Simulation of groundwater flow in steep basin with shallow surface soil

Authors
Citation
M. Niedda, Simulation of groundwater flow in steep basin with shallow surface soil, J HYDR ENG, 126(9), 2000, pp. 670-678
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Civil Engineering
Journal title
JOURNAL OF HYDRAULIC ENGINEERING-ASCE
ISSN journal
0733-9429 → ACNP
Volume
126
Issue
9
Year of publication
2000
Pages
670 - 678
Database
ISI
SICI code
0733-9429(200009)126:9<670:SOGFIS>2.0.ZU;2-4
Abstract
A coupled ground-water/channel flow distributed model has been developed fo r continuous simulation in a 123-km(2) basin. The aim was to analyze the st reamflow generation processes in natural vegetated environments. Finite-dif ference schemes have been used to solve conservation equations of the 2D sa turated subsurface flow and the 1D kinematic surface flow. Because of the h igh hydraulic conductivity of the surface soil, only the saturation excess mechanism of runoff production has been considered. Parameter sensitivity a nalysis showed the overriding influence of soil storage capacity and conduc tivity. A grid discretization >100 m produces a hydraulic conductivity grea ter than physically meaningful, which considerably increases as the space-g rid step increases. Results indicate that the model can satisfactorily simu late the water-few behavior of the catchment after fitting the three parame ters of surface hydraulic conductivity, effective porosity, and evapotransp iration losses. These are done after calculating the conductivity as a func tion of the height of the water table. The simulation efficiency has varied from 87% in the first 5-year calibration period to 85.8% in the subsequent 5-year validation period.