By Shilpa Singh
Forests represent the feminine principle in ‘Prakriti’, i.e., pure nature. They have been worshipped as Goddess ‘Aranyani’ in Hindu literature. People have also considered forests as the ‘mothers’ of rivers and given significant importance to the sources of these water bodies. Apart from providing clean water to the ecosystem, forests improve the water cycle by absorbing rainfall, recharging the groundwater aquifers, and reducing the stormwater runoff. They also contribute to mitigating climate change. In addition, they also maintain watershed stability and resilience.
Yet, despite our huge dependence on forests for balancing the water ecosystem, we are still allowing them to disappear.
Forests help in controlling the water cycle by regulating its components of precipitation, evaporation, and flows. The forest canopy layers, roots, and branches store and release water vapor, which controls rainfall. The continuous destruction of tropical forests has disturbed the movement of water in the atmosphere, causing major shifts in precipitation. A study conducted by NASA revealed that the smoke generated from forest fires hinders the cloud formation, thereby resulting in less rainfall. Moreover, by turning rainforest land into crop plantations or ranches, we reduce the surface area of the Earth that is able to reflect back the sun’s rays thus absorbing less of the sun’s energy. This entirely disturbs the patterns of the water cycle as forests play the role of natural pumps, sending precipitation which gathers in coastal areas further inland. Studies also prove that, through condensation and transpiration, forests create low-pressure regions that draw in moist air from the oceans, thereby causing winds capable of carrying moisture and sustaining rainfall.
Forests also serve as buffers to natural calamities like floods by blocking and slowing down the flow of the runoff. But human activities like increasing deforestation weakens this process, leading to irregular rainfall patterns causing droughts and flooding.
Overall, forests play an important role in water availability. They influence the various factors that affect the water cycle by intercepting them together. These factors are precipitation, transpiring soil moisture, evaporating moisture from vegetative surfaces, fog water, and soil infiltration.
On the other hand, cities also often rely on expensive water treatment techniques and infrastructures for cleaning and filtering water as per their suitable quality norms and measures. But increasing levels of degradation of forests results in the sediment flows into streams thereby polluting water. This increases the cost of water treatment. Rather, it would be beneficial for the cities to rely on natural infrastructure like forests as they act in the form of water treatment plants. because the roots of the trees filter out the heavy metals and nitrates before the water makes its way through the water table and along the rest of the water cycle. This would prove beneficial by not only contributing economically but also culturally through recreational green spaces and wildlife habitats.
Forests also influence local and global temperatures and the flow of heat. Individual trees can transpire hundreds of liters of water per day. Every 100 liters of water transpired equals a cooling power equivalent to two average household central air-conditioning units per day.
Research has also discovered that there are three main potential impacts of forestry on water resources i.e. acidification, eutrophication, and siltation.
Mountain forests also have a close association with freshwater as they collect water not only through normal vertical precipitation (i.e. rain and snow) but also by ‘water-stripping’ the fogs and clouds that move horizontally through them. Cloud forests are therefore important for water production. Trees can be planted in the strategic cloud and fog locations to maximize the water-stripping.
It should be sooner realized that better forest management is needed to maximize water-related benefits from forests. The efforts should be made towards managing and balancing forest-water nexus as it will largely contribute towards three Sustainable Development Goals i.e. SDG3 – Good Health and Well-being, SDG 6 – Clean Water & Sanitation, and SDG15 – Life on Land. Therefore, measures should be taken towards sustainable water supply management and increasing rainfall through natural regeneration by aggressive afforestation, land protection, forest conservation, and comprehensive management as well as policy formulation and implementation.
About the Author
Shilpa Singh is an Urban Planner and a Water Management expert. She has completed her post-graduation in ‘Water Policy and Governance’ from the Tata Institute of Social Sciences (TISS), Mumbai.
She is currently working as a Smart City Fellow with the Ministry of Housing and Urban Affairs (MoHUA), Government of India under the India Smart Cities Fellowship Programme. She has been working with her team on developing a ‘Digital Water Balance Tool’ which aims towards achieving water security in Smart Cities under the leadership and guidance of Joint Secretary and Mission Director, MoHUA, Govt of India. She was previously associated with Tata Trusts and Ministry of Women and Child Development (MoW&CD) as District Lead – Swasth Bharat Prerak for the implementation of the National Nutrition Mission under POSHAN Abhiyaan. She looks ahead to explore her interest areas of urban planning, water management, climate change, transportation, and housing.
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