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Sites AMMA in Niamey in Niger

One of the significatives consequences of the dryness has been a significative decrease of the rivers debits :
In Niger, the medium debit decreased to 55%, whereas the decrease of the rain in the same period had been between 25 to 30%.
The transports of dust and wind machine erosion had also increased incredibly. The damage of the vegetal blanket drove to the general state of active erosion which has for consequence the damage of the soil and the silt up of the shallows. Because of this, significatives changes were brought about the landscape and the hydrologic environement : ponds are moving, appearance of news spreading zones in the side or at the feet of a gulch, changing of outflow and their localization.

In this context AMMA is a unique opportunity to treat the scales problems inherents for the understanding of the complex relations between the climate, the environment and the water cycle .
The Niamey area has a rich hydrologic history in observation since 1990, the site naturally became one of the three sites meso-scales of the AMMA observation system.
Located between the 13N and 14N, this meso-scale of Niger is central, located between the soudanian site of Oueme (9,5N-10,5N) and the sahelian site of Hombiri in Mali (15N-17,5N).

Gourma site in Mali

- Analysis of the vegetation in relation between the atmospheric variability (precipitations in principal)

- Analysis of the water variability and energy fluxes of the local scale to meso scale

- Study of the control of the biogeochemical cycles by process in land surface

- Estimated of surface fluxes of meso-scale, for compared with the behavior of the vegetation, the humidity and water ressources thank to the assimilation of satelites data

Oum site in the Republic of Benin

Most of the instruments were used in the area where the annual precipitations are 1200mm (in one season)
Some of the instruments used :

- Radars
- Balloons with constant volume
- rain gauges
- Limnigraph
- Meteorologics stations
- Radiosonde
- radiosonde of ozone

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Carte des principaux sites d’observations au sol

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