Future Meteorological Drought Research Articles

Interactive Changes in Climatic and Hydrological Droughts, Water Quality, and Land Use/Cover of Tajan Watershed, Northern Iran

In response to novel and complex uncertainties, the present research is conducted to characterize the most significant indicators of watershed health including drought, water quality, and vegetation for the Tajan watershed, Mazandaran, Iran. The Standardized Precipitation Index (SPI) and Streamflow Drought Index (SDI) are, respectively, used to quantify the meteorological and hydrological droughts in the present (1993–2020) and future (2023–2050) employing optimistic RCP2.6 and pessimistic RCP8.5 scenarios. To concoct discharge data for the future, IHACRES v1.0 software is used with a Nash–Sutcliffe coefficient (NSE) of 0.48 and a coefficient of determination (R2) of 0.58. Maps of land use and Normalized Difference Vegetation Index (NDVI) are also prepared using Landsat images. Subsequently, the surface water quality is assessed using AqQA v1.1.0 software. The results show the difference in the severity of future meteorological droughts in different stations. In addition, the predominance of non-drought (SDI≥0) or mild drought (−1 ≤ SDI < 0) is indicated for future hydrology. The land use changes show a decrease in rangeland (−5.47%) and an increase in residential land (9.17%). The water quality analysis also indicates an increase in carbonate ions in the watershed outlet. Communicating the relationships between study indicators, which is a big gap in the current watershed management approach, avoids future failures and catastrophes.

Spatial-temporal evolutions of historical and future meteorological drought center in Beijing area, China

Drought has received increased attention due to its serious disasters and significant impacts. The drier areas usually deserve more attention, and thus the drought center, the area where high drought values aggregate in a region, was defined here. This study aims to access the the evoluations of three-dimensional (i.e., latitude, longitude, and time) drought center in both space and time over Beijing area. The observed meteorological data from 1961 to 2016 and the future data from 2031 to 2080 derived from the optimal GCM model were used to calculate the Standardized Precipitation and Evapotranspiration Index. A normalized drought comprehensive feature (NCf) was constructed using the entropy weight method to fully assess the drought, and then the three-dimensional drought center, the high clustering region for NCf in a given space and time, was determined by employing the K-means algorithm. The results showed that, 80% of historical drought centers were dominated by high-grades and above. The 2000s experienced the most serious drought, with larger drought center areas and greater drought center grades. The future droughts were projected to alleviate in Beijing area, with decreased drought duration, frequency, intensity, severity, and weak drought center grade. 76% of future drought centers were predicated to be middle-grades and below. The high-grade drought centers would be less and the center areas would be smaller, although the center areas for the extreme-grade would be larger. The 2060s was projected to experience the worst drought in the future. In the northern mountainous areas, the future drought may intensify with more statistically significant changes points and more centroids of drought centers (45%) migrating there.

Future climate-driven drought events across Lake Urmia, Iran.

Climate change has increased the vulnerability of arid and semi-arid regions to recurrent and prolonged meteorological droughts. In light of this, our study has sought to assess the nature of future meteorological drought in Lake Urmia basin, Iran, within the context of future climate projections. To achieve this, data from 54 general circulation models (GCMs) was calibrated against both in situ and Global Precipitation Climatology Centre datasets. These GCMs were then employed to project drought conditions expected over 2016-2046 under RCP2.6 and RCP8.5 as the most optimistic and pessimistic scenarios, respectively. To provide a comprehensive analysis, these RCPs were combined with two different time scale Standardized Precipitation Index (SPI), leading to eight different scenarios. The SPI was calculated over two temporal scales for the past (1985-2015) and future (2016-2046), including the medium-term (SPI-6) and long-term (SPI-18) index. Results showed that while precipitation is expected to increase by up to 34%, parts of the basin are projected to face severe and prolonged droughts under both RCPs. The most severe drought event is expected to occur around 2045-2046 under the most pessimistic RCP8.5 scenario. Severe droughts with low frequency are also anticipated to increase under other scenarios. By characterizing meteorological drought conditions for Lake Urmia basin under future climate conditions, our findings call for urgent action for adaptation strategies to mitigate the future adverse effects of drought in this region and other regions facing similar challenges. Overall, this study provides valuable insight into the impacts of climate change on future droughts that can adversely influence water resources in arid and semi-arid regions.

