The EROSFIRE project (POCI/AGR/60354/2004), funded by Portugal's Foundation for Science and Techn... more The EROSFIRE project (POCI/AGR/60354/2004), funded by Portugal's Foundation for Science and Technology (FCT), has as overall aim the development of a software tool that allows to assess and map, at the scale of individual hill slopes, soil erosion hazard in recently burned forest areas for different scenarios of post-fire land management. At the origin of the EROSFIRE project was the ''Soil losses after the forest fires of the summer of 2003''-map elaborated by Portugal's Water Institute (INAG) using some modified version of the Universal Soil Loss Equation (USLE), and the idea to test the applicability of erosion models with a more up-to-date scientific basis than USLE.
The Limburg Soil Erosion Model (LISEM) soil erosion model was calibrated for a 2-km 2 catchment o... more The Limburg Soil Erosion Model (LISEM) soil erosion model was calibrated for a 2-km 2 catchment on the Chinese Loess Plateau. The most important calibration factors were saturated conductivity and Manning's n. Calibration on catchment discharge was done by using the discharge peak (timing and discharge) followed by an adjustment for the total discharge to obtain the correct amount of sediment output. The results showed that LISEM can be successfully calibrated for a Loess Plateau catchment, and that small runoff events need to be calibrated separately from large runoff events. A separate calibration might even be needed for each event. The model performance was also evaluated using catchment wide spatially distributed data on rill erosion. Rill erosion intensity was mapped in the field and compared to spatial patterns of erosion predicted by LISEM. The simulated erosion patterns do show some resemblance with mapped erosion patterns in a general sense but they are very different in detail. The cause for this can be found in the extremely steep slopes and abrupt slope changes in the catchment. Some of the process descriptions in LISEM are not intended for such an environment, while the grid based kinematic wave routing cannot cope with the abrupt changes in flow conditions. The effects of this are amplified by inaccuracies in the input data and the DEM. For topographically complex catchments it will be very difficult to obtain data that are good enough for an accurate simulation of erosion patterns. This limits the use of a model such as LISEM as a predictive tool for future events. Simulation of different land use scenarios is less problematic, if a known event is used for all scenario simulations. D
Hydrology and Earth System Sciences Discussions, 2012
Four hydrological models (LISEM, MIKE SHE, CoupModel and HBV) were compared with respect to their... more Four hydrological models (LISEM, MIKE SHE, CoupModel and HBV) were compared with respect to their capability to predict peak flow in a small catchment upstream of a road in SE Norway on an hourly basis. All four models were calibrated using hourly observed streamflow. Simulated and observed discharge generated during three types 5 of hydrological situations characteristic of winter/spring conditions causing overland flow were considered: snowmelt, partially frozen soil and heavy rain events. Using parameter sets optimised for winter/spring conditions, flows simulated by HBV coupled with CoupModel were comparable to measured discharge from the catchment in corresponding periods. However, this combination was best when all the parameters were 10 calibrated in HBV. For ungauged basins with no real-time monitoring of discharge and when the spatial distribution is important, MIKE SHE may be more suitable than the other models, but the lack of detailed input data and the uncertainty in physical parameters should be considered. LISEM is potentially capable of calculating runoff from small catchments during winter/spring but requires better description of snowmelt, infiltration 15 into frozen layers and tile drainage. From a practical road maintenance perspective, the usefulness and accuracy of a model depends on its ability to represent site-specific processes, data availability and calibration requirements.
Surface runoff may be generated when the rainfall intensity exceeds the infiltration capacity, or... more Surface runoff may be generated when the rainfall intensity exceeds the infiltration capacity, or when the soil profile is saturated with water. Indications exist that both types of overland flow may occur in hilly agricultural loess regions. Here, for a loessial hillslope under maize in the southern part of The Netherlands, it was shown, with pressure head and runoff measurements, that Hortonian overland flow occurs during typical summer rain events. Surface runoff was initiated after saturation of the top 5-10cm of the soil. Deeper in the soil, unsaturated conditions prevailed while runoff took place. Peak runoff discharges at the outlet of the subcatchment occurred a few minutes after peak rainfall intensities were measured. It appeared that SWMS_2D, a two-dimensional water flow model, was capable in simulating observed pressure head changes and runoff. Simulated potential runoff for the transect studied was higher by a magnitude of three than the measured areal average. This indicates effects of surface ponding, and the probable location of this particular transect in a region with high runoff production.
