2021年12月9日 · Due to its arid and semi-arid climate, Iran is exposed to such drought tensions. Therefore, the present study monitored drought events in Iran by using SPI and SPEI for a 60-year period (1960–2019), proposing a model for drought management to minimize drought damages by implementing drought management measures.

Using a 50-year (1971–2020) time series of multivariate Standardized Precipitation-Evapotranspiration Index (SPEI) data (3, 6, 9, and 12-month timescales), the study employs Mann-Kendall, modified Mann-Kendall, and Sen's slope analyses to determine drought trends, examines spatial patterns using Severity Area Frequency (SAF) curves, and finally,...

2024年3月1日 · Based on the SPEI, Iran has experienced mild to extreme droughts throughout the country, with an average duration (DD) of 4 to 16 months, an average severity (DS) of 3 to 13, and an average intensity (DI) of 0.5 to 0.7.

2024年11月20日 · We examined the responses of three natural vegetation types (forest, grassland, and shrubland) to drought conditions across Iran using the Normalized Difference Vegetation Index (NDVI) and the Standardized Precipitation Evapotranspiration Index (SPEI) at different time scales and temporal lags from 2001 to 2022.

5 天之前 · Drought is a climate risk that affects access to safe water, crop development, ecological stability, and food production. Therefore, developing drought prediction methods can lead to better management of surface and groundwater resources. Similarly, machine learning can be used to find improved relationships between nonlinear variables in complex systems. Initially, the standardized ...

2021年4月12日 · The RDI, SPEI and SPI were investigated because they represent three of the strongest and newest drought indices used in various recent studies worldwide. They also employ more effective climatic parameters for drought calculation than other indices.

2025年2月24日 · This study addresses this gap through two key contributions: (1) comprehensive assessment of CanCM3 and CanCM4 models from the NMME system across four semi-arid to arid basins in Iran and (2) implementation of the standardized precipitation evapotranspiration index (SPEI) for assessing drought prediction accuracy, which provides a more nuanced ...

Evapotranspiration Index (SPEI) in four scales of 3, 6, 12, and 24 months, which represent meteorological, agricultural, hydrological, and socio-economic droughts. To calculate the SPEI, the precipitation variable (P) is analyzed with the cumulative difference between P and potential evapotranspiration (PET). In other words,

2024年11月5日 · In this research, meteorological drought monitoring was conducted using the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) drought indices at 34 synoptic stations of the Karkheh watershed in …

2022年2月18日 · The Standardized Precipitation-Evapotranspiration Index (SPEI) is used for the analysis and monitoring of drought events. SPEI is calculated from difference between precipitation (P) and potential evapotranspiration (PET).