Publications

By a proper treatment of the known boundary conditions of a boundary value problem, a complex variable boundary element method (CVBEM) can be used to exactly satisfy the known nodal point boundary values. In this fashion, a numerical model can be developed which generates relative error information along the problem boundary that can be used to reduce the modelling error by either an integrated me

Primary productivity was measured monthly at 6 sites within San Francisco Bay, USA, throughout 1980. The 6 sites were chosen to represent a range of estuarine environments with respect to salinity, phytoplankton community composition, turbidity, and water depth. Annual net production over the photic zone ranged from 95 to 150 g C m-2, and was highest in regions of lowest turbidity. Daily photic zo

Injections of NO3 and PO4 were made during September 1975 into Little Lost Man Creek, a small pristine stream in Redwood National Park, California. Chloride, a conservative constituent, was added in a known ratio to the nutrients. Nutrient loss at a downstream point was calculated using concentration of added Cl as a reference. Nitrate nitrogen (NO3‐N), added for 4 h, reached 920 μg/1 (above 5 μg/

Three models describing solute transport of conservative ion species and another describing transport of species which adsorb linearly and reversibly on bed sediments are developed and tested. The conservative models are based on three different conceptual models of the transient storage of solute in the bed. One model assumes the bed to be a well-mixed zone with flux of solute into the bed propor

For slowly moving freezing fronts in soil, the heat-transport equation may be approximated by the Laplacian of temperature. Consequently, potential theory may be assumed to apply and the temperature state can be approximated by an analytic function. The movement of freezing fronts may be approximated by a time-stepped solution of the phase-change problem, thus solving directly for heat flow across

Ideal and actual ground-water-quality monitoring networks are proposed for the San Joaquin Valley basin in California. The ideal network, which comprises several subnetworks, provides direction in the development of an actual network of wells currently monitored by known operating agencies. The ideal network can serve as a basis for the future expansion of the actual network as more wells are incl

A two-dimensional, finite-element, digital model was developed for the Carmel Valley alluvial ground-water basin using measured, computed, and estimated discharge and recharge data for the basin. Discharge data included evapotranspiration by phreatophytes and agricultural, municipal, and domestic pumpage. Recharge data included river leakage, tributary runoff, and pumping return flow. Recharge fro

Phytoplankton dynamics in the upper reach of the northern San Francisco Bay estuary are usually characterized by low biomass dominated by microflagellates or freshwater diatoms in winter, and high biomass dominated by neritic diatoms in summer. During two successive years of very low river discharge (the drought of 1976-77), the summer diatom bloom was absent. This is consistent with the hypothesi

During three weeks of September 1979, the breakdown of a waste treatment plant resulted in the discharge of a large volume (1.5×107m3) of primary-treated sewage into a tributary of South San Francisco Bay, California. Chemical and microbial changes occurred within the tributary as decomposition and nitrification depleted dissolved oxygen. Associated with anoxia were relatively high concentrations

Measurements of D and 18O concentrations of ground waters in seismically active regions are potentially useful in earthquake prediction and in elucidating mechanisms operative during earthquakes. Principles of this method are discussed and some preliminary data regarding a magnitude 5.7 earthquake at the Oroville Dam in 1975 and a series of events near San Juan Bautista in 1980 are presented to su

Field tests were conducted in California and Oregon from July to October 1978 to evaluate the effectiveness of Mesurol as a repellent to reduce bird damage to ripening wine grapes. A block of vines composed of two similar, adjacent plots was delineated at each of 20 vineyards. One randomly chosen plot within each block was treated with up to three applications of Mesurol (75% wettable powder) at a

A pseudo-two-dimensional model is developed to simulate population dynamics of one dominant phytoplankton species (Skeletonema costatum) in northern San Francisco Bay. The model is formulated around a conceptualization of this estuary as two distinct but coupled subsystems—a deep (10–20 m) central channel and lateral areas with shallow (<2 m) water and slow circulation. Algal growth rates are gove