A Multivariate Water Quality Investigation of Select Drainage Ditches in the Arroyo Colorado River Watershed, Texas

摘要

Drainage ditches are widely used for agricultural water management to help remove excess water from fields, which mitigates the effects of water logging and salinization. These ditches act as a direct hydraulic link between the agricultural field and streams and rivers. As such, there is an increasing concern that drainage ditches can act as conduits for nutrient transport and, in conjunction with other point and nonpoint sources, can contribute to eutrophication and decreased dissolved oxygen levels in receiving water bodies. Studies have linked drainage ditches to hypoxia in the Gulf of Mexico and eutrophication of the Great Lakes (Dagg and Breed, 2003; Moore et al., 2010). However, there is also evidence suggesting that drainage ditches can help attenuate the loadings of phosphorus and suspended sediments (R. Kr?ger et al., 2008) and thus foster water quality improvements at a watershed scale. There is a growing interest in understanding the nutrient behavior in drainage ditches both in the United States (Bhattarai et al. 2009; Moore, et al. 2010; Ahiablame et al. 2011) as well as other parts of the world (Nguyen and Sukias 2002; Leone et al. 2008; Bonaiti and Borin 2010).