How does NAWQA define an “agricultural”, “urban”, and “undeveloped” stream site?
“Agricultural” streams drain watersheds that contain greater than 50 percent agricultural land and less than 5 percent urban land. The agricultural streams sampled are diverse in climate, geography, and crop types, and span coastal, desert, and temperate environmental settings. Agricultural settings included, for example, areas dominated by production of corn in the Midwest; wheat in the Great Plains; poultry in the east; pineapple in Hawaii; and vegetables in California. “Urban” streams drain watersheds that contain greater than 25 percent urban land and less than 25 percent agricultural land. The urban settings studied were primarily residential, typically with low-to-medium population densities (300 to 5,600 people per square mile). “Undeveloped” streams drain watersheds that contain less than 5 percent urban land and less than 25 percent agricultural land.
