GIS-based riparian buffer analysis: injecting geographic information into landscape planning

The establishment and maintenance of riparian buffer zones along shorelines or streams is a common best management practice (BMP) in the United States. These vegetated areas function as sinker, filter, and transformer to delay, absorb, or purify contaminated runoff before it enters surface waters. Their effectiveness for nonpoint source pollution control has been widely appreciated. Presented in this paper is a case study in which a GIS-based (geographic information system based) buffer analysis was conducted on a North Carolina watershed in support of landscape plannersʹ planning activities. By implementing scientifically tested models on generally available data sets in a GIS framework, the study accomplished a series of tasks that would have been extremely difficult if done in conventional ways. These tasks include (1) calculating and mapping variable riparian buffer zones; (2) identifying inadequately regulated areas (i.e. areas outside the currently regulated buffer zones but within the calculated buffer zones); (3) estimating land acquisition costs associated with these inadequately regulated areas. The analytical results were well received by the decision makers and advanced their knowledge about landscape planning issues that they were facing.