Storage of water within a drainage basin is often estimated indirectly by analyzing the recession flow curves as it cannot be directly estimated with the aid of available technologies. However, two major problems with recession analysis are: i) late recession flows, particularly for large basins, are usually not observed ii) and early recession flows indicate that initial storage is infinite, which is not realistic. We address this issue by using the recently proposed geomorphological recession flow model (GRFM), which suggests that storage-discharge relationship for a recession event is exponential for the early recession phase and power-law for the late recession phase, being distinguished from one another by a sharp transition. Then we obtain a simple expression for the 'drainable' storage within a basin in terms of early recession curve characteristics and basin geomorphology. The predicted storage matches well with the observed storage (R^2=0.96), indicating the possibility of reliably estimating storage in river basins for various practical purposes.
The proposed India-based Neutrino Observatory (INO), the largest underground science laboratory in the world, with a finished volume of 235,000 m3, will be blasted out in Idukki- Theni mountains of the Western Ghats. The proposed site is in the highly deformed portion of the the Suruli ductile Shear Zone. There are 12 reservoirs within 50 km radius of the complex, storing about 5 billion m3 of water. Idukki is the water capital for five severely water-stressed districts in Tamil Nadu and Kerala. The 'geotechnical' study report (GTR), based on sparse and low quality primary data has been treated as a confidential document. The impacts of blasting 800,000 tons of rock on the aquifer, the rivers and the reservoirs were not among the endpoints of the geotechnical study. Besides responding to the INO scientists and a geo-engineer, here we extend our arguments against the project with a critique of the GTR, a summary of studies on hydro-geology of the region, visible impacts of mountain tunnelling in India and elsewhere and the regulatory regime that is evolving globally. Starting the construction without conducting a proper, scientific impact assessment may be suicidal. We also doubt whether the physics requirement of filtering the cosmic background radiation, essential for a neutrino detector, will be possible at the present site.
Keywords: Mountain tunnelling, neutrino observatory, hardrock aquifer, tunnelling shear zone, environmental impact assessment, geotechnical study, global catastrophic risk