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| Titel |
Runoff production in a small agricultural catchment in Lao PDR : influence of slope, land-use and observation scale. |
| VerfasserIn |
J. Patin, O. Ribolzi, C. Mugler, C. Valentin, E. Mouche |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250030260
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| Zusammenfassung |
| We study the surface and sub-surface hydrology of a small agricultural catchment (60ha) located in the Luang
Prabang province of Lao PDR. This catchment is representative of the rural mountainous south east Asia. It
exhibits steep slopes (up to 100% and more) under a monsoon climate. After years of traditional slash and burn
cultures, it is now under high land pressures due to population resettling and environment preservation policies.
This evolution leads to rapid land-use changes such as shifting cultivation reduction or growing of teak forest
instead of classical crops. This catchment is a benchmark site of the Managing Soil Erosion Consortium since
1998. The international consortium aims to understand the effects of agricultural changes on the catchment
hydrology and soil erosion in south east Asia.
The Huay Pano catchment is subdivided into small sub-catchments that are gauged and monitored. Differ-
ent agricultural practices where tested along the years. At a smaller scale, plot of 1m2 are instrumented to follow
runoff and detachment of soil under natural rainfall along the monsoon season.
Our modeling work aims to develop a distributed hydrological model integrating experimental data at the
different scales. One of the objective is to understand the impact of land-use, soil properties (slope, crust, etc) and
rainfall (dry and wet seasons) on surface and subsurface flows.
We present here modeling results of the runoff plot experiments (1m2 scale) performed from 2002 to 2007. The
plots distribution among the catchment and over the years gives a good representativity of the different runoff
responses. The role of crust, slope and land-use on runoff is examined. Finally we discuss how this plot scale will
be integrated in a sub-catchment model, with a particular attention on the observed paradox: how to explain that
runoff coefficients at the catchment scale are much slower than at the plot scale ? |
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