Inverse modeling of groundwater flow in the semiarid evaporitic closed basin of Los Monegros, Spain |
| |
Authors: | F J Samper-Calvete M A García-Vera |
| |
Institution: | Escuela de Ingenieros de Caminos, Universidad de la Coru?a, Campus de Elvi?a, s/n, E-15192 La Coru?a, Spain Fax: +34-8-110-2876; e-mail: samper@iccp.udc.es, ES Po Constitución 37, 30, E-50001 Zaragoza, Spain, ES
|
| |
Abstract: | Only minor attention has been given in the past to the study of closed-basin hydrogeology in evaporitic environments, because
these basins usually contain poor-quality groundwater. The motivation for hydrogeological research in the Los Monegros area
in northeastern Spain was the approval in 1986 of a large irrigation project in the Ebre River basin. The irrigation of 60,000
ha is planned, partly in an evaporitic closed basin containing playa lakes. The project has given rise to environmental concerns.
The evaluation of the hydrologic impacts of irrigation requires quantifying properly the hydrogeology of the area. With the
available information, a conceptual hydrogeological model was formulated that identifies two main aquifers connected through
a leaky aquitard. On the basis of the conceptual model, a numerical model was calibrated under steady-state conditions using
the method of maximum-likelihood automatic parameter estimation (Carrera and Neuman, 1986a). The calibrated model reproduces
the measured hydraulic heads fairly well and is consistent with independent information on groundwater discharge. By the solution
of the inverse problem, reliable parameter estimates were obtained. It is concluded that anisotropy plays a major role in
some parts of the lower aquifer. The geometric average of model conductivity is almost two orders of magnitude larger than
the average conductivity derived from small-scale field tests. This scale effect in hydraulic conductivity is consistent with
the findings of Neuman (1994) and Sánchez-Vila et al. (1996).
Received, December 1997 · Revised, December 1997 · Accepted, January 1998 |
| |
Keywords: | inverse modeling numerical modeling Salinization salt-water/fresh-water relations Spain |
本文献已被 SpringerLink 等数据库收录! |
|