| OCR Text |
Show Alternately the water rights preservation constraint may be specified for each agency k, in terms of the sum of the flows across all of its boundaries. This may be stated as N ( l- TOl4) XFb - **£' * ( 1+ T0Lt> XFb k- l..... K ( 3.11) bek bek where Tolb k is some acceptable tolerance for deviation in the flow across the boundaries for agency k. The prescribed boundary flows Fj may be determined as the values of the flows across the boundary b, at time 0, or as the average historical flows across the boundary, or through an evaluation of the average flows across the boundary if all existing water rights are enforced through simulation in the proper hierarchical fashion. 4. Contamination control through flow control The spread of contamination from contaminated areas is controlled by requiring that the groundwater flow entering/ leaving its boundaries be above/ below a prescribed level respectively. As was the case with the water rights constraints, the flow across the boundary of a contaminated area can be estimated using equation 3.6. The flows across a boundary segment c of a contaminated area are identified by Fct rather than F^. The flow constraint for contamination control is then specified across each boundary segment c, by specifying that the maximum flow out of the contaminated area, or the minimum flow into the contaminated area, be smaller/ greater than a prescribed value respectively. The prescribed value may be based either on the existing flow rate, the historical average, or a desirable flow rate that would reverse or severely curtail the migration of contaminants out of the area. The constraint may be stated in terms of the flow leaving ( considering flow entering the area across the segment of interest as a negative outflow) the contaminated area across each boundary segment c as: max F < F?" C= 1 C ( 3.12) t CI C where Fa is the flow leaving the contaminated area across boundary segment c in year t and F€ is the maximum allowable flow leaving the contaminated area c 5. Bounds on pumpages There are physical bounds on the maximum pumping rate at each well node w during any year t. Upper limits on pumping are also necessary to avoid a significant localized depletion of the aquifer. Similarly there may be a minimum amount an agency may wish to pump from a node, if wells already exist at that location. Upper and lower limits on pumpage may be stated as : (£ m < Q^ < Q ™ x w= l.... W, t= l N ( 3.13) 50 |
