Dry weather struck Vermont again in 2001, with conditions as bad as, or worse than, the drought of 1999. Brown lawns and low river levels were common by midsummer, and the State Climatologists Office issued a statement in August calling the situation a flash drought due to its rapid onset.
Shortfalls in precipitation began in April, but with the remaining heavy snow pack from above-normal winter snowstorms, the shortfall was not noticeable. Although rain fell regularly through June, rainfall amounts were below normal, just enough to keep lawns and gardens growing.
Drought conditions accelerated in July. From July 15 through August 8, the fire weather station in Essex received less than one-tenth of an inch of rain. Rainfall in northern Vermont was below normal by as much as nine inches in several locations by mid-August, but rebounded slightly with storms on August 29 and September 1. Despite showers in September and October, drought conditions persisted well into autumn.
PDSI is the most widely recognized and most effective in determining long-term drought. During the growing season, the Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA) updates the PDSI on a weekly basis. Each week, temperature and precipitation observations from sites within predefined zones are averaged and compared with soil moisture contents and changes from the previous week to derive a PDSI value. This value describes a range from extreme moist spells to extreme drought.
Northern Vermont was first classified as having moderate drought conditions during the week ending July 21, and the northern half of the state was in severe drought by August 11. Northern Vermont remained in severe drought through October 20; severe drought conditions persisted in the northwestern region of the state even later into the autumn.
The National Fire Danger Rating System (NFDRS), developed by the U.S. Forest Service to assist land management agencies in calculating fire danger based on current and accumulated weather observations, uses the Keetch-Bryam Drought Index because it better represents moisture deficiencies in forest settings. The National Fire Danger Rating System assumes that drought conditions cause premature wilting and death of live plant materials, increasing the amount of available fuel for a wildfire. KBDI values range from zero, when soil and duff are saturated, up the maximum value of 800, indicating the absence of available moisture. The computer-based rating system calculates the value based on cumulative daily temperature and precipitation observations.
The KBDIs calculated at Vermonts fire weather stations exceeded any previously recorded level by the end of August and continued well above normal into mid-October. Table 1 compares the stations at their highest KBDI levels during the past summer which occurred in August 2001 to their normal level at any time throughout the fire season (April 1 though November 1) and the previous maximum at any time during a fire season.
More information on drought and drought indices is available at the websites of the National Oceanic and Atmospheric Administrations Climate Prediction Center (http://www.cpc.ncep.noaa.gov/index.html) and the Vermont State Climatologist (http://www.uvm.edu/~ldupigny/sc/).
Vermonts parks provide access to streams, rivers, ponds, and lakes across the state for swimming, boating, fishing, or simple relaxation. Campgrounds and day-use areas on shorelines are substantially more popular than those not on water. About 80 percent of the annual visits to Vermont State Parks are to the 37 parks located on shorelines.
The Vermont State Parks system has 36 designated swimming areas and thousands of feet of shoreline available for other uses. Sand Bar State Park, on the shore of Lake Champlain and close to Burlington and its suburbs, is Vermonts busiest day-use area, with more than 54,000 guests visiting the park in 2001 (Figure 2). Shoreline campsites in any park are the most sought after. They tend to be reserved earlier, more often, and for longer periods.
Vermont State Parks are known for the quality experience they offer. Since water is such an important component of recreation, excellent water quality is critical to sustaining the reputation and long-term health of the park system.