Search results for "Runoff"
showing 10 items of 294 documents
The erosional response of Calcareous soils along a climatological gradient in Southeast Spain
1998
Abstract The erosional response of calcareous soils along a climatological gradient in Alicante, SE Spain was studied. The erosional response was defined in terms of indicators obtained from field rainfall simulation experiments and laboratory studies of soil aggregation. Measurements were made at seven sites on limestones and marls between Benidorm with an annual average rainfall of 400 mm yr −1 and Coll de Rates (annual rainfall 900 mm yr −1 ). The sites were on matorral vegetation affected to varying intensities by grazing and fire. At the seven locations, soil aggregation was studied by sieving, by the single water drop test and by a Microscan particle-sizer. Rainfall simulation experim…
Scale effects on plot runoff and soil erosion in a mediterranean environment
2017
Explaining scale effects for runoff and erosion improves our understanding of hydrological and erosion processes. In this investigation, plot-scale effects on event runoff per unit area, Qe, sediment concentration, Ce, and soil loss per unit area, SLe, were checked at the Sparacia (Italy) site. Similar information on the scale effects was obtained with different dependent variables, i.e., individual values of Qe, Ce, and SLe for each plot or the mean of their replicated values, and scale indicators, i.e., plot length, l, or plot area, A. The most common result, occurring for 57 to 62% of the events depending on the considered variable, was the lack of any scale effect. When scale effects we…
The effect of ant mounds on overland flow and soil erodibility following a wildfire in eastern Spain
2010
This study examines the soil hydrological and erosional effects of ant mounds during summer and winter conditions following a wildfire in scrub terrain in eastern Spain. Forty rainfall simulations (1 m2 plots, 1 h duration, 78 mm h−1 intensity) were carried out over plots with mounds (n = 20) and mound-free control plots (n = 20) in August 2002, and repeated in December. By winter, some of the mound material had been removed and some vegetation regrowth occurred. Overall, mound presence increased soil erodibility in summer and winter due to the availability of highly erodible mound material. However, mound plots showed higher mean overland flow rates in summer (10·1 vs 6·9% for control plot…
Relationships between climate and soil hydrological and erosional characteristics along climatic gradients in Mediterranean limestone areas
1998
An investigation was undertaken to determine the relationships between climate and soil hydrological and erosional characteristics. Rainfall simulation experiments were carried out along three climatological gradients on similar limestone lithologies in the Mediterranean region. Standard experiments were used to characterize each site so that an objective comparison could be made. At each of the eleven south-facing slopes three experiments were carried out. A total of 33 plots were selected for the experiments; located in the Galilee and Carmel Mountains (Israel), Crete (Greece) and Alicante (Spain). Simulated rainfall was used in order to measure time to ponding and runoff, steady-state in…
Multiple recharge processes to heterogeneous Mediterranean coastal aquifers and implications on recharge rates evolution in time
2018
Abstract Climate change is nowadays widely considered to have major effects on groundwater resources. Climatic projections suggest a global increase in evaporation and higher frequency of strong rainfall events especially in Mediterranean context. Since evaporation is synonym of low recharge conditions whereas strong rainfall events are more favourable to recharge in heterogeneous subsurface contexts, a lack of knowledge remains then on the real ongoing and future drinking groundwater supply availability at aquifers scale. Due to low recharge potential and high inter-annual climate variability, this issue is strategic for the Mediterranean hydrosystems. This is especially the case for coast…
Causes and underlying processes of measurement variability in field erosion plots in Mediterranean conditions
2007
Published online 25 May 2006
Soil wettability, runoff and erodibility of major dry-Mediterranean land use types on calcareous soils
2007
This study examines six land uses (pine woodland, long unburnt scrubland, recently burnt scrubland, orange grove, olive grove and cereal crop), typical for calcareous soils in a dry-Mediterranean region such as eastern Spain, with regard to soil surface water repellency occurrence, hydrological response and erodibility. For each land use, we performed water drop penetration time (WDPT) tests and rainfall simulations respectively on in situ soils at ten replicate plots for extremely dry antecedent conditions in summer 2002 and for wet winter conditions, in early 2003 in the Canyoles river valley. In contrasts to what might have been expected, water repellency was absent or subcritical (WDPT …
Magnitude-frequency analysis of water redistribution along a climate gradient in Spain
1999
Abstract Banded patterns in soils and vegetation form part of important discontinuities on semi-arid slopes in Spain. At fine scales (
The impact of cotton geotextiles on soil and water losses from Mediterranean rainfed agricultural land
2010
High soil erosion risk of Mediterranean cultivated soils is due to steep slopes, high rainfall intensities and low vegetation cover. Traditional land management as ploughing and herbicides give rise to high soil erosion rates. This paper reports on the use of a cotton geotextiles to control soil and water losses on agricultural land under Mediterranean climatic conditions. Eight paired plots (1, 2, 4 and 16 m2) were studied during 1-year period under natural rainfall. Forty rainfall simulations under wet and dry climatic conditions, and water drop penetration time (WDPT) tests, were carried out in order to analyze the effect of a geotextile on soil and water losses on a typical rainfed orch…
Rainfall-runoff modelling of ephemeral streams in the Valencia region (eastern Spain)
2002
This paper presents preliminary results from the application of a transfer-function rainfall–runoff model to ephemeral streams in Mediterranean Spain. Flow simulations have been conducted for two small catchments (Carraixet and Poyo basins), located in close proximity to one another yet with significantly different geological characteristics. Analysis of flow simulations for a number of high-flow events has revealed the dominant influence of the rainfall on the catchment response, particularly for high-rainfall events. Particular success has been attained modelling the highest magnitude events in both catchments and for all events in the faster responding (Poyo) catchment. In order to inves…