Water Resources Research Act Program

Principal Investigators:

Abstract: Problem: Rainfall and other climate data are required for studies of water quantity and water quality (WQ2) in our region. With the obvious importance of rainfall data, other climatic data with possible influence on WQ2 include (but not limited to): the typhoon distribution; local and regional sea level; the MAX and MIN temperature, and the effects of wind and amount of sunshine. The project PI is constantly being asked to provide climate data for a wide array of WQ2 efforts, such as the recent EPA-sponsored GWUDI study, and a host of USGS-sponsored projects. A common request to the project PI by local water resource managers (and outside environmental consulting businesses) involves acquiring storm data to assess return-period calculations for storm drain projects, stream-flow estimates, reservoir management, etc. Acquiring climate data for such projects is hampered by the multiplicity of sources, incomplete or missing data in official records, short periods of record, and an absence of metadata on recording sites. Derived products (e.g., recurrence intervals) have ignored key aspects of the distributions (through missing data or flaws in method). Official records of local climate data are more fraught with deficiencies than is commonly recognized. There are known errors in the officially-available climate records, even from Guam’s best long-term stations. Official climate data for Guam available on-line from the National Climatic Data Center (NCDC) suffer from losses of data that are recoverable from local sources. For example, the NCDC record of daily data for AAFB suffers from 2.7% missing data, in contrast to the local AAFB record, which is more than 99.9% complete. Another problem was the discovery that the NOAA long-term record for the Weather Service Forecast Office (WFO) at the Guam International Airport is a concatenation of data from two separate stations that are several miles apart, and with substantial differences in temperature and rainfall. Given the Project PI’s familiarity with the local climate, access to original complete data sets, knowledge of missing typhoon data, knowledge of errors in the data and access to supplemental unofficial climate data, the PI is confident that he can assemble a better climate record than can be obtained off-the-shelf