Morpho-dynamic Avulsion, Source Blockage, and Wetland-Mediated Transboundary Water Sharing in the Ganges-Padma System

Historical Context & Source Blockage: Tracks the major historical shift of the Ganges from the Bhagirathi channel towards the Padma River (following events like the 1505 earthquake). It highlights a consolidated sediment blockage by 2025 near Giria, causing a severe hydraulic disconnection from the main river source. Braiding & Bank Erosion: Shows that the Ganges-Padma reach near Suti-Dhuliyan has transformed from a single-thread channel to a highly dynamic, braided river system accompanied by aggressive bank erosion. Role of Wetland Systems: Details how local wetlands (such as Ahiran beel) and local rivers (such as the Masna/Bagmari) supply baseflow directly into the Indian section of the Padma River via artificial siphon infrastructure beneath the Farakka Feeder Canal. Transboundary Implications: Demonstrates that these wetland-mediated flows provide an essential net addition of fresh water entering Bangladesh. The paper argues that with the 1996 India-Bangladesh Ganges Water Sharing Treaty expiring in 2026, renegotiations must consider sediment, wetland ecosystems, and siphon infrastructure rather than relying solely on volume allocations.历史背景与源头阻滞：追踪恒河（Ganges）从巴吉拉蒂河（Bhagirathi）河道向帕德玛河（Padma）的重大历史变迁，该变迁伴随1505年地震等事件发生。本模块重点提及，至2025年，吉里亚（Giria）附近已形成固结泥沙阻滞带，导致与主河道源头出现严重水力连通中断。 辫状河道与岸线侵蚀：展示了苏蒂-杜利扬（Suti-Dhuliyan）附近的恒河-帕德玛河段，已从单一河道转变为高度动态的辫状水系，同时伴随剧烈岸线侵蚀现象。 湿地系统的作用：详述了当地湿地（如阿希兰比尔湿地（Ahiran beel））与本地河流（如马斯纳河/巴格马里河（Masna/Bagmari））如何通过法拉卡引水渠（Farakka Feeder Canal）下方的人工虹吸基础设施，将基流直接补给至帕德玛河的印度境内河段。 跨界影响：表明这些由湿地介导的径流为进入孟加拉国的水体提供了至关重要的净新增淡水补给。该研究指出，随着1996年《印孟恒河分水条约》将于2026年到期，后续重新谈判必须纳入泥沙、湿地生态系统及虹吸基础设施等考量因素，而非仅依赖水量分配方案。