The state of Assam is the most populated state in the northeast region of India. The Brahmaputra valley and the Barak valley are the lifelines of the state. The Brahmaputra Valley stretches through 30 districts, while the Barak valley covers three districts. A major part of the state is inundated by the Brahmaputra, a transboundary river and one of the biggest rivers in Asia, exposing the state to the risk of flooding.
The river valleys bear testimony to the menace of devastating floods every year. A crippled rural economy, riverbank erosion, destruction of lives and valuable crops, and drainage congestion are the aftermath of the flood. The state is most vulnerable during monsoons because it is a basin for a large amount of runoff water from higher ground. It is surrounded by the hills of the neighbouring state of Arunachal Pradesh (Government of Assam, 2018).
The state of Assam lies at the foothills of the Himalayas. The geographical location is such that it is neither in the highly irrigated nor semi-arid tropic areas. The state is enriched with heavy rainfall, abundant water resources and fertile soil. The large perennial rivers and other enormous water bodies with rich aquifer speak the vastness of its rich water resources.
Surface water is available in the form of river, stream, lake, swamps, pond, etc. The groundwater is available at low to moderate depth almost in the entire state (ENVIS centre, Assam).
Despite such favourable condition with rich water sources, the state is combating the issue of degrading water quality. Arsenic contamination can be found in the Brahmaputra basin along with elevated levels of fluoride, nitrate and iron contamination in the state.
Further, the flashiness and unpredictability of some tributaries of the Brahmaputra combined with contaminated surface sources due to industrial and agricultural activities are the burning issues regarding the quality of surface water sources.
Fluoride, arsenic and other heavy metal contamination have made the option of alternative surface waters seem like a viable alternative. However, the inadequacy of surface water sources near areas with contaminated water has become a hurdle in the availability of these sources. There is also a lurking ambiguity about the availability of these surface water sources.
The most probable impact of climate change on the water can be summarised by stating that: climate change will shorten or hasten the water cycle. Higher temperatures mean evaporation rates will rise, which will affect all other processes in the water cycle and their interrelationships.
Climate change is already altering “the distribution of precipitation, and intensity and frequency of precipitation events could potentially exacerbate both flooding and water scarcity”.
It will not be an exaggeration to state that that the recurring problem of floods in the state of Assam is the product of climate change. Prior to the devastating earthquake of 1950, which registered an 8.7 on the Richter scale, floods occurred only in the northern region of the Brahmaputra. But after the 1950s, the entire Brahmaputra valley and Barak valley region have been witnessing floods year after year.
Several records from the last century indicate the widening phenomenon of the Brahmaputra. The Brahmaputra river occupied around 4000 sq. km in the 1920s and now the Brahmaputra occupies about 6000 sq. km.
Further analysis on the impact of climate change on flood characteristics in the Brahmaputra river suggests that for both the pre-monsoonal and monsoonal seasons, peak discharges and flood wave durations are expected to increase under the projected climate change scenario.
Groundwater serves as the source of a significant portion of drinking water and makes for approximately 85% of rural drinking water. It is estimated that the gross per capita availability of water in India is projected to decline from 1820 cubic meter per year in 2001 to 1140 cubic meter per year in 2050.
One of the important reasons cited is that due to recurrent flash floods, the downpour of water will increase, making the availability of water scarcer. We are already witnessing recurrent flash floods in many parts of India, including Assam.
However, groundwater reacts at a slower pace to rainfall and temperatures and can thereby be resilient to water stress. Groundwater storages can also contribute towards mitigating the problem by absorbing the excess runoff.
Floods not only severely affect the environment but also leave behind a trail of adverse effects on women. Several challenges related to access to sanitation facilities, menstrual hygiene and maternity care leading to other longer-term adverse health outcomes have been faced by Health and WASH Women in this context.
Not just these, during floods, access to hospitals can be difficult for pregnant women leading to their death. An impact of water-related disaster analysis (J. Jagnoor et al.) has revealed that banana leaves are used as toilets during floods. Children defecate in the water, thereby rendering it unfit for public consumption.
During a flood, people are compelled to consume such contaminated water, which can lead to death by deadly diseases such as diarrhoea.
Bank erosion has been continually wiping out more than 2500 villages and 18 towns, including cultural heritage and tea gardens, affecting the lives of nearly 5,00,000 people.