Environmental conditions in river segments intercepted by culverts

Resumen

The conservation and maintenance of the quality of the rheophilic environment are directly related to knowledge of the physical and chemical characteristics and structural patterns of these systems, especially in streams. Long stretches of small water bodies are highly altered by the construction of highways and roads, which tend to modify their natural characteristics, affecting the environmental quality. This study describes vegetation and morphogeometric parameters of streams with culverts along their courses, reporting spatial differences in environmental characteristics (vegetation, morphogeometric, physical, and chemical) between sampling points upstream and downstream of the culvert. Specifically, we evaluated the width, depth, riparian vegetation, substrate background, and physical and chemical properties of the water, to identify possible differences between the sections above and below (upstream and downstream) of the culvert. The rapid assessment protocol (RAP) was applied to stretches of 200 meters upstream and downstream of culverts in two Neotropical streams, between the months of November 2009 and October 2010. The vegetation and morphogeometric attributes differed between the portions upstream and downstream of the culverts, the latter because of the impoundment effect of these structures. The upstream section becomes flooded, is often shallow, and directly influences the movement of sediment. The physical and chemical variables of the water showed no spatial variation.