Instrumentation
Monitoring of the diphasic stream
- Liquid flow rate
- Liquid speed
- Depth of the column foot
- Pressure at different depths
- Differential of temperature (cooling of the water)
- Axial strength on the column (level of the raft)
Surveillance of the de-stratification
- CO2 dissolved concentration:
- liquid flow rate
- gas flow rate
- Conductivity
- Temperature
Fundamental parameters
- Temperature of the bottom of the lake
- Temperature gradient in the sediments
Meteorology
- Rain gauge
- Air temperature
- Suface lake water temperature
- Lake water level
- Flow rate at the spillway
- Temperature of the stream feeding the lake from the South
Technological parameters
- Battery levels
- Pressurised bottle pressures
Nyos
Composition (1992) :
- Layer 40 - 170 m :
- Water : 105 Mm3
- Gas: 190 Mm3
- Layer 170 - 208 m :
- Water: 17.5 Mm3
- Gas: 80 Mm3 (1992)
5 pipes at 205 m, internal diameter = 139.8 mm;
Liquid flow rate ˜ 2 Mm3/year/pipeConclusion: after 3 to 5 years, the situation will be safe.
Monoun
Composition :
- Layer 30 - 60 m :
- Water : 4.75 Mm3
- Gas: 3.65 Mm3
- Layer 60 - 96 m :
- Water: 2.1 Mm3
- Gas: 5.8 Mm3
3 pipes, internal diameter = 102.2 mm
Liquid flow rate ˜ 0.8 Mm3/year/pipe
- Step 1: depth 70 m; ˜ 1 year,
- Step 2: depth 80 m; 6 months,
- Step 3: depth 95 m; 6 months.
Conclusion: after 2 years, the lake will be safe.