A dam and weir system was constructed to measure the discharge of water and sediment from a selec... more A dam and weir system was constructed to measure the discharge of water and sediment from a selected small catchment on the Loess plateau in China. The aim of the system described here was to collect data on discharge and sediment content during occasional summer storms. ...
The Hilly Purple area of the Sichuan Basin has been degraded by constant soil erosion, which has ... more The Hilly Purple area of the Sichuan Basin has been degraded by constant soil erosion, which has reached to 3 035 t/km 2 . Soil erosion has direct negative effects on the productivity of the land by loss of nutrients, water and soil. This loss of productivity affects the farmers income. Also, it increases the pollution and siltation of the Yangtze river, causing several problems downstream. The EROCHINUT project has started in 1998 with the overall objective to develop a new methodology to improve land and water management on farm and watershed level in the current socio-economic situation by integrated use of participatory and soil erosion and nutrient modeling techniques. By using a calibrated model, calibrated on a small catchment, and upscale the results base on slope classes, a reliable view of possible effects of alternatives on these features is achieved. These results are visualized on maps, and act as support tools to discuss with farmers and policy makers on the feasibility and possibilities of alternative land use.
In opdracht van de provincie Noord-Brabant is een studie gedaan naar de totale nutriëntenbelastin... more In opdracht van de provincie Noord-Brabant is een studie gedaan naar de totale nutriëntenbelasting van het oppervlaktewater over geheel Noord-Brabant. Voor alle deelstroomgebieden binnen de verschillende waterschappen in Noord-Brabant is deze totale belasting en de relatieve bijdragen hieraan van diffuse en puntbronnen bepaald. Deze informatie is op kaart weergegeven. Op basis van deze kaarten kunnen de voornaamste bronnen van nutriëntenbelasting
The EROSFIRE project (POCI/AGR/60354/2004), funded by Portugal's Foundation for Science and Techn... more The EROSFIRE project (POCI/AGR/60354/2004), funded by Portugal's Foundation for Science and Technology (FCT), has as overall aim the development of a software tool that allows to assess and map, at the scale of individual hill slopes, soil erosion hazard in recently burned forest areas for different scenarios of post-fire land management. At the origin of the EROSFIRE project was the ''Soil losses after the forest fires of the summer of 2003''-map elaborated by Portugal's Water Institute (INAG) using some modified version of the Universal Soil Loss Equation (USLE), and the idea to test the applicability of erosion models with a more up-to-date scientific basis than USLE.
The Limburg Soil Erosion Model (LISEM) soil erosion model was calibrated for a 2-km 2 catchment o... more The Limburg Soil Erosion Model (LISEM) soil erosion model was calibrated for a 2-km 2 catchment on the Chinese Loess Plateau. The most important calibration factors were saturated conductivity and Manning's n. Calibration on catchment discharge was done by using the discharge peak (timing and discharge) followed by an adjustment for the total discharge to obtain the correct amount of sediment output. The results showed that LISEM can be successfully calibrated for a Loess Plateau catchment, and that small runoff events need to be calibrated separately from large runoff events. A separate calibration might even be needed for each event. The model performance was also evaluated using catchment wide spatially distributed data on rill erosion. Rill erosion intensity was mapped in the field and compared to spatial patterns of erosion predicted by LISEM. The simulated erosion patterns do show some resemblance with mapped erosion patterns in a general sense but they are very different in detail. The cause for this can be found in the extremely steep slopes and abrupt slope changes in the catchment. Some of the process descriptions in LISEM are not intended for such an environment, while the grid based kinematic wave routing cannot cope with the abrupt changes in flow conditions. The effects of this are amplified by inaccuracies in the input data and the DEM. For topographically complex catchments it will be very difficult to obtain data that are good enough for an accurate simulation of erosion patterns. This limits the use of a model such as LISEM as a predictive tool for future events. Simulation of different land use scenarios is less problematic, if a known event is used for all scenario simulations. D
Hydrology and Earth System Sciences Discussions, 2012
