Use of sequential aerial photographs to detect and monitor soil management changes affecting cropland erosion

ABSTRACT:

Interpretation of sequential aertal photographs enabled land planners in New Brunswick to detect and monitor the effects of changes in soil management practices on cropland erosion. Sequential aerial photographs taken between 1944-1945 and 1980 provided a permanent, chronological landscape record. Used in conjunction with the universal soil loss equation, these photographs showed that where soil conservation systems had not been constructed the net effect of soil management changes had resulted in an increase in the average annual erosion rate of at least 5.3 times over the 1944-1945 rate. Where systems had been constructed, the erosion rate increased 1.2 times. As well as showing the nature and approximate date of management changes, the photographs located precisely the changes. This permitted yield plots to be located to establish relationships between crop yield and past erosion rates. A potato yield reduction of 16 percent was recorded in 1980 on replicated plots with the same present, but different past, management and erosion levels.