Riparian restortion for protecting water quality in tropic agricultural watersheds

Background

In the Sarapui River watershed in southeastern Brazil, the water quality system was measured for six subwatersheds in the region.  In addition to measuring the subwatersheds, the entire watershed system was also measured and compared to a simulation model that included riparian zones throughout the river watershed.

Conclusions & Takeaways

The study found that all subwatersheds were different, in that one contained more forest cover, and another had less forest cover with a higher percentage of agriculture, pasture or residential area. The subwatersheds with the higher amounts of forest cover were found to have less sediment and nutrient load. On areas with more agricultural cover, the nutrient load was higher, and erosion from the river banks was also higher. The result was again the same for the full watershed measurement. The simulation model show that riparian zones would decrease the sediment load and nutrient (nitrogen) load by 9.26% and 22.6%, respectively. The overall results supported the argument that riparian restoration is essential in watersheds that are comprised of mostly agricultural and pastoral lands. Riparian zones aid in the improvement of the water quality by removing pollutants, sediments and the accumulation of nutrients into the river.