""The spatial distribution of rainfall is recognized to play a fundamental role in determining the hydrolog- 25. ical response of river basins. Factors which dampen or enhance its role, while extensively discussed in 26. previous literature, have not been fully assessed. We propose an analytical approach to investigate 27. how basin hydrograph depends on the heterogeneity of a spatially distributed unit pulse of excess- 28. rainfall. Catchment response is assumed to be completely described for a uniform input by the time- 29. invariant distribution of travel times, derived through a geomorphological approach. Excess-rainfall field 30. is represented as a stationary and isotropic random process, defined by its variance and integral scale. The 31. uncertainty of the hydrologic response due to rainfall spatial variability is evaluated computing the var- 32. iance of the generated hydrograph as function of the properties of both drainage basin and excess-rainfall 33. field. Results suggest that hydrograph variability is negligible in the asymptotic conditions when the 34. integral scale of the excess-rainfall field is much smaller or much larger than basin drainage area. For 35. intermediate conditions, rainfall heterogeneity may still produce relevant effects; these have been inves- 36. tigated (i) deriving the analytical solution for the simple case of a rectangular sloping plane and (ii) per- 37. forming numerical simulations on a real basin. Results appear to be of general interest, all the 38. approximations notwithstanding.""
Volpi, E., DI LAZZARO, M., Fiori, A. (2012). A simplified framework for assessing the impact of rainfall spatial variability on the hydrologic response. ADVANCES IN WATER RESOURCES, 46, 1-10 [10.1016/j.advwatres.2012.04.011].
A simplified framework for assessing the impact of rainfall spatial variability on the hydrologic response
VOLPI, ELENA;DI LAZZARO, MICHELE;FIORI, ALDO
2012-01-01
Abstract
""The spatial distribution of rainfall is recognized to play a fundamental role in determining the hydrolog- 25. ical response of river basins. Factors which dampen or enhance its role, while extensively discussed in 26. previous literature, have not been fully assessed. We propose an analytical approach to investigate 27. how basin hydrograph depends on the heterogeneity of a spatially distributed unit pulse of excess- 28. rainfall. Catchment response is assumed to be completely described for a uniform input by the time- 29. invariant distribution of travel times, derived through a geomorphological approach. Excess-rainfall field 30. is represented as a stationary and isotropic random process, defined by its variance and integral scale. The 31. uncertainty of the hydrologic response due to rainfall spatial variability is evaluated computing the var- 32. iance of the generated hydrograph as function of the properties of both drainage basin and excess-rainfall 33. field. Results suggest that hydrograph variability is negligible in the asymptotic conditions when the 34. integral scale of the excess-rainfall field is much smaller or much larger than basin drainage area. For 35. intermediate conditions, rainfall heterogeneity may still produce relevant effects; these have been inves- 36. tigated (i) deriving the analytical solution for the simple case of a rectangular sloping plane and (ii) per- 37. forming numerical simulations on a real basin. Results appear to be of general interest, all the 38. approximations notwithstanding.""I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
