Future Work

Although the results of this preliminary study are encouraging, many uncertainties remain before elevation and conductivity data can be used routinely and accurately in coastal habitat classification. From the lidar perspective, further work is needed to determine where vegetation density is great enough to prevent the lidar instrument from detecting the top of vegetation rather than the ground surface. In coastal areas, where errors of fractions of a meter can lead to significant habitat misclassification, methods of correcting for vegetation height become important.

From the EM perspective, we measured conductivity during winter and examined the relationship with habitat and environment based on those measurements. It is likely that conductivities within the uppermost meter of the subsurface will change seasonally with precipitation and ambient temperature, but we have not reoccupied the same sites in different seasons and at different times following precipitation or flooding events to examine the magnitude of these changes or the environments that are most susceptible to seasonal change.

We made our conductivity measurements using a ground-based instrument that explores 0.8 to 1.5 m in the subsurface. This instrument is practical for field investigations and additional preliminary studies, but is too labor-intensive for large mapping projects. Similar instruments can be towed beneath low-flying helicopters to rapidly and remotely acquire conductivity data along flight lines at an arbitrary line spacing. Airborne measurements can be made simultaneously at multiple explorations depths, enabling shallow data to be used for vegetation mapping and deeper data (to a few tens of meters) to be used for other purposes such as saline-water intrusion into coastal aquifers and geometry of the fresh-water lens that underlies many coastal barriers.