13.8% soil loss across Aravallis: Study

NEw new delhi: speedy urbanisation, minelaying and increased rainfall feature goaded an average 13.8% increase in soil loss across the Aravalli Mountain System between 2017 and 2024, a new research paper stated.Built-up areas in the region grew by 53%, or 2,644 sq km, during the seven-year period -- expansion that primarily replaced croplands and rangelands.Researchers from the Jindal School of Environment and Sustainability (JSES) at OP Jindal Global University and the Indian Institute of Technology Kharagpur published the findings in the journal Geographies on March 6. The study concluded that steep slopes, susceptible soils and mining areas are strongly associated with erosion hotspots. It noted that local conservation efforts, despite a significant increase in afforestation, cannot compensate for massive land conversion.Aravallis are long held as the only natural barrier between Delhi and its surrounding regions and the deserts of Rajasthan to the west, with the mountain range having lost 31 of its hills since 1967-68, according to a 2018 report by the Supreme Court-appointed Central Empowered Committee.The paper stated forest cover increased by 147.31 sq km between 2017 and 2024. However, built-up areas increased by 2,644.32 sq km, while bare land reduced by 101.76 sq km, rangeland by 1,349.3 sq km and cropland by 1,382.5 sq km.The study defined the Aravalli Mountain System (AMS) extent based on available literature. The area covers older alluvium, the Thar Desert, Kumbhalgarh, Gogunda, Alwar, Sandmata, Jharol, Ajabgarh, Mangalwar and Udaipur.The paper analysed soil erosion across the entire AMS over 20 years. Using high-resolution soil erosion models, such as the Revised Universal Soil Loss Equation (RUSLE), and multi-resolution datasets like MODIS and ESRI, the study provided the first AMS-scale evaluation of the relationship between soil erosion processes and land-use change.“The mean annual rainfall increased by 8.7% between 2017 (735.8 mm) and 2024 (1,026.2 mm), leading to an increase in the rainfall erosivity factor. However, when this was combined with topography dominated by slopes and urban development, the mean annual soil loss increased by 13.8%... Mining, especially lead-zinc, marble, sandstone, and industrial minerals, places significant pressure on the landscape, with high number of active leases that cause geomorphic disturbance,” JSES dean Abhiroop Chowdhury said.The paper stated the future of the Aravalli range is an issue of national importance, noting that the Supreme Court deliberated on redefining the geographical scope of the range, which spans several states. The ruling, issued on November 20, 2025, was based on the classification of the hills primarily by altitude, limiting legal protection to locations above the 100-metre contour line. The court suggested creating an expert board to conduct a thorough examination of the matter.“Comprehensive scientific studies are needed in the region, given recent developments, to facilitate informed policymaking. This research sought to address some of the policy gaps by developing a scientific understanding of the concerns (soil erosion, land degradation, and forest cover) surrounding the conservation of the AMS,” the paper stated.