Remote Sensing of Suspended Sediment Concentration and Hydrologic Connectivity in a Complex Wetland Environment.

摘要

We use daily MODIS imagery in bands 1 and 2 to monitor suspended sediment and, by proxy, hydrologic recharge in the Peace-Athabasca Delta, Canada from 2000 to present. To identify an appropriate suspended sediment concentration (SSC)-reflectance model, we compare 31 published equations using field observations of spectral reflectance and SSC. Results suggest potential for spatial transferability of such models if they 1) use of a near infrared band in combination with at least one visible band, 2) were developed based on SSCs similar to those in the new site, and 3) are nonlinear. We develop a twelve-year time series of SSC in Lake Athabasca and observe timing and sources of major sediment fluxes. We also track the influx of Athabasca River water to floodplain lakes. In three lakes we identify discharge thresholds required for hydrologic recharge, and we find a significant decline in the threshold exceedence frequency since 1970.