Baseflow refers to the portion of stream flow that originates from groundwater discharge seeping into the stream or river over an extended period.
Groundwater discharges into the water bodies when the water table intersects the surface of the ground along rivers or wetlands, contributing to their flow.

Factors influencing Baseflow

Topography of the land: affects the movement of water across the surface and the subsurface, thereby influencing the infiltration and flow process.
Nature of the Soil: influences the rate of infiltration, hydraulic conductivity and groundwater recharge.
- Hydraulic conductivity is a measure of how easily water can pass through soil or rock.
Land use pattern: The conversion of forest to urban land increases baseflow owing to the presence of impervious surfaces in urban areas.
Climate Change: Changes in precipitation volume and timing can alter infiltration and groundwater levels, which in turn affect the baseflow discharge.

Environmental significance of Baseflow

Maintains the river flow and ecosystem: Baseflow recharges the river runoff and replenishes water demand during the dry season.
Reduces silt accumulation: Additional flow streams along with higher water quantities help decrease silt accumulation.
Maintains the water quality: Groundwater is subject to natural filtration, thus the water added via baseflow improves the overall quality of river water.

Potential effects of change in Baseflow

Increases Flood Risk: Catchments with higher baseflow reflect more wet conditions, which increases the chances of rapid runoff during heavy rainfall.
- Alternatively, prolonged periods of below-average precipitation and high temperatures lead to a decrease in the groundwater recharge rate leading to a situation known as baseflow droughts.
Affects the riverine ecosystem: Reduced baseflow leads to stagnant condition of water in river beds which also leads to depletion of dissolved oxygen thereby threatening the riverine species.
Affects the water temperature: As the groundwater is cooler than the surface water, reduced inflow of baseflow water in a stream increases its temperature.
Other effects include alteration in downstream flow, water utilization patterns and increased silt accumulation among others.

Conclusion

Baseflow of a river can be effectively managed through integrated water management approaches like optimal land use policies, recharging of groundwater, continuous monitoring and assessment of the river basins among others.