integrating multi-hazard risk assessment and climate change projections for adaptive water resource management: a case study of the ajichai river basin

This research develops an in-depth hydrologic risk analysis for the ajichai river catchment by using the flow series at the veniar station for the period from 1966 to 2013. a complete methodology was used to analyze the flood and drought risks, as well as the long-term trends and eventual impact of climate change on the flow regime of the river. annual maximum flow data were fitted using the generalized extreme value distribution and provided a 100-year flood estimate of 224.9 m3/s, 95% ci: 177.7-272.1 m3/s. a significant decreasing trend in annual mean flow was detected: sen’s slope -0.25 m3/s/year, p < 0.01. the low-flow frequency analysis yielded a high value of the coefficient of correlation r = 0.98, which explained the duration and severity relationship of droughts described by the power-law equation s = 0.0012 × d1.85. it is evident from the seasonal analysis that during the spring season, 68.7% of the annual maximum flow occurs with an average peak flow of 89.6 m3/s. there was a very important shift in the timing of the floods, a 26-day earlier date of annual maximum flows between the 1970s and the 2010s. it quantified the relationship between annual maximum flow and precipitation: q = 0.0015×p2.1, r2 = 0.88, underlining the probable impact of the changes in precipitation on flood risk. in fact, it exposes the complex and dynamic hydrological environment of the ajichai river basin and signifies a requirement for adaptable water management that concurrently contributes to decreasing flood and drought risks in response to climate change.