A three-component hydrograph separation based on geochemical tracers in a tropical mountainous headwater catchment in northern Thailand
| Autor: | Thilo Streck, W. Sangchan, Stefan Uhlenbrook, Joachim Ingwersen, Andreas Duffner, C. Hugenschmidt, Y. Sukvanachaikul |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Bodemscheikunde en Chemische Bodemkwaliteit
Headwater catchment hydrological processes rain-forest catchment Hydrograph lcsh:Technology lcsh:TD1-1066 soil Streamflow Temperate climate lcsh:Environmental technology. Sanitary engineering Subsurface flow lcsh:Environmental sciences lcsh:GE1-350 Hydrology model lcsh:T lcsh:Geography. Anthropology. Recreation Tropics PE&RC hillslope flow pathways lcsh:G transport runoff generation Environmental science west-africa Surface runoff Groundwater Soil Chemistry and Chemical Soil Quality stormflow generation |
| Zdroj: | Hydrology and Earth System Sciences 18 (2014) Hydrology and Earth System Sciences, 18, 525-537 Hydrology and Earth System Sciences, Vol 18, Iss 2, Pp 525-537 (2014) Hydrology and Earth System Sciences, 18 (2), 2014 |
| ISSN: | 1027-5606 1607-7938 |
| Popis: | Land-use change in the mountainous parts of northern Thailand is reflected by an increased application of agrochemicals, which may be lost to surface and groundwater. The close relation between flow paths and contaminant transport within hydrological systems requires recognizing and understanding the dominant hydrological processes. To date, the vast majority of studies on runoff generation have been conducted in temperate regions. Tropical regions suffer from a general lack of data, and little is known about runoff generation processes. To fill this knowledge gap, a three-component hydrograph separation based on geochemical tracers was carried out in a steep, remote and monsoon-dominated study site (7 km2) in northern Thailand. Silica and electrical conductivity (EC) were identified as useful tracers and were applied to calculate the fractions of groundwater (similar to pre-event water), shallow subsurface flow and surface runoff on stormflow. K+ was a useful indicator for surface runoff dynamics, and Ca2+ provided insights into groundwater behaviour. Nevertheless, neither measure was applicable for the quantification of runoff components. Cl- and further parameters (e.g. Na+, K+, and Mg2+) were also not helpful for flow path identification, nor were their concentrations distinguishable among the components. Groundwater contributed the largest fractions to stormflow (62–80%) throughout all events, followed by shallow subsurface flow (17–36%) and surface runoff (2–13%). Our results provide important insights into the dynamics of the runoff processes in the study area and may be used to assess the transport pattern of contaminants (i.e. agrochemicals) here. |
| Databáze: | OpenAIRE |
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