Towards an ecohydrologic classification of reclaimed watersheds : methods for estimating soil water regime on reclaimed mine waste materials; and relationships between reclamation and surface water balances in Teck's reclaimed coal-mining watersheds

The concept of a “soil moisture regime” or soil water regime is used worldwide to understand edaphic conditions, plant communities, and water balances. In particular, in western and northern Canada, Biogeoclimatic Ecosystem Classification (“BEC”, B.C. and Yukon) and Ecological Land Classification (“ELC”, AB and SK) use soil moisture regime as one of two primary variables in edaphic or edaptopic grids used to describe ranges of soil conditions and naturally occurring plant communities characteristics of these conditions. In most applications, soil moisture regime is a relative or unquantified parameter estimated from the presence of indicator plants, or from dichotomous keys using surficial material/soil properties observed in natural ecosystems. Applications of these estimation approaches to post-mining landforms and watersheds is challenging, because a) there are often few or no indicator plants and plant communities, and b) soils and surficial materials are reconstructed. Some quantitative approaches to estimation of properties that influence soil moisture regime (e.g., available water storage capacity) have been developed, but these are generally based on broad textural categories, and ignore the effects on water retention of all particles >2 mm. These approaches have limited utility to many post-mining materials, where the majority of particles may be >2 mm. Methods for estimating soil moisture regime on reconstructed post-mining landscapes were developed using concepts from land-capability and biogeoclimatic-ecosystem classification systems combined with new analyses of effects of particle-size distribution on soil water retention. These methods are both quantified and objective, in that they provide consistent results when applied by different users. This paper discusses methods development, application, and testing of this estimation approach.Non UBCUnreviewedOthe