UPSC CSE 2021 Main GS Paper 1.
Question 6- What are the environmental implications of the reclamation of water bodies into urban land use? Explain with examples.
Answer
Reclamation of water bodies into urban land use is the process of converting natural or artificial water bodies, such as lakes, ponds, rivers, wetlands, etc., into land for urban development, such as buildings, roads, parks, etc. This process can have significant environmental implications, such as:
Loss of biodiversity: Reclamation of water bodies can lead to the loss of habitat for aquatic plants and animals, which can have negative impacts on local biodiversity. For example, the reclamation of Hussain Sagar Lake in Telangana has increased the biochemical oxygen demand and reduced the dissolved oxygen levels in the water, affecting the survival of fish and other aquatic organisms. Similarly, the reclamation of wetlands in Mumbai has resulted in the decline of migratory birds and endemic species, such as flamingos and mangroves.
Degradation of water quality: Reclamation of water bodies can also lead to the degradation of water quality, as the natural functions of water bodies to filter, purify, and store water are disrupted. For example, the reclamation of water bodies in West Bengal has led to high levels of arsenic pollution in the groundwater, posing health risks to millions of people. Likewise, the reclamation of water bodies in Delhi has contributed to the contamination of the Yamuna river by sewage, industrial effluents, and solid waste.
Changes in local climate: Reclamation of water bodies can also affect the local climate, as water bodies play a role in regulating temperature, humidity, and precipitation. For example, the reclamation of water bodies in Chennai has reduced the cooling effect of evaporation and increased the urban heat island effect, leading to higher temperatures and lower rainfall. Similarly, the reclamation of water bodies in Bengaluru has altered the micro-climate and reduced the groundwater recharge potential.
Increased risk of flooding and erosion: Reclamation of water bodies can also increase the risk of flooding and erosion, as water bodies act as natural buffers and sinks for excess runoff and sediment. For example, the reclamation of water bodies in Mumbai has reduced the drainage capacity and increased the vulnerability to floods during monsoon seasons. Likewise, the reclamation of water bodies in Kerala has increased the soil erosion and landslide susceptibility during heavy rains.
Therefore, reclamation of water bodies into urban land use can have significant environmental implications that need to be considered and mitigated. Some possible measures to prevent or reduce these implications are:
Conservation and restoration: Conservation and restoration of existing water bodies should be prioritised over reclamation for urban development. Water bodies should be protected from encroachment, pollution, and degradation by enforcing laws and regulations, creating awareness and participation among stakeholders, and implementing best management practices. Water bodies should also be restored to their natural state by removing invasive species, enhancing native vegetation, improving water quality, and increasing biodiversity.
Sustainable development: Sustainable development should be adopted as a guiding principle for urban planning and design. Urban development should be based on ecological principles that respect the natural functions and values of water bodies. Urban development should also minimize the negative impacts on water resources by adopting low-impact techniques such as permeable pavements, green roofs, rain gardens, etc.
Adaptation and resilience: Adaptation and resilience should be enhanced to cope with the changing environmental conditions due to reclamation of water bodies. Urban infrastructure should be designed to withstand extreme weather events such as floods and droughts by incorporating features such as flood barriers, storm water retention basins, rainwater harvesting systems, etc. Urban communities should also be empowered to adapt to climate change by improving their access to information, resources, and services.