A distributed hydro-environmental watershed model with three-zoned cell profiling |
| |
Authors: | Junichiro Takeuchi Toshihiko Kawachi Koichi Unami Shigeya Maeda Tomoki Izumi |
| |
Institution: | (1) Graduate School of Agricultural Science, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan |
| |
Abstract: | A cell-based distributed watershed model is developed which enables us to simulate the hydrological and hydraulic aspects
of the watershed in a refined fashion. With three-zoned cell profiling, the model is composed of three sub-models; tank model
for a surface water zone, soil moisture model for a surface soil zone, and unconfined shallow groundwater flow model for a
subsurface zone. Inclusion of the soil moisture sub-model modified to reroute the infiltration, routed from the tank sub-model,
into the return flow and the groundwater recharge features the model. The groundwater flow sub-model, numerically approximated
by use of the finite volume method and the implicit time-marching scheme, considers a network of on-farm drainage canals as
internal boundaries, which is an essential need for modeling the watershed including farmlands. Cascade-linking of the three
sub-models in a cell and assembling of all the cells over the entire watershed domain provides the global equations system
to be solved. Applicability of the model is demonstrated with its practical application to a real watershed in that paddy
and upland crop fields take great part of the land-use practice. It is then indicated in a quantified manner that rice farming
significantly contribute as a major groundwater recharger in an irrigation period to fostering and conservation of regional
water resources. Along with appropriately profiling a cell, the model is so versatile and tough that it can be applied without
difficulty to a watershed of diverse terrains and land-uses and the computations can stably be carried out. It is thus concluded
that the model presently developed could be a powerful “watershed simulator” to investigate and assess the time-varying hydro-environmental
properties of a watershed while separating and integrating the hydrological and hydraulic components of particular importance. |
| |
Keywords: | Tank model Soil moisture model Dupuit’ s assumption Groundwater drainage Finite volume method Groundwater recharge |
本文献已被 SpringerLink 等数据库收录! |
|