Prospective Evolution of Meteorological Drought in the Haihe River Basin and Its Connection With Large‐Scale Atmospheric Circulations Using CMIP6 Multimodel Ensemble

AbstractClimate change modifies monsoon rainfall patterns, leading to significant impacts on future meteorological droughts. This study investigated the spatiotemporal pattern of future precipitation, drought features, and the dynamic mechanisms governing their evolution induced by teleconnected atmospheric circulation in the Haihe River Basin, situated in the north China monsoon region. The investigation was conducted under SSP1‐2.6, SSP2‐4.5, and SSP5‐8.5 scenarios of CMIP6, utilizing the Standardized Precipitation Index and an improved run theory at seasonal and annual scales. The findings revealed that high‐emission scenarios cause a wetter climate trend, particularly in autumn and winter, related to the attenuation of the East Asian Trough from climate warming. The uneven intra‐annual precipitation patterns within the basin, induced by the Asian monsoon climate, are expected to improve in the far future, particularly under the SSP2‐4.5 scenarios. The drought frequency, intensity, and duration of future meteorological drought are expected to improve compared to historical conditions under all three scenarios. SSP2‐4.5 shows the shortest duration and lightest intensity of annual droughts. Extreme droughts are primarily driven by strong subsidence with low‐level moisture divergence. However, in the far future, the eastward shift of the western Pacific subtropical high results in reducing moisture transport from the western Pacific, leading to increasing contribution of advection term to atmospheric drying, particularly under the SSP1‐2.6. In winter, the increase in radiative forcing leads to enhanced evapotranspiration from the Eurasian continent, providing additional moisture and alleviating drought, especially in the far future under the SSP1‐2.6 and SSP2‐4.5 scenarios.

Projection of Future Meteorological Droughts in Lake Urmia Basin, Iran

Future changes (2015–2100) in precipitation and meteorological droughts in Lake Urmia Basin were investigated using an average mean ensemble of eight general circulation models (GCMs) with high-resolution datasets in socioeconomic pathway scenarios (SSPs) from the Coupled Model Intercomparison Project (CMIP6). In order to project the drought, the standardized precipitation index (SPI) was calculated. Overall, the results revealed that precipitation in Lake Urmia Basin will decrease by 3.21% and 7.18% in the SSP1-2.6 and SSP5-8.5 scenarios, respectively. The results based on 6-month-timescale SPI indices projected more “Extremely dry” events in SSP5-8.5 scenarios. The frequency of “Extremely dry” months in SSP5-8.5 compared to SSP1-2.6 is expected to increase by 14, 7, 14, 10, 5, 14, and 7 months for the Mahabad, Maragheh, Saqez, Sarab, Tabriz, Takab, and Urmia stations, respectively. In contrast, the frequency of “Extremely wet” months will decline for all stations in Lake Urmia Basin. The results of this study provide useful insight for considering drought prevention measures to be implemented in advance for Lake Urmia Basin, which is currently experiencing various environmental issues.

Future meteorological drought conditions in southwestern Iran based on the NEX-GDDP climate dataset

Future meteorological drought conditions in southwestern Iran based on the NEX-GDDP climate dataset

Possible Future Climate Change Impacts on the Meteorological and Hydrological Drought Characteristics in the Jinghe River Basin, China

