Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: June 15, 2003
Publication Date: October 27, 2003
Citation: Rawls, W.J., Pachepsky, Y.A. 2003. Use of soil survey information for determining soil hydraulic properties. In: Proceedings of the American Society Of Agricultural Engineering Meeting, July 28-31, 2003, Las Vegas, Nevada. 2003 CDROM.
Knowledge of hydraulic properties is a key element in hydrologic modeling. Laboratory and field methods for determining soil hydraulic properties are time consuming and expensive. Pedotransfer functions (PTF's) which predict various soil hydraulic properties (water retention and hydraulic conductivity) based on various levels of soil survey information were developed by applying regression tree analysis to the NRCS national soils database. The qualitative information used in the pedotransfer functions were USDA soil texture classes, structure, grade, size and shape classes, dry and moist consistency classes and stickness and plasticity classes. Topographic features, organic matter and taxonomic units which are subjectively estimated in the field and are part of every soil profile description appear to be useful predictors of soil hydraulic properties.