Future Drought Risk Research Articles

Diverging Projections of Future Droughts in High‐End Climate Scenarios for Different Potential Evapotranspiration Methods: A National‐Scale Assessment for Poland

ABSTRACTIt has been broadly reported that future climate change will most likely affect the spatio‐temporal distribution of water resources and consequently droughts. There is a prevailing notion that an increase in temperature and frequency of heat waves are expected to result in more intense droughts in the coming years. In this study, we aimed to evaluate the effect of the potential evapotranspiration (PET) method selection on future drought projections over Poland. In our study, simulations of the Soil and Water Assessment Tool (SWAT) model were conducted, utilising an ensemble of six EURO‐CORDEX projections, spanning the period from 2006 to 2100 under the RCP8.5 scenario. Two model setups with two different PET methods (Penman‐Monteith—PM and Hargreaves—HAR) were used. For drought conditions evaluation we selected the Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI) for meteorological drought, Standardized Streamflow Index (SSI) for hydrological drought, and Standardized Soil Moisture Index (SMI) for agricultural drought. The meteorological and hydrological droughts were calculated using a 12‐month time aggregation window, while agricultural drought was calculated using a 3‐month window. Climate projections revealed that by 2080s annual mean temperature and precipitation increase is expected by up to +3.4°C and +10.3% respectively. Under future climate conditions duration and severity of meteorological droughts are projected to decrease. PM method leads to a higher PET increases (1.35 mm year−1) than the HAR method (1.1 mm year−1) throughout the century which entail diverging signal of change for agricultural and hydrological droughts. PM‐ and HAR‐based simulations indicate increase in the total duration and cumulative severity of agricultural droughts, buthowever, for HAR‐based projections, the increase is much less. For hydrological droughts the signal of change is similar for both PET methods, but considerably distinct in magnitude. Considering the entire simulation period, by the end of the century cumulative severity of hydrological droughts is projected to decrease, with a much more pronounced decline for HAR (70% reduction) than for the PM method (35% reduction). Our study demonstrated that methodological choices are crucial to the assessment of future drought risk under climate change.

Identification of thresholds and key drivers on Water Use Efficiency in different maize ecoregions in Yellow River Basin of China

Identifying the constrains on water use efficiency (WUE) of crops along a wet-to-dry gradient is important due to irrigation water scarcity, as well as the increasing drought risk under climate change in China. This study coupled five high-resolution climate models from Coupled Model Intercomparison Project Phase 6 (CMIP6) with the Decision Support System for Agrotechnology Transfer (DSSAT)-CERES-Maize model to quantify drought risk and the drivers affecting WUE in five major maize ecoregions of the Yellow River Basin (YRB) under three future scenarios (SSP126, SSP370, and SSP585) for both the historical baseline (1985-2014) and three future periods: 2021-2040 (2030s), 2041-2070 (2050s), and 2071-2100 (2080s). And a bias correction method was implemented for the crop model to analyze optimal WUE thresholds for maize across varying dry-wet gradients. The results indicated that future drought risk will likely persist in the YRB under all scenarios, but with regional differences in drought severity and frequency. The southwestern region (V) experienced the highest frequency of drought (62.50%-SSP126), while the northwestern region (III) exhibited the lowest frequency (33.00%-SSP585) in 2030s, and 83.30% of areas in the southwestern (V) showed significant wetting in the 2080s under SSP126. The bias-corrected CERES-Maize model effectively simulated crop yield and evapotranspiration (ET), resulting in an average reduction of 4.00% and 9.73% in normalized root mean square error (nRMSE) respectively. Distinct WUE thresholds ranging from 1.96 to 8.41 kg ha−1 mm-1 were observed across various scenarios-periods in the maize regions, mostly under slight and moderate dry/wet conditions. Notably, all SSP585 scenarios demonstrated a decrease in WUE thresholds compared to the baseline. Across all scenarios and periods, WUE was mainly driven by yield in the eastern regions (I and II) but by ET in the western regions (III, IV, and V). These findings suggest that regions experiencing varying degrees of drought severity should undergo differentiated management and optimization of agricultural practices to improve WUE under future climate scenarios.

