Soil Morphology and Water Table Relations: II. Correlation Between Annual Water Table Fluctuations and Profile Features1
- G. H. Simonson and
- L. Boersma2
The frequency of occurrence of water tables at certain depths below the soil surface and the length of time water tables remained at or above these depths were calculated on the basis of rainfall records from a 29-year period. Results were correlated with soil morphological features.
Faint and distinct mottling correlated with water table behavior. The average depth below the surface to the midpoint of the uppermost mottled horizon increased as the drainage condition of the series improved. At the depth of a given degree of mottling, the percentage of time a soil was submerged was essentially the same in a given month for all series. Color designations of Munsell value and chroma for dry crushed material were also correlated with the percentage of time a soil was submerged during the first 6 months of the year. The relations were not consistent for all soils within the drainage sequence, but the poorly-drained Dayton and Concord soils had the highest values and lowest chromas.
Munsell hues of 10YR occurred in horizons of well-drained soils, whereas Munsell hues of 2.5Y and 5Y occurred in horizons of poorly-drained soils. The size and abundance of iron and manganese concretions increased in a consistent manner in the sequence from well-drained to poorly-drained soils. The sequence of bleached A2 horizons over “clay pan” IIB2t horizons was specifically related to the perched water tables of the Dayton and Concord series.
Attempts to isolate relationships between water table regimes and a single color feature of the soil which might be useful as a tool for quantitatively appraising water table regimes were not successful. However, when color features were considered jointly, the morphological assessment of natural drainage class was found consistent with the water table regimes of the soils. The results illustrate the relationship between morphological indicators of soil drainage and water table regimes under climatic conditions peculiar to the Pacific Northwest.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .