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

(a) 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 (2013, South Asia's first) combines early warning with cool roofs and reflective surfaces, and Telangana's Cool Roof Policy (2023) mandates them for new buildings; the India Cooling Action Plan (2019) frames the national response. 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 reduce vehicular waste heat by displacing private vehicles and encourage compact, walkable development, while protecting urban lakes and wetlands (as in Bengaluru) preserves natural cool spots.

(b) Sagarmala and transport-communication network

Sagarmala (launched 2015) 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, with coastal shipping and inland waterways added as a further pillar. New deep-draft capacity such as Vadhavan port (approved 2024) and the proposed Galathea Bay transhipment port on Great Nicobar aim to capture cargo now transhipped at Colombo and Singapore. 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 along the Gujarat coast around Mundra, at Visakhapatnam and on Great Nicobar, 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.

(c) Sex-ratio and child sex-ratio

India’s sex-ratio shows strong regional variation (Census 2011: Kerala 1,084 highest, Haryana 879 lowest among states): 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 (949) had a higher sex-ratio than urban areas (929), partly because of male-selective migration to cities. 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 (7+) sex-ratio, about 946 in 2011, has improved over the decades, 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, The immediate arithmetic effect on the general ratio is modest because the 0–6 group was about 13.6% of the population in 2011, but the deficit is cumulative: each cohort of missing girls ages into the adult population, so today's child sex-ratio becomes tomorrow's adult ratio. Haryana's child sex-ratio of 834 in 2011 shows the extreme. NFHS-5 (2019–21) reported a sex ratio at birth of 929 and an overall household ratio above 1,000, signalling improvement, though survey and census measures are not directly comparable. This demographic distortion also affects future marriage markets, household structure and the quality of the demographic dividend. Policies such as Beti Bachao Beti Padhao (2015), stronger PC-PNDT enforcement, girl-child education, and social campaigns are essential to arrest the decline.