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DIFFERENCES BETWEEN MODELED SURPLUS AND USGS‐MEASURED DISCHARGE IN LAKE PONTCHARTRAIN BASIN, LOUISIANA 1
Author(s) -
Rohli Robert V,
Grymes John M.
Publication year - 1995
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.1995.tb03367.x
Subject(s) - structural basin , hydrology (agriculture) , water balance , environmental science , drainage basin , spring (device) , subtropics , geological survey , water discharge , geology , geography , ecology , geomorphology , mechanical engineering , geotechnical engineering , cartography , engineering , biology , paleontology
A one‐layer decreasing‐availability monthly water balance model is used to estimate monthly surplus that flows into the Lake Pontchartrain Basin from the Amite, Tickfaw, Natalbany, Tangipahoa, and Tchefuncte Rivers for water years 1949 through 1990. The modeled annual surplus for each drainage basin is compared to gauged annual discharge obtained from the United States Geological Survey. This provides an estimate of the differential success of the model over watersheds of various sizes, and also suggests appropriate adjustment factors to be used in future water balance analyses of similar basins in humid subtropical climate regions. Results show that annual surplus values agree well with the USGS values, after an annual adjustment of about 140 mm (11 to 28 percent of the basin surplus) is subtracted from the annual modeled totals to compensate for overestimation by the model. However, inter‐annual variability is high in the annual cycles. Winter and spring discharges can also be modeled successfully.