HS02p  IAHS (Hydrology)
HS02 Hydrologic Non-Stationarity and Extrapolating Models to Predict the Future

27-Jun-2015 15:00 16:30
Abstract: HS02p-031
Scaling behaviour in the relationship between land use changes and flood regime

Socio-economic activities taking place in a watershed produce changes in land uses that modify the behaviour of infiltration and its relationship with the generation of surface runoff. This study has two main objectives: a) determine the effect of the static storage (initial abstractions plus soil capillary retention) and saturated infiltration capacity variation on the flood magnitude, and; b) incorporate the scalability properties of fractal models to describe the flood variability with respect to changes in static storage. The study area corresponds to the Combeima River basin in Colombia, South America, where historic changes in land use between 1991 and 2007 were analysed, along with the watershed’s hydrological response, modelled through a distributed hydrological model. A frequency analysis was carried out with the Generalized Extreme Value (GEV) and Gumbel probability distribution functions. Later, a joint estimation of scaling theory was implemented to synthesise regularities of flood behaviour using the mean watershed static storage and saturated infiltration capacity as scales. This scaling behaviour was found not only for the flood moments, but also for the probability distribution parameters. The obtained results were useful to determine that, through potential equations, it is possible to describe both the variation in static storage brought about by land use changes and the magnitude of flood quantiles.

L.E. Peña Rojas1,2,3, F. Francés García2, M.I. Barrios3.
1Research Group on Environment and Energy (GMAE), Universidad de Ibagué, Ibagué, Colombia.
2Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Valencia, Spain.
3Forest Engeenering Faculty, Universidad del Tolima, Ibagué Tolima, Columbia.


Keywords: land use changes     flood regime     scalability properties     flood variability     Frequency analysis