Laserfiche WebLink
<br />'00 <br /> <br />Site A <br /> <br />90 <br />60 <br /> <br /> <br />70 <br />60 <br />_SO <br />w <br />~ 40 <br />~ <br />::> 30 <br />~ <br />~ 20 <br />w <br />" 10 <br />g <br />w 0 <br />" <br />~ <br />It 100 Site C <br />ill 90 <br />"' <br />"' <br />9 60 <br />ffi 70 <br />> <br />ii: 60 <br /> <br /> <br />60 <br /> <br />SlteB <br /> <br />SiteD <br /> <br />Pumping Nonpumping <br /> <br />40 <br />30 <br />20 <br />10 <br />o <br />o 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 <br />TIME, IN YEARS TIME, IN YEARS <br />EXPLANATION <br /> <br /> <br />Eastern Snake River <br />.. Thousand Springs reach <br /> <br />Figure c-4. Simulated losses to the Snake River resulting from pumping at well sites A to D. <br />(Modified from Hubbell and others. 1997; reprinted with permission of the National Ground Water <br />Assodahon.CopyrightI99~) <br /> <br />The results of pumping at site D illustrate how surface- <br />water depletion can continue long after pumping is discon- <br />tinued at a well. These residual effects are demonstrated at <br />site D by simulating continuous pumping for 30 years followed <br />by a 70-year non pumping period. Depletion of flow to the river <br />increases for approximately 15 years after pumping at site D <br />is discontinued. Depletion is still occurring 70 years after <br />pumping ceases at a rate equivalent to 15 percent of the <br />average pumping rate during the 30 years of pumping at <br />site D. <br /> <br />The simulated results for sites A to D indicate that the <br />location of a well relative to the ground-water-flow system has <br />a significant effect on where changes in flow in the system <br />take place and how long the system continues to adjust before <br />equilibrium is reached. These results highlight the importance <br />of taking transient response times of ground-water systems <br />into account in long-term water-resources planning. <br /> <br />39 <br />