Revitalization of Rivers in India Draft Policy - Isha Guru Jaggi Vasudev

Revitalization of Rivers In India
Draft Policy Recommendation
FIGURE 6(B): SCHEMATIC DIAGRAM OF HIGH INFILTRATION IN FOREST AREA
Johnson and Lehmann (2006) determined that infiltration of stem
flow, which results from the partition of rainfall by the tree canopy, is
enhanced by root-induced preferential flow. The amount of precipitation
accounted for as stem flow ranged from less than 1 to as much as 22
percent of incident rainfall above the forest canopy where the rainfall
averaged 24 to 200 inches per year. The hydrological role of stem flow is
as a water source to the soil beneath the forest. Although the ratio of stem
flow to precipitation is small in a forested basin, the effect of stem flow
on groundwater recharge might be relatively large. 41
Not only will the overall quantum of river water stabilize by
afforestation but the quality of water will also improve. This is because
the major source of pollutant in our rivers is the agro-chemicals used in
agriculture. Having green cover will ensure that the rhizosphere of the
tree filters out these agro-chemicals from the soil and runoff water before
it seeps into the river itself. 42 A detailed reasoning on the effect of tree
plantation on the ground water and the hydrological cycle is presented in
Annexure 1.
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