Detection of Drought Events in Setúbal District: Comparison between Drought Indices

Silva, T.; Pires, Vanda; Cota, Tânia; Silva, Álvaro

doi:10.3390/atmos13040536

Cited by 5 publications

(3 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One of the very common methods for calculating SPI and SPEI is the use of software packages such as the SPEI package in R studio (Silva et al 2022;Mirgol et al 2021), which strictly follows a xed mean method. And so, the user should be cautioned on the reliability of drought intensities for years early in the record, as these will be relative to meteorological conditions of the subsequent years and not their own historical ranges.…”

Section: Discussionmentioning

confidence: 99%

Between Fixed and Extending Means for Quantifying Historical Drought Events

Al-Kilani

Al-Bakri

Rahbeh

2022

Preprint

View full text Add to dashboard Cite

Drought analysis has become an essential task, due to the impacts of drought on global food security and all aspects of human life. However, drought monitoring does not follow a specific formula but is more a process, thus it is important to examine the details accounted by using different approaches. The Standardized Precipitation Index (SPI), the most widely used for quantifying drought, represents drought intensity for a given time window based on a long-term precipitation mean for a time series. This paper briefly discusses the use of “fixed” or “extending” means; a meteorologist or a webapp recording drought in real time and documenting values in a fixed archive may be using an extending mean, as their long-term mean may change each subsequent year. Meanwhile, someone calculating SPI for historical years may consider that the mean precipitation time series up to his current time as the long term “fixed” mean. In this paper, the 3-month SPI for Al-Mafraq in Northern Jordan was calculated for the period 2011 – 2019, once using a fixed mean, and once using an extending mean method. The results show that no considerable difference in values can be detected (mean absolute error = 2%), but different drought categories may result from the two methods, particularly in the beginning of the time series. This paper strongly suggests that all details involved in calculating drought indices should be communicated when sharing drought-related data, and some terminology should be agreed upon. This paper also presents some suggestions when considering an approach or software for drought analysis and quantifying historical drought.

show abstract

Section: Discussionmentioning

confidence: 99%

Between Fixed and Extending Means for Quantifying Historical Drought Events

Al-Kilani

Al-Bakri

Rahbeh

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…The commonly used drought indices mainly include the Standardized Precipitation Index (SPI) [5], Palmer Drought Severity Index (PDSI) [6], and Standardized Precipitation Evapotranspiration Index (SPEI) [7]. The SPI with multiple time scales has been widely used for meteorological drought monitoring, but SPI only considers precipitation and ignores the effect of surface evapotranspiration, which is not conducive to characterizing monthly drought variations [8]. Although PDSI takes into account the impact of evapotranspiration on surface water balance, its applicability is limited by its large data requirement and the fact that some parameters can only be calculated empirically [9].…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Variability Characteristics and Applicability of SPEI in Mainland China from 1985 to 2018

et al. 2023

View full text Add to dashboard Cite

Drought is one of the most destructive natural disasters in China and can cause serious environmental and socio-economic impacts. Based on monthly precipitation and temperature data from 571 meteorological stations, the Standardized Precipitation Evapotranspiration Index (SPEI) was calculated on a 12-month scale (SPEI-12) from 1985 to 2018 in mainland China, and it was compared with the records of the Bulletin of Flood and Drought Disasters in China to verify its drought monitoring accuracy. Then, run theory was used to explore in depth the spatiotemporal distribution of drought characteristics and trends in various climatic sub-regions. The results showed that: (1) the comparison with the Bulletin of Flood and Drought Disasters in China indicated that the results of SPEI-12 monitoring drought had high accuracy and could identify drought events in mainland China. (2) About 70% of the regions in mainland China experienced droughts more than 50 times, and about 43% of the regions had drought durations of between 100 and 110 months. Nearly 11% of the regions had drought severities of more than 130, which were mainly located in the Northwest Desert (NWC), the southern part of Northeast China (NEC), and the western part of North China (NC). (3) In the past 34 years, the droughts in the Northwest Desert (NWC), the western part of Inner Mongolia (IM), and the Qinghai-Tibet Plateau (TP) showed an aridity trend, while the droughts in South China (SC) and eastern Central and South China (CSC) presented a mitigation tendency. (4) Specifically, the droughts in South China (SC) were more influenced by precipitation, while those in the Northwest Desert (NWC) and Northeast China (NEC) were influenced by temperature and potential evapotranspiration, and the evolution of drought in North China (NC) and the Qinghai-Tibet Plateau (TP) was mainly influenced by soil moisture. The study could provide scientific guidance and a reference for drought response and sustainable development in China.

show abstract

“…The logical precedence of one index to the other is not always observed, which may be due to the use of different input data (models and satellite observations) and different spatial scales [29]. The correlations between drought indices in specific regions can be used to examine the relationship between various types of droughts or to seek interactions and feedback mechanisms between these drought types [31][32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Toward a Redefinition of Agricultural Drought Periods—A Case Study in a Mediterranean Semi-Arid Region

Oukaddour,

Le Page,

Fakir

2023

Remote Sensing

View full text Add to dashboard Cite

Drought is a powerful natural hazard that has significant effects on ecosystems amid the constant threats posed by climate change. This study investigates agricultural drought in a semi-arid Mediterranean basin through the interconnections among four indices: precipitation (meteorological reanalysis), vegetation development, thermal stress, and soil water deficit (remote sensing observations). While drought seems to be a clear concept with effective assessment tools (e.g., SPI and SPEI), the definition of drought periods is blurrier. This article examines the main drivers of agricultural drought, precipitation, soil moisture deficit, incipient vegetation development, and rising soil surface temperature. Their temporal connections in various agrosystems of the basin and the determination of drought periods by revisiting the run theory were investigated. The Pearson correlations at different spatial scales showed a medium to low level of agreement between the indices, which was explained by the geographical heterogeneity and the climatic variability between the agrosystems within the basin. It was also shown that the cascade of impacts expected from lower precipitations was revealed by the cross-correlation analysis. The connection between precipitation deficit and vegetation remains significant for at least one month for most pairs of indices, especially during drought events, suggesting that agricultural drought spells can be connected in time through the three or four selected indices. Short-, mid-, and long-term impacts of precipitation deficiencies on soil moisture, vegetation, and temperature were revealed. As expected, the more instantaneous variables of soil moisture and surface temperature showed no lag with precipitation. Vegetation anomalies at the monthly time step showed a two-month lag with a preceding effect of vegetation to precipitation. Finally, the determination of drought events and stages with varying thresholds on the run theory showed large variability in duration, magnitude, and intensity according to the choice of both normality and dryness thresholds.

show abstract

Detection of Drought Events in Setúbal District: Comparison between Drought Indices

Cited by 5 publications

References 31 publications

Between Fixed and Extending Means for Quantifying Historical Drought Events

Between Fixed and Extending Means for Quantifying Historical Drought Events

Analysis of the Variability Characteristics and Applicability of SPEI in Mainland China from 1985 to 2018

Toward a Redefinition of Agricultural Drought Periods—A Case Study in a Mediterranean Semi-Arid Region

Contact Info

Product

Resources

About