(a) Describe the causes of the phenomenon of 'urban heat island'. What are the effective measures to deal with this phenomenon in…

Urban heat island. Urban heat island (UHI) arises because cities replace natural surfaces with built ones. Dark roofs, asphalt and concrete have low albedo, absorbing more solar radiation than vegetation or soil. Their high heat capacity and thermal conductivity store daytime heat and release it at night, delaying cooling. Anthropogenic heat from vehicles, industries, air-conditioning and appliances adds directly to the urban energy balance. Paved surfaces reduce soil moisture and vegetation, lowering evapotranspiration, which otherwise cools air through latent heat. Tall buildings and narrow streets form urban canyons that trap long-wave radiation, reduce sky view, and weaken wind mixing, so heat accumulates. The effect is most visible in dense Indian cities where open space is limited and night-time temperatures remain high. In India, mitigation must be low-cost and climate-sensitive. Ahmedabad’s Heat Action Plan promotes cool roofs and reflective surfaces to lower roof temperatures. Urban greening, including Miyawaki forests, street trees and parks, increases shade and evapotranspiration. Permeable pavements and rainwater harvesting reduce sealed surfaces and recharge groundwater. Building codes should require cross-ventilation, thermal insulation, and orientation that reduces cooling loads. Metro corridors can create cool islands by displacing private vehicles, reducing congestion heat, and encouraging compact, walkable development.

Sagarmala and transport-communication network. Sagarmala is a port-led development strategy that links India’s transport and communication networks. It modernises ports through dredging, berths, cargo handling and multi-modal terminals; enhances connectivity through roads, railways, inland waterways and intermodal corridors; promotes port-linked industrialization in coastal zones; and supports coastal community development. Its communication-network dimension is equally important: port community systems, single-window customs clearance, e-port cargo platforms, real-time logistics data and telecom/IT links connect customs, ports, railways, shipping and industry, reducing clearance time and improving supply-chain visibility. This makes ports nodes in a national logistics and information network, not isolated terminals. Critically, implementation remains uneven. Some projects face delays, land acquisition, financing and institutional coordination problems. Environmental concerns are visible at Mundra and Vizag, where port expansion, dredging and industrial activity raise issues of coastal ecology, siltation and community displacement. Hinterland connectivity deficits persist in many ports, limiting cargo movement and reducing the multiplier effect. Digital integration also needs stronger inter-agency data sharing, cybersecurity and last-mile connectivity.

Sex-ratio and child sex-ratio. India’s sex-ratio shows strong regional variation: southern states generally have higher female representation, while northern and north-western states such as Punjab, Haryana, Rajasthan and Uttar Pradesh have lower ratios. Rural and urban ratios differ: in 2011 rural areas had a slightly higher sex-ratio than urban areas, though state patterns vary. The general sex-ratio in 2011 was 943 females per 1000 males, but the child sex-ratio for 0–6 years was only 918, down from 945 in 1991. The adult sex-ratio, 976 in 2011, has improved since then, reflecting better female survival and ageing, yet the persistent decline in child sex-ratio remains the main drag on the overall ratio. Prenatal sex selection, son preference and weak enforcement of the PC-PNDT Act have created a daughter deficit in the 0–6 group, depressing the general sex-ratio because children form a large share of the population. This demographic distortion also affects future marriage markets, household structure and the quality of the demographic dividend. Policies such as Beti Bachao Beti Padhao, stronger PC-PNDT enforcement, girl-child education, and social campaigns are essential to arrest the decline.

Thus, UHI mitigation, Sagarmala and sex-ratio correction are not separate issues but parts of sustainable development. Cooler, greener, ventilated cities reduce health risks and energy demand. A port-led, digitally connected coastal economy can raise productivity if environmental safeguards and hinterland links are strengthened. A balanced child sex-ratio is the demographic foundation for a just and productive society. India’s way forward lies in combining urban climate action, integrated transport-communication infrastructure, and gender-just demographic policies.