Sites Description Land use changes Monitoring
Laos

Houay Pano catchment, Luang Prabang Province (photo: L. Boithias)
5 catchments from 0.6 ha to 60 ha (Houay Pano), 10 km² (Houay Xon)

Research actions also on Nam Khan (6100 km²) watershed

Shales and argilites with average slope of 30-46%

Shortening of the fallow period, reducing food crop of upland rice to annual commercial productions (Job’s tears, maize) and perennial (teak); urbanization. Annual comprehensive map of land use since 1998

Hydrometeorological monitoring, sediment and water table since 2001

Soil moisture monitoring along 3 transects of geophysical measurements (electrical resistivity panels)

Thailand

Huay Ma Nai catchment, Phrae Province (photo: C. Valentin)
4 catchments from 1 to 96 ha (Huay Ma Nai) and 120 km² Mae Thang watershed (reservoir)

Argillaceous sandstones with average slopes of 8-15%

Soybean cultivation abandonment and fruit trees for the benefit of intensive corn. Annual comprehensive map of land use since 2000

Hydrometeorological and sediment monitoring since 2001

Vietnam

Dong Cao catchment, Hoa Binh Province (photo: C. Valentin)
3 catchments from 7.7 to 50 ha (Dong Cao)

Shale soils with average slopes of 28-38%

Abandonment of cassava for planted trees (Acacia mangium) and fodder; urbanization. Annual comprehensive map of land use since 2000

Hydrometeorological and sediment monitoring since 2002

The 3 MSEC experimental catchments have similar geological (sandstone, shale, schists) and pedological (Alfisol, Ultisol, Entisol) features. However, they are subjected to a dual gradient of both climate (from Thailand the driest to Vietnam the wettest) and agricultural intensity (from intensive agriculture in Thailand to tree plantations in Vietnam).

To estimate the total water and soil loss going out of the watersheds, several devices are used in the different sub-catchments:

  • Manual rain gauges and automatic weather stations for rainfall and evapotranspiration measurements (Campbell weather station)
  • Water level recorders for flow measurement (OTT SE 200 + Campbell data logger) and water electric conductivity (Aquistar CT2X sensor)
  • Automatic water and sediment samplers for suspended load quantification
  • Sediment traps for soil losses quantification (bed load)
  • Electrical resistivity tomography for bank and hillslopes groundwater and streamwater interactions analysis
  • GIS tools (Q-gis, Grass, ArcGIS) to build annual land use maps based on satellite images (Sentinel) and field observations (once per year)