie.
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Udluft, P., Dünkeloh, A., Mederer, J., Külls, C., & Schaller, J. (2006). Re-evaluation of the groundwater resources of Cyprus. Lefkosia.
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Adar, E. M., & Külls, C. (2002). MCM sf–Mixing-cell model for a steady flow MIG–Mixing-cell input generator: A short manual for installation and operation of MCM sf using the MIG–mixing-cell input generator.
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Heaton, T. H. E., Talma, A. S., & Vogel, J. C. (1983). Origin and history of nitrate in confined groundwater in the western Kalahari. Journal of Hydrology, 62(1), 243–262.
Abstract: Data are presented for nitrate, dinitrogen and argon concentrations and 15N14N ratios in groundwater, with radiocarbon ages up to 40,000 yr. for three confined sandstone aquifers in the western Kalahari of South West Africa/Namibia. The nitrate is probably generated within the soil of the recharge areas, and its production rate during the period 3000-40,000 B.P. has remained between 0.5 and 1.6 meq NO−3l−1 of recharge water, with ° 15N between + 4 and + 8‰. Variations in the amount of nitrate and of “excess air” in groundwater recharge are found, and can only reflect changes in the environmental conditions during recharge. They must therefore be caused by the climatic changes that have taken place during the past 25,000 yr.
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Gasse, F. (2000). Hydrological changes in the African tropics since the Last Glacial Maximum. Quaternary Science Reviews, 19(1), 189–211.
Abstract: Paleohydrological data from the African tropics and subtropics, including lake, groundwater and speleothem records, are reviewed to show how environments and climates from both hemispheres are inter-related. Although orbitally induced changes in the monsoon strength account for a large part of long-term climatic changes in tropical Africa, the Late Pleistocene–Holocene hydrological fluctuations rather appear to have been a series of abrupt events that reflect complex interactions between orbital forcing, atmosphere, ocean and land surface conditions. During the Last Glacial Maximum (23–18ka BP), most records indicate that generally dry conditions have prevailed in both hemispheres, associated with lower tropical land- and sea-surface temperatures. This agrees with simulations using coupled ocean–atmosphere models, which predict cooling and reduced summer precipitation in tropical Africa; the global hydrological cycle was weaker than today when the extent of large polar ice-sheets and sea-ice was a prominent forcing factor of the Earth’s climate. Glacial-interglacial climatic changes started early: a first wetting/warming phase at ca. 17–16ka BP took place during a period of rapid temperature increase in Antarctica. Next, two drastic arid-humid transitions in equatorial and northern Africa occurred around 15–14.5ka BP and 11.5–11ka BP. Both are thought to match the major Greenland warming events, in concert with the switching of the oceanic thermohaline circulation to modern mode. However, part of the climatic signal after 15 ka BP also seems related to the Antarctica climate. During the Holocene, Africa has also experienced rapid hydrological fluctuations of dramatic magnitude compared to the climatic changes at high latitudes. In particular, major dry spells occurred around 8.4–8ka and 4.2–4ka BP in the northern monsoon domain. Comparison with other parts of the world indicates that these events have a worldwide distribution but different regional expressions. In the absence of large polar ice sheets, changes in the continental hydrological cycles in the tropics may have a significant impact on the global climate system. Climate information gathered here allows to identify geographical and methodological gaps, and raise some scientific questions that remain to be solved to better understand how the tropics respond to changes in major climate-forcing factors, and how they influence climate globally.
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Brook, G. A., Marais, E., Srivastava, P., & Jordan, T. (2007). Timing of lake-level changes in Etosha Pan, Namibia, since the middle Holocene from OSL ages of relict shorelines in the Okondeka region. Quaternary International, 175(1), 29–40.
Abstract: In 2003 examination of aerial photographs revealed a series of previously unknown relict shorelines on the arcuate ridge, possibly a clay lunette dune, that marks the western boundary of Etosha Pan in Namibia. The shorelines are 120–600m wide and the most prominent extend for tens of km around the lunette dune. The shorelines were examined on the ground in 2004 and an attempt was made to date the three lowest levels at ca. 5, 2.5 and 1m above the present pan surface. The OSL ages obtained indicate higher and more prolonged lake conditions than today at ca. 6.4, 4.0 and 2.1ka with the youngest shoreline sediments resting on an ancient pan surface dating to ca. 13ka. The evidence indicates dry conditions in the pan at ca. 13ka, wetter conditions and higher lake levels in the middle Holocene followed by a decline in lake levels to the present. Periods of inundation were of sufficient duration to produce shorelines at the southwestern end of the pan due to the prevailing northeasterly winds that would have maximized wave action along this section of the pan margin. The Etosha findings, together with other regional paleoclimate data, suggest four periods of increased wetness in SW Africa during the Holocene at 7–5, 4.5–3.5, 2.5–1.7 and ca. 1.0ka. There is widespread evidence for the oldest of these periods suggesting that it was a prominent and widespread interval of wetness. Prior to ca. 8.0ka the climate may have been drier than today.
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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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