Land & Water Conservation

"The bedrock of India’s ecological security lies beneath our feet. As climate change exacerbates hydrological extremes, the preservation of topsoil and the scientific management of subterranean aquifers transition from environmental concerns to matters of national sovereignty. This chapter dissects India's multilateral commitments to halt desertification and the technological frameworks employed to map and conserve our rapidly depleting water resources."

1. Desertification & Land Degradation

It is crucial for UPSC aspirants to distinguish between two frequently conflated terms: Land Degradation and Desertification. Land degradation is the broader term, referring to the reduction or loss of the biological or economic productivity of land. Desertification is a specific subset of land degradation—it is defined officially as land degradation occurring strictly in arid, semi-arid, and dry sub-humid areas resulting from various factors, including climatic variations and human activities. Contrary to popular misconception, it does not mean the physical expansion of existing deserts like the Sahara or the Thar.

1.1 The Scale of the Crisis in India

The Space Applications Centre (SAC), ISRO publishes the definitive Desertification and Land Degradation Atlas of India. According to the latest comprehensive data, approximately 97.85 million hectares (nearly 29.7% of India's total geographical area) is undergoing land degradation.

The primary drivers of this degradation, in order of magnitude, are:

1. Water Erosion: The most significant factor, responsible for the loss of nutrient-rich topsoil, largely driven by deforestation and poor agricultural practices.
2. Vegetation Degradation: Driven by overgrazing and the relentless expansion of agriculture into marginal forest lands.
3. Wind Erosion: Predominant in the arid western states (Rajasthan, Gujarat).

1.2 The UNCCD: The Global Legal Framework

The United Nations Convention to Combat Desertification (UNCCD) was established in 1994. It is the sole legally binding international agreement linking environment and development to sustainable land management. It is one of the three "Rio Sister Conventions" (alongside the UNFCCC for climate and CBD for biodiversity) emerging from the 1992 Earth Summit.

2. Integrated Watershed Management

To combat the dual threats of soil erosion and water scarcity, India has adopted the Watershed Management approach. A watershed (or catchment basin) is a geo-hydrological unit draining to a common point by a system of drains. Integrated management implies the rational utilization of land and water resources for optimum production with minimum hazard to natural resources.

2.1 The "Ridge to Valley" Approach

The fundamental scientific principle governing modern watershed management in India is the Ridge to Valley approach. Soil and water conservation treatments must commence from the topmost portion of the watershed (the ridge) and systematically proceed downwards to the valley. Treating the lower reaches without stabilizing the upper catchments inevitably leads to the silting and destruction of lower structures (like check dams) due to unchecked high-velocity runoff from above.

2.2 PMKSY - Watershed Development Component (WDC)

The former Integrated Watershed Management Programme (IWMP) was amalgamated into the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) as its Watershed Development Component. Executed by the Department of Land Resources, its primary objective is restoring ecological balance by harnessing, conserving, and developing degraded natural resources such as soil, vegetative cover, and water.

Key interventions under PMKSY-WDC include:

• Contour Bunding & Trenching: Building earthen barriers along the natural contours of the land to intercept runoff.
• Check Dams & Percolation Tanks: Small masonry or earthen structures built across gullies to slow water velocity, trap sediment, and force water to percolate into the aquifer.
• Capacity Building: Training local watershed committees to maintain these micro-structures post-construction, ensuring community ownership.

3. Groundwater Management & Aquifer Mapping

India is the largest user of groundwater in the world, extracting more than the US and China combined. This hyper-extraction, driven heavily by subsidized electricity for agricultural pumping and the cultivation of water-intensive crops (rice, sugarcane) in semi-arid zones, has plunged the nation into a severe hydro-geological crisis.

3.1 The Central Ground Water Board (CGWB) & Dark Zones

The CGWB periodically assesses the Dynamic Ground Water Resources of India. Assessment units (blocks/mandals/talukas) are categorized based on the Stage of Ground Water Extraction (extraction as a percentage of net annual recharge):

• Safe: Extraction < 70%.
• Semi-Critical: Extraction between 70% and 90%.
• Critical: Extraction between 90% and 100%.
• Over-Exploited (Dark Zones): Extraction > 100% (More water is pumped out than is naturally recharged). States like Punjab, Haryana, Rajasthan, and Delhi have a catastrophic concentration of over-exploited units.

3.2 NAQUIM (National Aquifer Mapping and Management Programme)

To manage what we cannot see, the government launched NAQUIM. It is one of the world's largest programs of its kind, aiming to map the 3D geometry of aquifers across the country, characterize their yield potential, and identify areas of chemical contamination (like arsenic and fluoride). The ultimate goal of NAQUIM is to prepare robust, participatory Aquifer Management Plans to facilitate sustainable extraction.

End of Chapter 13.
Proceed to Chapter 14 for Climate Organizations and Treaties.