Community-based early warning systems installed on a pilot basis two years ago along two flood-prone tributaries of the turbulent Brahmaputra river in Assam have helped saving livestock and property of villagers, scientists say.

Each solar-enabled alarm system - comprising a transmitter and a receiver - costs around Rs. 60,000 ($1,000). It covers at least 20-25 villages located downstream along the Jiadhal and Singora rivers in eastern Assam's Dhemaji and Lakhimpur districts.

"Our institute has installed seven wireless warning alarms along the Jiadhal and Singora rivers. Our impact studies indicate that these locally-built devices really help the villagers in saving livestock and property from flash floods," Nand Kishor Agrawal, programme coordinator for the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD), told IANS.

The warning device, developed by ICIMOD, mainly comprises electronic sensors that set off an alarm when the water rises in the river. The transmitter is placed on the riverbank and the receiver is placed in a nearby house.

The family of that house, which is trained, subsequently informs other villagers through SMS or mobile phone, who further alert vulnerable people downstream if there is a flood alarm.

The ICIMOD has implemented the project, named Himalayan Climate Change Adaptation Programme, in collaboration with Aaranyak, a prominent bio-diversity conservation organisation in the northeast.

The programme aims to minimise the flood risks and enhance the adaptive capacity of the communities.

"We are trying to link warning alarms with GSM (global system for mobile

communications)," Agrawal added.

After their installation, the alarm systems are managed by the local villagers. ICIMOD says villagers estimate that the warning signals sent by one of the systems saved livestock and property worth Rs.210,000 ($3,300) in 2013.

"These flood alarms really help in saving livestock and household items. Earlier, the loss was alarmingly high every year during the monsoon when flash floods in the Jiadhal river are common," Bahadur Rai, the resident of a village in Dhemaji, told IANS.

For flexible flood management planning, ICIMOD-trained field facilitators have worked with the locals to record rainfall and temperature data and to create flood maps.

Survey data with ICIMOD says the flood plains of the Brahmaputra, a 2,900-km-long river that originates in Tibet and flows into the Bay of Bengal, estimate substantial economic loss per household, with Dhemaji being one of the most-affected ones.

An ICIMOD study has also indicated increased uncertainty of water flow and availability in the five river basins in the Himalayan region.

"Hydrological modelling was carried out in the upstream areas of five river basins (Indus, Ganges, Brahmaputra, Salween and Mekong) that indicate the glaciers are likely to reduce by 20 to 55 percent by 2050," one study says.

However, due to melting of glaciers and increased precipitation, the overall river flows are likely to increase or remain unchanged from 2041 to 2050 compared to 1998 to 2007 for all five river basins, it says.

"Though by 2050, the total runoff is likely to increase from zero to 13 percent in the upper Brahmaputra basin, one to 27 percent in the upper Ganges basin and minus five to 12 percent in the upper Indus basin, the increase is not going to be evenly distributed. In fact, there is expected to be much higher level of variability in runoff and more water in pre-monsoon period," the study indicates.

"The results strongly indicate that there is a need to be better prepared to deal with unexpected floods and drier rivers periods, despite greater water flows on an aggregate basis," the study says.

(Vishal Gulati can be contacted at vishal.g@ians.in)