Rainwater chemistry at the eastern flanks of the Sierra Madre Oriental, Veracruz, Mexico

Abstract

Abstract. A rainwater chemistry study was carried out at a single site in Xalapa located at the eastern flanks of the Sierra Madre Oriental, Veracruz, Mexico, during the rainy and dry seasons under the influence of different meteorological conditions. Rain samples were analyzed for the most important ions. The statistical results indicated that there were significant differences at the 95% confidence level between the ionic concentration measured in samples collected in both seasons. The lower concentration values found during the rainy season could be attributed to dilution processes since in this season 79% of the annual precipitation occurs, compared to only 21% in the dry season. High and positive ion-pair correlations were found among the most important ions in both seasons. Although Xalapa is situated at less than 100 km from the coast, marine contribution of SO42-and Ca 2+ is negligible compared with the nonmarine contribution. In the rainy season, enrichment of SO42-, NH•-, and NO•-is due to upwind medium-and long-distance emission sources of Veracruz, as back trajectories of the predominant winds from the southeast indicate. On the other hand, in the dry season this enrichment is due to emission sources situated in Tampico, Madero, and Poza Rica and south-southeastern Texas, as indicated by the predominant winds from the northeast. Finally, wet deposition rates were, as expected, higher during the rainy season in spite of the dilution processes. [1978] reported that slow moving active frontal systems and anticyclones, characterized by the convergence of moist air and by light winds that prevail for several days, respectively, favor the occurrence of episodes of sulfate wet deposition. Singh and Noberr [1982] showed that precipitation acidity was inherently related to air masses in Quebec, Canada. Colin et al. [1989] reported that two main mechanisms are responsible for the enrichment of rain: the dissolution of gases and the impacting of particles that occur in the air column below the cloud base, when raindrops fall (a local phenomenon), and the incorporation of gases and aerosols to the 23,329

Land use change effects on runoff generation in a humid tropical montane cloud forest region

“…2.4.4). Because wet season rainfall in this area is primarily of convective origin (Báez et al, 1997), this type of rain-producing system was particularly targeted for the rainfall-runoff sampling. The following criteria were used to decide whether a storm event sampled was considered for isotope analysis: (1) rainfall had to be greater than 20 mm to ensure a substantial rise in the stream hydrograph, and (2) the sampling should have covered the entire stream hydrograph and include at least one baseflow sample before the storm started.…”

Seasonal and temporal changes in the fluxes of major inorganic ions via wet and dry depositions, observed in Matsumoto, central Japan

“…However, it has been reported that cyclones passing through the south of Honshu, and not winter monsoon pressure patterns, have led to higher concentrations of acidic chemical substances in the winter precipitation (Suzuki and Endo, Y., 1994). Long-term fluctuations, such as seasonal and yearly fluctuations, have been reported in many papers (e.g., Al-Momani et al, 1998;Andreae et al, 1990;Baez et al, 1997;Galloway et al, 1996;Jordan et al, 2000;Stottlemyer and Toczydlowski, 1999).…”

Captación de agua de lluvia y niebla en la época de secas en la ciudad de Xalapa, Veracruz, México

“…Entre los trabajos que se han realizado, se encuentran los de Padilla et al, (1996) y Báez et al, (1997, quienes encontraron que en 17 horas y media se pueden captar hasta 219.1 mm de agua y que la composición química de la niebla puede ser afectada por las actividades urbanas. Barradas (1983) midió la capacidad de captura natural de niebla por parte de un pino (Pinus montezumae) y encontró que estos pinos pueden captar en promedio 57.9 L/h.…”