• Environmental impacts on Guam's water security and sustainable management of the resource

      Khalaj-Teimoury, Masoud; Duffy, Lawrence; Aguon, Alicia; Barnes, David; Taghizadegan, Salman (2018-05)
      Impacts of climate change on the already severely strained freshwater resources of approximately 1000 inhabited islands in the Pacific Ocean are of great concern. The Western Pacific region is one of the world's most vulnerable when it comes to risk of disaster particularly for the several of the low-lying coral islands. Impacts have already been felt regarding the security of water resources that would directly impact agriculture, forestry, tourism and other industry-related sectors. The ironic and tragic aspect of the environmental crisis of greenhouse emissions is the fact that those parts of the world least responsible for creating the water security issues are the first to suffer its consequences. Pacific Island Nations are responsible for only 0.03 percent of the world's carbon dioxide emissions, and the average island resident produces only one-quarter of the emissions of the average person worldwide. Utilizing the historical data, the evidence of change in water quality and access on Guam has been examined. All indicators except for the precipitation support the hypotheses that climate change trends are impacting Guam's water security. This will eventually weaken Guam's resilience. As a result of this research and its recommendations, a sustainable freshwater resources management plan, for a water-secured Guam can be produced. Adaptive management provided here is based on a process that can measure the resilience of Guam to the issue of water security.
    • Investigation of thermal regimes of lakes used for water supply and examination of drinking water system in Kotzebue, Alaska

      Bendlova, Tereza; Arp, Christopher D.; Duffy, Lawrence K.; Schnabel, William E.; Barnes, David L. (2012-08)
      Many villages in Arctic Alaska rely on lakes for water supply, such as the Alaskan City of Kotzebue, and these lakes may be sensitive to climate variability and change, particularly thermal regimes and corresponding effects on water quality. Thus, I initiated a study of water supply lakes in Kotzebue to collect data for developing a model to hindcast summer thermal regimes. Surface (Tws) and bed (Twb) temperature data collected from two water supply lakes and two control lakes from June 22nd-August 28th 2011 showed a similar pattern in relation to air temperature (Ta) and solar radiation with more frequent stratification in the deeper lakes. The average Tws for all lakes during this period was 14.5°C, which was 3.4°C higher than Ta for the same period. I modeled Tws from 1985 to 2010 using Ta, and theoretical clear-sky solar radiation (TCSR) to analyze interannual variability, trends, and provide a baseline dataset. Similar to patterns in Ta for this period, I found no trend in mean Tws for the main lake used for water supply (Devil's Lake), but considerable variation ranging from 12.2°C in 2000 to 19.2°C in 2004. My analysis suggests that 44% of years during this 25 year period maximum daily Tws surpassed 20°C for at least one day. This hindcasted dataset can provide water supply managers in Kotzebue and other Arctic villages with a record of past conditions and a model for how lakes may respond to future climate change and variability that could impact water quality.