Taxonomic approach and potential anthropic indices to understanding cross-sectional morphology and landscape modification of a tropical river Basin, India

Abstract

During the Anthropocene, human modifications to fluvial landscapes have become a common aspect of their progress and development. The primary objective of this research is to delve into the humaninduced alterations on fluvial landscapes at both the channel and basin scales. For channel scale investigation, we classify the channel cross-sections in terms of human interventions and relate them with the potential anthropic (or anthropogenic) geomorphology in the Kopai River basin (KRB) in India. A total of 35 cross-sections (CS) were surveyed at an interval of ~ 3 km from source to mouth, and a perceptional survey was executed among randomly selected 960 respondents in the seven community development blocks. The CS are classified into natural (alluvial and bedrock) and anthropogenic (monatogenic – mining-influenced, traffic- road-stream crossings, hydrogenic-influenced by hydrological projects like dams, and agrogenic- agriculture-influenced) categories following Sźabo’s (1971) taxonomic approach. The statistical difference between natural and anthropic cross-sections is measured using seven hydromorphological characteristics. Basin scale investigation adopting Nir’s index (1983) of potential anthropic geomorphology (IPAG) from 1961 to 2021 depicts that the IPAG is progressively decreasing with time, although the reality is different. We propose to extend the basic notion of the IPAG by incorporating more relevant parameters.