Decision Support System for Conjunctive Stream-Aquifer Management

Abstract

PREFACEAlthough much progress has been made in the development ofregional grOlmdwater models and river basin simulation models, previous attempts at linking these two types of models into a workable conjunctive use decision support system for use in comprehensive river basin planning, management, and administration, have not been successful. With recent advances in computer hardware and software technology such as geographic information systems (GIS) and data base management system technology (DBMS), it is now possible to develop a computer based river basin decision support system for improved conjunctive use management ofgroundwater and surface water by linking a finite difference groundwater flow model with a river basin network model.A microcomputer based decision support system is presented for conjunctive stream-aquifer management mder prior appropriation This has been accomplished through a synthesis of existing technology ratherthan development ofnew models. The computer-aided design and drafting package, AUTOCAD, and a powerful, low-cost, raster GIS package for PC's called IDRISI, are used for preparing and processing grid-based spatial data. These data are processed for input into MODRSP, amodified version of1he USGS three-dimensional finite difference groundwater model, MODFLOW, to generate numerical groundwater response coefficients for considering distributive aquifer characteristics and realistic aquifer boundary conditions. These response coefficients are provided as input to the generalized river basin network mode~MODSIM, to simulate spatially varied and timelagged return/depletion flows from stream-aquifer interaction. The integration of GIS, DBMS, MODFLOW, and MODSIM allows analysis ofconjunctive use plans capable ofconsidering decreed flow and storage rights, river calls, exchanges, trades, and plans for augmentation. The groundwater hydrologic components provided with MODSIM include reservoir seepage, irrigation infiltration, well pumping, channel loss, channel routing, return flows, river depletion due to pumping, and aquifer storage.To demonstrate the capabilities ofthe Stream Aquifer Management Decision Support System (SAMDSS), a case study is presented for a portion ofthe Lower South Platte River Basin, Colorado. A 370 by 140 groundwater grid network (l000 ft x 1000 ft cell) was prepared for the case study area using GIS techniques. Groundwater response coefficients were generated using MODRSP for the 200 wells and over 30 recharge sites ofthe Bijou Irrigation Company groundwater augmentation plan. The water right return/depletion flow account for the Bijou augmentation plan was simulated using MODSIM. A separate MODSIM network was set up for a 70 mile section ofthe Lower South Platte River, Colorado, between the Kersey and Balzac river gage stations, under administrative control of State Engineer's Water District #1, to simulate daily administration of a river regulated under prior appropriation water right laws. The river system network model, which included 11 existing or proposed res...

Modeling Crop Water Productivity Using a Coupled SWAT–MODSIM Model

“…MODSIM represents a river basin as a network of links and nodes. Unregulated inflows, evaporation and channel losses, reservoir storage rights and exchanges, stream-aquifer modeling components, reservoir operating targets, and consumptive and instream flow demands are considered in MODSIM [56]. More details can be found in Labadie [55].…”

Hydroeconomic Models as Decision Support Tools for Conjunctive Management of Surface and Groundwater

“…DSSs often involve capabilities of computer assisted graphical design, geographically referenced data bases, and interactive and user-friendly graphical interfaces and tools for input management, results display and analysis. Some examples of DSS with conjunctive use capabilities, such as CALVIN , MODSIM (Fredericks et al 1998), WEAP (Yates et al 2005) or AQUATOOL (Andreu et al 1996), although with significant differences in how water resource systems and conjunctive use are modeled and optimized.…”

“…Simulation and optimization models often have been used to support effective conjunctive programs and operations, including approaches with physical stream/ aquifer interaction (Gorelick 1983;Peralta et al 1995;Fredericks et al 1998;Belaineh et al 1999) and operating decisions to minimize surface reservoir spills (Schoups et al 2006a, b). While these approaches help the understanding of surface and groundwater interaction, and how to manage it, its application to local management still lacks representation of detailed users' decisions behind water demands, including water and irrigation technology use under uncertain (stochastic) surface water supplies.…”

Holistic versus monomeric strategies for hydrological modelling of human-modified hydrosystems

“…This serial operation, apart from being computationally inefficient, suffers from a number of drawbacks: (a) it requires iterations when decision-related interactions between the hydrological and the man-made sub-systems are significant; (b) it is infeasible when real abstractions are not measured, since these serve as the boundary conditions for hydrological and hydrogeological models; (c) it may require making simplified yet unrealistic assumptions regarding the water allocations (e.g., a "first-come, first-served" management policy); (d) it requires data transfer from the hydrological model to the water management model and hence the space-time scale compatibility of the related variables; (e) the above problems introduce high uncertainty in the parameters obtained through automatic calibration or even make the calibration impossible, since models with unknown yet interrelated parameters have to run individually . Attempts to cope with the above problem are rare in literature (Fredericks et al, 1998;Dai and Labadie, 2001). Coping with these problems requires a fully integrated computational scheme, as employed in strategy B.…”