Seasonal Drought Events Research Articles

Global eight drought types: Spatio-temporal characteristics and vegetation response

The traditional classification of drought events into seasonal and flash types oversimplified the complexity and variability of global drought phenomena, limiting a deeper understanding of drought characteristics and their impacts on vegetation. To address this issue, soil moisture percentile methods and the Soil Moisture Anomaly Percentage Index (SMAPI) were employed to create time series for flash drought (FD) and seasonal drought (SD) events globally from 1981 to 2020. A novel categorization framework was proposed to subdivide the two basic drought categories into eight distinct drought types using a set relationship identification method. The results showed fluctuating trends in the frequencies of Independent FD and Inclusion FD, which declined rapidly after 2011 at rates of 0.05 and 0.04 times/year, respectively. Independent FD frequency was highest in humid areas and decreased with increasing aridity. The spatial distributions of Inclusion FD and SD were similar, with both frequencies highest in extremely arid areas and decreasing with increasing humidity. The frequency of Independent SD, which peaked in semi-arid areas, increased significantly after 2011 at a rate of 0.01 times/year. The occurrence of FD evolving into SD or emerging at the end of SD was rare, with a global average of 0.46 events/decade and little spatial variation. Between 1981 and 2020, FD showed a U-shaped trend in drought duration, while SD showed no clear pattern. The duration of FD showed little difference across arid and humid zones, but the duration of SD decreased significantly with increasing humidity. Vegetation responses to drought varied, with arid regions showing longer response time compared to humid regions. A positive correlation between temperature and solar-induced chlorophyll fluorescence (SIF) during droughts was observed, while precipitation generally showed a negative correlation with SIF. Radiation had a minimal effect on SIF during droughts. The study offered a comprehensive categorization of drought events, enhancing our understanding of their spatiotemporal characteristics and vegetation responses on a global scale.

An innovative method integrating run theory and DBSCAN for complete three-dimensional drought structures

Drought displays dynamic and uncertain spatiotemporal characteristics, thus it is typically not confined to fixed temporal-spatial boundaries. Existing drought clustering methods often involve spatially clustering drought points or grids into patches, subsequently connected over time to form three-dimensional structures. Despite this process being able to extract three-dimensional drought clusters, it is likely to overlook mild or relatively small, isolated drought patches. To overcome this limitation, this paper presented an effective method (named STD-CLUSTER) for identifying drought clusters with complete three-dimensional structures. The method initially employed run theory to extract drought events as “lines” and subsequently clustered these events using the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm. A case study on the 2006 flash drought in the Yangtze River Basin demonstrated that STD-CLUSTER successfully clustered drought events and ensured the integrity of drought clusters by considering small, isolated, or disconnected patches. Additionally, an in-depth analysis using STD-CLUSTER examined seasonal drought events in China from 1991 to 2022, identifying a total of 35 drought clusters. These clusters began and ended with small-area patches, exhibiting features of expansion, contraction, spread, merging, and splitting over time. Furthermore, seasonal changes significantly influenced the evolution of drought clusters, with affected area and severity increasing in spring and summer and decreasing in autumn and winter. The applicability of the proposed method extends beyond various geographical regions and time scales, providing effective support for comprehensively investigating the spatiotemporal evolution of drought.

Do Mature Quercus aliena Primarily Use Deep Soil Water?

Seasonal drought events induced by climate change have exacerbated the water deficit in trees. This is particularly pronounced in mature trees with considerable heights and extensive branches, where the long water transport distance leads to a reduction in hydraulic transportation efficiency. Therefore, investigating the water uptake patterns of mature trees is essential to enhance their growth and resilience to climate change. However, previous studies have predominantly focused on trees aged 10–60 years, with limited research on the water uptake patterns of trees over 60 years old. In this study, we employed hydrogen and oxygen stable isotopes coupled with the MixSIAR model to determine the water uptake patterns of mature Quercus aliena var. acuteserrata (40–60 years, 60–90 years, 120–150 years, >150 years) during the growing seasons of 2021 and 2022 in Baotianman Nature Reserve, Henan Province, China. Additionally, we utilized a random forest model to quantify the relative contributions of vegetation (fine root biomass) and soil properties (soil moisture, bulk density, total porosity, field capacity, and soil texture) to the water uptake patterns of Q. aliena. Our findings demonstrate that most mature Q. aliena predominantly extracted deep soil water (60–100 cm) in the early growing season, but shifted towards utilizing shallow soil water (0–40 cm) in the late growing season. The water uptake pattern of mature Q. aliena was primarily regulated by soil moisture. These results reveal that mature Q. aliena trees exhibit a flexible water use strategy, enabling them to cope with seasonal drought by altering the soil depth from which they extract water. In the future, in the process of the cultivation and conservation of mature oak trees, surface soil irrigation can be increased to prevent tree mortality resulting from water deficit during drought conditions.

