The effect of anisotropy on selected soil properties in a deep alluvial soil

مرکز و کتابخانه مطالعات اسلامی به زبان های اروپایی

منو

" The effect of anisotropy on selected soil properties in a deep alluvial soil "
M. H. H. Nash L. A. Daugherty

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1112674
Doc. No	:	TLpq303843152
Main Entry	:	L. A. Daugherty
	:	M. H. H. Nash
Title & Author	:	The effect of anisotropy on selected soil properties in a deep alluvial soil\ M. H. H. NashL. A. Daugherty
College	:	New Mexico State University
Date	:	1990
student score	:	1990
Degree	:	Ph.D.
Page No	:	154
Abstract	:	A trench 6 meters deep, 5 meters wide and 26 meters long was dug in sequential deposited alluvial sediments. Three sediment units were differentiated based on different episodes of carbonate accumulation and lithological discontinuities. Each unit was sub-divided into 3 additional layers representing major morphological changes within the unit. From each of the nine layers, a total of 50 samples were collected for physical and chemical analyses. Selected soil physical and chemical analyses were performed to test the distribution of soil properties in vertical and horizontal directions. It was found that abrupt changes in these properties coincided with abrupt boundaries between the sediment units. Data distribution were examined through its spatial relation with distance in the trench soil by using geostatistical analysis (kriging). This analysis produced sets of data that were used to develop meaningful contour maps. These contour maps from the trench soil supported the separation of three sediment units identified and an arroyo backfill. The separations were tested by analysis of variance to find the differences between the mean of each group of data set at usd\alphausd =.05. The three sediment units and the arroyo backfill were significantly different from each other with respect to the amount of carbonate accumulation, clay content and hydraulic conductivity. Regression models were developed for measured soil properties to determine relationships of those soil physical properties in estimating soil hydraulic conductivity, soil water retention, clay and calcium carbonate content. Several soil physical properties were correlated with soil hydraulic properties. The best relationship was found between soil water retention data and soil physical properties. The trench anisotropy was high in both vertical and horizontal directions. The anisotropy was presented in contour map generated by using cokriging to consider sample location. The estimated values were plotted onto 3-D contour maps. The 3-D contour maps were very close to the field soil morphological observations. This indicated that cokriging is a good estimater for spatially correlated soil properties. The results of this study should be useful in the interpolation of water and solute movement in similar soil and to explain the anisotropy of such movement, which is closely associated with soil properties.
Subject	:	Agronomy
	:	Biological sciences
	:	Earth sciences
	:	Environmental science
	:	Geology
	:	Health and environmental sciences