New satellite imagery shows a rapid increase in water and vegetation cover in just the past three years, with the marshes rebounding to about 37% of their 1970 extent, from about 10% in 2002, the United Nations Environmental Programme (UNEP) said. ``The evidence of their rapid revival is a positive signal, not only for the environment and the local communities who live there, but must be seen as a contribution to wider peace and security for the Iraqi people,'' UNEP executive director Klaus Toepfer said.

Saddam drained much of the Mesopotamian waters between the Tigris and Euphrates rivers to punish the Marsh Arab inhabitants for supporting a Shi'ite Muslim rebellion following the 1991 Persian Gulf War.

Of almost 9,000 square kilometres (3,600 square miles) of marshes in 1970, the area shrank by 90% to 760sqkm (304sqm) in 2002. As recently as 2001, some experts forecast the marshlands would disappear by 2008. But restoration efforts since the fall of Saddam reversed much of the damage, bringing the current area to 3,500sqkm (1,400sqm). The expanse swelled to 50% of the 1970 range in the spring, but dwindled due to summer evaporation rates. Still, re-flooding the marshes requires a delicate balance of salt and plant life. ``It will be very difficult to restore the entire marshlands,'' said Abdul Latif Jamal Rashid, Iraq's minister of water resources.

Calling Saddam Hussein's decision to drain the marshlands ``a crime against humanity'', Mr Rashid said he hopes 80% of the marshlands will be restored in three years. The UNEP warns that more detailed field analysis of soil and water quality is need to gauge the exact state of rehabilitation. ``While the re-flooding bodes well for the Iraqi marshes, their recovery will take many years,'' Mr Toepfer said.

Mr Rashid noted, however, that the project also has other benefits, including symbolic value for the Iraqi people and the potential to reduce migration to cities by improving agriculture. Iraqi engineers and tribes began re-flooding parts of the wetlands by cutting gashes in dykes in the euphoria of Saddam's ouster in 2003.

Last year, the United Nations announced a $11 million project funded by Japan to help restore the marshes and provide clean drinking water and sanitation for 100,000 people living there. The programme is providing settlements with water treatment systems and restoring reed beds that act as natural water filters. It is also training 250 Iraqis in wetland management and restoration.

At one time, the wetlands were the largest in the Middle East, filtering polluted water from northern cities and purifying it before it reached the southern rivers and the city of Basra. As Shi'ite Muslims in the region revolted, Saddam ordered thousands killed and built new dams, canals and pipelines to dry up the marshes _ the source for fishing, boating and small agriculture that once sustained a population of up to 500,000 people.

Azzam Alwash, director of Eden Again, an NGO which is working to restore the marshes, said one of the difficulties facing the project is that dams built in the surrounding region, particularly Turkey, since the 1990s have disrupted natural water cycles that helped nourish the wetlands.

Trying to replicate that was critical, he said. ``We don't want to just have marshes for the sake of marshes. We want to return the biodiversity to the way it was and the biodiversity is not going to increase unless we actually replicate that,'' Mr Alwash said.

Southern Iraq marshlands before drainage by Saddam