Revealing the impact of future climate change on the characteristics and evolutionary patterns of meteorological and hydrological droughts and exploring the joint distribution characteristics of their drought characteristics are essential for drought early warning in the basin. In this study, we considered the Jinghe River Basin in the Loess Plateau as the research object. The standardized precipitation index (SPI) and standardized runoff index (SRI) series were used to represent meteorological drought and hydrological drought with monthly runoff generated by the SWAT model. In addition, the evolution laws of the JRB in the future based on Copula functions are discussed. The results showed that: (1) the meteorological drought and hydrological drought of the JRB displayed complex periodic change trends of drought and flood succession, and the evolution laws of meteorological drought and hydrological drought under different spatiotemporal scales and different scenario differ significantly. (2) In terms of the spatial range, the JRB meteorological and hydrological drought duration and severity gradually increased along with the increase in the time scale. (3) Based on the joint distribution model of the Copula function, the future meteorological drought situation in the JRB will be alleviated when compared with the historical period on the seasonal scale, but the hydrological drought situation is more serious. The findings can help policy-makers explore the correlation between meteorological drought and hydrological drought in the background of future climate change, as well as the early warning of hydrological drought.

Projection of future extreme meteorological droughts using two large multi-member climate model ensembles

Several studies have looked at the evolution of droughts in a changing climate in various locations and have typically found that droughts are expected to become more severe in the future. However, relatively little work has been done on extreme droughts. This study focuses on the evolution of extreme meteorological droughts over near (2036–2065) and far (2071–2100) future time periods. Monthly precipitation from two large multi-member climate model ensembles: the Canadian Earth System Model (CanESM2) 50-member ensemble and the Community Earth System Model (CESM1) 40-member ensemble, was used to calculate the Standard Precipitation Index (SPI) to quantify and explore the evolution of future meteorological droughts. The use of these large ensembles allows for the calculation of the 20- and 100-year droughts return period and offers a unique perspective into those rare events.Both climate models project increases in extreme meteorological drought frequency over many of the world’s regions. The spatial patterns of regions with worsening droughts generally match those of projected change in mean annual precipitation, although the former is more extensive, indicating that changes in internal variability will increase drought frequency even in some regions projected to see increased mean annual precipitation. The projected increase in meteorological drought frequency is more significant for short-term JJA droughts, and for the larger return periods. Large increases in frequency are observed in many regions, all the way up to 20 times for the historical100-year JJA drought indicating a return period shift from 100 to 5 year.Considering the significant predicted increases in temperature, it follows that future changes for both agricultural (soil water deficit) and hydrological droughts (low stream levels), which result from the interaction between precipitation deficit and temperature (as well as other variables), will be even more severe.

Analysis of Future Meteorological Drought Changes in the Yellow River Basin under Climate Change

The Yellow River Basin is an important economic belt and key ecological reservation area in China. In the context of global warming, it is of great significance to project the drought disaster risk for ensuring water security and improving water resources management measures in practice. Based on the five Global Climate Models (GCMs) projections under three scenarios of the Shared Socioeconomic Pathways (SSP) (SSP126, SSP245, SSP585) released in the Sixth Coupled Model Intercomparison Project (CMIP6), this study analyzed the characteristics of meteorological drought in the Yellow River Basin in combination with SPEI indicators over 2015–2100. The result indicated that: (1) The GCMs from CMIP6 after bias correction performed better in reproducing the spatial and temporal variation of precipitation. The precipitation in the Yellow River Basin may exhibit increase trends from 2015 to 2100, especially under the SSP585 scenario. (2) The characteristics of meteorological drought in the Yellow River Basin varied from different combination scenarios. Under the SSP126 scenario, the meteorological drought will gradually intensify from 2040 to 2099, while the drought intensity under SSP245 and SSP585 scenarios will likely be higher than SSP126. (3) The spatial variation of meteorological drought in the Yellow River Basin is heterogeneous and uncertain in different combination scenarios and periods. The drought tendency in the Loess Plateau will increase significantly in the future, and the drought frequency and duration in the main water conservation areas of the Yellow River Basin was projected to increase.

