MADISON, WI, June 28th, 2010 – When water travels through soil and bedrock to the water table, it carries minerals, nutrients or chemicals from the surface with it. Environmental research is increasingly concerned with preferential flow, or the movement of water through pores and cracks at a faster rate and bypassing most of the surrounding material, either soil or fractured rock.
A special section on preferential flow features in the May 2010 Vadose Zone Journal, a publication of the Soil Science Society of America. This journal focuses on a multidisciplinary approach to the piece of earth between soil and the water table.
The number of scientific articles on preferential flow has increased since the late 1990’s, symptomatic of environmental concerns of contaminant leaching and unintended pollution of subsurface and surface waters in agricultural landscapes. In 1999 there were 100 articles on the topic, and in 2009 that number had increased to 160.
Articles in this issue represent research relevant to agricultural contamination of groundwater, the effect of land use change on water resources, rainstorm runoff and erosion, transport of heavy metals and other toxins, and irrigation.
The special section contains 18 new articles on preferential flow, ranging from testing, developing and calibrating models, measuring techniques, and observations and experiments of unique flow patterns. Mirroring the current state of research in the field, these articles represent the latest in concepts and topics related to preferential flow.
While the featured articles represent incredible progress in the development of preferential flow modeling and concepts, the research also highlights the remaining problems and challenges, such as the need for noninvasive experimental and imaging techniques, and incorporating smaller scale observations into larger scale formation.
Two discernable trends are noticeable from the research, namely images that produce greater resolution of water distribution and the extension of principles onto preferential flow models. Future advancements in modeling and concepts will occur with the advancement of experimental methods.