Reduction in runoff

Second basic type (C and D) General reduction in runoff volumes. An even more pronounced influence on the runoff regime occurs when water is withdrawn from a river or stream and diverted to another catchment area. Depending... 

Reduction in runoff during the summer half-year and increase in winter half-year due to storage management... 

Changes in the runoff regime can also have an aesthetic impact on the landscape or influence other forms of use (e.g. irrigation, drinking water supplies) due to the absence or reduction in volumes of water [35]. 

Thus, any reduction in vegetation cover causes a reduction in water retention and evaporation, which ultimately increases surface runoff and the mnoff concentration times [58]. Human-induced soil sealing and soil compaction has the same effect (Fig. 7). 

A cotton farm in Narrabri, New South Wales, was contaminated with irrigation runoff. The 80,000-liter holding pond was treated with a free form of the Orica enzyme. A 90% reduction in methyl parathion was affected within 10 minutes. The final concentration decreased to 0.4 ppb after 1 hour from an initial concentration of 7 ppb. ... 

UV absorption and fluorescence, leads to an enhancement of microbial decomposition and remineralization, whereas photodegradation of DOM with minimal CDOM has no net effect or reduces subsequent microbial decomposition and remineralization. Continental runoff is rich in CDOM, and photodegradation results in substrates that enhance microbial decomposition and the remineralization of terrestrial DOM (Miller and Moran, 1997 Smith and Benner, 2005). Very little CDOM in the open ocean appears to be of terrestrial origin (Hernes and Benner, 2006), and the photodegradation of surface water DOM results in a reduction in microbial decomposition, whereas photodegradation of deep water DOM results in an increase in microbial decomposition (Benner and Biddanda, 1998). 

Figure 3Z1 Reduction in herbicide runoff with BMPs as compared to runoff in the absence of BMPs.

The chemical form of phosphorus in the water column available for uptake by biota is important. The biologically available phosphorus is usually taken to be soluble reactive phosphorus (orthophosphate) , i.e. which, upon acidification of a water sample, reacts with added molybdate to yield molybdophosphoric acid, which is then reduced with SnCl2 to the intensely-coloured molybdenum blue complex and is determined spectrophotometrically (Imax = 882 nm). Reduction in inputs of phosphate, for example from point sources or by creating water meadows and buffer strips to contain diffuse runoff, has obviously been one of the major approaches to stemming eutrophication trends and... 

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