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Title: Barrier erosion control test plan: Gravel mulch, vegetation, and soil water interactions

Technical Report ·
DOI:https://doi.org/10.2172/6438624· OSTI ID:6438624
;  [1]
  1. Pacific Northwest Lab., Richland, WA (USA)

Soil erosion could reduce the water storage capacity of barriers that have been proposed for the disposal of near-surface waste at the US Department of Energy's Hanford Site. Gravel mixed into the top soil surface may create a self-healing veneer that greatly retards soil loss. However, gravel admixtures may also enhance infiltration of rainwater, suppress plant growth and water extraction, and lead to the leaching of underlying waste. This report describes plans for two experiments that were designed to test hypotheses concerning the interactive effects of surface gravel admixtures, revegetation, and enhanced precipitation on soil water balance and plant abundance. The first experiment is a factorial field plot set up on the site selected as a soil borrow area for the eventual construction of barriers. The treatments, arranged in a a split-split-plot design structure, include two densities of gravel admix, a mixture of native and introduced grasses, and irrigation to simulate a wetter climate. Changes in soil water storage and plant cover are monitored with neutron moisture probes and point intercept sampling, respectively. The second experiment consists of an array of 80 lysimeters containing several different barrier prototypes. Surface treatments are similar to the field-plot experiment. Drainage is collected from a valve at the base of each lysimeter tube, and evapotranspiration is estimated by subtraction. The lysimeters are also designed to be coupled to a whole-plant gas exchange system that will be used to conduct controlled experiments on evapotranspiration for modeling purposes. 56 refs., 6 figs., 8 tabs.

Research Organization:
Westinghouse Hanford Co., Richland, WA (United States)
Sponsoring Organization:
DOE/EM
DOE Contract Number:
AC06-87RL10930
OSTI ID:
6438624
Report Number(s):
WHC-EP-0067; ON: DE91001291
Country of Publication:
United States
Language:
English