Watershed Monitoring and Evaluation (WME) component of the Tana Beles Integrated Water Resources Development Project (TBIWRMP) in

Ethiopia

Hydrological Baseline and monitoring programme

8th July 2009Bahr Dar

Dr. Mikaela Kruskopf, WRM Advisor

Soil loss sediment loadStation Length of

recordCatchment area (km2)

Sediment load ('000 tons/yr)

Soil loss in (t/km2/yr)

Annual av. discharge (m3/s)

Gilgel Abay, near Merawi 1980-1992 1,664 2,821.0 1,695.3 58.17

Gumara, near Bahir Dar 1980-1992 1,394 1,937.1 1,390 27.18

Megech at Azezo 1980-1992 462 263.0 569 7.5

Abay at Kessie 1982-1992 65,784 49,404.0 751 450.5

Muger, near Chancho 1980-1992 489 38.2 78 9.26

Abay at Bahir Dar 1980-1992 15,321 2,191.0 143 111.32

Guder at Guder 1980-1992 524 47.2 90 12.63

Birr, near Jiga 1980-1992 975 2,075.4 2,129 17.86

Dura, near Metekel 1980-1992 539 386.5 717

Angar, near Nekemte 1980-1985 4,674 701.9 150 62.79

Dabana, near Abasina 1980-1984 2,881 452.9 157 57.35

Angar, near Gutin 1982-1983, 1986-1992

1,975 176.3 89

Beles, near Metekel 1983-1992 3,431 1,563.3 456 51.38

Abay at border 1980-1991 172,254 140,000.0 700 1555.73

Source: Abay Basin Master Plan Study

Sampling and testing 2009

Existing site – Hydrology Department annual monitoring

WME sites

Activities in the microwatersheds• Identification of sites for sediment

measurement• Installation of basic measurement stations• Village Based Monitoring System• Detailed hydrological monitoring baseline

(with hydrology department staff)• In-depth studies (e.g. Runoff plot

measurements, modelling, intensive sampling using automatic loggers)

•Sites with well defined water channel•Sites where Watershed management activities are taking place•Sites were no activities will be implemented (control)•Sites of a suitable catchment size

•Defining the channel cross section•Measuring current (three to four times during various water heights)

•Staff gauge (for water level recording)

• Alternative staff gauge!•Measuring water level (daily, through KWT / villager participation)

WME TA staff will:

•Install rain gauges,•Install staff gauges

WME TA staff will teach one data collector from the site to:

•Take readings of daily (or hourly) rainfall•Take readings of daily water level (and during floods)•Measure secchi depth and •Take water samples at high turbidity (when secchi < 1 cm) for analysis

TA staff of BDU student will:

•Collect samples and data once a month•Take current measurements 3-4 times

Village Based Participatory Monitoring Programme

Other factors affecting the hydrology, requiring additional studies

•Lithology, land use, gully density, topography and connectivity (part of the NRM baseline, and of Community Watershed activities)

•Variations in rainfall amount and intensity – possible intensive recording to detect natural variation

Other factors affecting the hydrology, requiring additional studies

•Extreme events (floods, droughts, storms) – possible intensive recording to detect natural variation in soil transport

Other factors affecting the hydrology, requiring additional studies

•Variation in eroded soil type: suspended or bedload – possible in-depth study to measure bedload•Impact of land use on sedimentation – possible in-depth study using runoff plot experiments