ENSO and IOD contributions to seasonal meteorological droughts over the Yangtze River basin

AbstractThe Yangtze River basin (YRB) has experienced frequent extreme drought events in recent years. Many studies have explored the impact of anomalous tropical sea surface temperatures on seasonal meteorological droughts over the YRB, yet two critical issues remain: (1) the regimes of the El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) causing YRB droughts; (2) the timing and spatial pattern of YRB droughts caused by ENSO and IOD. To address these knowledge gaps, we employed a comprehensive investigation. First, the Severity–Area–Density (SAD) method is applied to identify seasonal drought events over the YRB during 1971–2022. Second, we utilize composite analysis to specify the effects of ENSO and IOD. Our findings indicate that YRB droughts are significantly increased in the August of combined Eastern Pacific (EP) El Niño and positive IOD developing years, October of Central Pacific (CP) El Niño developing years, January of EP La Niña years, and April of CP El Niño decaying years. Third, we conduct numerical simulations and conclude that ENSO and IOD events contribute to the YRB droughts by modulating large‐scale circulation patterns, triggering the formation of cyclones and anticyclones over the Western North Pacific (WNP) and the Tibetan Plateau, and affecting the westerlies and other water vapour transport processes. These results on the physical mechanisms causing seasonal drought in the YRB can guide drought monitoring and prediction in the region.

A simulated drier climate reduces growth and alters functional traits of Eucalyptus trees: A three-year experiment in South China

Global climate change is triggering more occurrences of drought events, which is continuously enlarging a worldwide area of arid and semi-arid regions. South China is a typical area that suffers seasonal drought events, which reduce plantation productivity and increase tree mortality. Eucalyptus is widely cultivated in South China due to its fast growing speed and high dry mass yield, but its response to severe drought stress is still not assessed. In this study, we analyzed how a 50 % throughfall reduction (TR) and season affected stand growth, foliar gas exchange parameters, leaf stomatal morphological traits, and hydraulic conductance. Three-year observations showed that TR intensified drought stress in the dry season by decreasing soil relative water content, resulting in the diameter at breast height growth, tree height growth, and stand volume growth of TR were 12.6 %, 19.0 %, and 23.7 % lower than those of the control treatment (CK), respectively. With the continuous drought, TR decreased the net photosynthetic rate, while having little effect on the transpiration rate and water use efficiency. Photosynthetic pigment analysis revealed a significant interaction between throughfall reduction and season, TR markedly decreased photosynthetic pigments during the wet season. Hydraulic conductivity declined by TR, which primarily existed during the dry season. To limit water loss, Eucalyptus adapted to drought stress by altering these functional traits, which were not entirely consistent with the drought resistance mechanisms of other tree species. Overall, our study indicated that the simulated drier climate included growth decline and variation in functional traits of Eucalyptus trees in South China. This study is important for understanding the drought resistance mechanisms of Eucalyptus, as well as predicting the risk of declining Eucalyptus timber production owing to global climate change.

The regional characteristics of meteorological drought event and its multidimensional factors measurement by daily SPEI in Guangxi, China

