Vast expanses earlier covered by sand dunes now show up blue in...

Vast expanses earlier covered by sand dunes now show up blue in satellite images


Jaipur, India, 18 September 2006 – After the surprise flooding of Barmer and other arid parts of western Rajasthan last month, vast expanses once covered by sand dunes now lie under water and show up blue in satellite images. Scientists believe all this water will change not only the look of this desert region but also its ecology.

The floods have created at least three large lakes — in Kawas, Malwa and Uttarlai — all in Barmer district, and each covering 7-8 sq km. NGO field-workers involved in conservation and water harvesting estimate that there are more than 20 new water bodies in the Barmer-Jodhpur region. Several water channels or natural drains have also shown up after the flooding.

Magsaysay Award winner Rajendra Singh of Jal Biradari says that there is already discernible greening of the areas around these lakes, ponds, and channels. “The accumulated water can be used for agriculture. It will be favourable for farmers to grow cumin or mustard,” he said. “There’s no need to remove water.”

Geologists too are studying the change in topography with a view to help revive ancient watersheds and drainage channels that existed before the sand dunes covered them up.

R S Goyal, Deputy Director of the Geological Survey of India, Jaipur, says the accumulation and flow of flood water follows the drainage pattern that existed in the region before it was covered by sand. He says previous studies have proved the existence of several natural channels in the region, believed to have been once fed by the river Luni. The channels formed now lie where its tributaries and distributaries flowed.

Like Singh, Goyal stresses the importance of preserving the water bodies and reviving the channels. “Satellite images will show which of these channels, though they may seem dry, have sub-surface water, usable for nominal water supply or drip irrigation,” he says.

Dr S M Mohnot, Executive Director of the School of Desert Sciences, Jodhpur, says it may take time before the changes are visible, but studies conducted by his school have shown that “apart from the land profile, the floods have also had an effect on the microflora and germplasm in the area.”

“Over a certain period of time, we anticipate a change in the reproductive profile of flora in the area,” he says.