The landscape amenities offered by some types of agricultural land use furnish open spaces and visual prospects that are increasingly valued by growing suburban populations (American Farmland Trust, 1997). Because such a large proportion of the U.S. population resides near agricultural land and because agriculture significantly affects the environment, the way agricultural land is managed is likely to affect human health, recreational activities, and general well-being.
The challenge of designing an environmental targeting mechanism that brings the greatest benefits relative to costs is not merely to identify agricultural land uses causing the largest ecological impacts, but also to consider how important these impacts are to the American public. This blog will mainly demonstrate the environmental effect on land use pattern in lower Bad River watershed.
No direct relationship is evident between the instability in the subwatersheds and a particular land use. The entire subwatersheds of Bad River contained both cropland and rangeland. The cropland areas are usually within the uplands landform. The uplands are less susceptible to bank erosion compared to the breaks landform which would typically be rangeland. This is contrary to what would be expected if land uses are a primary factor affecting stability. Cropland generally would produce higher volume, higher intensity runoff events compared to rangeland. This is not to say that conversion from rangeland to cropland in modern times has had no effect on some of the watersheds; but an analysis of such a scenario is beyond the scope of this analysis.
In lower watershed, bank erosion is a predominant feature on unstable channels. The pattern of stream types indicates these unstable channels are the result of the watersheds being in an active down cutting phase which began at the mouth of the watersheds and has progressed upstream. Channel erosion is the largest source of sediment and is comprised of erosion from the following channel sources:
- Stream bank erosion along the main channel of the River
- Stream bank erosion from areas identified in the field inventory as having active bank erosion
- Geologic erosion from those channels identified during the field inventory
The erosion channel sources can be controlled by implementing the cost effective range management practices. Environmental targeting refers to the practice of directing program resources to lands where specific environmental goals are achieved for the least cost. The best cost versus sediment reduction benefits in the lower watersheds are primarily range management practices. However, the practices which increased vegetative cover and improved hydrologic condition showed the greatest benefit on channel types. In addition, these practices have the largest effect on sediment reduction to Lake Sharpe. The broad extent of management practices leads to widespread environmental effects on surface- and ground-water quality, air quality, fish and wildlife habitats, species diversity, and land characteristics. It can also generate ecosystem health and many outdoor activities, such as water-based recreation, hunting, and nature viewing. In practice, environmental targeting helped us calculate the benefits derived from environmental improvements in the lower watershed.