Changes in drought characteristics based on rainfall pattern drought index and the CMIP6 multi-model ensemble

Drought monitoring and understanding of spatiotemporal patterns of drought characteristics are beneficial for sustainable agricultural water management at a regional scale. Changes in rainfall and drought patterns in future could impact decision-making in water resources allocation. The impacts of potential climate change on future meteorological droughts could be better analysed by utilizing an index that incorporates the number of rainy days information in addition to magnitude of rainfall to characterize the drought severity. In this study, we propose a bivariate copula-based multi-scalar rainfall pattern drought index (RPDI), a variant of the popular standardized precipitation index (SPI), and then the drought characteristics in India based on RPDI and SPI at different time scales (3-, 6- and 12-months) are analysed. When compared to RPDI, SPI underestimated drought severity and indicated low spatial heterogeneity of drought characteristics. The RPDI analysis identified changes in average drought severity and total number of drought events between two sample time slices (1920–1960 and 1961–2000) in the historical period. Future RPDI drought characteristics based on the coupled model intercomparison project phase 6 (CMIP6) multi-model ensemble under two emission scenarios known as shared socioeconomic pathways (SSPs): SSP126 and SSP245 are then computed. When drought characteristics in the near future (2020–2049) and far future (2070–2099) periods are compared with their baseline period (1985–2014) values, the results show that a significant declining trend is likely in the total number of drought events over the study region, while increases are projected in the maximum drought duration and maximum drought severity in future. Long-term drought characteristics extracted using 12-months scale RPDI, are likely to intensify in future under both scenarios. Considering the effects of erratic rainfall pattern on agricultural productivity, the RPDI drought monitoring framework could be utilized for efficient agricultural water management in future.

Spatiotemporal patterns of future meteorological drought in the Yellow River Basin based on SPEI under RCP scenarios

PurposeThe purpose of this study is to assess the spatiotemporal patterns of future meteorological drought in the Yellow River Basin under different representative concentration pathway (RCP) scenarios.Design/methodology/approachDelta method is used to process the future climate data of the global climate models, then analyzed the spatiotemporal variation trend of drought in the Yellow River Basin based on standardized precipitation evaporation index (SPEI) under four RCP scenarios.FindingsThis research was funded by the National Natural Science Foundation of China (41901239), Soft Science Research Project of Henan Province (212400410077, 192400410085), the National Key Research and Development Program of China (2016YFA0602703), China Postdoctoral Science Foundation (2018M640670) and the special fund of top talents in Henan Agricultural University (30501031).Originality/valueThis study can provide support for future meteorological drought management and prevention in the Yellow River Basin and provide a theoretical basis for water resources management.

Spatial–Temporal Assessment of Historical and Future Meteorological Droughts in China

Drought is a natural phenomenon in which the natural amount of water in an area is below the normal level. It has negative impacts on production in numerous industries and people’s lives, especially in the context of climate change. Investigating the spatial–temporal variation of drought is of great importance in water resource allocation and management. For a better understanding of how drought has changed in China from 1961 to 2020 and will change in the future period of this century (2021–2100), a spatial–temporal assessment of drought based on the standardized precipitation evapotranspiration index (SPEI) was carried out. The trends and characteristics (number, duration, and severity) of historical and future droughts in China were evaluated based on 12-month SPEI by employing the Mann–Kendall test, Sen’s slope and run theory. The similarities, differences, and spatial–temporal evolution of droughts in these two periods were analyzed. The results showed that in the historical period the number of droughts decreased gradually from the south of China to the north. Less frequent drought but with longer duration and stronger severity occurred in the northeast and the northern areas. In the future period, most parts of China are projected to suffer more severe droughts with longer duration, especially for Northeast China, North China, Qinghai–Tibetan Plateau, and Southwest China. The likely increasing severity and duration of droughts in most areas of China in the future makes it very necessary to formulate the corresponding drought prevention and relief strategies to reduce the possible losses caused by droughts.