Future aridity and drought risk for traditional and super-intensive olive orchards in Portugal

Portugal, a leading olive oil producer, boasts six Protected Denomination of Origin (PDO) regions, with distinct olive orchard (OR) densities (traditional rainfed to super-intensive irrigated). This study aimed to assess future drought and aridity conditions and the impacts on ORs located in the PDOs. Therefore, drought and aridity indicators were considered for the historical (ERA5: 1981–2000) and future periods (2041–2060; 2081–2100), and anthropogenic forcing scenarios (RCP4.5 and RCP8.5), using a 7-member ensemble of global climate models. From Spearman’s correlation analysis, Annual Mean Aridity (AIA) was selected as the most representative indicator of the climate conditions, to which the ORs were exposed. Readily Available Soil Water (RAW; mm) was considered to represent the available soil water reservoir for olive trees. Moreover, the Olive Drought and Aridity Risk Index (ODAR) was developed to determine each OR's future risks. This index considered that the AIA and RAW were weighted by OR density fractions. In the future, southern Portugal will be more arid (0.69) than northern and central (0.60). ORs soil shows lower RAW in southern PDOs (< 60 mm) than in central and northern regions (> 90 mm). These results suggest that the south of ORs will be more exposed to water stress than the northern regions. According to ODAR, the ORs exposed to low and high risk will be mainly located in the central parts of the PDOs. In northern ORs, moderate to high risk will predominate. In the south, however, the risk will be very high, which means that the olive tree growth, fruit development, and olive oil quality could be negatively affected. Implementation of tailored adaptation measures will be required to improve the climate resiliency of the sector.

The effects of climate change and regional water supply capacity on integrated drought risk

Due to climate change, the frequency and duration of meteorological drought have increased. In addition, local water supply capacity has not met water demand in many regions, which will eventually lead to serious water shortages. To mitigate the effects of drought on sustainable water use, it is necessary to understand how climate change affects regional water supply capacity and drought risk. To this end, this study evaluated the drought response capacity of regional water supply systems and assessed the comprehensive drought risk in terms of drought hazard, vulnerability, and response capacity. To avoid subjectivity in risk analysis, structural equation modeling was used to select primary indicators and probability and statistical methods were used to assign weights to the indicators. The changes in drought risk in different climate change scenarios were assessed using sensitivity analyses. The overall results indicate that the future drought risks in Gyeonggi, Gyeongsang, Chungcheong, Jeolla, and Gangwon are 18, 12, 13, 9, and 10% higher, respectively, than the current risk level. The sensitivity analyses showed that Jinju in Gyeongsang province, which has a high drought response capacity, had the largest decreasing rate in drought risk. The quantified changes in drought risk under future climate change scenarios will be useful for identifying areas with a high drought risk and making decisions about drought mitigation under climate change.

Incorporation crisis lifecycle theory into full-stage flash drought spatio-temporal pattern identification and risk analysis

Compared to conventional slow-developing droughts, the characteristics and drivers of flash droughts are often more complex. This complexity challenges global drought early warning systems, leading to severe losses in crop yields during flash drought events. To address this problem, our study introduces the Full Life Cycle Flash Drought Identification Framework (FLCFDIF), which incorporates crisis lifecycle theories to link the lifecycle progression of flash droughts with corresponding risk management measures. The results indicate significant differences in the risk characteristics of flash drought events are observed between monsoon and non-monsoon regions of China, with flash droughts in monsoon regions erupting more rapidly, lasting longer, and recovering more slowly than flash droughts in non-monsoon areas. Flash droughts typically feature negative precipitation anomalies and positive anomalies in maximum temperature and evapotranspiration during the progression of the droughts. However, the high-intensity precipitation events that drive flash drought recovery primarily occur during the termination phase rather than the previously assumed recovery phase. Therefore, employing a 40% soil moisture percentile as a threshold for determining the end of flash droughts can reduce disturbances from low-intensity precipitation events and establish a link between flash droughts and seasonal droughts. In Southeast China, the probability of flash droughts transitioning to seasonal droughts is approximately 10%. In future flash drought risk management, it is crucial to integrate the four stages of flash drought progression (development, duration, recovery, and termination) and implement timely emergency response actions, including warning, assessment, mitigation, and monitoring, to address the environmental impacts of flash drought events.

