LNWB Ch09 Artificial Drainage - watershed and hydric minus tile shape files

Compressed GIS files used in PhaseIIITask4 to create ditch and tile drain layers.

Spatial data files specifying the areas with ditch and tile drainage were developed in 2004 by the USDA, Natural Resources Conservation Service (NRCS; Resource Conservationist, John Gillies, and Agricultural Engineer, Dean Renner). Drainage coefficients from NRCS technical guides are shown in Table 2. The drained areas were estimated using a geographic information system (GIS) to identify hydric soils on agricultural land use areas, based on the assumption that if a hydric soil was cleared and in agricultural use, then there was a drainage system in place to manage water using sub-surface (tile) and surface (open ditch) practices. For the Lower Nooksack Water Budget these are areas used to determine the tile drained and ditch drained fraction of each drainage model element as well as to assign drainage coefficients.

This resource is a subset of the LNWB Ch09 Artificial Drainage Collection Resource.