Development of an Integrated Approach for the Assessment of Climate Change Impacts on the Hydro-Meteorological Characteristics of the Mahaweli River Basin, Sri Lanka

Climate change is increasingly sensed by nations vulnerable to water-related disasters, and governments are acting to mitigate disasters and achieve sustainable development. Uncertainties in General Circulation Models’ (GCM) rainfall projections and seamless long-term hydrological simulations incorporating warming effects are major scientific challenges in assessing climate change impacts at the basin scale. Therefore, the Data Integration and Analysis System (DIAS) of Japan and the Water Energy Budget-based Rainfall-Runoff-Inundation model (WEB-RRI) were utilized to develop an integrated approach, which was then applied to the Mahaweli River Basin (MRB) in Sri Lanka to investigate climate change impacts on its hydro-meteorological characteristics. The results for the Representative Concentration Pathway (RCP8.5) scenario from four selected GCMs showed that, with an average temperature increase of 1.1 °C over the 20 years in future (2026 to 2045), the basin will experience more extreme rainfall (increase ranging 204 to 476 mm/year) and intense flood disasters and receive sufficient water in the future climate (inflow increases will range between 11 m3/s to 57 m3/s). The socio-economic damage due to flood inundation will also increase in the future climate. However, qualitatively, the overall trend of model responses showed an increasing pattern in future meteorological droughts whereas there is uncertainty in hydrological droughts. Policymakers can utilize these results and react to implementing soft or hard countermeasures for future policymaking. The approach can be implemented for climate change impact assessment of hydro-meteorology in any other river basin worldwide.

Identification of future meteorological drought hotspots over Indian region: A study based on NEX‐GDDP data

AbstractThe present study aims to answer the following two research questions using the future outputs from 19 GCMs of the novel NASA Earth Exchange Global Daily Downscaled Projections (NEX‐GDDP) under two Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. (a) What will be the possible variability of future meteorological drought properties during the 21st century? (b) What will be the possible influence of temperature in modulating the drought properties? In order to answer the above questions, five different drought properties namely frequency, severity, duration, peak, and areal spread are analysed for future (2022–2099) using two meteorological drought indices such as Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI) for short (3‐month scale) and long (12‐month scale) term drought conditions. The essential outcomes from the study indicate a warming and wetting climate over Maharashtra during the 21st century. With an increase in monthly precipitation, severity and duration of future meteorological droughts are likely to decrease in long‐term drought condition. Conversely, in the short‐term condition, the properties are expected to increase. The drought properties like peak and areal spread are expected to increase for both short and long‐term drought conditions in most of the regions. Temperature plays a vital role in modulating the meteorological droughts, and the present study notices the same in most of the cases in all the drought properties, especially in drought severity, duration, and peak. All the division are identified as hotspot regions during the mid and later part of the 21st century for short‐term drought condition. The number of hotspot regions decreases in long‐term drought condition as compared to short‐term drought condition.

Projections of future meteorological droughts in China under CMIP6 from a three‐dimensional perspective

In recent years, serious drought-related disasters in China have received increased attention due to their significant impacts. Assessing drought variations was critical to ensure agricultural activity, social development, and human health. This study used the three-dimensional clustering method to investigate variations of drought events in historical (1971–2010) and future (SSP126 and SSP585, 2061-2100) periods in China based on observations and model simulations from Coupled Model Inter-comparison Project Phase 6 (CMIP6). The variations and risk analysis of drought characteristics were assessed by copula-based methods. Results indicated that precipitation was projected to increase by 12.0% and 19.5% for the SSP126 and SSP585 scenarios, respectively, with substantial increases in arid and semi-arid regions. The drought duration, severity, and affected area are shown to increase based on the CMIP6 projections compared with historical periods. We also assessed drought return periods of multiple drought characteristics for each scenario by using the copula-based joint distribution. Based on the joint analysis of duration, severity, and affected area for meteorological drought, both the “or” and “and” return periods in the future indicated increased risks. Under global warming, extreme drought events with long duration, high intensity, and extended affected area were shown to occur more frequently in the future, especially under the SSP585 scenario. These results can aid the understanding and characterization of drought events for drought risk management under global warming.

