Long Term Changes
Viking forays which brought Leif Ericson to North America about 1000 A.D. occurred during a climatic period far more congenial than that experienced by the first English settlements on the East Coast in the early 1600's. There are suggestions that climate may still be shifting, but as yet the evidence is not conclusive. The facts on long range changes in water supplies in the East are few. Even though sections of the East have been settled by white men for more than 300 years, continuous records on climate do not begin until about 1850. The oldest stream flow records date from 1863, and only a few exceed 50 years in duration. Records of fluctuations in ground water levels are rarely older than 30 years. So far as instrumental data are concerned, the situation in Europe is not much different (1)