Aravalli Definition Should Be Based on Science, Not Height: Dr. Anil Mehta

Presentation before Supreme Court Committee highlights limitations of using Murphy’s classification solely for defining Aravalli Hills Udaipur, August 10: The scientific and legal basis for defining the Aravalli Hills came under focus in a presentation made before the Supreme Court Committee on Monday. Dr. Anil Mehta argued that the permanent and legally enforceable definition of the Aravalli Hills should not be determined solely through a judicial process or a single elevation threshold, but through a comprehensive legislative and policy framework supported by multidisciplinary scientific expertise. The presentation raised two key questions: Who should define the Aravalli Hills?

and Why Richard E. Murphy’s landform classification cannot be used to define the Aravallis solely on the basis of height. Need for legislative and scientific framework Dr. Mehta’s presentation noted that while the judiciary has an important constitutional role in environmental protection and in interpreting existing laws, the comprehensive classification of an entire mountain system involves complex issues of geology, geomorphology, ecology, hydrology, land use, cultural heritage, mineral resources and development policy. The presentation argued that these issues are more appropriately addressed through a transparent legislative and policy process, supported by multidisciplinary scientific institutions, expert assessment and public consultation. It further pointed out that there is currently no single, universally applicable statutory definition of a “hill” or “mountain range” for all purposes of environmental protection, land-use planning and development across India. According to the presentation, creating a judicially determined definition specifically for the Aravallis could potentially have wider implications for the classification of other hill systems and natural landscapes. The presentation also suggested that Parliament could consider whether “hills and mountain ranges”, or an appropriately defined category of natural landforms, should receive a place in the Concurrent List through the constitutionally prescribed process, enabling a coordinated national framework while allowing recognition of the distinct characteristics of different mountain systems. Murphy’s classification does not support a height-only definition A major focus of the presentation was the interpretation of Richard E. Murphy’s landform classification. It noted that the Rajasthan Government had relied upon Murphy’s Landforms of the World during 2002–03 while identifying the Aravalli Hills. However, according to the presentation, a detailed examination of Murphy’s original 1968 work, along with its 2023 scientific reinterpretation, shows that his classification cannot be reduced to a simple elevation criterion. Murphy’s approach was developed to move beyond classifications based only on measurable terrain parameters such as percentage slope or local relief. His framework sought to reconcile genetic and empirical approaches to landform classification. Three variables form the basis of Murphy’s framework The presentation highlighted that Murphy’s classification uses three independent groups of characteristics: Structural regions — geological and tectonic framework Topographic regions — terrain morphology Erosional or depositional landscapes — geomorphic processes and climate The final classification is derived by combining these three variables. A 2023 reconstruction of Murphy’s work similarly identifies structural, topographic and erosional-depositional characteristics as the core components of the methodology. The presentation therefore concluded that height alone is not the basis of Murphy’s classification. Landform classification linked to geological history According to the presentation, Murphy’s approach is essentially genetic rather than merely morphometric. It incorporates geological history along with observable landform characteristics. The 2023 reconstruction further describes the framework in terms of structure, process and time, making geological origin and evolutionary history important components of landform classification. The presentation also noted Murphy’s recognition that landforms cannot adequately be represented through simple statistical thresholds because they are products of long geological evolution and involve complex spatial relationships. Modern reconstruction also relies on multiple scientific inputs The presentation highlighted that the 2023 global reconstruction of Murphy’s work did not reproduce the classification through height thresholds alone. Instead, it incorporated global lithology, Hammond landform regions, digital elevation models, climatic and bioclimatic information, and extensive expert interpretation. It further noted that considerable manual geomorphological interpretation was required because landform boundaries cannot be derived mechanically from topography alone. Aravallis are a living geological and civilizational landscape The presentation also emphasised the cultural and civilizational dimension of the Aravallis. It described the range as a living civilizational landscape that has shaped the cultural identity of western India over millennia. It proposed viewing the Aravallis not merely as an ancient mountain chain, but as a “Sacred Ecological Landscape”, where nature, culture and spirituality have evolved together. Sacred geography, traditional water systems, pilgrimage routes, regional languages, folklore, archaeological heritage and indigenous knowledge were identified as integral elements of the landscape’s identity. Why elevation alone could fragment the Aravallis The presentation noted that the Aravalli Range is among the oldest fold mountain systems in the world and has undergone hundreds of millions of years of erosion and denudation. As a result, many Aravalli ridges now occur at relatively low elevations. It stressed that low elevation does not necessarily mean the absence of mountain character. Geological continuity can remain intact despite differential erosion, while watershed functions, ecological connectivity and ridge morphology continue to define the mountain system. The presentation consequently argued that a definition based solely on elevation could fragment a naturally continuous mountain chain and overlook the geomorphic evolution that forms an essential part of Murphy’s own classification framework. Call for evidence-based definition The presentation before the Supreme Court Committee ultimately emphasised the need for an evidence-based, multidisciplinary and scientifically robust approach to defining the Aravalli Hills. Rather than relying on a single numerical elevation threshold, it advocates consideration of geological structure, terrain morphology, geomorphic processes, ecological connectivity, watershed characteristics, cultural heritage and the evolutionary history of the Aravalli landscape.