(a) Critically examine the factors affecting the unpredictability of South-West Monsoon system in India. 20 (b) The peninsular…

(a) Unpredictability of the south-west monsoon

The South-West Monsoon operates as a complex thermodynamic engine driven by coupled planetary teleconnections and regional land-atmosphere dynamics. Ocean-atmosphere interactions like the El Niño-Southern Oscillation (ENSO) significantly dictate monsoonal behaviour; El Niño generally suppresses precipitation by weakening the Walker circulation, while La Niña enhances it, as in the El Niño droughts of 2002 and 2009 and the below-normal 94% of the long period average in 2023. However, this relationship is non-linear, as a positive Indian Ocean Dipole (IOD) often offsets El Niño-induced deficits. The Madden-Julian Oscillation (MJO) further introduces intra-seasonal unpredictability, triggering active or prolonged break spells depending on its phase over the Indian Ocean. Regionally, the sensible heating of the Tibetan Plateau, the timely northward retreat of the Subtropical Westerly Jet, the development of the Tropical Easterly Jet, and the land-sea thermal contrast govern the onset, spatial progression, and withdrawal. The strength of the Mascarene High and the Somali (Findlater) jet set the cross-equatorial moisture supply, and late-season interaction of western disturbances with the monsoon trough can produce extreme rain, as in Himachal Pradesh in July 2023.

Critically, anthropogenic forcing has intensified these uncertainties. High atmospheric aerosol loading and black carbon alter cloud microphysics and radiative balances, while rapid land-use changes and Urban Heat Islands (UHIs) induce erratic, high-intensity localized convective storms. Consequently, traditional statistical frameworks and high-resolution dynamical models (like IMD's Coupled Forecast System) face persistent challenges in simulating meso-scale cloud processes and multi-scale ocean interactions.

(b) Peninsular location and non-conventional energy

India’s peninsular orientation and tropical location provide an exceptional geographical foundation for renewable energy deployment.

A coastline of about 11,100 km (2024 re-measurement, earlier 7,516 km) facilitates substantial onshore and offshore wind energy generation, concentrated along high-velocity corridors in Tamil Nadu (e.g., Muppandal, fed by winds funnelled through the Aralvaimozhi gap) and Gujarat, where the first offshore wind sites are also being tendered. Marine energy resources remain viable in the macro-tidal regimes of the Gulf of Khambhat and Gulf of Kutch, alongside wave energy potential along the south-western littoral.

Solar insolation of about 4–7 kWh/m²/day, above 5 over most of the peninsular plateau, supports parks such as Pavagada (Karnataka) and Kamuthi (Tamil Nadu), and is also high in the semi-arid tracts of Gujarat, Rajasthan, and the high-altitude cold desert of Ladakh. In mid-2025 non-fossil sources crossed half of India's installed power capacity. Peninsular agriculture supports substantial biomass energy via agro-industrial residues like sugarcane bagasse in Maharashtra and Karnataka. Geothermal prospects exist along structural rifts such as the Damodar-Son valley, the Godavari graben, and the thermal springs of the Western Ghats.

(c) Urban groundwater contamination and public health

Unregulated urban sprawl has severely degraded groundwater quality through anthropogenic loading and over-abstraction-induced geogenic leaching. Inadequate sewerage networks cause extensive septic tank leakage, while unlined landfills generate toxic leachate that infiltrates unconfined aquifers. Industrial effluents and urban surface runoff significantly elevate nitrate, phosphate, and heavy metal concentrations. Simultaneously, over-extraction alters local hydrogeology, mobilizing geogenic contaminants such as arsenic in the urban belts of the Ganga-Brahmaputra plains and fluoride in peninsular cities like Bengaluru and Hyderabad. The CGWB Annual Ground Water Quality Report 2024 found nitrate above the permissible limit in 19.8% of 15,259 samples, fluoride in 9.04%, uranium in 6.6% and arsenic in 3.55%.

The resulting public health burden is acute. Elevated nitrate levels cause methaemoglobinemia (blue baby syndrome) in infants, while prolonged exposure to geogenic toxins leads to debilitating skeletal fluorosis, arsenicosis, and long-term carcinogenic risks.

The burden falls hardest on peri-urban colonies outside piped networks that depend on private borewells, which AMRUT 2.0 water-supply coverage and CGWB aquifer mapping (NAQUIM) are meant to reach.