Table 1. Study sites and catchments characteristics.
Country | Laos | Thailand | Vietnam |
---|---|---|---|
Catchment name | Houay Pano | Huay Ma Nai | Dong Cao |
Province | Luang Prabang | Phrae | Hoa Binh |
Latitude | 19°51′10′′N | 18°13′20′′N | 20°57′40′′N |
Longitude | 102°10′45′′E | 100°23′40′′E | 105°29′10′′E |
Catchment size | 60.2 ha | 93.0 ha | 49.7 ha |
Elevation range | 430–718 m | 400–480 m | 130–482 m |
Mean slope | 48% | 30% | 40% |
Mean annual rainfall | 1585 mm | 1385 mm | 1556 mm |
Rainfall during 2015 | 1465 mm | 921 mm | 1474 mm |
Mean annual temperature | 25 °C | 27 °C | 23 °C |
Mean annual global irradiance | 1385 J cm−2 | 751 J cm−2 | 340 J cm−2 |
Geology | Shale, schist | Siltstone, sandstone | Schist |
Soils | Alfisol, Entisol Ultisol | Alfisol, Ultisol | Ultisol |
Population (number of people.days)1 | No permanent population, many daily activities (548 +/− 120) | No permanent population, up to 80 during planting and harvest time (380 +/− 72) | A household of 4 with a toilet for which the overflow empties into the stream, 3 farmers that go through basin every 3 days (68 +/− 14) |
Animal husbandry | Two to three pigs in the lower sections and some (~20) chickens in both the upper and lower sections | Animal husbandry limited to a few chickens | 20 cows, 10 buffalos in the upper sections and 20 chickens and 2 or 3 pigs in the lower sections |
Crusting rate2 | 17 (+/−7)% | 48 (+/−5)% | 7 (+/−5)% |
Runoff coefficient3 | 26 (+/−8)% | 40 (+/−12)% | 9 (+/−3)% |
Bi-weekly sampling dates | 15 October 2014 to 5 October 2015 | 23 October 2014 to 16 October 2015 | 27 October 2014 to 15 October 2015 |
A short description of the human population in each catchment is given as is an estimate of the people.days which gives an estimate of the number of whole days a person is in the catchment.
1Estimated from the number of people using informal latrines in the catchment on a daily basis.
2Calculated from ref. 16 and from land use for 2015.
3Calculated over the four wettest months of the year (June to September) using streamflow depth ÷ rainfall depth and expressed as a percentage.