Wednesday, November 15, 2006 - 9:00 AM

Unsaturated Flux Variability Measurements at Droplet/minute/ 3x3cm(10x10grid) Resolution in Summer Rainstorm Conditions.

Franck A. N. Hogervorst, Esther Bloem, and Ger H. Rooij de. Wageningen University, Nieuwe Kanaal 11, Wageningen, 6709PA, Netherlands

High intensity and high volume rain increases preferential flow in many soils and thereby reduces the many beneficial effects of water in the biosphere. We quantified the variability of the unsaturated flux below the root zone to trap enhanced groundwater recharge by variably saturated soil domains in the field during heavy summertime rainstorms. Enhanced groundwater recharge and its spatiotemporal distribution was investigated as a potential cause of fast reacting phreatic levels in homogeneous sand. In this presentation, we present details on the 100 cell tensiometer controlled sampler device, results of field experiments performed in 2005 and results of simulations that identify the application range of the sampler and enable comparison with other flux measurement methods for the unsaturated zone.