A sustainability analysis on the trends and frequency of the channel flow of a carp breeding river against human interventions and governing public–private partnership (PPP) as adaptation

Abstract

This study presents the trends of channel flow against human interventions and proposes an adaptation plan through a public–private Partnership (PPP) model to overcome the existing deteriorating condition of the Halda River. Being the only natural carp breeding ground in Bangladesh, the Halda River is significant for the national economy. However, the river’s destiny is now stricken with infrastructural obstructions, industrial and residual usage exploits, and short-sighted interventions, whereas the impacts of climate change are likely to worsen the scenarios with high salinity intrusion. The unplanned human interventions due to agricultural purposes are continuously obstructing the river flow and demolishing the carp habitats and spawning within the Halda River extremely. Most of the river bends are potential carp breeding grounds along the river stretch, and the low river flow during pre-monsoon is also impacting the sustainability of the aquatic eco-system. To understand the issues behind the endangering Halda River, this study conducted a sustainability analysis through the river planform, stage trend, and frequency analyses. The planform analysis showed the encroachment of the river impacting the river bends, significant for aquaculture over the last three decades, whereas the stage trends showed the low availability water scenario in these four locations of the river stretch. Besides, the frequency analysis reviewed the threshold minimum flow for the survival of the aquatic habitat, showing that the flow during the pre-monsoon is unsuitable and unacceptable for the survival of the fish habitats using Gumbel distribution. Conservation of the Halda River is a national priority due to its unique ecological and commercial importance, and it is expected that the proposed PPP framework will ensure the long-term sustainability of the river ecosystem. This article is analysing the existing situation of the Halda River and proposing a joint effort from government and private organisation through the PPP model for sustainable ecosystem management as well as the economic benefits of the country. Working together, each of the stakeholders will find direct benefits and can be instrumental for the survival of the Halda River.