HR: 09:15h
AN: H31M-06    [Abstracts]
TI: Correlation of groundwater withdrawal and fluctuation of stream stage for steam depletion
AU: Intaraprasong, T
EM: trinint@neo.tamu.edu
AF: Texas A & M university, Department of Geology and Geophysics, College Station, TX 77843-3115, United States
AU: * Zhan, H
EM: zhan@geo.tamu.edu
AF: Texas A & M university, Department of Geology and Geophysics, College Station, TX 77843-3115, United States
AB: Stream depletions have two components which are due to groundwater withdrawal from a nearby pumping well and due to stream stage fluctuation itself. Previous studies often focus on each component separately. This study examines and compares two components together for various hydraulic settings and pumping schemes. It presents generalized solutions for stream depletions with and without streambeds. Since this study concerns seasonal stream depletion rates, it assumes that stream stage fluctuation is solely a function of time and a cosine function of time is chosen as an example. Three pumping schedules are 1) pumping for two months during dry season with a rate Q; 2) pumping for four months during the dry season with a rate of Q/2; and 3) constant pumping through out a year with a rate of Q/6. The values of Q are chosen to be 1000m³/d and 5000m³/d to simulate a small irrigation or a municipal well. One of the primary characteristics affecting stream depletion is the period of the stream stage fluctuation, in addition to the pumping rate and the hydraulic conductance of the streambed. For a pumping rate of Q=5000 m³/d and a period of one year, percentages of the stream depletion rate due to stream stage fluctuations to the total stream depletion rate range from 1.5% to 15% for a hypothetical case investigated. If reducing the stream fluctuation period to 30 days and keeping other setting the same, that percentages then range from 5.4 % to 38.5%. The amplitude of the stream stage fluctuation was found to have less important influence on the depletion rates.
DE: 1821 Floods
DE: 1829 Groundwater hydrology
DE: 1830 Groundwater/surface water interaction
SC: Hydrology [H]
MN: 2007 Fall Meeting