Sequestering Carbon in Ravine-prone and Eroded Landscapes

Abstract

Ravine lands, the most severe form of water erosion leading to formation of badlands, occupy about 4 Mha (1.22%) of land area in India. These lands have strongly impacted economic, social, cultural, and environmental features of the region. This article describes the cause-effect relationship, suggests some preventive and control measures, and assesses the potential of soil carbon sequestration. Formation of ravine lands is triggered by tectonic activity, climate change, or drastic change in land use. In India, ravines are formed in the semiarid climate with short (3-month) monsoonal rains and a long dry season. On the basis of morphological features (depth, width, density, etc.), ravines can be categorized into shallow, medium, and deep. An effective restoration/rehabilitation necessitates characterization of ravines using satellite imagery and other remote sensing techniques validated by ground-truthing. For an effective control measure, runoff into the ravine land must be diverted using techniques of safe disposal and a perennial vegetation cover established. Deep ravines must also be afforested to stabilize further growth. Medium and shallow ravines can be bulldozed for agricultural forestry land use. Carbon sequestration in soil and biomass, with a technical potential of 2.6–5.3 TgC year⁻¹, can generate another income stream for farmers (US$300–640 million year⁻¹) and promote the adoption of best management practices for both preventative and control measures.