The frequent occurrence of extreme drought events in Guangxi has caused huge losses to human beings and economy in the region for many years. For fine identification of drought evolution characteristics, this study adopted the objective identification method of regional extreme events (OITREE) to carry out the comprehensive feature identification involving multidimensional elements such as intensity, duration and area of meteorological drought events based on the daily standardized precipitation evapotranspiration index (SPEI) data of Guangxi from 1979 to 2018a. By comparing the evolution characteristics of drought elements identified by grid SPEI statistical analysis and OITREE, a comprehensive analysis framework for drought characteristics of multidimensional factor’s measurement is formed in this study. Specifically, the grid analysis is more convenient to identify single point drought characteristics, and the OITREE method is better at describing the overall spatiotemporal evolution of drought events. The study found that flash droughts and seasonal droughts occurred alternately and were superimposed concurrently in Guangxi, and the multidimensional spatial and temporal characteristics of these two types of droughts were significantly different. In concrete terms, the average annual frequency of flash drought events in Guangxi was 2.0–3.8, the average annual duration varied from 20 to 60 d, and the concentration point of drought events had a region-wide dispersion; while the average annual frequency of seasonal drought events in Guangxi was 0.82–1.65, the average annual duration varied from 40 to 105 d, and the concentration point of drought events had a local concentration. Furthermore, for the flash drought, seasonal drought and total drought in Guangxi, the three-dimension clustering method was introduced to realize the comprehensive intensity spatial heterogeneity clustering partition and temporal heterogeneity clustering mapping of meteorological drought in Guangxi. The research results can provide important scientific support for promoting the operational risk assessment and regulation of regional drought disasters and forecasting and warning.

Current climate change impacts and risks reviewed in Africa by giving especial emphasis in Ethiopia: Short review

Climate change is a long-lasting change in the weather arrays across tropics to polls. It is a global threat that has embarked on to put stress on various sectors in the world. Climate change represents a major threat to Africa. The climate change grave consequences of a temperature increase above 1.5°C, Rainfall patterns are disrupted, glaciers are disappearing and key lakes are shrinking. In all Africa in general, and east Africa in particular is the most vulnerable continent to climate change impacts under all climate scenarios. Despite that Africa having contributed the least to global warming and having the lowest co2 emissions, the continent faces exponential collateral damage, posing systemic risks to its economies, infrastructure investments, water and food systems, public health, agriculture, and livelihoods, threatening to undo its modest development gains and slip into higher levels of extreme poverty. By 2030, 108-116 million people be exposed to sea level rise risk and Drought. Similarly Ethiopia faces numerous development challenges that exacerbate its vulnerability to climate change, including high levels of food insecurity and ongoing conflicts over natural resources. Climate resolvase projects solve problems of increases in temperature, erratic rainfall and unpredictability of seasonal rain, drought and other extreme events. Therefore it is timely call to control and work on climate smart agriculture and adaptability practices that Climate change would have not negative impacts on agriculture, livestock, water and human health in Ethiopia. Thus the present reviews aims to point out climate impact and risk management with organizing publication from concerned scholars so that make easy for researchers, implementers and police makers working on climate resilient and mitigation as well as to support researcher for father gaze ring information about disaster of climate change.

Seasonal Water Uptake Patterns of Different Plant Functional Types in the Monsoon Evergreen Broad-Leaved Forest of Southern China

The precipitation changes induced by climate warming have substantially increased extreme precipitation and seasonal drought events. Different plant functional types (PFTs) could exert an important role in resisting extreme climate. However, the patterns of plant water uptake in different PFTs remain uncertain, especially under different magnitudes of rainfall events. Here, we employed a stable hydrogen isotope (δD) to determine the water sources of different PFTs, including Castanopsis chinensis in the canopy layer, Schima superba in the canopy sublayer, Psychotria asiatica in the shrub layer, and Blechnum orientale on the forest floor in the monsoon evergreen broad-leaved forest in Dinghushan Biosphere Reserve, China. We further used a two-end linear mixing model to explore the water utilization among different PFTs. Our results revealed that precipitation and soil water before rainfall were the water sources of different PFTs. Furthermore, the proportions of precipitation utilized by S. superba in the canopy sublayer under light and moderate rainfalls were 6.9%–59.4% and 30.5%–66.3%, respectively, which were significantly higher than those of other species in both the dry and wet seasons. After heavy rainfall, the proportion of precipitation utilized by S. superba was the lowest (4.7%–26.5%), while B. orientale had the highest proportion of precipitation utilization (31.6%–91.5%), whether in the dry or wet season. These findings imply that different PFTs would compete with one another for water uptake. Especially under climate warming, the uneven distribution of precipitation would intensify the water competition among species, ultimately resulting in the plant community structure becoming much more unstable than before.

