H13C-1546
Modeling the fate of nitrogen on the catchment scale using a spatially explicit hydro-biogeochemical simulation system
Monday, 14 December 2015
Poster Hall (Moscone South)
Steffen Klatt, Karlsruhe Institute of Technology, Institute for Meterology and Climate Research - Institute for Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
Abstract:
The continuous growth of the human population demands an equally growing supply
for fresh water and food. As a result, available land for efficient
agriculture is constantly diminishing which forces farmers to cultivate
inferior croplands and intensify agricultural practices, e.g., increase the use
of synthetic fertilizers. This intensification of marginal areas in particular
will cause a dangerous rise in nitrate discharge into open waters or even
drinking water resources. In order to reduce the amount of nitrate lost by
surface runoff or lateral subsurface transport, bufferstrips have proved to be
a valuable means. Current laws, however, promote rather static designs (i.e.,
width and usage) even though a multitude of factors, e.g., soil type, slope,
vegetation and the nearby agricultural management, determines its
effectiveness. We propose a spatially explicit modeling approach enabling to
assess the effects of those factors on nitrate discharge from arable lands
using the fully distributed hydrology model CMF coupled to the complex
biogeochemical model LandscapeDNDC. Such a modeling scheme allows to observe
the displacement of dissolved nutrients in both vertical and horizontal
directions and serves to estimate both their uptake by the vegetated
bufferstrip and loss to the environment. First results indicate a significant
reduction of nitrate loss in the presence of a bufferstrip (2.5 m). We show
effects induced by various buffer strip widths and plant cover on the nitrate
retention.