Stepwise clustering future meteorological drought projection and multi-level factorial analysis under climate change: A case study of the Pearl River Basin, China

Climate change has significant impacts on the Pearl River Basin, and the regional ecological environment and human production may face severe challenges in the future due to changes in temperature and precipitation, as well as their derivative disasters (e.g., drought). Therefore, a full understanding of the possible impacts of climate change on Pearl River Basin is desired. In this study, the potential changes in temperature, precipitation, and drought conditions were projected through a stepwise clustering projection (SCP) model driven by multiple GCMs under two different RCPs. The developed model could facilitate specifying the inherently complex relationship between predictors and predictands, and its performance was proven to be great by comparing the observations and model simulations. A multi-level factorial analysis was employed to explore the major contributing factors to the variations in projecting drought conditions. The results suggested that the Pearl River Basin would suffer significant increasing trends in Tmean (i.e., 0.25–0.34 °C per decade under RCP4.5 and 0.42–0.60 °C per decade under RCP8.5), and the annual mean precipitation would increase under both RCPs. The drought events lasting for 1–2 months would be decreased by 7.7%, lasting for 3–4 months would be increased by 4.3%, and lasting for more than five months would be increased by 3.4% under RCP4.5, respectively. While they changed to 6.1%, 1.4%, and 4.7% under RCP8.5, respectively. More medium and long-term drought events with higher drought severity would occur. GCM has dominant influences on four different responses of drought duration, accounting for 50.20%, 52.61%, 56.71%, and 56.24% of total variabilities, respectively. Meanwhile, the effects explained by GCM*RCP interactions cannot be neglected, with an average contribution rate of 44.37%, 37.86%, 37.66%, and 35.83%, respectively.

Assessment of Inter-Model Variability in Meteorological Drought Characteristics Using CMIP5 GCMs over South Korea

Although many studies have sought to characterize future meteorological droughts, a few efforts have been done for quantifying the uncertainty, inter-model variability, arises from global circulation models (GCM) ensemble. A clear understanding of the uncertainty in multiple GCMs should be preceded before future meteorological droughts are projected. Therefore, this study evaluates the uncertainty in future meteorological drought characteristics that are induced by GCM ensemble using the custom measure “the degree of GCM spreading”. Future meteorological drought indices, the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI), were computed to five different time scales: 3, 6, 9, 12 and 24 months using statistically downscaled 28 GCMs under Representative Concentration Pathway (RCP) 4.5 and 8.5 at 60 weather stations in South Korea. The frequency, duration, and severity of drought events were estimated for three different future periods; F1 (2010–2039), F2 (2040–2069), and F3 (2070–2099). It was found that the uncertainty increases as the time scale lengthens regardless of a choice of drought indices or RCP scenarios. It also turned out that the SPI exhibits larger uncertainty rather than the SPEI, because temperature data exhibit a relatively much smaller variability comparing to precipitation data. Moreover, there was a shift of regions having larger values of the increasing rate between F1 and F2, which is shift from the north-western to southern region of South Korea.

Projections of future meteorological drought events under representative concentration pathways (RCPs) of CMIP5 over Kenya, East Africa

Understanding future evolution of drought scenario across localized domains remains an imperative process in bid to adapt tailor suit innovative solutions to drought risks and their impacts. The present study examines drought events by characterizing the trend, intensity, severity and frequency based on Standardized Precipitation Index (SPI), over Kenya, East Africa for near future (2010–2039), mid-century (2040–2069), and late century (2070–2100). The study utilizes Multi-model mean ensemble (MME) of five selected regional climate models (RCMs). Further, the models are bias corrected based on a quantile mapping bias corrected algorithm in order to minimize possible bias for accurate projections. The changes in annual and seasonal precipitation over Kenya is examined in order to associate with changes in drought occurrence. Results demonstrate positive shift, indicating an increase in projected rainfall change during all the three timescales. Projections of possible future meteorological drought events under RCPs scenario over study locale was conducted using SPI. The results demonstrate relatively better performance of biased corrected MME derived from Rossby Centre regional climate model (RCA4) in simulating drought indices over the Kenya. The MME projections for drought duration show an increase in moderate drought incidences with fewer incidences of extreme events across the RCP4.5 and 8.5 scenarios respectively. However, the duration of occurrences varies from one region to another with most hotspots located around northeastern sides of the country. Examination of projected changes in drought frequency and severity depict an occurrence of severe to extreme drought incidences that are expected to intensify during the near future time slice while overall projections show that more wet scenarios is depicted, with fewer cases of drought expected to occur during mid and towards end of the century of projection period. The study calls for enactment of appropriate mitigation measures to cope with possible scenarios of drought risks over Kenya in the future.

