Water Resources Assessment Issues and Application of Isotope Hydrology in North East India

Abstract

The freshwater resources are likely to be severely impacted by climate change as reported by many researchers around the globe. India already facing a shortage of freshwater resources due to rapid urbanization and industrialization and acceleration of economic development activities. Assessment of water resources plays a key role in the development of the economy of any nation. Northeastern states of India are blessed with huge water resources. The region faces inconsistent circumstance as devastating floods in monsoon months and water scarcity in non-rainy periods at many places. Most of the areas having high reliefs or undulating terrains where rainwater does not get sufficient time to infiltrate into the soil. As a result, quick runoff is dominant in the region, and ultimately reduces the recharge of springshed, and results in the reduction of discharge of many springs and streams during the non-rainy season. To overcome freshwater stress in the region, a proper understanding of the water cycle, its management, and development of various infrastructure is highly required. Though some problems could not be solved due to the lack of hydrological data like spring discharge data, water quality, etc. The alternate use of environmental isotope technologies aids researchers to estimate origin, recharge source age, and its movement within the hydrologic cycle can be of ultimate solutions. The stable isotopes (Deuterium and Oxygen-18) are excellent indicators of the water circulation, whereas radioisotopes (Tritium and Carbon-14) distinct value in detecting the mean residence time (MRT). This methodology has special value in terms of its cost-effectiveness and the investigative encouragement of the specialists. This paper presents the use of isotopic hydrology for sustainable development of the water resources of northeastern region of India.