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KarstBase a bibliography database in karst and cave science.
Featured articles from Cave & Karst Science Journals
Characterization of minothems at Libiola (NW Italy): morphological, mineralogical, and geochemical study, Carbone Cristina; Dinelli Enrico; De Waele Jo
Chemistry and Karst, White, William B.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
The karst paradigm: changes, trends and perspectives, Klimchouk, Alexander
Long-term erosion rate measurements in gypsum caves of Sorbas (SE Spain) by the Micro-Erosion Meter method, Sanna, Laura; De Waele, Jo; Calaforra, José Maria; Forti, Paolo
Featured articles from other Geoscience Journals
Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
Karst processes and landforms, De Waele, J.
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
Biogeochemistry, 2005, Vol 72, Issue 1, p. 67-86
Estimation of denitrification potential in a karst aquifer using the N-15 and O-18 isotopes of NO3-
Einsiedl F, Maloszewski P, Stichler W,
Abstract:
A confined aquifer in the Malm Karst of the Franconian Alb, South Germany was investigated in order to understand the role of the vadose zone in denitrifiaction processes. The concentrations of chemical tracers Sr2 and Cl- and concentrations of stable isotope O-18 were measured in spring water and precipitation during storm events. Based on these measurements a conceptual model for runoff was constructed. The results indicate that pre-event water, already stored in the system at the beginning of the event, flows downslope on vertical and lateral preferential flow paths. Chemical tracers used in a mixing model for hydrograph separation have shown that the pre-event water contribution is up to 30%. Applying this information to a conceptual runoff generation model, the values of delta(15)N and delta(18)O in nitrate could be calculated. Field observations showed the occurence of significant microbial denitrification processes above the soil/ bedrock interface before nitrate percolates through to the deeper horizon of the vadose zone. The source of nitrate could be determined and denitrification processes were calculated. Assuming that the nitrate reduction follows a Rayleigh process one could approximate a nitrate input concentration of about 170 mg/l and a residual nitrate concentration of only about 15%. The results of the chemical and isotopic tracers postulate fertilizers as nitrate source with some influence of atmospheric nitrate. The combined application of hydrograph separation and determination of isotope values in delta(15)N and delta(18)O of nitrate lead to an improved understanding of microbial processes (nitrification, denitrification) in dynamic systems
A confined aquifer in the Malm Karst of the Franconian Alb, South Germany was investigated in order to understand the role of the vadose zone in denitrifiaction processes. The concentrations of chemical tracers Sr2 and Cl- and concentrations of stable isotope O-18 were measured in spring water and precipitation during storm events. Based on these measurements a conceptual model for runoff was constructed. The results indicate that pre-event water, already stored in the system at the beginning of the event, flows downslope on vertical and lateral preferential flow paths. Chemical tracers used in a mixing model for hydrograph separation have shown that the pre-event water contribution is up to 30%. Applying this information to a conceptual runoff generation model, the values of delta(15)N and delta(18)O in nitrate could be calculated. Field observations showed the occurence of significant microbial denitrification processes above the soil/ bedrock interface before nitrate percolates through to the deeper horizon of the vadose zone. The source of nitrate could be determined and denitrification processes were calculated. Assuming that the nitrate reduction follows a Rayleigh process one could approximate a nitrate input concentration of about 170 mg/l and a residual nitrate concentration of only about 15%. The results of the chemical and isotopic tracers postulate fertilizers as nitrate source with some influence of atmospheric nitrate. The combined application of hydrograph separation and determination of isotope values in delta(15)N and delta(18)O of nitrate lead to an improved understanding of microbial processes (nitrification, denitrification) in dynamic systems
Keywords: aquifer, bedrock, chemical tracers, cl, conceptual model, conceptual-model, denitrification, event water, events, field, flow, flows, germany, groundwater, headwater catchment, hydrograph, hydrograph separation, hydrograph separations, information, input, interface, isotope, isotopes, isotopes karst, isotopic tracers, karst, karst aquifer, lead, microbial processes, mixing, model, n-15, nitrate, nitrification, nitrogen, o-18, precipitation, preferential flow, reduction, runoff, runoff generation, separation, source, south, south-central indiana, spring, stable isotope, stable-isotope, storm, stormflow, system, systems, time, times, toluene, tracer, tracers, vadose zone, values, water, zone,