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Improving Distributed Runoff Prediction in Urbanized Catchments with Remote Sensing based Estimates of Impervious Surface Cover

View Article: PubMed Central - PubMed

ABSTRACT

The amount and intensity of runoff on catchment scale are strongly determined by the presence of impervious land-cover types, which are the predominant cover types in urbanized areas. This paper examines the impact of different methods for estimating impervious surface cover on the prediction of peak discharges, as determined by a fully distributed rainfall-runoff model (WetSpa), for the upper part of the Woluwe River catchment in the southeastern part of Brussels. The study shows that detailed information on the spatial distribution of impervious surfaces, as obtained from remotely sensed data, produces substantially different estimates of peak discharges than traditional approaches based on expert judgment of average imperviousness for different types of urban land use. The study also demonstrates that sub-pixel estimation of imperviousness may be a useful alternative for more expensive high-resolution mapping for rainfall-runoff modelling at catchment scale.

No MeSH data available.


Comparison of hydrographs for the 3 scenarios using Ikonos data for the period 3rd of May 2005 1.00 am till 6th of May 2005 9.00 am.
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f9-sensors-08-00910: Comparison of hydrographs for the 3 scenarios using Ikonos data for the period 3rd of May 2005 1.00 am till 6th of May 2005 9.00 am.

Mentions: Finally, in scenario 3 each cell in the urban area is assigned its own proportion of impervious surfaces, vegetation, water and bare soil, as obtained from the Ikonos- and Landsat-derived proportion maps. Analysing and comparing the results for the 3 scenarios, the runoff calculated in scenario 3, and based on the Ikonos data, produces the highest peak discharges. The peak discharges are up to 15 % higher than in the non-distributed simulation based on Ikonos data (scenario 1) (Figure 9). Using cell-specific information about the spatial distribution of imperviousness within urban areas seems to have a clear impact on the modelling of peak discharges at the outlet of the catchment and, as such, on flood prediction. Even for less intense rainfall events, the effect of using detailed information on the spatial distribution of impervious surfaces for estimating peak discharges is clear. The spatial variation in runoff is obvious from the map of runoff coefficient values obtained for scenario 3 (Figure 11). High values for the runoff coefficient, in the range of 0.8-1.0, prove to be linked to a closely connected pattern of impervious areas.


Improving Distributed Runoff Prediction in Urbanized Catchments with Remote Sensing based Estimates of Impervious Surface Cover
Comparison of hydrographs for the 3 scenarios using Ikonos data for the period 3rd of May 2005 1.00 am till 6th of May 2005 9.00 am.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3927506&req=5

f9-sensors-08-00910: Comparison of hydrographs for the 3 scenarios using Ikonos data for the period 3rd of May 2005 1.00 am till 6th of May 2005 9.00 am.
Mentions: Finally, in scenario 3 each cell in the urban area is assigned its own proportion of impervious surfaces, vegetation, water and bare soil, as obtained from the Ikonos- and Landsat-derived proportion maps. Analysing and comparing the results for the 3 scenarios, the runoff calculated in scenario 3, and based on the Ikonos data, produces the highest peak discharges. The peak discharges are up to 15 % higher than in the non-distributed simulation based on Ikonos data (scenario 1) (Figure 9). Using cell-specific information about the spatial distribution of imperviousness within urban areas seems to have a clear impact on the modelling of peak discharges at the outlet of the catchment and, as such, on flood prediction. Even for less intense rainfall events, the effect of using detailed information on the spatial distribution of impervious surfaces for estimating peak discharges is clear. The spatial variation in runoff is obvious from the map of runoff coefficient values obtained for scenario 3 (Figure 11). High values for the runoff coefficient, in the range of 0.8-1.0, prove to be linked to a closely connected pattern of impervious areas.

View Article: PubMed Central - PubMed

ABSTRACT

The amount and intensity of runoff on catchment scale are strongly determined by the presence of impervious land-cover types, which are the predominant cover types in urbanized areas. This paper examines the impact of different methods for estimating impervious surface cover on the prediction of peak discharges, as determined by a fully distributed rainfall-runoff model (WetSpa), for the upper part of the Woluwe River catchment in the southeastern part of Brussels. The study shows that detailed information on the spatial distribution of impervious surfaces, as obtained from remotely sensed data, produces substantially different estimates of peak discharges than traditional approaches based on expert judgment of average imperviousness for different types of urban land use. The study also demonstrates that sub-pixel estimation of imperviousness may be a useful alternative for more expensive high-resolution mapping for rainfall-runoff modelling at catchment scale.

No MeSH data available.