Compliance of discharge estimates from proxy parameters: a study on an ungauged station of a Himalayan river

This research delves into the intricate process of estimating bankfull discharge using proxy parameters for the upper Murti River and Khar Khola, two Himalayan streams. Through five distinct proxy parameter-based approaches, the study reveals a broad spectrum of findings that underscore the complexity inherent in discharge estimation within river systems. For upper Murti River, the lowest discharge value was 10.18 m³s^–1, derived through average depth; the highest discharge value was 181.87 m³s^–1, estimated based on channel width; and the calculated average discharge was 99.45 m³s^–1. The variation in estimated discharge expressed in terms of standard deviation (SD) is 74.76 m³s^–1. For Khar Khola, the lowest discharge value was 1.78 m³s^–1, derived through average depth; the highest discharge value was 25.12 m³s^–1 \(,\) $,$ estimated based on basin area; and the average discharge was 11.127 m³s^–1. The variation in estimated discharge expressed in terms of standard deviation (SD) is 11.124 m³s^–1, almost equal to the average of three estimates. The utilization of specific proxy parameters, such as the largest entrained sediment size and corresponding flow velocity from the Hjulstrom curve, the power relationship between velocity and discharge, basin area, average depth, and channel width underscores the diversity of factors shaping river behavior. The study underscores the significance of comprehending natural complexities and limitations of proxy parameters, and provides valuable insights aimed at refining and responsibly managing discharge estimation methods, thereby enhancing strategies for river management.