Listar Congresos 2011 y anteriores por fecha de publicación
Mostrando ítems 21-40 de 124
-
Historical gully erosion with loess areas of SE Poland – Natural conditions and human impact
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaGullies constitute one of the most characteristic elements of loess relief in SE Poland. Particularly dense net of permanent gullies – in some places more than 10 km?km-2 – appears in areas of specific conditions of ... -
Soil erosion on the bottom of hollows in steppe zone of Ukraine
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaSoil erosion, undoubtedly, is one of the main ecological and agricultural problems in the world. Quantity of eroded lands in Ukraine achieves 10.5 millions ha. Annual losses of soil constitutes about 600 millions tons ... -
Influence of soil structure, pore-water pressure, and tailwater height on headcut migration in upland concentrated flows
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThe primary objective of this study was to determine the impact of soil texture, soil pore-water pressure, and tailwater height on scour hole dimensions, migration rate and sediment yield in headcuts migrating under steady ... -
Some examples of ephemeral gully erosion in an Atlantic area of NW Spain
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThis study aimed to describe types of ephemeral gullies and to determine their origin, evolution and importance as sediment sources in Galicia (Northwest Spain). Concentrated erosion was surveyed on medium textured soils, ... -
Seepage erosion impacts on edge-of-field gully erosion
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaConcentrated flow is generally considered the controlling mechanism for gully erosion whereas subsurface flow is often overlooked. The two mechanisms of subsurface flow attributed to gully erosion are seepage flow and ... -
The role of preferential flow through soil-pipes in ephemeral gully erosion
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThe objective of this study was to quantify the hydrologic conditions under which discontinuous soil-pipes reestablish ephemeral gullies and continuous soil-pipes initiate ephemeral gullies. -
A general sediment transport model for linear incisions
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaPrevious research has shown that the functional relationship between sediment transport and shear stress, discharge and slope is non-linear. The different datasets that support this hypothesis are however all derived from ... -
Morphology and controlling factors of landslide cirque gullies: a case study from the Sprogu gravas nature monument (SE Latvia)
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaHuman-induced changes of landscape and the vegetation cover have been recognized in the majority of studies focusing on gully formation as one of the most important factors triggering the development of gullies throughout ... -
Effectiveness of palm and bamboo geotextiles in reducing concentrated flow erosion
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaRills and gullies, caused by concentrated flow erosion, represent an important sediment source in many environments (Poesen et al., 2003). Studies indicate that vegetation can be very effective in controlling gully ... -
Estimating sediment yield from gully erosion using easily measurable morphometric characteristics in Darehshahr region, south of I.R. Iran
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaA case study was conducted in a part of Ilam Province, I.R. Iran, to establish a reliable model for estimating sediment yield from gully erosion. The attempt was satisfactory and led to an applicable model whose input could ... -
Discharge and gully erosion in a small rangeland catchment
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaValley bottom gullies are a common feature in rangelands. Although these gullies are found in the bottom of drainage lines, information about the relationship between discharge and gullying is scarce (Crouch, 1990; ... -
Surfaces of gullies generated by piping process in abandoned fields (south-east of Spain)
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThe piping process have an important development in old agricultural terraced fields. The abandonment of these fields, together with the lithologies, hydraulic and climatic characteristics favour the quick development of ... -
Causes of gully erosion in arid ecosystem: case study southern part of I.R. Iran
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThis research demonstrated that the I.R. region is prone to gully erosion. The study area had limited gully erosion four decades ago. With accelerating urban development during the past, two to three decades, areas of gully ... -
The importance of the presence of gullies in the production of sediments in semiarid areas (Murcia, south-east of Spain)
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThe study has shown how the existence of gullies remarkably increases the rates of erosion and, therefore, the volume of sediments that arrives at the dikes of hydrological correction. A consequence of this is the need to ... -
Waterfall erosion as a main factor in ephemeral gully initiation in a part of Northeastern Iran
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThe present study assesses the factors controlling gully formation in a study area located in northeastern Iran. Gully erosion in northeastern Iran is very high because of the high rate of human encroachment and the resulting ... -
Seepage flow in aquifers with open and closed boundaries
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaAt previous gully erosion conferences, the effect of surface seal development on gully formation and growth was analyzed (Prasad and Römkens, 2003) and the effect of hydrological conditions on gully growth was discussed (Römkens ... -
Progress in gully erosion research: IV International Symposium on Gully Erosion
The classic forms of water erosion of the soil comprise sheet, rill, and gully erosion. According to the concept most generalized, in sheet erosion, thin layers of material are uniformly removed from the soil surface due ... -
Urban gullies in São Luis City, Maranhão State, Brazil
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaUrban gully erosion is a serious problem in São Luís City, Maranhão State, Brazil. São Luís Municipality covers 831.7 km? and is situated in west-central Maranhão Island (2º19’09”-2º51’00” S; 44º01’16”-44º19’37” W). ... -
Agricultural land use, piping and gullies activity in the Huelva lower valley (Saragossa, Spain)
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaThe variations in the total amount of surface used for arable crops both for dry farming and fallow land, with regard to the different “agricultural policies”, have modified the natural dynamics of some processes such ... -
Gully erosion in mountain area of SW-China, assessed using 137Cs and 210PBEX tracers and GPS survey
(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Contribución a congreso / Biltzarrerako ekarpenaGullies are extensively distributed in the Upper Yangtze River Basin, SW-China. But the impact of these gullies on total sediment output is still not clear because there is no reliable technique for quantifying this ...