Spatiotemporal analysis of droughts characteristics and drivers in the Omo-Gibe River basin, Ethiopia

BackgroundDrought is one of the leading destructive natural disasters adversely affecting natural resources and livelihoods. Thus, this study evaluated the spatial and temporal meteorological drought characteristics and their drivers in the Omo-Gibe River basin (OGRB) from 1981 to 2017. The drought analysis used the standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) with 4- and 12-month timescales. The Mann–Kendall (MK), Sen's slope estimator, and Pettit test were used to evaluate the trend and change points of the time series. Pearson correlation was used to examine the teleconnection between large-scale global climate signals with the basin's seasonal and annual drought indices.ResultsAccordingly, extreme and severe drought events were observed in 1988, 2000, and 2009. In the basin, prolonged drought events were recorded from 2000 to 2015. The statistically significant (P < 0.05) increasing trend of seasonal and annual drought events was observed in all basin parts. However, more drought events distribution was exhibited in the south than in the north and central parts. The Sawla station (southern part) showed a higher drought frequency, ranging from 18.18 to 20.36%. The maximum intensity and peak drought events were observed in this sub-basin, with SPEI reaching − 2.27 and − 4.89, respectively. The global indices NINO3.4, SOI, and DMI are drivers for triggering the meteorological droughts in OGRB.ConclusionsSubstantial warming and erratic rainfall have made OGRB vulnerable to drought events. The intensification of droughts in the basin has also been recorded in humid parts of the basin which has a significant adverse effect on the water availability of down streams. This indicates that the observed drought intensity can increase the water deficit and other natural resources degradation. Therefore, this study provides essential information on drought characteristics for decision-makers to plan appropriate strategies for early warning systems to adapt and mitigate drought hazards in the basin.

The Kroof experiment: realization and efficacy of a recurrent drought experiment plus recovery in a beech/spruce forest

AbstractForest ecosystems play a central role in global water and carbon cycles, yet the impact of global climate change, in particular drought, on trees and forests is poorly understood. Therefore, there is an urgent need for forest‐scale experiments in improving our understanding of trees’ responses to extreme drought events and subsequent recovery under field conditions. Here, we present the design and efficacy of a novel throughfall exclusion experiment with retractable roofs in a mature forest allowing for flexible drought and recovery periods. A total of 12 plots (144 ± 26 m2 on average) with 3–7 European beech and Norway spruce trees each were established by root trenching to a depth of one meter, four years prior to the experiment. Subsequent installation of roofs (n = 6) allowed for the removal of throughfall precipitation and almost a complete non‐availability of soil water in the upper 70 cm during five subsequent growing seasons, that is, 2014–2018. This reduction in available soil water resulted in pre‐dawn leaf water potentials down to −1.8 MPa in mature trees. Stem diameter growth decreased by 30% in beech and 70% in spruce, and fine root abundance was reduced by 57% in beech and 73% in spruce compared with controls. After only one growing season, the mycorrhizal community composition changed in response to drought. Careful watering of hydrophobic forest soils in early summer of 2019 resulted in recovered pre‐dawn leaf water potentials of drought‐stressed trees within one week. Recovery of stem diameter growth, however, did not occur within the same growing season and remained reduced by 33% in beech and 69% in spruce compared with controls. The implemented throughfall exclusion system imposed recurrent seasonal drought events on a mature beech/spruce forest with high efficacy. Shifts in community composition of mycorrhizae in parallel to tree growth decline advocate for a more holistic view on forest‐scale drought and watering experiments, particularly in light of more frequently predicted drought events in future. The perennial nature of mature trees and their subsequent slow recovery from drought, that is, over multiple growing seasons, argues for more long‐term experiments that span several years.

Seasonal drought events in tropical East Asia over the last 60,000 y

The cause of seasonal hydrologic changes in tropical East Asia during interstadial/stadial oscillations of the last glaciation remains controversial. Here, we show seven seasonal drought events that occurred during the relatively warm interstadials by phytolith and pollen records. These events are significantly manifested as high percentages of bilobate phytoliths and are consistent with the large zonal sea-surface temperature (SST) gradient from the western to eastern tropical Pacific, suggesting that the reduction in seasonal precipitation could be interpreted by westward shifts of the western Pacific subtropical high triggered by changes of zonal SST gradient over the tropical Pacific and Hadley circulation in the Northern Hemisphere. Our findings highlight that both zonal and meridional ocean-atmosphere circulations, rather than solely the Intertropical Convergence Zone or El Niño-Southern Oscillation, controlled the hydrologic changes in tropical East Asia during the last glaciation.

Seasonal Patterns of Dominant Microbes Involved in Central Nutrient Cycles in the Subsurface.

