Chesapeake Research Consortium

ABSTRACTClimate change in the Chesapeake Bay watershed will affect the effort to achieve nutrient and sediment reductions called for in the total maximum daily load (TMDL) regulations. To determine how nutrient and sediment loads may change in response to climate, a systematic review evaluated research literature related to the impacts of climate change and variability on hydrologic fluxes and nutrient and sediment cycling and transport. Climate change impacts hydrologic fluxes, nutrient and sediment cycling, and export in the Chesapeake Bay region via several factors, including changes in precipitation volume and intensity, rising temperatures, and increased atmospheric carbon dioxide concentrations. Increased precipitation volume is expected to increase the water budget expressed via greater runoff, streamflow, and freshwater flows to the estuary, but seasonal changes, such as increased winter and spring precipitation and hotter, drier summers, increase the variability of these responses. Climate change will also alter the cycling and transport of nutrients and sediment, with higher temperatures increasing the rate of nutrient cycling, and increased precipitation, expressed as wetter soils, increasing losses. While there was considerable variability among studies, there was common ground that suggests the Chesapeake Bay watershed will experience greater nonpoint source nutrient and sediment loads. Ultimately, this information informs how climate change may impact efforts to meet the TMDL.

Analyzing wind loads on moored vessels is integral to the design process of small craft marinas to ensure the structural integrity of dock infrastructure. Existing methods are effective but present certain limitations in their ability to provide a seamless and accurate approach. Key shortcomings include the subjective determination of effective area, particularly due to the lack of comprehensive vessel data, and the reliance of engineering judgement for selecting drag coefficients. In response to these challenges, a novel method is proposed for calculating wind loads on vessels and subsequently transferring these loads to piles, chains, or other supporting structures within marinas. The method described here combines aspects from existing methodology while offering flexibility to address individual project requirements. It provides a more accurate service load for vessels, particularly when oblique winds are reaching the vessels. This proposed design process merges the structural and coastal design approaches to produce one universal method for analyzing and designing marina structures.

The 1,988-acre Crestwood (CW) 2&3 watershed is a Virginia coastal (Atlantic) plains watershed that is prone to flooding because such watersheds are typically low-lying areas with less relief, have high groundwater tables, experience heavy rainfalls and high tides. In addition, such watersheds often contain old urban cities with more imperviousness, aged infrastructure lacking maintenance, and stormwater infrastructure not meeting current standards. In this study, a Master Drainage Plan (MDP) was developed for the CW-2&3 watershed to examine the current flooding problems and develop solution measures through improvements to the drainage infrastructure. PCSWMM, based on the US EPA’s Storm Water Management Model (SWMM), was used in developing the MDP. An existing conditions model was developed using topographic, stormwater infrastructure, and survey data. The model was calibrated using Weather Underground Station rainfall data, USGS tide gage data, and high-water levels measured at 11 monitoring stations during a significant rainfall event. The calibrated model was then run with six design storms for developing drainage improvements adequate for the required design storms at known and model dictated flooding areas. The presentation and the paper summarize the study alluding to the level of efforts and details going into these kinds of numerous studies by practicing engineers and scientists for municipalities (local governments) having limited resources that could be far from ideal elaborate research studies. It also shows the challenges that needed to be overcome while developing and calibrating the model and developing the MDP for this Virginia coastal plain and similar watersheds anywhere.

The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9°C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase by 0.8-1°C. Summer average anoxic volume is estimated to increase 1.4 percent compared to the Base Scenario, because of an increase in algal blooms in the spring and summer, promotion of oxygen consumptive processes, and an increase of stratification. However, a 0.5-meter Sea Level Rise Scenario results in a 12 percent reduction of anoxic volume. This is mainly due to increased estuarine circulation that promotes oxygen-rich sea water intrusion in lower layers. The combined Sea Level Rise and Warming Scenario results in a 10.8 percent reduction of anoxic volume. Global warming increases precipitation and consequently increases nutrient loads from the watershed by approximately 5-7 percent. A scenario that used a 10 percent increase in watershed loads and current estuarine circulation patterns yielded a 19 percent increase in summer anoxic volume, while a scenario that used a 10 percent increase in watershed loads and modified estuarine circulation patterns by the aforementioned sea level rise and warming yielded a 6 percent increase in summer anoxic volume. Impacts on phytoplankton, sediments, and water clarity were also analysed.

The power and influence of the American television industry in today's world market is examined. Based on interviews with media buyers and sellers from the United States and other countries, the argument is advanced that the goal of attracting large audiences dominates program selection. It is the audience in each country, with its own system of cultural values and beliefs, that ultimately decides the popularity of programs. This plays a decisive role in influencing the types of shows imported from the United States.

Human visual preferences for slides of five natural landscapes or biomes-tropical rain forest, temperate deciduous forest, coniferous forest, savanna, and desert-were examined. Subjects were third graders, sixth graders, ninth graders, college students, adults, senior citizens, and a group of professional foresters. A series of 20 slides, 4 examples of each biome, was shown twice to each group of subjects. On one pass through the slides, subjects judged how much they would like to live in an area similar to the one represented; on the other pass, subjects rated the slides for how much they would like to visit an area similar to the one shown. Judgments were made on a 6-point Likert scale. Elementary schoolchildren showed a significant preference for savanna over all other biomes. From midadolescence and through adulthood, more familiar natural environments were equally preferred to savanna. Results were interpreted as providing limited support for the hypothesis that humans have an innate preference for savanna-like settings that arises from their long evolutionary history on the savannas of East Africa.