text: Some activists and scholars have, between 2002 and 2008, questioned the merits of Indian rivers inter-link projects, and questioned if appropriate study of benefits and risks to environment and ecology has been completed so far. Bandyopadhyay et al. claim there are knowledge gaps between the claimed benefits and potential threats from environment and ecological impact. They also question whether the inter-linking project will deliver the benefits of flood control. Vaidyanathan claimed, in 2003, that there are uncertainty and unknowns about operations, how much water will be shifted and when, whether this may cause water logging, salinity/alkalinity and the resulting desertification in the command areas of these projects. Other scholars have asked whether there are other technologies to address the cycle of droughts and flood havoc's, with less uncertainties about potential environmental and ecological impact. Rivers may change their courses every (approximately) 100 years, so the interlinking may not be useful after 100 years. Interlinking may also lead to deforestation and cause ecological imbalances, widely expected to alter fish communities. A study concluded that the project could reduce rainfall and change rainfall patterns in the region.