Microbial communities play a key role for central biogeochemical cycles in the subsurface. Little is known about whether short-term seasonal drought and rewetting events influence the dominant microbes involved in C- and N-cycles. Here, we applied metaproteomics at different subsurface sites in winter, summer and autumn from surface litter layer, seepage water at increasing subsoil depths and remote located groundwater from two wells within the Hainich Critical Zone Exploratory, Germany. We observed changes in the dominance of microbial families at subsurface sampling sites with increasing distances, i.e., Microcoleaceae dominated in topsoil seepage, while Candidatus Brocadiaceae dominated at deeper and more distant groundwater wells. Nitrifying bacteria showed a shift in dominance from drought to rewetting events from summer by Nitrosomandaceae to autumn by Candidatus Brocadiaceae. We further observed that the reductive pentose phosphate pathway was a prominent CO2-fixation strategy, dominated by Woeseiaceae in wet early winter, which decreased under drought conditions and changed to a dominance of Sphingobacteriaceae under rewetting conditions. This study shows that increasing subsurface sites and rewetting event after drought alter the dominances of key subsurface microbes. This helps to predict the consequences of annual seasonal dynamics on the nutrient cycling microbes that contribute to ecosystem functioning.

The impact of seed deficiency on productivity and on negative drought effect in semi‐natural grassland

AbstractQuestionsVegetative re‐sprouting and recruitment from seed determine grassland recovery after severe drought, but the mechanisms determining vegetation composition are not fully understood. We ask how the timing of drought and seed availability modify the drought legacy effects on composition and function in a temperate, semi‐natural grassland.LocationNegrentino, southern Alps, Switzerland.MethodsUnder automated rainout shelters, we simulated extreme seasonal drought events in a late summer and in the following spring, added rainwater to simulate normal conditions in no‐drought controls and maintained haymaking at times of normal practice. Towards the end of the summer drought, we added seeds of ten local species in a three‐factor split‐plot arrangement with seven blocks as the replicated unit. We measured fine‐scale variation in soil depth. We assessed the biomass of graminoids and forbs at regular harvesting dates and the species frequencies of established plants and recruits before treatment start, repeating these assessments for three years thereafter. We measured the biomass proportions of post‐drought annual recruit cohorts in year 4 after drought.ResultsOne‐time seed addition augmented recruits, modified species composition and enhanced species diversity; these effects propagated to increased reproductive shoots of recruits and community biomass four years later. Single and repeated seasonal droughts only caused low adult plant mortality but clearly reduced recruitment from seed, while post‐drought establishment was slightly enhanced. Seed augmentation compensated the negative spring drought effect on forb recruits and in turn mitigated the negative impact of drought on species diversity after drought.ConclusionsOur experiment shows that seed deficiency limits productivity and that seed deficiency compensation can help to stabilize diversity and productivity in semi‐natural grassland. Releasing the current constraints of management on seed supply in grassland would therefore assist in mitigating negative drought impacts.

Prolonged seasonal drought events over northern China and their possible causes

The features and possible causes of prolonged seasonal drought (PSD) events over northern China (NC) during 1960–2012 are explored in this study using the multi‐scale standardized precipitation evapotranspiration index (SPEI). The results show that PSD events (i.e., drought events with a timescale of 9 months or less) have had a relatively high probability of occurrence from spring to autumn during the past five decades. The results of the empirical orthogonal function (EOF) analysis show that the leading mode of the SPEI09 in autumn reflects a broad pattern of drought in NC, which confirms the existence of the PSD events. Furthermore, we conclude that two factors, teleconnection patterns in the mid‐latitudes of Eurasia and transitions from La Niña to El Niño, are mainly responsible for the PSD events. On the one hand, the associated teleconnection patterns in the upper‐level troposphere show an Eurasian (EU)‐like pattern in spring, the Silk Road (SR) pattern or the circumglobal teleconnection (CGT) pattern in summer, and a Scandinavia (SCA)‐like pattern in autumn, respectively. Associated with these teleconnection patterns, descending anomalies are detected in the whole atmosphere over NC in all seasons. On the other hand, the transition from La Niña (winter) to El Niño (the following autumn) also exerts effects on the PSD through modulating the Walker circulation and the meridional vertical circulation along the coast of East Asia. However, this process is more effective in spring relative to summer and autumn. In addition, physical connections likely exist among these factors, and their combined effects, together with the insufficient moisture supply, regulate the PSD events over NC.

