Check the article published in Hydrological Processes summarizing the M-TROPICS activity in Cameroon here
The monitored sites constitute a network of nested sub-basins within the Nyong River Basin (18,500 km2) in a tropical humid forest mildly impacted by anthropogenic activities on the South Cameroon Plateau. The monitoring network consists of the Nsimi SEW (Mengong stream; 0.60 km2), and the sampling/gauging stations of Messam on the Awout River (206 km2), Pont So’o on the So’o River (3000 km2), and Mbalmayo (13,500 km2) and Olama (18,500 km2), both on the Nyong River
Monitoring setup of the Nyong River Basin
| Station | River | Longitude | Latitude | Elevation (m) | Area (km²) | Length (km) | Slope (‰) | Order |
|---|---|---|---|---|---|---|---|---|
| Nsimi | Mengong | 11° 50′ E | 3° 10′ N | 669 | 0.60 | 0.75 | 13.3 | 1 |
| Messam | Awout | 11° 47′ E | 3° 17′ N | 647 | 206 | 30 | 1.2 | 3 |
| Pont So’o | So’o | 11° 29′ E | 3° 19′ N | 634 | 3 070 | 107 | 1.1 | 4 |
| Mbalmayo | Nyong | 11° 30′ E | 3° 31′ N | 634 | 13 555 | 360 | 0.16 | 5 |
| Olama | Nyong | 11° 17′ E | 3° 26′ N | 628 | 18 510 | 419 | 0.15 | 5 |
Monitoring setup of the Nsimi SEW
Variables and sampling/acquisition frequencies
| Variable | Method | Time frame | Frequency |
|---|---|---|---|
| Weather variables (Nsimi SEW only) – data available here | |||
| Rainfall (RFm) | manual and weather station | 1991 and since 1994 | daily and hourly |
| Temperatures (Tmin, Tmax, Tmean), relative humidity (Hummean), wind direction and speed (Dirwind, Vwind), global radiation (GRinstant, Grcumul), daily evapostranspiration (PETday) | weather station | 2004-2008 and since 2018 | hourly |
| Hydrological variables (all sites) – data available here | |||
| Water discharge (Q) calculated from water level | water level acquired with automatic limnimeter and manual (limnimetric scale) | since 1991 (Nsimi SEW outlet), 1995-1999 (Nsimi SEW spring), since 1998 (large river sites) | 10 min (automatic), daily (manual) |
| Hydrochemical variables (all sites) – data available here | |||
| Major elements (anions, cations, silica), dissolved organic carbon (DOC) | Ion chromatography at LAGE (Cameroon), TOC analyzer, spectrophotometer, ICP-OES at GET (France) | since 1994 (Nsimi SEW), since 1998 (large river sites), from 2002 to 2007 (piezometers in Nsimi SEW) | fortnightly |
| pH, electric conductivity, water temperature, alkalinity, suspended particulate matter (SPM) | pH- and conductivity meter, thermometer, titrimeter, filtration unit | since 1994 (Nsimi SEW), since 1998 (large river sites) | fortnightly |