Of late, we’ve experienced a global increase in frequencies of floods, be it flash flood or urban flooding or any other categories, the water spillover, the incidents of waterlogging in urban and rural areas – all have increased many folds in recent years. And there are many studies conducted across the globe by different universities, research institutes and other associated academia, which shows that these increments in magnitude are caused due to anthropogenic activities, be it bad town planning, or rapid urbanization, industrialization, contamination of waterbodies, over-extraction or the groundwater and under refilling, lack of rainwater harvesting, air pollution, chemical-based farming, global warming, PVHI or UHI – all factors have been contributing immensely towards the cause. Thus, we can conclude that anthropogenic activities (which can be defined as, processes, objects, or materials that are derived from human activities, as opposed to those occurring in natural environments without human influences) have presented great concerns toward regions affected by disastrous floods in the past and is presently affecting many agroclimatic zone across the globe too.
Research done in the year 2018, by School of Environment and Geographical Sciences, University of Nottingham, observed that “from 1980 to 2009, floods have resulted in more than 500,000 deaths and affected above 2.8 billion people worldwide based a national climate assessment”.
Anthropogenic activities contribute to flooding through landscape modification and atmospheric changes. Implications of these findings should be included in policy decision-making to address their impact on flooding to reduce flooding vulnerability. Landscape modification through urbanization, deforestation and large-scale agricultural practices promotes flooding in urban and rural areas. However, we must always remember that, anthropogenic impacts related to land use have an influence on the intensity of flood discharge. It must be remembered that each flood event has its own set of causes, which can be categorized as anthropogenic and natural event-dependent (meteorology) and event-independent.
On the other hand, anthropogenic atmospheric changes have largely contributed towards flood disasters or at least increased human settlements' impact or vulnerabilities. Industrialization or chemical-based farming in developing countries increases carbon emissions, activating the ‘aerosol-enhanced conditional instability’ mechanism. Also, rainfall levels in urban areas have risen due to the ‘urban heat island’ (UHI) effect. In recent years, anthropogenic activities have played a crucial role in major flooding events and further research will help manage and mitigate flood risks.
On one hand the waste water discharge in the natural waterbodies deposit a layer of sludge in the bottom restricting or chocking the natural soil capillary link to the aquifer (which enables natural recharge), on the other hand UHI & PVHI have their role in incremental rainfall. Thus, the water is bound to spill over cause flooding and water logging in the area.
It’s high time for humanity to learn to live in harmony with nature and mend our ways for sustainability of our own race, else these massive impacts on the native biodiversity might one day cause a reboot of the whole planet, like it happened in earlier history of the planet with global floods and ice ages for restart of life and civilization again.