EGU23-16949, updated on 26 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Effective hydrological drought monitoring depending on the catchment's hydrological regime

Oscar Manuel Baez Villanueva1 and Mauricio Zambrano-Bigiarini2,3
Oscar Manuel Baez Villanueva and Mauricio Zambrano-Bigiarini
  • 1Institute for Technology and Resources Management in the Tropics and Subtropics (ITT), TH Köln, Cologne, Germany
  • 2Department of Civil Engineering, Universidad de la Frontera, Temuco, Chile
  • 3Center for Climate and Resilience Research, Universidad de Chile, Santiago, Chile

There is an expected increase in the occurrence and severity of hydrometeorological extremes in many regions worldwide. Current research indicates that despite a positive trend in reducing drought impacts, most regions still need to adapt their monitoring practices to cope with projected drought events effectively. On the other hand, we still need a clear understanding of how a changing climate can modify the hydrological regime of catchments in the future. Therefore, it is essential to understand which drought indicators are relevant to monitoring catchments with different hydrological regimes.

Therefore, this study aims to elucidate which drought indices are required to effectively monitor hydrological drought depending on the catchment’s hydrological regime, using  100 near-natural Chilean catchments with contrasting climatic conditions and hydrological regimes as a case study. For this purpose, different drought indices were computed at different temporal scales: SPI and SPEI at 3, 6, 9, 12, and 24 months; the Empirical Standardised Soil Moisture Index (ESSMI) at 3, 6, and 12 months; and a standardised snow water equivalent index (SSWEI) at 3 and 6 months. State-of-the-art gridded datasets used for computing the drought indices were: CR2MET v2.5 (a Chilean dataset based on ERA5) for precipitation and potential evapotranspiration; ERA5, ERA5-Land, and SMAP (L3 and L4) for soil moisture; and ERA5 and ERA5-Land for snow water equivalent. These indices were evaluated against the Standardised Streamflow Index (SSI) to select indices that are able to effectively monitor hydrological droughts, considering different hydrological regimes. A cross-correlation analysis and an event coincidence were used to assess which index had the highest correlation with SSI. Results showed that the indices and temporal scales used to effectively monitor hydrological droughts changed according to the catchment's hydrological regime. The results of the present work are pivotal for water managers as they provide insights on how the hydrological regime of the catchments should be considered in drought monitoring.

How to cite: Baez Villanueva, O. M. and Zambrano-Bigiarini, M.: Effective hydrological drought monitoring depending on the catchment's hydrological regime, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-16949,, 2023.