Savenije, H. Civil Engineering and Geosciences. It includes: vegetation, soil surface, litter, build-up surface, etc. How much of the precipitation evaporates depends on land cover characteristics, rainfall characteristics, and on the evaporative demand. One can distinguish many types of interception, which can also interplay with each other.
For example canopy, forest floor, fog, snow, and urban interception. This study we focus on canopy and forest floor interception. We measured interception of three dominant European vegetation types at three locations.
In the Huewelerbach Luxembourg a beech forest has been investigated, in Westerbork the Netherlands grasses and mosses, and in the Botanical Garden Delft, the Netherlands a Cedar tree.
Canopy interception is determined by the difference between gross precipitation and the sum of throughfall and stemflow. To measure forest floor interception a special device has been developed.
It consists of two aluminium basins which are mounted above each other. The upper basin is permeable and contains the forest floor. By weighing both basins simultaneously, evaporation from interception can be calculated. Hence the number of raindays and the potential evaporation are stronger drivers of interception.
Furthermore, the spatial correlation of the throughfall and infiltration has been investigated with semi-variograms and time stability plots.
Within m distance throughfall and infiltration are correlated and the general persistence is weak. The effect of spatial variability of interception on subsurface storm flow has also been investigated with a virtual experiment. A virtual experiment is a numerical experiment driven by collective field intelligence. It provides a learning tool to investigate the effect of separated processes in a complex system. We used this approach to better understand the generation and behaviour of subsurface stormflow SSF at the hillslope scale, because this is still poorly understood.
Interactions between the permeable soil and the less permeable bedrock may cause non-linearity in subsurface flow depending on several hillslope attributes such as soil depth, slope angle, and bedrock permeability.
It is known that the size of storm events also controls subsurface flow generation. The objectives of this study were three-fold: 1 to investigate if and how different configurations of throughfall patterns change the SSF behaviour; 2 to investigate the interplay between the spatially variable input and the hillslope attributes slope angle and soil depth on the generation of SSF; and 3 to investigate a geo-statistical tool that uses semi-variogram characteristics to analyse if soil moisture patterns during an event are dominated by throughfall patterns or by bedrock topography patterns.
In our virtual experiment we combined spatial throughfall data from the Huewelerbach catchment in Luxembourg with the topography characteristics of the Panola hillslope in Georgia, USA. The effect of the spatial throughfall pattern appears to be large on both SSF generation and the spatial variability of SSF along the hillslope, but only marginal on total SSF amounts.
The spatial variability of SSF along the hillslope appears to be closely related to the drainage pattern of the bedrock. The geo-statistical analysis indicates that during the event soil moisture distribution reflects throughfall patterns, whereas after the event, during the drainage of the hillslope, the bedrock topography increasingly dominates soil moisture patterns. Making the decision to study can be a big step, which is why you'll want a trusted University.
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Course content Course content. Water use and the water cycle Start this free course now. Free course Water use and the water cycle. Long description. Activity 6 Figure 2. Answer The Southern Hemisphere has more ocean than the Northern Hemisphere, and as evaporation is greatest from open water, evaporation is greater in the Southern Hemisphere.
The red lines are the evapotranspiration contoured values, in mm. Question 7 Are the areas of greatest precipitation in Britain also the areas of greatest potential evapotranspiration? Answer No. Question 8 Is the potential evapotranspiration in Britain greater or less than the precipitation? Answer In Britain and other places with a temperate climate, the potential and actual evapotranspiration is usually less than the precipitation.
The blue shading represents the excess of precipitation over potential evapotranspiration in the winter months and the red shading represents a greater potential evapotranspiration than precipitation in the summer months. This area has about 50 mm of precipitation a year and a potential evapotranspiration of up to mm a year. Crops cannot be grown in this arid area, and natural vegetation is very sparse.
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