Abstract - Soil erosion in the Apennines is a relevant issue, being a cause of farming land degradation and abandonment of mountain areas caused by a lack of direct and indirect erosion control practices. Estimates of soil erosion activity in mountain basins are usually made with a significant uncertainty, because few data are available to calibrate erosion models or to estimate eroded soil amounts, thus leading to an inability to take decisions in conservation policy. In this study the mountain basin of the Gaiana torrent (8,6 km2) in the Apennines near Bologna (Italy), is examined in order to estimate the basin soil loss according to three different methods: the application of Universal Soil Loss Equation to make the USLE basin map, the second is the preparation of the geomorphologic and erosion map through photogrammetric interpretation of aerial photography, and finally estimating yearly suspended sediment yield (SSY). SSY has been assessed at mountain basin outlet, through a linear model built on a flow and suspended sediment concentration ten years dataset of the nearby instrumented Sillaro torrent. The USLE analyses on the whole basin but badlands predicted 11,100 Mg y-1 soil loss, a per-unit-area sediment flux rate is of 15 Mg ha-1 y-1. Finally the Gaiana sediment delivery ratio, estimated from the soil loss rate of the basin by USLE and yearly SSY, resulted about 29%. ARTICOLO ALLEGATO 1-5
Donatella Pavanelli, A. Bigi, M. Rigotti (2009). A multiple approach to estimate soil erosion and sediment sources in a small Apennines watershed: USLE, photogrammetric analysis and suspended sediment yield. REGGIO CALABRIA : ARTEMIS.
A multiple approach to estimate soil erosion and sediment sources in a small Apennines watershed: USLE, photogrammetric analysis and suspended sediment yield
PAVANELLI, DONATELLA;BIGI, ALESSANDRO;RIGOTTI, MARCO
2009
Abstract
Abstract - Soil erosion in the Apennines is a relevant issue, being a cause of farming land degradation and abandonment of mountain areas caused by a lack of direct and indirect erosion control practices. Estimates of soil erosion activity in mountain basins are usually made with a significant uncertainty, because few data are available to calibrate erosion models or to estimate eroded soil amounts, thus leading to an inability to take decisions in conservation policy. In this study the mountain basin of the Gaiana torrent (8,6 km2) in the Apennines near Bologna (Italy), is examined in order to estimate the basin soil loss according to three different methods: the application of Universal Soil Loss Equation to make the USLE basin map, the second is the preparation of the geomorphologic and erosion map through photogrammetric interpretation of aerial photography, and finally estimating yearly suspended sediment yield (SSY). SSY has been assessed at mountain basin outlet, through a linear model built on a flow and suspended sediment concentration ten years dataset of the nearby instrumented Sillaro torrent. The USLE analyses on the whole basin but badlands predicted 11,100 Mg y-1 soil loss, a per-unit-area sediment flux rate is of 15 Mg ha-1 y-1. Finally the Gaiana sediment delivery ratio, estimated from the soil loss rate of the basin by USLE and yearly SSY, resulted about 29%. ARTICOLO ALLEGATO 1-5I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
