LIMA, May 9 (AlertNet) - In April, the normally calm Piura River turned overnight into a raging torrent. More than 3,500 families in northern Peru escaped but lost their homes and livelihoods.

Scientists disagreed over whether the dramatic weather was connected to the climate phenomenon El Niño, due to make a reappearance this year.

The Piura River's normal average flow is 15 cubic metres a second, but on April 9 it became an uncontrollable fluid mass raging at 3,600 cubic metres a second.

The flooding reached Cura Mori community around midnight. "The river sounded as if it had waves. It was horrible. I hugged my two children to me and we ran to a hill with other families. The Civil Defence had told us to be ready at any moment, but we never imagined that we would never see our houses again. Now they are water-filled boxes or else they've collapsed completely," Rosa Tezén said.

Thousands of people escaped to safety on higher ground, but were unable to save their belongings or their livestock and were left with just the clothes on their backs.

Tezén said: "The men helped to rescue people. First the children. The water was waist-high and rising fast. It's a miracle that no one died, but we don't know what will happen to us, with no houses, with no things and no work because the crops are gone. There's nothing left."

Iris Quintana, from a devastated community, said the water rose almost as high as the roofs of the traditional adobe houses. "We have been left with just what we had on. The river took everything. The children have colds and there are respiratory problems. We have nowhere to go. Our relatives lost their houses too," said Quintana, who has four children, the youngest just eight months old.

Almost 18,200 people -- 3,645 families -- were made homeless, according to the Civil Defence Department.

A shelter in Piura AlertNet photo by RENEYRO GUERRA

The government donated wood and corrugated iron for temporary shelters while families rebuilt their adobe houses, but people living in precarious conditions in temperatures up to 35 degrees Celsius and high humidity said they were worried about potential outbreaks of malaria, which is endemic to the region.

District Mayor José Vílchez said thousands of domestic animals were swept away by the waters, and people had lost their crops.

An estimated 6,000 hectares (15,000 hectares) of cotton, beans and corn were turned into an enormous mud bath, with the medium-term effect of large-scale unemployment and economic crisis in the Bajo Piura region.

"In the hamlets of Chato Grande and Chato Chico, they won't be able to go back to their houses. People are sleeping on top of plastic bags on the floor of the council offices," he said. Vílchez said that people also needed food, blankets, clothing, cooking materials, tarpaulins and mosquito nets.

SCIENTISTS DISAGREE

Most scientists in Peru said that the flooding in the north of the country was connected to El Niño.

Peruvian climate specialists are part of the Multi-Sector Committee, which incorporates the Civil Defence Department, the Peruvian Geophysics Institute, the Department of Hydrography and Marine Navigation, the Sea Institute of Peru and the Meteorology and Hydrology Service.

One of the scientists on the committee, Dr Ronald Woodman, executive president of the Geophysics Institute, told AlertNet that current sea temperature was two degrees Celsius above its normal level.

He said this would be defined as a "weak" El Niño impact, but taking into account the intense rains and greater water flows, it could be described as a "moderate" El Niño.

"There are serious infrastructure problems in Piura. That's what leads to the considerable damage," he said.

"There are serious infrastructure problems in Piura. That's what leads to the considerable damage"

According to Woodman, there were no adequate flood prevention defences along the river.

Dr Mateo Casaverde, meteorological adviser to the National Civil Defence Institute, also on the Multi-Sector Committee, distanced himself from this assessment.

He told AlertNet that the climate disturbances producing catastrophic effects in the north were not necessarily related to El Niño.

Casaverde said they could have been produced by the Intertropical Convergence Zone, the cloud formation where the trade winds meet, which causes northern Peru's rainy season between January and April.

"We've seen it in satellite images and I think that it is an atmospheric disturbance unrelated to El Nino." Casaverde said the small increase in sea temperature close to Ecuador and Peru had been recorded since 2001, with effects on fish in the area.

He said the heavy rainfall and flooding affecting several mountain and jungle regions since late December were related to this. Casaverde said there were additional disturbances from the Atlantic.

NO PREVENTATIVE MEASURES

He said that the Andean range was relatively young in formation and therefore registered high erosion. He said this generated material under the hydrographic basins and deposited it in the lower part of the riverbed. This silting means that each time the rivers rose, they overflowed.

"In El Niño of 1998, the Piura River accumulated 4,500 cubic metres a second and overflowed the city's bridges. It could have reached the city if the Civil Defence had not done work to dredge the riverbed. The authorities need to carry out preventative measures on a permanent basis and build defences in vulnerable areas," Casaverde said.

The scientists agreed that the rains should end soon with the change of season and climatic conditions would return to normal.

They also agreed that in August it would be easier to predict el Niño's likely effect on the Peruvian summer, which starts in December.

"The authorities need to carry out preventative measures on a permanent basis and build defences in vulnerable areas"

El Niño has left its imprint on Peru's northern coast since ancient times.

The coastal rivers of the north, usually calm on their journey to the Pacific, expand to unusual volume and strength as a result of heavy rains, and have caused havoc to communities along their banks.

Historic research has found signs of el Niño in 1100 BC, AD 1100 and in a continuous sequence since 1578.

The worst El Niño of the 20th century struck Peru in the 1982-83 season, leading to the establishment of a grading system for the seriousness of El Niño's effects.

The so-called "meganiño" affected the whole country that year, caused flooding, landslides, tidal waves, six months of rain in the north and serious drought in the south.