Spatiotemporal Drought Risk Assessment Considering Resilience and Heterogeneous Vulnerability Factors: Lempa Transboundary River Basin in The Central American Dry Corridor

Abstract

Drought characterization and risk assessment are of great significance due to drought’s negative impact on human health, economy, and ecosystem. This paper investigates drought characterization and risk assessment in the Lempa River basin in Central America. We applied the Standardized Evapotranspiration Deficit Index (SEDI) for drought characterization and drought hazard index (DHI) calculation. Although SEDI’s applicability is theoretically proven, it has been rarely applied. Drought risk is generally derived from the interactions between drought hazard (DHI) and vulnerability (DVI) indices but neglects resilience’s inherent impact. Accordingly, we propose incorporating DHI, DVI, and drought resilience index (DREI) to calculate drought risk index (DRI). Since system factors are not equally vulnerable, i.e., they are heterogeneous, our methodology applies the Analytic Hierarchy Process (AHP) to find the weights of the selected factors for the DVI computation. Finally, we propose a geometric mean method for DRI calculation. Results show a rise in DHI during 2006–2010 that affected DRI. We depict the applicability of SEDI via its relationship with El Nino-La Nina and El Salvador’s cereal production. This research provides a systematic drought risk assessment approach that is useful for decision-makers to allocate resources more smartly or intervene in Drought Risk Reduction (DRR). This research is also useful for those interested in socioeconomic drought.

Wet-environment Evapotranspiration and Precipitation Standardized Index (WEPSI) for drought assessment and monitoring

“…Based on basin management by local authorities and physiographic characteristics, the Lempa River basin was divided into the following eight sub-basins: Lempa 1, Lempa 2, Lempa 3, Guajillo, Suquioyo, Acelhuate, SS6, and SS3 (Figure 1). Khoshnazar et al (2021aKhoshnazar et al ( , 2021b showed that the WEAP-derived variables are reliable for drought assessment in the Lempa River basin. For the description of the validation and calibration procedure of the model, interested readers are referred to our previous publication (Khoshnazar et al 2021a(Khoshnazar et al , 2021b.…”

“…Khoshnazar et al (2021aKhoshnazar et al ( , 2021b showed that the WEAP-derived variables are reliable for drought assessment in the Lempa River basin. For the description of the validation and calibration procedure of the model, interested readers are referred to our previous publication (Khoshnazar et al 2021a(Khoshnazar et al , 2021b.…”

“…In this order, the daily datasets of wind speed (u a ), net shortwave radiation (R S, net ), and vapor concentration (c a ) for 31 years and for each sub-basin are used to calculate the monthly average of these three inputs. The meteorological data u a , R S, net , and c a were retrieved from MARN (2019a) and Khoshnazar et al (2021aKhoshnazar et al ( , 2021b. The ranges of the obtained b values are validated by comparing them with the values available in the literature (Aminzadeh et al 2016).…”

“…This raises doubts about the use of P-T model outputs without calibration of its coefficient (Aminzadeh & Or 2014). Accordingly, we used an asymmetric Complementary Relationship (CR) to obtain ET w using ET a and ET p , based on our reliable data (Khoshnazar et al 2021a(Khoshnazar et al , 2021b. To evaluate the performance of WEPSI, we first compared its results with both well-known drought indices (SPI, SPEI), as well as with the Standardized Runoff Index (SRI).…”

Spatio‐temporal drought susceptibility assessment of Ken River Basin, Central India, and its evaluation through river's morphometry

“…Quantitatively, it may be defined by its effects as a dry period of sufficient length and severity to induce a least partial crop failure or impair the ability to fulfil average water demand (Rogers, 1971, p.118). Drought is a complex climatic phenomenon that harms the ecosystem and anthropogenic activities, including agriculture, service, and production sectors (Gopinath et al, 2015; Khoshnazar et al, 2021).…”