@article{skaggs_phillips_chescheir_trettin_2011, title={Effect of minor drainage on hydrology of forested wetlands}, volume={54}, DOI={10.13031/2013.40665}, abstractNote={Results of a simulation study to determine the impacts of minor drainage for silviculture on wetland hydrology are presented in this article. Long-term DRAINMOD simulations were conducted to determine the threshold drainage intensity (ditch depth and spacing) that removes wetland hydrology from forested wetlands. Analyses were conducted for 13 soil series and profile combinations at ten locations from Norfolk, Virginia, to Baton Rouge, Louisiana, in the Atlantic and Gulf coastal states. Threshold ditch spacings (LT) were obtained for five ditch depths for all combinations of soil profiles and locations. Analysis of the results showed that LT can be approximated as LT = , where T is the horizontal hydraulic transmissivity of the soil profile, and C is a coefficient dependent on ditch depth and geographic location. The C values for all combinations of ditch depth and location are given in this article. The threshold spacings can be used as benchmarks to directly evaluate the impact of drainage alternatives on wetland hydrology. They were also used herein to determine T25 inputs for previously developed methods to predict the lateral impact of a single ditch on wetland hydrology. Lateral impacts were determined and presented for a 0.9 m (3 ft) deep drainage ditch for all soils and locations considered. The T25 values presented can be used to determine lateral impacts for other ditch depths and soils. The analyses in this study were conducted for a surface depressional storage of 5 cm. More work is needed to define T25 values for smaller surface storages, including those smaller values needed for application to agricultural cropland.}, number={6}, journal={Transactions of the ASABE}, author={Skaggs, R. W. and Phillips, B. D. and Chescheir, G. M. and Trettin, C. C.}, year={2011}, pages={2139–2149} }
@article{phillips_skaggs_chescheir_2010, title={A method to determine lateral effect of a drainage ditch on wetland hydrology: Field testing}, volume={53}, DOI={10.13031/2013.32599}, abstractNote={An approximate method was previously developed to predict the lateral effect of a drainage ditch on wetland hydrology. The method predicts the lateral distance of influence of a single ditch constructed through, or adjacent to, a wetland in terms of T25 values, which are dependent on climatological conditions. The lateral effect, or distance of influence, is defined as the width of a strip adjacent to the ditch that is drained such that it no longer satisfies wetland hydrologic criteria. T25 represents the time required for the water table to be drawn down by drainage from the surface to a depth of 25 cm at the location on the landscape that will just barely satisfy the wetland hydrologic criterion. Data to test the method were collected at two wetland mitigation sites in eastern North Carolina: Mildred Woods in Edgecombe County and ABC near Pinetown in Beaufort County. The approximate method predicted lateral effects of 42.6, 7.2, and 14.1 m for Mildred Woods, ABC shallow ditch, and the ABC deep ditch, respectively. Compared to direct interpolation of 3-year average field results for Mildred Woods (41 m) and the deep ditch (12 m), the method performed well. The lateral effect predicted by the method for the shallow ditch at the ABC site was at least two times that measured in the field (<3.75 m). In this case, the ditch was located in a tight clay layer, which substantially reduced the effective transmissivity of the profile and the lateral effect of the ditch on the hydrology of adjacent wetlands.}, number={4}, journal={Transactions of the ASABE}, author={Phillips, B. D. and Skaggs, R. W. and Chescheir, G. M.}, year={2010}, pages={1087–1096} }
@article{skaggs_chescheir_phillips_2005, title={Methods to determine lateral effect of a drainage ditch on wetland hydrology}, volume={48}, number={2}, journal={Transactions of the ASAE}, author={Skaggs, R. W. and Chescheir, G. M. and Phillips, B. D.}, year={2005}, pages={577–584} }