Identification of critical drought thresholds affecting vegetation on the Mongolian Plateau

The increasing frequency of drought events due to global climate change has significant impacts on ecosystems, often resulting in reduced vegetation productivity. However, vegetation responses to drought often exhibit non-linear threshold phenomena, where vegetation growth sharply decreases once water stress reaches a certain level. Our study, conducted on the Mongolian Plateau, focuses on revealing the drought response thresholds and distribution patterns of different vegetation types. These thresholds mark critical turning points from high drought resistance to high vulnerability in vegetation response and serve as early warning indicators, crucial for accurately assessing how terrestrial ecosystems adapt to climate change. We utilized remote sensing observation datasets and inversion datasets spanning from 2001 to 2020, including six representative vegetation indices. The results indicate that: (1) Over 70 % of the Mongolian Plateau experiences low vegetation growth (<10th) predominantly influenced by drought, with low vegetation growth often occurring when water availability falls below the 30th percentile; (2) Areas with higher vegetation coverage and relatively moist climates have lower proportions of drought thresholds, implying that more complex ecosystems can better mitigate water stress, while background climatic conditions also regulate vegetation response to water availability; (3) According to multi-model climate predictions, the overall probability of drought risk on the Mongolian Plateau is projected to significantly increase during 2080–2100, especially in drought-prone regions. These findings provide important insights into better understanding the impacts of drought on ecosystems. Additionally, they emphasize the urgency of taking early measures to adapt to future drought risks.

Evaluating climate models to analyze drought conditions in the western region of Bangladesh

Being susceptible to natural disasters, Bangladesh is one of the most disaster-prone countries. Among the various natural calamities, droughts are a frequent occurrence in the western region of the country. Hence, this study first compared the efficacy of five bias-corrected Regional Climate Models (RCMs) - MIROC, NOAA, MPI, IPSL, and CCCma - for the Western region of Bangladesh with observed monthly precipitation and subsequent SPI values. Various evaluation methods- RMSE, Taylor Diagram, Mann–Whitney U Test, and t-test, were applied to precipitation and SPI3 values for the historical base period. Through these analyses, the MIROC model exhibited the highest level of accuracy. Accordingly, future projections for short-term droughts (SPI-3) and their characteristics were conducted using the ensemble of top three climate model under the RCM 8.5 W/m2 scenario. Short-term droughts are anticipated to become less frequent and severe in the 2060s and 2080s compared to the 2020s. Nonetheless, North-West region is projected to be more drought-prone than South-West until 2100. This research shows the importance of evaluating the better-fitting RCMs for assessing historical droughts and making reliable projections for the future. The methodology and findings can be employed in evidence-based decision-making and applied in other drought-prone areas to understand future drought risks.

Air Temperature Projections over the Mid and Southern of Iraq during the 21th Century Under Representative Concentration Pathways (RCPs), RCP 4.5 and RCP 8.5 Scenarios

Global climate conditions and hydrologic processes have changed significantly as a result of climate change, and as long as global warming persists, extreme events will probably more frequently happen. Climate change significantly affects Iraq through variations in air temperature, environment, agriculture and water supply. This study aimed to evaluate the observed period of temperature 19 80–2023 and the Projecting future trends of air temperature for mid and southern Iraq using BNU-ESM, CCSM4, HadGEM2-AO, and MIRIOC5 climate models from CMIP5 under the RCP4.5 and RCP8.5 scenarios during the periods 2016–2035, 2046–2065, and 2081–2100. The findings verified that, in each of the two RCPs scenarios temperature would increase with different levels. the results showed that the temperature anomaly increased to +15.6 °C, and +18.8 °C under RCR4.5 and RCP8.5 in the MIRIOC5 model, especially in the last decade of the twentieth century. The areas of Iraq most impacted by high temperatures are the south and southeast (Basra, Missan, Thi-Qar, and Muthanna) provinces. In the first period, On the other hand, the less effect areas for the temperature increase were (Anbar and northeast of Diyala) +2.4°C, and +4.4°C for HadGEM2-AO model under RCR4.5 and RCP8.5 respectively. Through all periods, CCSM4, and MIRIOC5 models were the most identical in results. The findings can aid in the evaluation of future drought risks in Iraq by policymakers. Developing suitable adaptation techniques to counter act climate change can also be beneficial.

Leveraging unsupervised machine learning to examine women's vulnerability to climate change

AbstractWe provide an application of machine learning to identify the distributional consequences of climate change in Malawi. We compare climate impact estimates based on drought indicators established objectively from the k‐means algorithm to more traditional measures. Young women affected by drought were 5 percentage points more likely to be married by 18 than those living in nondrought areas. Our approach generates robust results when varying the number of clusters and definition of treatment status. In some cases, we find the design using k‐means to define treatment is more likely to satisfy the assumptions underlying the difference‐in‐differences strategy than when using arbitrary thresholds. Projections from the estimates indicate future drought risk may lead to larger declines in labor productivity due to women's engagement in early age marriage than other factors affecting their participation rates. Under the extreme representative concentration pathway scenario, drought exposure encourages the exit of 3.3 million women workers by 2100.

