The HiFlo-DAT (Himalayan Flood Database) serves as a significant resource for disaster risk reduction (DRR) in the context of mountain floods, specifically focusing on the Kullu District of Himachal Pradesh, India. This database is designed to enhance methodologies for collecting, analyzing, and applying disaggregated disaster loss data at subnational levels. By utilizing English-language documents, primarily newspapers and government reports spanning from 1835 to 2020, HiFlo-DAT encompasses 128 flood events across 59 locations over a period of 175 years (1846-2020). This open-access database represents a substantial advancement over existing compilations, providing a more comprehensive understanding of historical flood events.The analyses derived from HiFlo-DAT reveal significant temporal and process patterns related to flooding in the region. Notably, two flood-rich periods have been identified: the late 19th century (1890-1900s) and the 1990s to the present, which together account for 68% of the recorded events. Furthermore, there is a discernible increase in flood occurrences in recent years, with rainfall being the primary causative factor in 55% of the events. The data also indicates that summer monsoon flooding, occurring between June and September, is responsible for 87% of the recorded floods.

Geographically, the database highlights that 76% of the 59 locations have recorded only a single flood event, while 24% have experienced two or more events. Four tributaries within the region have recorded between 8 to 14 flood events. The impacts of these floods are significant, particularly on infrastructure such as roads (55 floods), bridges (54 floods with 94 impacts), and vulnerable laborer-migrant communities, which account for 70% of fatalities and 83% of those affected, particularly in relation to construction projects in remote and exposed areas.HiFlo-DAT not only contributes to the understanding of historical flood events but also presents opportunities for policy and practice development. The methodology used in HiFlo-DAT can be transferred to other areas within the Indian Himalayan Region and trans-boundary basins. There is a call for multi-disciplinary approaches to corroborate and extend documentary-based databases, as well as improved access to public archive materials. The integration of historical flood data into DRR and climate change adaptation management planning is essential for effective infrastructure development. Additionally, fostering deeper partnerships among various agencies to record contemporary flood impacts can provide valuable data for current and future DRR efforts.The introduction of the HiFlo-DAT project emphasizes the importance of methodologies for compiling disaggregated disaster loss data at subnational scales.

The UNDRR (United Nations Office for Disaster Risk Reduction) has highlighted the significance of data disaggregation, particularly concerning socio-economic metrics and the generation of data for contemporary events. HiFlo-DAT exemplifies the value of assembling disaggregated data across all metrics for past flood events, which can support the review and updating of existing key documents such as Disaster Management Plans and state-level Hazard Vulnerability Risk Assessment (HVRA) collections.A case study of the September 2018 Phojal Nalla flood (F124) illustrates the potential for developing more detailed records of contemporary events. The comparison between real-time social media data and field reconnaissance conducted a month later revealed the residual capacity for technical knowledge and collaboration across sectors.

This case also underscored the role of digital technology, including social media imagery, videos, mobile applications, and emerging AI capabilities, in capturing and evaluating flood processes and impacts. Such technologies enable decentralized and local community engagement, fostering ownership of hazard and disaster knowledge at the local level.However, access to historical archives remains inconsistent and often inefficient, with many collections still bound by paywalls, which can inhibit progress in disaster risk reduction and sustainable development. While digitization and open access collections are on the rise, many historical data collections remain inaccessible. There is a pressing need for improved inter-agency connectivity to facilitate better access to public archive collections. Long-term research funding is also necessary to support the systematic review of archive materials in alignment with global challenges.Disaster risk challenges are particularly pronounced in mountain environments and across Asia, where floods pose a significant hazard and contribute to disaster losses. International DRR efforts, including the UNDRR Sendai Framework, have identified gaps in disaster loss databases, especially at subnational levels. Therefore, developing methodologies for the systematic assembly and analysis of disaggregated.