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LOCAL WAYS START TO CHANGE AS LAKE CHAD RECEDES
Per un quindicennio con lunghe trattative si č cercata invano un'intesa su come regolare l'apporto idrico diretto al bacino lacustre, oggi ridotto a un decimo dell'antica superficie
David White

FINANCIAL TIMES
For decades Lake Chad, in the semi-desert region where Chad joins Niger, Nigeria and Cameroon, has been retreating into itself, a geographic backwater on the frontier between west and central Africa, where regional co-operation has so far achieved little in the attempt to manage a vital and shrinking resource.
On the map, the lake is clearly delineated, the biggest expanse of water for 1,000 km in any direction. About 30m people live in its drainage basin, a vast area of 2.4m sq km reaching to Algeria and Sudan. Like the Aral Sea in central Asia, another closed system with no outlet, it has been drying up at an alarming rate, reduced to a tenth of its size barely 40 years ago.
This has a direct impact on food security and migration patterns, increasing competition for productive land and fishing grounds. Friction between communities and herders and farmers has been growing.

Experts blame the shrinkage mainly on a decline in rainfall, consistent with other evidence of global climate change, but also on diversion of water for irrigated farming. Once a giant sea, Lake Chad has fluctuated over the centuries. It is thought to have disappeared and reappeared several times during its history. But experts at the Lake Chad Basin Commission, a body representing the four surrounding countries and the Central African Republic, believe what is happening today cannot be compared with other variations recorded since the 19th century. «We feel it's different,» says Lambert Tam, assistant head, in the Chad capital N'Djamena.
He puts the lake's current area at 2,500-3,500 sq km, compared with 25,000 sq km in the last peak year of 1963. But even the measurements are uncertain. A Nasa-supported project five years ago found the open part of the lake reduced to 1,350 sq km. But experts in the US and at the UN Environment Programme (Unep) in Nairobi say Nasa has not provided more recent satellite data. A Nigerian satellite picture from 2003 suggests just 900 sq km. On the other hand, water levels have varied in the past few years, showing some signs of recovery. ...
But the area of «free water» is only part of the picture. Chadian experts say a more detailed aerial and ground survey is needed, since part of what shows up from space as dry land is actually a carpet of islands and floating vegetation. ...

Lake Chad's receding shoreline has altered local ways. Islands that used to be underwater for most of the year have become permanent. A bustling frontier market has become established on one island. Fishermen from Nigeria and other parts of west Africa have moved into Chad territory. Farmers grow cereals and beans on fertile polders where the lake water has moved back. But land further from the lake has become unusuable. Former islands and streams have turned to dunes. And, as the lake has become shallower, many fish species have vanished.
Tle Lake Chad Basin Commission wants to reverse the trend by increasing the lake's inflow. This relies almost wholly on the Chari and Logone river systems, which converge south of the lake. For about 15 years, a scheme has been talked about to divert water from the Ubangi, a tributary of the Congo, into the Chari. This would mean building a dam in the Central African Republic and a channel linking the two basins. The scheme would replenish the lake, provide a much needed source of electric power and open transport links. ...

DAVID WHITE
Tratto dal «Financial Times» del 4 febbraio


  • Aerial survey: rilevamento aereo
  • Assistant head (in realtą: deputy executive secretary): vicesegretario esecutivo
  • Backwater: distesa di acqua stagnante
  • Closed system: sistema chiuso
  • Dam: diga
  • Drainage basin: bacino idrografico
  • Dry land: terraferma
  • Expanse of water: distesa d'acqua
  • Farmers: agricoltori
  • Fishing grounds: zone di pesca
  • Food security: sicurezza alimentare
  • Free water: superficie libera d'acqua
  • Frontier market: mercato di frontiera
  • Global climate change: mutamento climatico a livello globale
  • Ground survey: rilevamento a terra
  • To grow: coltivare
  • Herders (anche herdsmen): pastori
  • Lake Chad Basin Commission (LCBC): Commissione per il Bacino del Lago Ciad
  • Migration patterns: processi migratori
  • NASA (National Aeronautics and Space Administration): Agenzia nazionale per il settore aeronautico e spaziale
  • Outlet: sbocco
  • Polders: polder (terreno sotto il livello dell'alta marea, bonificato e reso coltivabile) (Ragazzini 2005 Zanichelli)
  • Productive land: terre fertili
  • Rainfall: piogge
  • River systems: reti fluviali
  • Satellite data: dato da satellite
  • Semi-desert: subdesertico
  • Shoreline: linea costiera
  • Tributary: affluente
  • UNEP (United Nations Environment Programme): Programma per l'Ambiente delle Nazioni Unite
  • Water levels: livello delle acque