| Autor: |
B.H. Poganski, K.A. Littlejohn, S. C. Pierce, Corrin Flora, J.D. Prevost, James E. Henderson, J. Brandt, Robert Kröger |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Ecological Engineering. 51:249-255 |
| ISSN: |
0925-8574 |
| Popis: |
The Mississippi River Healthy Basins Initiative calls for best management practices (BMPs) that actively avoid, control, and trap non-point source pollutants such as sediments and nutrients. Typical edge-of-field practices of forested riparian buffers and native warm season grass buffers control and trap sheet flow surface runoff. Slotted inlet pipes are drainage water management structures that theoretically slow runoff velocities, detain a variable pool of water, and encourage sedimentation. The objective of this study was to document sediment accumulation behind four newly installed slotted inlet pipes in the Lower Mississippi Alluvial Valley. Further analysis of installation geometry and total phosphorus (TP) of accumulated sediments provided sediment volumes and TP loads retained on agricultural landscapes as a result of slotted inlet pipes. There were significant differences (p < 0.001) in sediment accumulation (mm) between all sites, however, there were no significant differences in sediment accumulation rates (mm/day) between the four pipes (H = 2.611; p = 0.625). Overall curvi-linear trend (r2 = 0.76) and the Von Bertalanffy non-linear model for sediment accumulation through time for all four sites, suggests highest sediment accumulation occurs at approximately 235 days following pipe installation at 65 ± 22% of pipe volume. A Mann–Whitney U test showed highly significant differences in sediment accumulation rates between T0–235 (1.5 mm/day) and T235–624 (−0.0357 mm/day). Overall sediment volumes and TP loads retained ranged between 3.88 and11.5 m3 and thus 3.32–18.86 kg TP respectively, with average present value costs per kg per ha of TP accumulated ranging from $250.66 (low TP concentration) to $136.51 (high TP concentration) over the 15 yr project horizon. Results document performance measures of slotted inlet pipes for sediment accumulation and phosphorus load retention per pipe. Furthermore, estimates of time that maximize sediment accumulation (t = 235 days) provide a potential management protocol that could maximize sediment and nutrient reductions with slotted inlet pipes as edge-of-field management practices. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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