Using isotopic techniques to investigate soil erosion processes

Description

Soil displacement and net production of sediments from fields with different soil textures in the Ruisseau Ewing watershed and Rivière aux Brochets subwatershed can be quantified by measuring the spatial redistribution of 137Cs and 210Pb. The 13C signature of suspended solids (SS) can be compared with that of potential SS sources (cultivated fields, meadows, woods, river banks) to quantify the relative contribution of these sources to SS loads. This study is one of a series of projects conducted by IRDA and its partners in the Missisquoi Bay watershed in recent years.

Objective(s)

• Quantify the scale of soil displacement and net sediment production in the past 50 years for various soil textures and compare these results with those generated by modeling the watershed with SWAT
• Examine the relationship between soil displacement and runoff patterns and the contribution of subsurface drainage to the export of suspended solids
• Evaluate the relative contribution of various forms of land use in the watershed to suspended solid loads measured at the watershed outfall and compare it to that predicted by the SWAT model