Résultats de la recherche (42 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre
  • Topographical thresholds for ephemeral gully initiation in intensively cultivated areas of the Mediterranean
  • Concept ; Cultivated land ; Gully erosion ; Mediterranean area ; Murcia ; Portugal ; Rill wash ; Slope gradient ; Soil erosion ; Spain ; Threshold ; Watershed
  • Ephemeral gullying is an important erosion process in Mediterranean areas. The objective of this study was to investigate to what extent one could use field measurements of S (local slope) and A (drainage-basin area) to predict the location
  • of ephemeral gully initiation in intensively cultivated Mediterranean environments. Two relatively homogeneous study areas in Southeast Spain and Northeast Portugal with widespread ephemeral gullying were selected.
  • Effects of region-wide soil and water conservation in semi-arid areas : the case of northern Ethiopia
  • Arid area ; Ecosystem ; Ethiopia ; Gully erosion ; Plant canopy ; Rill wash ; Semi-arid area ; Soil conservation ; Soil erosion ; Water erosion
  • This study makes a multi-scale assessment over a time span of 30 years of environmental rehabilitation in one of the world's most degraded areas : the Tigray highlands. It study shows that in Tigray sheet and rill erosion rates have decreased
  • Arid area ; Europe ; Gully erosion ; Land use ; Lithology ; Mediterranean area ; Slope gradient ; Soil ; Soil erosion ; Soil properties ; Watershed
  • In Mediterranean areas the dynamics of gully development act as an important indicator of desertification. However, little is known about the influence of climate and land-use changes, and almost no field data exist to assess the sensitivity
  • Mediterranean study areas were established. Discussion of the results.
  • Ethiopia ; Forest ; Microrelief ; Plant canopy ; Rainfall simulation ; Reforestation ; Runoff ; Scrub ; Semi-arid area ; Soil erosion
  • seeds in the bare inter-plant areas; and that seeds in the latter are more likely to be translocated by runoff to microsites under shrubs than to other open areas. The study area is located in the Geba river catchment, central Tigray, northern Ethiopia.
  • Andalusia ; Arid area ; Desertification ; Gully erosion ; Lithology ; Mediterranean area ; Rill wash ; Sediment transport ; Soil erosion ; Spain ; Water use ; Watershed
  • The AA. examine the factors that control the spatial distribution of bank gully heads along a reach of an ephemeral river (Rambla Salada) in an area threatened by desertification in Southeast Spain. The activity of 458 gully heads was assessed
  • Alentejo ; Cultivated land ; Erosion rate ; Gully erosion ; Land use ; Mediterranean area ; Model ; Murcia ; Portugal ; Soil erosion ; Spain ; Wasteland ; Watershed
  • An EGEM-input data set for 86 ephemeral gullies was collected : detailed measurements of 46 ephemeral gullies were made in intensively cultivated land in southeast Spain (Guadalentin study area) and another 40 ephemeral gullies were measured in both
  • intensively cultivated land and abandoned land in southeast Portugal (Alentejo study area). Together with the assessment of all EGEM-input parameters, the actual eroded volume for each ephemeral gully was also determined in the field. The resulting
  • Special issue. Geomorphic response of mediterranean and arid areas to climate change
  • Arid area ; Rill wash ; Sediment budget ; Semi-arid area ; Soil erosion ; Soil properties ; Spain ; Splash ; Valencia ; Vegetation ; Water erosion
  • compared to shallow ephemeral gullies. Several factors were analyzed to understand the formation of deep gullies. The relation between area-specific sediment yield in central Belgium and drainage area, indicates that the development of deep gullies
  • contributes significantly to the sediment output of small rural catchments and causes peaks in the mean area-specific sediment yield that are up to a factor of 3 higher compared with catchments where shallow ephemeral gullying occurs.
  • Forecast ; Italy ; Landslide ; Mediterranean area ; Model ; Sediment budget ; Soil erosion ; Watershed
  • From reservoir sedimentation data of 44 Italian catchments, it appeared that there was a (non-significant) positive relation between catchment area and sediment yield. This is in contrast to what is generally expected from the theory of decreasing
  • sediment delivery rates with increasing catchment area. Furthermore, this positive relation suggests that processes other than upland erosion are responsible for catchment sediment yield. Here, the AA. explore the potential of the Factoring Scoring Model
  • Arid area ; Desertification ; Gully erosion ; Land use ; Mediterranean area ; Rill wash ; Soil erosion ; Spain ; Statistics ; Watershed
  • In this paper, 2 topographic indices, closely related to mathematical expressions suggested by different AA. are used to characterize the influence of watershed topography on gully erosion. The AS1 index is defined as the product of watershed area
  • and the partial area-weighted average slope. The AS2 index is similar to the AS1 but uses the swale slope as the weighting factor. From studies made using different ephemeral gully erosion databases, it is shown that a high correlation consistently exists between
  • By studying the causal factors for landslides in a small mountainous area of Manjiya County, this paper tries to contribute to the restricted knowledge on landslides in East Africa. After a brief introduction of the study area and the spatial
  • The aim of this paper is to provide an overview of the different relations between drainage basin area (A) and area-specific sediment yield (SSY) as reported in literature, and to explore explanations for the differences in the observed trends
  • Holocene alluvial sediment storage in a small river catchment in the loess area of central Belgium
  • The study area is part of the Belgian loess belt and is located south of Leuven. The objectives of this study are : to determine the spatial distribution of closed depressions (CDs) within an ancient forest area and under cropland; to determine
  • Africa ; Arid area ; Duricrust ; Ecosystem ; Landscape ; Niger ; Plant cover ; Semi-arid area ; Soil erosion ; Soil properties ; Soil water ; Spatial analysis ; Vegetation ; World ; Zoning
  • Arid area ; Ecosystem ; Mediterranean area ; Microrelief ; Plant species ; Slope ; Slope dynamics ; Slope gradient ; Soil erosion ; Spain ; Splash ; Valencia ; Water erosion
  • Arid area ; Erosion rate ; Ethiopia ; Experiment plot ; Land use ; Mountain ; Plant cover ; Rill wash ; Runoff ; Semi-arid area ; Soil erosion
  • To study the effect of microbiotic soil crusts on soil erosion resistance of loess-derived soils under cropland during concentrated runoff, two study areas in central Belgium were selected in the vicinity of the cities of Leuven and Sint-Truiden
  • . The soils in both areas developed on the loess that covers Tertiary sandy deposits. Three stages of microbiotic crust development on cropland soils are distinguished. The results suggest that the possible magnitude of the microbiotic soil crust effect
  • Arid area ; Granada ; Gully erosion ; Lithology ; Regression analysis ; Semi-arid area ; Soil erosion ; Spain ; Watershed