An Open-Source Data Manager for Network Models

Developing simulation and optimisation models for resource networks like water or energy systems increasingly involves integrating multiple data sources and software. Connecting multiple models and managing data accessed by different groups of analysts is a software challenge. Many resource systems are represented in computer models as networks of nodes and links, driven by a range of objectives and rules. We present a data storage platform, written in Python, which exploits the commonality of network representations to store data for multiple model types within a single deployment. This open-source platform provides a common source of data to multiple models using consistent data formats, reducing likelihood of error compared to file based data management. When deployed as a web service, it allows data to be shared securely among authorised users over the internet, facilitating collaboration. A case study describes the hosting of a water utility planning model, with an accompanying worked example

Grain growth in Nio–MgO and its dependence on faceting and the equilibrium crystal shape

The impact of faceting on grain growth was approached by model experiments in NiO–MgO. Grain growth rates were found to be 10 times higher in NiO compared to MgO. As the self-diffusion acoefficients differ by a factor of 250, grain growth in NiO is unexpectedly slow compared to MgO. Recently, the movement of steps was identified as the atomic mechanism of grain boundary migration. According to the equilibrium crystal shape, grain boundaries in NiO are more faceted. The faceted grain boundaries of NiO have fewer steps at the grain boundaries resulting in a relatively lower mobility

Climate-Adaptive Water Year Typing for Instream Flow Requirements in California\u27s Sierra Nevada

Water year types (WYTs), whereby years are classified by river runoff quantity compared to historical runoff, are one tool to help make major water management decisions. Increasingly, these decisions include instream flow requirements (IFRs) below dams for river ecosystem management. However, WYTs are typically based on assumptions of stationarity, and are thus rendered less meaningful with climate change. Hydrologic alteration resulting from climate change means that a WYT-based IFR scheme using stationary historical observations might inadvertently result in long-term river management outcomes inconsistent with original water management goals. This study assesses the management implications of assuming hydrologic nonstationarity in a WYT-based IFR scheme in California\u27s upper Yuba River and demonstrates a rolling period of record as a climate adaptation strategy. The existing, nonadaptive water management scheme leads to vastly different possible water allocation outcomes than originally planned for. Results indicate that water year types, if regularly updated, can help maintain historical instream flow distributions. However, gains toward maintaining desired IFRs are obfuscated by future increases in unmanaged reservoir spill. These findings indicate that hydroclimatic uncertainty can partially be accounted for with simple modifications to existing operating rules for reservoirs, though other, risk-based management approaches are also likely needed

Optimizing Selective Withdrawal from Reservoirs to Manage Downstream Temperatures with Climate Warming

Selective withdrawal systems can take advantage of thermal stratification in reservoirs to manage downstream temperatures. Selective withdrawal might also help adapt operations to environmental changes, such as increased stream temperatures expected with climate change. This exploratory study develops a linear programming model to release water from different thermal pools in reservoirs to minimize deviations from target downstream temperatures. The model is applied with representative thermal dynamics to Lake Spaulding, a multipurpose reservoir on the South Fork Yuba River in California with climate warming represented by uniform increases in air temperature. Optimization results for thermal pool management with selective withdrawal are compared to a single, low-level outlet release model. Optimal selective withdrawal hedges the winter release of cold water to decrease summer stream temperatures. With climate warming, selective withdrawal can help lessen stream warming in the summer but at a cost of warmer stream temperatures in winter. As numerous assumptions are made, particularly regarding representation of thermodynamics, modeling improvements are needed to further develop selective withdrawal optimization models; several improvements are discussed. Read More: http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29WR.1943-5452.000044

Water and Energy Sector Vulnerability to Climate Warming in the Sierra Nevada: Simulating the Regulated Rivers of California’s West Slope Sierra Nevada

Climate warming is expected to affect the beneficial uses of water in the Sierra Nevada, impacting nearly every resident of California. This paper describes the development and results from an integrated water resource management model encompassing water operations and hydropower generation for the west slope Sierra Nevada spanning the Feather River basin in the north to the Kern River basin in the south at the weekly time step. This model application includes management of reservoirs, run-of-river hydropower plants, water supply demand locations, conveyances, and instream flow requirement. Model validation indicates that most major hydropower turbine flows were simulated well, with wetter years modeled more effectively than drier years. The results of this work indicated that hydropower generation will be reduced by approximately 8 percent with 6°C (10.8°F) warming, consistent with other studies, with a conservative parameterization of no change in precipitation. Reservoir operations adapt to capture earlier and greater runoff volumes that result from earlier and greater runoff due to climate warming. Seasonal compensation in operations is insufficient to overcome warming mediated losses

Water and Energy Sector Vulnerability to Climate Warming in the Sierra Nevada: Simulating the Regulated Rivers of California’s West Slope Sierra Nevada

Climate warming is expected to affect the beneficial uses of water in the Sierra Nevada, impacting nearly every resident of California. This paper describes the development and results from an integrated water resource management model encompassing water operations and hydropower generation for the west slope Sierra Nevada spanning the Feather River basin in the north to the Kern River basin in the south at the weekly time step. This model application includes management of reservoirs, run-of-river hydropower plants, water supply demand locations, conveyances, and instream flow requirement. Model validation indicates that most major hydropower turbine flows were simulated well, with wetter years modeled more effectively than drier years. The results of this work indicated that hydropower generation will be reduced by approximately 8 percent with 6°C (10.8°F) warming, consistent with other studies, with a conservative parameterization of no change in precipitation. Reservoir operations adapt to capture earlier and greater runoff volumes that result from earlier and greater runoff due to climate warming. Seasonal compensation in operations is insufficient to overcome warming mediated losses

Metabolic Risk Factor Reduction Through A Worksite Health Campaign: A Case Study Design

The purpose of this intervention study was to measure the impact of an onsite and online 12-week worksite heart-health campaign designed to reduce metabolic risk factors for employees at BMW of North America, LLC. All participants received three coaching sessions by a registered dietitian (RD), participated in eight educational sessions led by an RD, viewed their pre, midpoint and final biometric data online, and had access to other web-based tools and educational booklets. The program used team-based competition. At baseline and week 12, blood pressure, anthropometric and hematologic parameters were measured, including changes in weight, blood pressure, fasting blood glucose, waist circumference, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and smoking habits. Of the 100 individuals that enrolled, 95 completed the program, and 87 met criteria to be eligible for data analysis. Paired t tests demonstrated significant reductions in weight (