Based on the determination of the zero-flux plane, a water balance procedure
for large-scale experimental databases was automated to estimate the soil water
balance based on soil water content distribution with depth through time. The
automated procedure was verified using data from the BOREAS project obtained in
three Intensive Field...
The following report Introduces a documentation scheme for flow
oriented ecosystem models and shows its application to a carbon-water
model developed within the coniferous biome. This documentation scheme
has remained operative through revision of this model and expansion of
It to include nutrient flows. This model and subsequent versions are...
A mathematical model simulating mass transport of chemicals
in saturated porous medium is given in four parts. Included in the
development is the physical phenomenon of adsorption of molecules
of chemicals on the surrounding walls of the porous medium. The
four main areas of study are:
(1) Simple one dimensional...
A model is presented which predicts the net present
value of a stand level multi-entry harvest plan. The model
accounts for potential volume losses due to harvest-related soil compaction. The goal of this project was to answer five economic questions about the issue of soil compaction in forestry. The five...
The purpose of this study was to use computer analysis of soil and rainfall data to predict the possible occurrence of soil erosion in Central Tunisia. Analysis was done with the program OR-NATURE (M.Ungs et al, 1985) . Central Tunisia was subdivided into northern, central, and southern subzones. Data about...
Gaseous transport through soil in the presence of soil
microorganisms has been investigated. More recently, modeling of
gaseous transport in the unsaturated zone has been investigated.
However, the problem of mathematical model of oxygen and carbon
dioxide transport through soil, as affected by the climatic
conditions, the transport of soil...
An experimental and numerical modeling investigation was conducted to study interactions between microbial dynamics and transport processes in variably saturated porous media. These interactions are important in a variety of applied problems such as water and wastewater treatment, bioremediation, and oil-field recovery operations. These processes and interactions also have great...
A mathematical and then a numerical model were developed for simulating a convective batch lumber drying process. The model incorporates mass and heat transfer relationships within the lumber stack, as well as thermodynamic properties of the wood and drying air. It takes into account a change of air properties along...
The work reported herein was performed under the annual allotment from the Office of Water Resources Research to the Oregon Water Resources Research Institute. Funds were available over a three year period, but due to difficulty in acquiring graduate students, the total time spent on the project was only 21...
The onsite costs and benefits of conservation tillage in the
Camas Prairie Region of Northern Idaho were estimated. The evaluation
of these costs and benefits included a measurement of the
long-term effects of soil erosion on cropland productivity.
A model developed by Daniel Taylor (1982) was used as a base...
Variability in wood properties causes boards within a stack of lumber to
dry at different rates and reach different moisture content levels after drying is
completed. The consequence is that the boards will have properties that differ from
ones that were intended to be achieved by the drying process.
The...
A hypothesis used to explain the relationship between timber harvesting
and landslides is that tree roots add mechanical support to soil, thus increasing
soil strength. Upon harvest, the tree roots decay which reduces soil strength and
increases the risk of management -induced landslides. The technical literature
does not adequately support...
This report is one of a series issued in cooperation with Air Force-Navy-Civil Subcommittee on Aircraft Design Criteria under the supervision of the Aircraft Committee of the Munitions Board. Information reviewed and reaffirmed November 1954 and June 1959. Date of original report October 21, 1946.
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed 1956.
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on aircraft design criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed March 1956 and 1962. Original report issued November 1946.