Mahanadi’s water yield has decreased by a huge 10% in the recent decadesReport;Bureau,Orissabarta
This is the highest among major surplus basins in India, according to an IIT Study
This puts serious question mark on the plan of Interlinking of Rivers.
Odisha and Chhattisgarh joint dialogue must recognize climate change impacts
Sambalpur, 30th July 2016 – We have always been warning that Mahanadi is no more a water surplus basin, as being marketed by governments, but a deficit basin. “A study carried out by a team of researchers from IIT Madras and IIT Bombay has now come up with a scientific analysis and found out that Mahanadi’s water yield has decreased by a huge 10% in recent years owing to significant decrease in rainfall over the basin,” informed Ranjan Panda, Mahanadi River Waterkeeper, in a press release.
Refering to the study titled, “Indian Summer Monsoon Rainfall: Implications of Contrasting Trends in the Spatial Variability of Means and Extremes” by Prof. Subimal Ghosh of IIT Bombay and team, Panda said that the decrease in yield in Mahanadi is highest in the country along with another river. Panda referred the study and said, “The study has found out that he water yields of major surplus basins, such as Mahanadi, Godavari and West Flow River–I, have exhibited decreases in recent periods. The water yields show decreases of more than 10% for the Mahanadi and West Flow River–I. For other surplus basins, the changes are within 10%”.
“This is mainly because of significant decreases in rainfall,” said Panda referring to the study. Brahmani has also faced significant decrease in rainfall, informs he, quoting the study.
The study findings say that the decrease in the monsoon rainfall in the surplus river basins, which are majorly present in the core Indian monsoon zone, may be due to the drying of rainfall in these regions during recent decades. The monsoon over Indian region is typically associated with a strengthened cyclonic circulation, with the moisture flux converging over this region. However, when the changes in mean vertically integrated moisture flux (VIMF) and wind patterns are analyzed an anticyclonic circulation leading to divergence in VIMF was found, especially in the central part of India, along with convergence in the Gangetic plains. Hence, this could be the reason for which the major surplus basins have a decreasing rainfall trend.
“This study also confirms our apprehensions about the Interlinking of Rivers (ILR) plans of the government of India”, said Panda, adding, “We have been warning the government about Mahanadi being a deficit basin already and is going to further starved of water owing to climate change. The ILR plan for Mahanadi is not suitable at all.
The IIT study says, “Our analysis also raises concerns about the suitability of major nation-wide projects related to river water-basin interlinking, in which the sustainability of water surplus conditions in river basins in response to a changing climate is not ascertained. Therefore, the water demand in a surplus basin first needs to be assessed and met under decreasing water availability scenarios before transferring water to the deficit basins. Hence, we argue that planning for inter-basin water transfer necessitates an immediate reassessment with a systematic approach”.
“This study findings are significant and have come at the right time when we are trying to pursue both Odisha and Chhattisgarh to recognise that Mahanadi is a water deficit basin and hence planning all development projects need to consider this”, said Panda.
“We have initiated a Mahanadi River Basin Peace Initiative and are demanding both the state governments to initiate a dialogue for integrated planning and management of Mahanadi basin in which the ecological carrying capacity of the river needs to be assessed under such climate change induced scenarios in which the water availability of the basin would be further decreasing, “ said Pand hoping that the governments would be seriously considering this.
Mahanadi’s water yield has decreased by a huge 10% in the recent decades