Spatial Extent, Formation Process, Reclaimability Classification System and Restoration Strategies of Gully and Ravine Lands in India

Abstract

Land degradation has been a major global issue due to its adverse effect on food security, environment and ecology. Among different degraded lands, gullied and ravine lands are very important and remained a highly researchable topic. Gullies are continuous depression on the sloping land surface as a result of soil displacement caused by overland water flow and aided by gravity force, whereas ravines are most extreme form of erosion with intricate network of various forms of gullies, having high drainage density and multidirectional slopes. In India, ravines are mostly found in four states such as Uttar Pradesh, Madhya Pradesh, Gujarat and Rajasthan. During 1976, total ravine land in India was 3.67 million ha, which has been reduced to about 60% at present, and the treatable area including peripheral land is likely to be as high as 1.5 times the actual ravine.

High-intensity rainfall, loose, friable soil devoid of organic carbon and vegetation, faulty agricultural practices, removal of vegetation and overgrazing of lands along with upliftment of central highlands, Aravalli range, Bundelkhand and Chhota Nagpur plateau against lowering of Himalayan base are some of the major factors which are responsible for formation and extension of ravine. As these lands are socio-economically very important, they need reclamation. The main objectives of ravine reclamation are to arrest degradation process, promote ecological restoration, positive on-site and off-site hydrological influences and to establish socio-economic balance with a defined benefit-sharing mechanism. Land shaping, levelling and bench terracing along with riser stabilization are recommended for reclamation and productive utilization of narrow ravine systems with depth up to 3 m. Marginal bund of 1.5 m² cross section with 0.1–0.2% grades can be constructed at the periphery of agricultural land to regulate entry of runoff into ravine lands. Similarly, for ravine with gullies deeper than 3 m, reclamation process involves stabilization of gully heads, gully bed and side slopes, establishment of protective vegetation with economic importance and encouraging socio-ecological harmony for sustenance of protective measures. Perennial vegetation and wildlife along with eco-tourism can be considered as the best option for most degraded ravines. As the ravine area is ecologically sensitive complex system, its reclamation and sustainable development can be achieved through scientific planning at micro level and socio-eco-friendly policies.