Stream discharge characteristics through urbanization gradient in Danshui River, Taiwan: Perspectives from observation and simulation
Journal
Environmental Monitoring and Assessment
Journal Volume
184
Journal Issue
9
Pages
5689-5703
Date Issued
2012
Author(s)
Abstract
Urbanization and the subsequent changes in land use/cover inevitably influence the quality and even the quantity of stream water. This issue is widely studied through evaluations on land-use change scenarios or comparisons among historical patterns at the same watershed. However, observational stream discharge changes through urbanization gradient have rarely been discussed. In this study, we analyzed 5- year discharge data from 13 gauges in the Danshui River network with a wide range of urbanization gradient to explore the impacts on observational hydrological characteristics in individual catchments. The results reveal that stream discharge in pristine watersheds is characterized by a larger proportion of baseflow and is less fluctuating. When the forest coverage is <90%, the discharge fluctuation almost doubles. Meanwhile, the baseflow fraction decreases gradually with the increase of paddy area, which may concomitantly result from the increasing irrigation. Such a drop in baseflow may threaten the maintenance of the minimum flow required for the stream aquatic ecosystem. Furthermore, we simulated the stream discharges by TOPMODEL with blind landuse- independent parameters. The results show that the simulated discharges are satisfactory, particularly for the pristine catchments, but not as fitting for the paddy-intensive watersheds perhaps due to the unexpected irrigation. On the whole, the calibrated parameters are dependent with the landscape characteristics. The landscape-based parameter estimations can be applied to simulate discharge well, meaning the potential to assess the ungauged watersheds. © Springer Science+Business Media B.V. 2011.
Subjects
Land use; Taiwan; TOPMODEL; Urbanization
Other Subjects
Aquatic ecosystem; Baseflows; Hydrological characteristics; Independent parameters; Land use/cover; Land-use change; Landscape characteristic; Minimum flow; River network; Simulated discharges; Stream discharge; Stream water; Taiwan; TOPMODEL; Ungauged watershed; Urbanization; Catchments; Irrigation; Land use; Landforms; Parameter estimation; Runoff; Watersheds; Rivers; baseflow; catchment; computer simulation; discharge; hydrology; land use change; pristine environment; streamwater; urbanization; watershed; article; catchment; correlational study; environmental impact assessment; geographic distribution; hydrology; land use; landscape; observational study; river ecosystem; simulation; stream (river); Taiwan; urbanization; water flow; watershed; Environmental Monitoring; Models, Chemical; Rivers; Taiwan; Urbanization; Water Pollutants, Chemical; Water Pollution, Chemical; Danshui River; Taiwan
Type
journal article