What combination of factors both natural and man made is necessary for healthy river restoration and how does this enhance the sustainability of natural and human communities? Objective To understand the role that aspect, slope, sun, snow melt, blackbody absorption and elevation play in soil moisture conditions. Background This lesson focuses on the role of aspect, slope, seasonal sun availability, snow melt, blackbody absorption, and elevation in soil moisture conditions. Soil moisture is one of the most important factors determining the composition of plant communities and ultimately the eco Duration: 60 Minutes.