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Schmittner, K. - E., & Giresse, P. (1999). The impact of atmospheric sodium on erodibility of clay in a coastal Mediterranean region. Environmental Geology, 37(3), 195–206.
Abstract: Heavy rainfalls, between 25 and 100 mm·h–1, were simulated on Pliocene/Quaternary sediments. To reproduce the heterogeneity of natural environments, 231 small plots of various sizes (between 2.5 and 3.5 m2; mean: about 3 m2) were used. The duration of all simulations was 1 h. We used water that had been collected during natural rainfall. The concentration of clay particles in the sheet wash depended upon the concentration of dissolved sodium in the wash (for about 42%) and of the sheet wash quantity (for about 37%). Under natural water conditions colloidal matter, like clay minerals, is charged negatively and therefore is destabilized by metal cations such as in the case of Na+. Results suggest that relatively higher concentrations of montmorrillonite were related to higher concentrations of sodium as opposed to illite and kaolinite. Microflakes of up to 25 μ were observed to vary between face-to-edge and face-to-face modes (competition between protons and other cations). The concentration of dissolved sodium (Na+) in the runoff water depends on water and sodium balances such as atmospheric input, infiltration, evaporation and surface water runoff. The reduction of vegetation cover increases the amount of salt and amorphous matter in/on the topsoil between heavy rainfall generations. The best predictor to explain montmorillonite, illite and kaolinite in % of mineral clay-sized matter in the surface water runoff (sheet wash) is the percentage of each clay mineral in the topsoil. As opposed to illite and kaolinite, more sheet wash indicate for montmorillonite relatively higher concentrations in the wash. The results of model simulations were confirmed on different field plots of about 1 ha and small catchments during natural heavy rainfall events. Models can also be used to understand and to better simulate sheet, rill and gully erosion, micropedimentation; and pedimentation.
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Morales-Baquero, R., Pulido-Villena, E., & Reche, I. (2013). Chemical signature of Saharan dust on dry and wet atmospheric deposition in the south-western Mediterranean region. Tellus B: Chemical and Physical Meteorology, 65(1), 18720.
Abstract: We studied if the presence of Saharan dust intrusions and the rains modify the chemical signature of the wet and dry deposition in the southern Iberian Peninsula. We have sorted the 109 sampling weeks by the presence (rainy weeks) or absence (dry weeks) of rain and by the occurrence or not of Saharan dust intrusions. Dry deposition dominated the delivery of particulate material (PM), total phosphorus (TP), soluble reactive phosphorus (SRP), Ca2+, Mg2+ and K+, whereas wet deposition dominated the delivery of Na+, total nitrogen, and . In the dry weeks, the presence of Saharan dust intrusions lead to higher inputs of PM, TP, SRP, Ca2+, Mg2+ and K+ in the dry deposition. Conversely, in the rainy weeks, there were no differences in mean values of dry deposition irrespective of the occurrence of Saharan dust intrusions. Nevertheless, in the presence of Saharan intrusions and some rain, the weekly collection of PM, TP and Ca2+ in dry deposition were significantly higher and increased as rainfall was lower. By contrast, the ions Cl– and Na+ in wet deposition were higher in absence of Saharan dust intrusion and increased as rainfall increased.
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Celle-Jeanton, H., Travi, Y., Loÿe-Pilot, M. - D., Huneau, F., & Bertrand, G. (2009). Rainwater chemistry at a Mediterranean inland station (Avignon, France): local contribution versus long-range supply. Atmospheric Research, 91(1), 118–126.
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Demirak, A., Balci, A., Karaoğlu, H., & Tosmur, B. (2006). Chemical characteristics of rain water at an urban site of south western Turkey. Environmental monitoring and assessment, 123(1-3), 271–283.
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El-Sayed, S. A., Ramadan, A. B., Salama, M. H., & Diab, M. (2015). Geochemical and Radiological Characteristics of Harvested Rainwater and Surficial Soil in El-Alamein-Alam El-Rum Area, Western Mediterranean Coastal Zone, Egypt. Isotope and Radiation Research, 47(2), 177–198.
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