Future drought risk and adaptation of pastoralism in Eurasian rangelands

Drought risk threatens pastoralism in rangelands, which are already under strain from climatic and socioeconomic changes. We examine the future drought risk (2031–2060 and 2071–2100) to rangeland productivity across Eurasia (West, Central, and East Asia) using a well-tested process-based ecosystem model and projections of five climate models under three shared socioeconomic pathway (SSP) scenarios of low (SSP1−2.6), medium (SSP3−7.0), and high (SSP5−8.5) warming relative to 1985–2014. We employ a probabilistic approach, with risk defined as the expected productivity loss induced by the probability of hazardous droughts (determined by a precipitation-based index) and vulnerability (the response of rangeland productivity to hazardous droughts). Drought risk and vulnerability are projected to increase in magnitude and area across Eurasian rangelands, with greater increases in 2071–2100 under the medium and high warming scenarios than in 2031–2060. Increasing risk in West Asia is caused by longer and more intense droughts and vulnerability, whereas higher risk in Central and East Asia is mainly associated with increased vulnerability, indicating overall risk is higher where vulnerability increases. These findings suggest that future droughts may exacerbate livestock feed shortages and negatively impact pastoralism. The results have practical implications for rangeland management that should be adapted to the ecological and socioeconomic contexts of the different countries in the region. Existing traditional ecological knowledge can be promoted to adapt to drought risk and embedded in a wider set of adaptation measures involving management improvements, social transformations, capacity building, and policy reforms addressing multiple stakeholders.

Evaluation of future renewable energy drought risk in China based on CMIP6

With the growing share of the climate-sensitive renewable energy market supply in China, estimating future energy drought risk (ED) is essential. In this paper, based on CMIP6, energy demand and power generation are estimated from 2023 to 2100 under SSP2-4.5 and SSP5-8.5 climate scenarios, and ED is defined from high demand (HD), low wind-solar generation (LWS), and residual load (RL). The results show that the ED exacerbation is relatively high under the SSP5-8.5. Between 2023 and 2100, the duration and severity of HD and RL notably increase, while LWS changes are relatively weak. We find that HD and RL exhibit high summer risks in the south and high winter risk in the north. The return periods vary significantly and extends over time in most regions. Moreover, there are few ED when the installed power generation capacity (IPGC) is increased. When the IPGC increases by 2%–5%, the LWS will decrease at least 20%–72%. With a 10% increase, the LWS will be mitigated by at least 80%, whereas the mitigation for RL is limited, approximately 3–17% at different rates. This work performs the first evaluation of future ED and provides the useful references for risk mitigation in China based on CMIP6.

Modeling future (2021–2050) meteorological drought characteristics using CMIP6 climate scenarios in the Western Cape Province, South Africa

Consistent drought modelling under plausible shared socioeconomic–representative concentration pathways (SSP–RCPs) are crucial for effectively managing future drought risk in agricultural environments. The Western Cape (WC) is one of South Africa’s main agro-based provinces and faces a mounting threat of water insecurity due to recurrent drought. The objective of this study was to predict meteorological drought hazard for 2021–2050 based on three CMIP6 scenarios: SSP5–8.5, SSP2–4.5 and SSP1–2.6. Precipitation simulations generated by the sixth version of Model for Interdisciplinary Research on Climate (MIROC6) under the SSP5–8.5, SSP2–4.5 and SSP1–2.6 scenarios were used from fifteen stations across the six AEZs of the WC province. The Standardised Precipitation Index (SPI) was computed at 12-month timescales. Trend analysis of precipitation datasets and the SPI-values were done at p < 0.05 using the Mann–Kendall (M–K) test. The findings revealed negative precipitation trends of − 7.6 mm/year in Ceres, while positive trends of 0.3 mm/year were observed in Malmesbury. These findings indicate an improvement from − 7.8 and − 6.4 mm/year in the same regions, respectively, compared to historical trends observed between 1980 and 2020. The results suggest that in 2042 and 2044, Bredasdorp will experience − 2 < SPI < − 1.5 under the SSP2–4.5 scenarios, while Matroosberg in 2038 under the SSP5–8.5 will experience SPI > − 2. The findings of this study will assist in the development of proactive planning and implementation of drought mitigation strategies and policies aimed at reducing water insecurity in AEZs.

