Huay Ma Nai catchment
Huay Ma Nai is located in Northern Thailand, Phrae Province, and is divided into 2 nested sub-catchments (total 93 ha), on siltstone and sandstone soils. Slope gradient is 12-50%, and rainfall is about 1100 mm per year.
Land use change: switch from cassava + maize + fallow + orchards to maize mono-crop.
Hydro-meteorological and soil losses surveys
Off-site effects measurements of Maethang reservoir
The Maethang reservoir is located at the outlets of several catchments of the Maeyom watershed, including the Huay Ma Nai catchment. Upstream soil erosion generated by surface runoff may alter the quality of reservoir water, generating “off-site” effects: increased sedimentation, excess nutrients and suspended sediment inputs that may induce important environmental changes to the water column with respect to biological communities, and dissolved oxygen and trace element concentrations that may potentially be toxic. The Maethang reservoir is monitored since 2002.
Reservoir Area = 220 ha
Irrigated Area = 3520 ha
Maximum Depth = 43 m
Storage Volume = 31 million m3