Chapters
Introduction | Water Scarcity and the need for water management |Multi purpose river projects and integrated water resources management |Rain water Harvesting
Introduction
Despite three-fourths of the Earth's surface being covered in water, only a small fraction is freshwater available for use.
Freshwater primarily comes from surface runoff and groundwater, replenished through the hydrological cycle.
The hydrological cycle ensures water is continually renewed, making it a renewable resource.
Despite its abundance, water scarcity is prevalent globally due to various factors:
Unequal distribution of freshwater resources.
Pollution and contamination of available water sources.
Climate change altering precipitation patterns and increasing evaporation rates.
Predictions suggest that by 2025, nearly two billion people will face absolute water scarcity due to these factors
NCERT Class 10 Geography | Chapter 3 | Water Resources
Water Scarcity and the need for water management
Despite water's abundance and renewability, water scarcity is a pressing issue.
Water shortages are often associated with regions having low rainfall or drought-prone areas like the deserts of Rajasthan.
Over-exploitation, excessive use, and unequal access to water among social groups are primary causes of water scarcity.
Water scarcity can occur even in areas with ample water resources due to growing populations and demands for water.
Irrigated agriculture, industrialization, and urbanization exacerbate water scarcity by over-exploiting freshwater resources
Industries, urban centers, and urban lifestyles increase pressure on freshwater resources and energy demands.
Pollution from domestic, industrial, and agricultural sources further exacerbates water scarcity by degrading water quality.
The Jal Jeevan Mission (JJM) aims to provide potable piped water to every rural household to improve quality of life.
Conservation and proper management of water resources are essential to safeguard health, ensure food security, livelihoods, and prevent ecological crises.
Multi purpose river projects and integrated water resources management
Throughout history, sophisticated hydraulic structures like dams, reservoirs, embankments, and canals have been used for water management.
Dams, traditionally built to impound rivers and rainwater, now serve multiple purposes including irrigation, electricity generation, water supply, flood control, recreation, navigation, and fish breeding.
Modern dams are referred to as multi-purpose projects, integrating various uses of impounded water, such as the Bhakra-Nangal project for hydel power production and irrigation in the Sutluj-Beas river basin.
Multi-purpose projects were seen as vehicles for development and progress post-independence, but have faced scrutiny and opposition due to environmental and social concerns.
Issues with large dams include altering natural river flow, poor sediment flow, habitat degradation for aquatic life, fragmentation of rivers hindering fauna migration, and submergence of vegetation and soil.
Large dam projects have led to environmental movements like the Narmada Bachao Andolan and Tehri Dam Andolan, primarily due to the displacement of local communities.
Changes in cropping patterns due to irrigation have ecological consequences like soil salinization and social impacts, widening the gap between landowners and landless poor.
Conflicts arise over different uses and benefits of water resources, such as the Sabarmati-basin farmers' agitation over water supply priorities during droughts and inter-state water disputes over multi-purpose project benefits and costs.
Rain water Harvesting
Water harvesting systems offer a socio-economically and environmentally viable alternative to large multi-purpose projects.
Ancient India had a rich tradition of water harvesting, utilizing techniques tailored to local ecological conditions and water needs.
Techniques included diversion channels like 'guls' or 'kuls' in mountainous regions, rooftop rainwater harvesting in Rajasthan, and inundation channels in Bengal flood plains.
In arid regions like Rajasthan, underground tanks or 'tankas' were common for storing rainwater, with sophisticated systems for collection and storage.
Tanks were connected to sloping roofs, collecting rainwater for storage until the next rainfall, providing a reliable source of drinking water, especially during summers.
Despite the decline in traditional practices due to access to canal water, some areas still maintain rooftop rainwater harvesting, appreciating the purity and taste of rainwater.
Rural and urban areas are increasingly adopting rooftop rainwater harvesting systems for water conservation. For instance, in Gendathur, Karnataka, nearly 200 households have installed such systems, harvesting significant amounts of rainwater annually.