Background
Objectives
Urban Monitoring
Network
Spring Monitoring
In-Storm
Field Observations
Sprinkling
Experiments
Large Scale
Rainfall-Runoff Modelling
Database
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The field results were
used to directly determine parameters of a physically based, non-calibrated
rainfall-runoff model for the 250 km2 catchment of Nahal Natuf.
On natural, non terraced slopes runoff generation was quantified according to the results
of the sprinkling experiments, on urban areas all rainfall was assumed to turn into
immediate runoff.
To illustrate the impacts of urban development three different model
runs for one high magnitude flood (1991/1992) were performed. The first totally
disregarded the urban areas, the second included only those visible on airphotos of 1967,
the third included those of a 1994 land use map.
A catchment-wide urbanisation of 7.7% (1994) resulted in a simulated
16% increase in runoff peak and a 35% increase in runoff volume. Due to the high model
uncertainty (± 40 % in the simulated peak), these results must be treated with caution
and depend on event and catchment characteristics. Still the model helps to detect
possible shortcomings in hydrometric streamflow data and proves, on a regional scale, the
negative impacts of urbanization in an area with restricted water resources.
Simulated
hydrographs at different locations
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