Search Results

Ochers and Mineral Pigments of the Pacific Northwest : Occurrence, Possible Methods of Preparation, and Testing of Ochers, Siennas, and Colored Clays
From Introduction: "A review is given of the nomenclature, sources, imports, statistics, common methods of preparation, and testing of mineral pigments. A description of the Deer Park-Spokane colored-clay district and the laboratory methods of preparation of these colored clays, ochers, and siennas follows. The following report is merely preliminary in nature, only three months during the summer of 1927 being devoted to the laboratory investigation."
Storm Runoff as Related to Urbanization Based on Data Collected in Salem and Portland, and Generalized for the Willamette Valley, Oregon
Abstract: Storm runoff as related to urbanization is defined by a series of regression equations for Salem and for the Willamette Valley, Oregon. In addition to data from 17 basins monitored in the Salem area, data from 24 basins gaged in a previous study in Portland, Oregon-Vancouver, Washington were used defining the Willamette Valley equations. Basins used to define equations ranged in size from 0.2 to 26 square mi. Rainfall intensity varied from 1.8 to 2.2 in. for the 6-hour, 0.020 exceedance probability. Sensitivity analyses of equations indicate that urbanization of an undeveloped basin can increase peak discharge more than three times and almost double runoff volume. Much of Portland and Vancouver are located on porous river terraces where dry wells are used to shunt runoff. Much of east Salem is located on previously farmed land where drain tiles used to dewater soils still connect directly to streams.
Back to Top of Screen