Utilize High-resolution Distributed Temperature Sensing with Energy Balance Modeling to Evaluate River Restoration on the First-order Alpine Stream in Taiwan
Abstract
The interaction between river and streambed is considered as a fundamental role in the functioning of riparian ecosystems. When evaluating the surface water and groundwater interactions, the streambed has been considered as a critical pathway for water infiltration, nutrition exchange, and biological activities. The first-order stream of Chichiawan Creek is the crucial habitat for the endangered species of Formosan land-locked salmon, but the stream fragmentation, no surface streamflow, seriously reduced the salmon population, hampering the rehabilitation work. The utility of combining high spatial and temporal resolution of distributed temperature sensing (DTS) technology, monitoring wells, electrical resistivity tomography (ERT), and unmanned aerial vehicle (UAV) were demonstrated to comprehensive understand the exchange process and mitigate the effect of fragmentation on endangered salmon. Energy balance model of Heat Source has been developed through the field measurements with micro weather station to simulate the stream temperature and evaluate the exchange rate of energy gain and loss. The results show that the propagation of stream fragmentation has been observed and the locations of major groundwater inflows has been clearly identified. The concentrated locations of groundwater inflows at the downstream reveal the reason that the streamflow in the downstream channel never ceased. The upwelling fluxes is differentiated from the regional groundwater and their contributed ratios vary with time and space from 10 - 70%. If the river restoration is conducted to prevent the stream fragmentation, the stream temperature at the downstream can be reduced by 0.4 - 1.5oC. The river restoration to mitigate the stream fragmentation can extend the habitat of salmon and the upwelling cold water can provide the thermal refuge for salmons during the summer.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H13N1917C
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0496 Water quality;
- BIOGEOSCIENCES;
- 1830 Groundwater/surface water interaction;
- HYDROLOGY;
- 1839 Hydrologic scaling;
- HYDROLOGY