Summary and Analysis of Measurements of Discharge from Blue Spring, Near Orange City, Florida 1932-2002

摘要

This report presents a summary and analysis of 536 discharge measurements at Blue Spring near Orange City, FL, during the period March 1932-March 2002, to determine if measurements of spring discharge are affected by measuring-section location. The primary purpose of this analysis is to determine if, since the early 1990s, apparent persistent changes in temporal patterns (declines) in discharge that have been noted by other workers could be an artifact of changes in measurement locations, rather than an actual decline in the amount of water discharged from the spring. There does not seem to be a significant effect of measurement-section location on measured spring discharge. However, there is no way to prove definitely from examination of these long-term, yet still somewhat limited data, that measuring-section location does not affect determination of spring discharge to some, albeit small, degree. The actual spring discharge may change between monthly (or less frequent) measurements, and, thus, obscure any effects of measurement-section location. Multiple near-synoptic measurements along the spring run might provide sufficient data to determine if discharge varies along the spring run. In any case, the use of a single measuring-section location in future monitoring would eliminate uncertainly about effects of measurement location and would probably be advisable.