How will drought evolve in global arid zones under different future emission scenarios?

Study regionGlobal aridity zones. Study focusEvaluating drought under the impact of climate change is crucial for ensuring sustainable development and ecological security, especially in global arid zones where the environment is vulnerable to global warming. However, there are large uncertainties in evaluating the future drought risk of arid zones due to uncertainties within climate projections and the use drought-related indices that may not be appropriate for all assessments. Therefore, under the precondition of bias correction applied to CMIP6 data, the drought detection capability of drought indices calculated from multimodel ensemble was evaluated. Based on the drought index with the strongest detection capability and the Reliability-Resilience-Vulnerability (RRV) framework, the future drought risk in global arid zones were predicted. New hydrological insights for the regionAmong the drought indices calculated from CMIP6 historical simulations, SPEI offered the best representation of drought patterns. According to the CMIP6 future projections, SSP1–2.6 can effectively mitigate the impact of future drought risk compared with the historical period. In scenarios with higher emissions, the equatorial to northern latitude 30° region will experience more severe drought. For SSP5–8.5, the areas in the arid zones where drought risk deteriorates significantly are several times larger than in other scenarios. To mitigate drought risks, most nations should support a greener, low-emission approach in line with sustainable development goals, reducing the risk of drought-related damage.

Choosing the appropriate Coordinated Regional Downscaling Experiments South East Asia (CORDEX-SEA) Model for drought future hazard assessment in the Bintan Island

Management for sustainable water resources requires attention to future climate variability to anticipate the hazards that may arise, such as drought and flood. CORDEX-SEA is a downscale result of several gridded climate models that provide historical data and future projections for the Southeast Asia region useful to predict future climate, including the extreme event’s potential for deriving hazards. This research was done to determine which CORDEX-SEA climate model would be most suitable for predicting future drought risks, especially for small islands. This study uses statistical tests (probability density functions, skewness, etc.) in the historical period to determine the climate model that best fits the observed data, using Bintan Island as the case area. The model with historical data that best fits the observations will be considered the best model for predicting future (drought and flood) conditions. The corrected MPI and ensemble model of CORDEX-SEA showed well results in representing the drought index.

Examining past and projecting future: an 800-year streamflow reconstruction of the Australian Murray river

Managing water security and sustaining ecosystem functions under future warming poses substantial challenges for semi-arid regions. The Murray–Darling Basin (MDB) is particularly vulnerable given the considerable demand for water that underpins Australia’s agricultural production and contribution to the national economy. Understanding future drought risk requires a robust assessment of natural variability in drought length, frequency, and magnitude. In the absence of long instrumental records, past drought characteristics can be inferred from paleo-records. We reconstruct over 800 years of Murray River streamflow using a suite of tree-ring chronologies from regions with strong climate teleconnections to the MDB. The reconstruction (1190–2000 CE) captures a broad spectrum of natural climate variability, not fully represented in instrumental records, contributing to an improved understanding of the occurrence rate of multi-year droughts. We found that the Millennium Drought, which occurred in the 2000s, was the most severe (joint duration, magnitude, and peak) during the 800-year reconstruction. The return period of this event is estimated to be ∼2500 years. However, droughts in the early-1200s were of a longer duration and similar magnitude to the Millennium Drought. We used climate models to assess how the occurrence probability of severe droughts might change in the future. Compared to the 800-year baseline, climate models project an increase in future drought severity. While the increase in drought occurrence is within the uncertainty range for most future projections, the driest forecast shows a significant increase in the likelihood of severe droughts compared to natural variability. Our results highlight the need for water management strategies not to rely solely on instrumental data as it may not fully represent current and future risks. Ensuring a resilient MDB under future warming will require a robust water security policy that captures a broader range of natural and anthropogenic variability than currently recognised.