Four hydrological models (LISEM, MIKE SHE, CoupModel and HBV) were compared with respect to their... more Four hydrological models (LISEM, MIKE SHE, CoupModel and HBV) were compared with respect to their capability to predict peak flow in a small catchment upstream of a road in SE Norway on an hourly basis. All four models were calibrated using hourly observed streamflow. Simulated and observed discharge generated during three types 5 of hydrological situations characteristic of winter/spring conditions causing overland flow were considered: snowmelt, partially frozen soil and heavy rain events. Using parameter sets optimised for winter/spring conditions, flows simulated by HBV coupled with CoupModel were comparable to measured discharge from the catchment in corresponding periods. However, this combination was best when all the parameters were 10 calibrated in HBV. For ungauged basins with no real-time monitoring of discharge and when the spatial distribution is important, MIKE SHE may be more suitable than the other models, but the lack of detailed input data and the uncertainty in physical parameters should be considered. LISEM is potentially capable of calculating runoff from small catchments during winter/spring but requires better description of snowmelt, infiltration 15 into frozen layers and tile drainage. From a practical road maintenance perspective, the usefulness and accuracy of a model depends on its ability to represent site-specific processes, data availability and calibration requirements.
Surface runoff may be generated when the rainfall intensity exceeds the infiltration capacity, or... more Surface runoff may be generated when the rainfall intensity exceeds the infiltration capacity, or when the soil profile is saturated with water. Indications exist that both types of overland flow may occur in hilly agricultural loess regions. Here, for a loessial hillslope under maize in the southern part of The Netherlands, it was shown, with pressure head and runoff measurements, that Hortonian overland flow occurs during typical summer rain events. Surface runoff was initiated after saturation of the top 5-10cm of the soil. Deeper in the soil, unsaturated conditions prevailed while runoff took place. Peak runoff discharges at the outlet of the subcatchment occurred a few minutes after peak rainfall intensities were measured. It appeared that SWMS_2D, a two-dimensional water flow model, was capable in simulating observed pressure head changes and runoff. Simulated potential runoff for the transect studied was higher by a magnitude of three than the measured areal average. This indicates effects of surface ponding, and the probable location of this particular transect in a region with high runoff production.
A dam and weir system was constructed to measure the discharge of water and sediment from a selec... more A dam and weir system was constructed to measure the discharge of water and sediment from a selected small catchment on the Loess plateau in China. The aim of the system described here was to collect data on discharge and sediment content during occasional summer storms. ...
The Hilly Purple area of the Sichuan Basin has been degraded by constant soil erosion, which has ... more The Hilly Purple area of the Sichuan Basin has been degraded by constant soil erosion, which has reached to 3 035 t/km 2 . Soil erosion has direct negative effects on the productivity of the land by loss of nutrients, water and soil. This loss of productivity affects the farmers income. Also, it increases the pollution and siltation of the Yangtze river, causing several problems downstream. The EROCHINUT project has started in 1998 with the overall objective to develop a new methodology to improve land and water management on farm and watershed level in the current socio-economic situation by integrated use of participatory and soil erosion and nutrient modeling techniques. By using a calibrated model, calibrated on a small catchment, and upscale the results base on slope classes, a reliable view of possible effects of alternatives on these features is achieved. These results are visualized on maps, and act as support tools to discuss with farmers and policy makers on the feasibility and possibilities of alternative land use.
In opdracht van de provincie Noord-Brabant is een studie gedaan naar de totale nutriëntenbelastin... more In opdracht van de provincie Noord-Brabant is een studie gedaan naar de totale nutriëntenbelasting van het oppervlaktewater over geheel Noord-Brabant. Voor alle deelstroomgebieden binnen de verschillende waterschappen in Noord-Brabant is deze totale belasting en de relatieve bijdragen hieraan van diffuse en puntbronnen bepaald. Deze informatie is op kaart weergegeven. Op basis van deze kaarten kunnen de voornaamste bronnen van nutriëntenbelasting
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