Application of meteorological drought for assessing watershed health using fuzzy-based reliability, resilience, and vulnerability

Mahmood Fooladi, Mohammad H. Golmohammadi, Hamid R. Safavi, Vijay P. Singh

Abstract

Extreme events, such as droughts, lead to considerable detrimental impacts on watersheds, especially in arid and semi-arid regions. To develop measures for mitigation of drought and formulate management plans, efficient methods are needed for assessing watershed health and risk. This study developed a Reliability, Resilience, and Vulnerability-based fuzzy framework (DRRV-Fuzzy) compared to the traditional method (DRRV-Fixed) for assessing watershed health and risk under drought. To this aim, the Standardized Precipitation-Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI) of meteorological drought were employed to evaluating the proposed framework in the Zayandehrud river basin of Iran from 1983 to 2017. Also, to examine the role of both traditional and fuzzy methods for extreme droughts, the 2000 to 2017 period has been chosen to evaluate Rel, Res, and Vul indicators in the study area. The proposed framework yielded more efficient and different results from the traditional method. Results revealed that: (1) because of the evapotranspiration effects in SPEI drought index, vulnerability is expected to be larger than over SPI index, which fuzzy approach can clarify it better; (2) the fuzzy method can quantify the categories of failure types of drought in the watershed and detected drought failures relative to the threshold value; (3) the fuzzy framework was more efficient than the fixed approach for quantifying watershed health and drought risk, which was developed by DRRV metrics; (4) according to both fixed and fuzzy techniques, the health of Zayandehrud River basin was affected by drought, especially at a higher time scale (12-month time).

Keywords

Reliability, Resilience, Vulnerability, Fuzzy method, Watershed health, Drought risk.

https://doi.org/10.1016/j.ijdrr.2021.102616