Muddy flood
From Wikipedia, the free encyclopedia
A muddy flood is produced by an accumulation of run-off over agricultural land. Sediments are picked up by the run-off and carried as suspended matter or bed-load. Muddy floods are typically a hill-slope process, and should not be confused with mudflows produced by mass movements.
Muddy floods can damage the road infrastructure and may deposit layers of mud blanket and may also clog sewers and damage private property.
It has been referred to 'muddy floods' since the 1980s.[1] A similar designation appeared in French ('inondations boueuses'[2]) during the same period.
Muddy runoff is generated on agricultural land when the soil surface is exposed or sparsely covered by vegetation. Large quantities of run-off usually generated by heavy storms is needed to start such a flood.[3]
Occurrence
Muddy floods have been observed in the entire European loess belt. Other affected areas include Normandy and Picardy (France), central Belgium and southern Limburg, the Netherlands.
Muddy floods have also been observed in Slovakia and Poland.
Temporal evolution
An increase in muddy flood frequency has been observed during the last twenty years (e.g. in central Belgium,[4]). This increase in their frequency may be due to a number of factors including:
- Change in agricultural practices that leave field bare of crops in the autumn and winter
- A shift to crops that are more sensitive to soil erosion
- land consolidation (enlargement of fields, removal of landscape buffer elements such as hedges
- construction of new houses, upstream of cropland increasing run-off volumes and intensity
- increased frequency of heavy rainfall
