Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Fish Nutrient Cycling, Aquatic Respiration, And Terrestrial Insect Nutrient Subsidies To Lakes, Wayne A. Wurtsbaugh Nov 2007

Fish Nutrient Cycling, Aquatic Respiration, And Terrestrial Insect Nutrient Subsidies To Lakes, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Mehner et al. (2005) reported that fish feeding on terrestrial insects could be important for nutrient budgets and cycling in lakes. They studied bleak (Alburnus alburnus) that fed largely on terrestrial insects, and they suggested that this contributed 2.1% of the lake's nutrient budget and that the subsequent excretion by the fish was equivalent to 11% of epilimnetic dissolved phosphorus concentrations. They concluded that nutrients delivered to lakes via terrestrial insects and recycled by fish would be most important for small lakes because of the large perimeter-to-area ratio between donor and recipient habitats. Fish may have important impacts …


Probabilistic Estimation Of Water Conservation Effectiveness, David E. Rosenberg Jan 2007

Probabilistic Estimation Of Water Conservation Effectiveness, David E. Rosenberg

Civil and Environmental Engineering Faculty Publications

An analytical method is derived to describe the distribution of water quantity saved among customers within a water-use sector who adopt a water conservation action. Analytical results tend toward lognormal distributions with long tails, quantifying a smaller subset of customers that show potential to achieve large savings. Example effectiveness distributions are shown for seven long-term conservation actions potentially implemented by urban, domestic water users in Amman, Jordan. Monte Carlo simulations verify the analytical derivations. The probabilistic outputs contrast with common methods that estimate conservation action effectiveness as a product of typical (average) characteristics for disaggregated customer groups. Implications to size …


Modeling Integrated Water User Decisions In Intermittent Supply Systems, David E. Rosenberg, Tareq Tawarneh, Rania Abdul-Khaleq, Jay Lund Jan 2007

Modeling Integrated Water User Decisions In Intermittent Supply Systems, David E. Rosenberg, Tareq Tawarneh, Rania Abdul-Khaleq, Jay Lund

Civil and Environmental Engineering Faculty Publications

We apply systems analysis to estimate household water use in an intermittent supply system considering numerous interdependent water user behaviors. Some 39 household actions include conservation; improving local storage or water quality; and accessing sources having variable costs, availabilities, reliabilities, and qualities. A stochastic optimization program with recourse decisions identifies the infrastructure investments and short-term coping actions a customer can adopt to cost-effectively respond to a probability distribution of piped water availability. Monte Carlo simulations show effects for a population of customers. Model calibration reproduces the distribution of billed residential water use in Amman, Jordan. Parametric analyses suggest economic and …