Analysis of Temporal Drought Characteristic Using SPI Drought Index Based on Rainfall Data in Laikipia West Sub-County, Kenya

Severe drought has affected Kenya in the past decades reducing crop yields leaving millions of people in dire need of food. Drought cycle in Kenya has reduced increasing drought frequency in the recent decades. This study assessed drought characteristics in Laikipia West sub-County which lies in a region classified as arid and semi arid. The specific objective of the study was to analyze seasonal and annual drought characteristics in Laikipia West sub-County between 1984 and 2014. The study adopted documentary review design in the data collection. Standard Precipitation Index was used during the data analysis process. The drought years identified in Laikipia West sub-County were: 1984, 1985, 1987, 1991, 1995, 1999, 2000, 2005, 2008 and 2009. The seasonal drought events shows that for the period under study Laikipia West sub-County has never experience drought during the MAM and OND seasons in the same year. This explains the importance of seasonal climate forecast to crop farmers. The study also established that the average drought cycle in the study area is 3 years. The study recommends construction of mega water reservoirs which could collect water during the wet season to be utilized during the dry seasons. The study also recommends channeling of drought information through the government agencies at the beginning of every season.

Spatiotemporal analysis of droughts using self-calibrating Palmer’s Drought Severity Index in the central region of South Africa

The loss of life and property from drought events has forced society to focus on the development of reliable early warning systems which may enable farmers and other stakeholders to correctly and timely adapt to the expected impacts of climatic hazard. However, a scientific approach to a reliable early warning system for a region requires, among others, characterisation of drought events in the region in terms of duration, magnitude, intensity and frequency using standard drought indices. Therefore, the objective of this study was to identify and characterise drought events in the Modder River basin, central region of South Africa, using a self-calibrated Palmer’s Drought Severity Index (sc-PDSI). Attempts were also made to establish a relationship between meteorological and hydrological drought events in the region. During the period of analysis, the total number of drought episodes identified in the study area ranged between eight and sixteen. It was found that the most severe drought episodes occurred during the period 1992–1995 followed by the period 1982–1987. Results of analysis of seasonal drought events in one of the quaternary catchments (C52A) revealed that peak drought events during the three summer months (November, December and January) occurred in the area in 1993. However, in terms of event magnitude and intensity, the worst drought events were recorded during the period December 1982–July 1987, followed by the event that ensued during December 1989–September 1995. Results of analysis of decadal variation of drought events showed that the number of extreme and moderate drought events recorded in the catchment showed statistically significant increasing trends during the five decades at 5 % significance level. Moreover, spectral analysis of sc-PDSI time series in the region identified periodicities in the time series ranging from 6 years (C52E) to 16 years (C52K). In terms of the spatial extent of extreme drought events, the maximum areal coverage (91 %) was recorded in November 1998, followed by December 1998 and December–January 1999 (43 %). Analysis of the relative frequency of droughts of varying categories revealed that extreme drought events were most prevalent in the C52E (2.72 %) quaternary catchment, followed by C52C (2.21 %). The study also found an average lag time of 10 months between the onsets of meteorological and hydrological drought events in the region.

Characterization of seasonal droughts in Balochistan Province, Pakistan

Droughts are usually destructive when they coincide with crop growing season. Cross-seasonal drought characterization can better inform drought mitigation efforts. The present study relies on precipitation data from the Global Precipitation Climatology Centre to reconstruct historical droughts during different climatic seasons in Balochistan province, Pakistan. We identified seasonal drought events based on the standardized precipitation index for each season. The distribution of reconstructed drought events was analyzed to determine their seasonality and to calculate their return periods. Using these return periods, we constructed seasonal drought maps. The study revealed that early winter droughts are frequent in the north of Balochistan, where the return periods of moderate, severe, and extreme droughts are 7, 21, and 55 years, respectively. Severe and extreme late winter droughts are more frequent in the upper north, with return periods of 16 and 35 years, respectively. Early summer droughts occur more frequently in the east, returning every 8, 20, and 60 years; late summer droughts occur in the northeast, with moderate, severe, and extreme droughts returning every 8, 22, and 65 years, respectively. Rabi droughts are more frequently in the central and northeaster regions of Balochistan, while more severe kharif droughts occur primarily in the eastern regions. These seasonal droughts were found to be positively correlated with variations in the seasonal rainfall throughout the study area. The findings of this study contribute to our understanding of seasonal drought characteristics and help to inform drought mitigation planning.