A regional-scale groundwater flow model for the Leon-Chinandega aquifer, Nicaragua
Abstract Groundwater flow in the Leon-Chinandega aquifer was simulated using transient and steady-state numerical models. This unconfined aquifer is located in an agricultural plain in northwest Nicaragua. Previous studies were restricted to determining groundwater availability for irrigation,...
Autores Principales: | Calderón Palma, Heyddy, Bentley, Laurence R. |
---|---|
Formato: | Artículo |
Idioma: | Español Español |
Publicado: |
2007
|
Materias: | |
Acceso en línea: |
http://repositorio.unan.edu.ni/2466/ http://repositorio.unan.edu.ni/2466/1/798.PDF http://repositorio.unan.edu.ni/2466/6/88x31_cc.png |
Sumario: |
Abstract Groundwater flow in the Leon-Chinandega
aquifer was simulated using transient and steady-state
numerical models. This unconfined aquifer is located in an
agricultural plain in northwest Nicaragua. Previous studies
were restricted to determining groundwater availability for
irrigation, overlooking the impacts of groundwater development.
A sub-basin was selected to study the groundwater
flow system and the effects of groundwater
development using a numerical groundwater flow model
(Visual MODFLOW). Hydrological parameters obtained
from pumping tests were related to each hydrostratigraphic
unit to assign the distribution of parameter values
within each model layer. River discharge measurements
were crucial for constraining recharge estimates and
reducing the non-uniqueness of the model calibration.
Steady-state models have limited usefulness because of
the major variation of recharge and agricultural pumping
during the wet and dry seasons. Model results indicate that
pumping induces a decrease in base flow, depleting river
discharge. This becomes critical during dry periods, when
irrigation is highest. Transient modeling indicates that the
response time of the aquifer is about one hydrologic year,
which allows the development of management strategies
within short time horizons. Considering further development
of irrigated agriculture in the area, the numerical
model can be a powerful tool for water resources management |
---|