Future Global Meteorological Drought Hot Spots: A Study Based on CORDEX Data

AbstractTwo questions motivated this study: 1) Will meteorological droughts become more frequent and severe during the twenty-first century? 2) Given the projected global temperature rise, to what extent does the inclusion of temperature (in addition to precipitation) in drought indicators play a role in future meteorological droughts? To answer, we analyzed the changes in drought frequency, severity, and historically undocumented extreme droughts over 1981–2100, using the standardized precipitation index (SPI; including precipitation only) and standardized precipitation-evapotranspiration index (SPEI; indirectly including temperature), and under two representative concentration pathways (RCP4.5 and RCP8.5). As input data, we employed 103 high-resolution (0.44°) simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX), based on a combination of 16 global circulation models (GCMs) and 20 regional circulation models (RCMs). This is the first study on global drought projections including RCMs based on such a large ensemble of RCMs. Based on precipitation only, ~15% of the global land is likely to experience more frequent and severe droughts during 2071–2100 versus 1981–2010 for both scenarios. This increase is larger (~47% under RCP4.5, ~49% under RCP8.5) when precipitation and temperature are used. Both SPI and SPEI project more frequent and severe droughts, especially under RCP8.5, over southern South America, the Mediterranean region, southern Africa, southeastern China, Japan, and southern Australia. A decrease in drought is projected for high latitudes in Northern Hemisphere and Southeast Asia. If temperature is included, drought characteristics are projected to increase over North America, Amazonia, central Europe and Asia, the Horn of Africa, India, and central Australia; if only precipitation is considered, they are found to decrease over those areas.

Future Meteorological Droughts in Ecuador: Decreasing Trends and Associated Spatio-Temporal Features Derived From CMIP5 Models

Droughts are one of the most spatially extensive disasters that face societies. Therefore, it’s urgent to define mitigation strategies based on objective studies. However, research of droughts features in climate change (CC) have limitations due to the phenomenon complexity and the uncertainty of future precipitation from Global Climate Models (GCMs). The study of droughts in Ecuador is limited, despite the fact that CC will have more impact on developing countries. The study aims to assess the spatio-temporal characteristics of present and future droughts in Ecuador under 4.5 and 8.5 Representative Concentrations Pathways (RCP). Due to the intricate orography of Ecuador, e.g. coast, Andes and Amazon, the 10 km dynamically downscaled results from Couple Model Intercomparaison Project 5 (CMIP5). GCMs , GISS, CSIRO, and IPSL were used to calculate the Standardized Precipitation Index (SPI) droughts (present: 1981- 2005, future: 2041- 2070). The results show that overall there is a slightly decreasing trend of future droughts occurrence in the whole country, with larger reduction, for moderate, followed by severe and extreme. The intra-annual analysis shows that in the Andes and the coast, there is a reduction of moderate and severe future droughts for 4.5 and 8.5 RCPs and all DGCMs, throughout the year; extreme drought shows small decrease to statisticaly non-significant change. In the Amazon, moderate drought for IPSL and CSIRO show some increase/decrease in the probability of occurrence from May to October/rest of the year, for severe droughts the increase/decrease is expected from May to December/from January to april, and for extreme droughts increases are expected from January to April and higher increase in October and November. Thus, in the Amazon the rainy/drier period show a decreasing/increasing trend of droughts, which may be linked wetter in wet and drier in dry paradigm, although in the Andes and the coast may be different. Knowing that CC makes more challenging decision-making and adaptation strategies, this study contributes to the spatio-temporal representation of future droughts in Ecuador, highlighting areas and months where mayor changes are expected as well as the evaluation of GCMs ability to represent droughts in tropical mountains.