5 research outputs found
DOC and Nitrate fluxes from farmland; impact on a dolostone aquifer KCZ
DOC and nitrate in farmland represent key chemical species that
determine the water quality in the Karst Critical Zone (KCZ). The work
reported here focuses on quantifying fluxes of these species in an
experimental farm site (University of Leeds Farm, UK) overlying a
dolomitic karst aquifer of Permian age. In this research, the Transect
Method was applied for the first time to farmland by combining
hydrochemical data from soil and groundwater for computation of mass
fluxes. The Transect Method, developed for management of industrially
contaminated sites, was applied to a farm source due to the presence of
localised contamination from application of pig slurry.
Required inputs for our approach include concentrations of nitrate and
DOC in soil water and groundwater, net recharge flux (here derived from a
MODFLOW-2005 model) and local hydraulic gradient and conductivity
measurements. Key outputs are fluxes and downstream groundwater
concentrations of DOC and nitrate. Downstream concentrations were
validated against direct groundwater measurements, demonstrating the
veracity of the approach. The approach shows that the localised
contamination has a significant impact on both concentrations of nitrate
and DOC in groundwater, although the DOC impact is greater, because the
upstream land uses also produce nitrate as a result of agricultural
practices that are widespread in the region.
The results of the study also constrain the zone vulnerable to
contamination to the upper ~40 m below the ground surface. Future
modelling efforts on solute contaminant transport should focus on this
shallow vulnerability zone (0-40 mBGL) and the Transect Method applied in
this work can be used to define boundary conditions.
Hence, following this research, we envisage to export a generic approach
that combines physical flow parameters and hydrochemical analyses for
computation of subsurface mass fluxes using the Transect Method, to
identify the degree of impact of specific point sources and to support
conceptualization and modelling of contaminant transport in the KCZ of farm areas
Corrado Gini: the man and the scientist
The paper discusses the times in which Corrado Gini lived in an attempt to enrich our picture of him by adding some further information to his complex personality