Climate change impacts on spatial and seasonal meteorological drought characteristics for the island of Ireland

AbstractUnderstanding how climate change is likely to impact on meteorological droughts is key to informing adaptation planning. For Ireland, little research has examined how droughts are likely to change in future. Here we examine changes in the monthly climate water balance, aridity index and changes in magnitude, frequency and duration of droughts using standardized drought indices for the island of Ireland derived from bias‐adjusted CORDEX simulations for the 2080s (2070–2099), forced with a high (RCP8.5) and moderate (RCP4.5) emissions pathway. Findings highlight that increases in potential evapotranspiration, driven by increasing temperature, together with changing seasonal rainfall patterns increase aridity in summer with water deficits extending into spring months, especially in the east and midlands by the end of the century. Increases in drought frequency and magnitude are also evident, with greatest increases for RCP8.5. Critically, increases are considerably greater for the standardized precipitation evapotranspiration index (SPEI) than for the standardized precipitation index (SPI), emphasizing the importance of using metrics that capture potential evapotranspiration in monitoring and assessing future drought risk. Summer and spring show the greatest increase in drought magnitude and frequency, most marked in the east of the island. By contrast, multiseasonal droughts, assessed using 6‐month accumulation periods show more modest changes in magnitude and duration. The resultant impacts of climate change on drought for Ireland would require considerable adaptation given the vulnerabilities exposed by the 2018 drought.

Divergent flash drought risks indicated by evaporative stress and soil moisture projections under warming scenarios

Offline drought indices have been utilizable for monitoring drought conditions, but their reliability in projecting future drought risks is uncertain due to non-meteorological influences on atmospheric water demand (Ep ). This study investigated the impact of surface resistance sensitivity (rs ) to elevated CO2 (eCO2) on projections of future flash droughts (FD). We evaluated FD risks across an East Asian region during a historical period (1981–2020) and a future period (2021–2060) using two evaporative stress index (ESI) series. One series employs the conventional Penman-Monteith (PM) equation for Ep , while the other incorporates a generic rs sensitivity to eCO2 derived from advanced Earth System Models (ESMs). We compared the FD risks identified by the two ESI series with assessments based on soil moisture data from atmospheric reanalysis and multiple ESM projections under two emission scenarios linked with the Shared Socioeconomic Pathways. Results showed that the response of rs to eCO2 has had minimal influences on temporal variations of ESI for the past decades, likely due to its low sensitivity and the masking effects of other environmental factors. However, for the future decades, the ESI projected by the conventional PM equation significantly diverged from soil moisture projections, overestimating future FD risks even under a low emission scenario. We found that incorporating the generic rs sensitivity into the PM equation did not simply resolve the disparity in FD frequencies between ESI and soil moisture projections. Many associated factors contributing to stomatal responses to eCO2 complicate the understanding of future flash drought risks. This study suggests that overreliance on the conventional Ep formula, which neglects non-meteorological effects, could decrease the ability of ESI to detect future FD events under eCO2.

Can the combining of wetlands with reservoir operation reduce the risk of future floods and droughts?

Abstract. Wetlands and reservoirs are important water flow and storage regulators in a river basin; therefore, they can play a crucial role in mitigating flood and hydrological drought risks. Despite the advancement of river basin theory and modeling, our knowledge is still limited about the extent to which these two regulators could perform such a role, especially under future climate extremes. To improve our understanding, we first coupled wetlands and reservoir operations into a semi-spatially explicit hydrological model and then applied it in a case study involving a large river basin in northeast China. The projection of future floods and hydrological droughts was performed using the hydrological model during different periods (near future: 2026–2050, middle century: 2051–2075, and end century: 2076–2100) under five future climate change scenarios. We found that the risk of future floods and hydrological droughts can vary across different periods – in particular, it will experience relatively large increases and slight decreases. This large river basin will experience flood events of longer duration, with larger peak flows and volume, and of enhanced flashiness compared to the historical period. Simultaneously, the hydrological droughts will be much more frequent, with longer durations and more serious deficits. Therefore, the risk of floods and droughts will, overall, increase further under future climate change even under the combined influence of reservoirs and wetlands. These findings highlight the hydrological regulation function of wetlands and reservoirs and attest that the combining of wetlands with reservoir operation cannot fully eliminate the increasing future flood and drought risks. To improve a river basin's resilience to the risks of future climate change, we argue that the implementation of wetland restoration and the development of accurate forecasting systems for effective reservoir operation are of great importance. Furthermore, this study demonstrated a wetland–reservoir integrated modeling and assessment framework that is conducive to risk assessment of floods and hydrological droughts and that can be used for other river basins in the world.

Integrated drought vulnerability and risk assessment for future scenarios: An indicator based analysis

The dynamic interplay between climate change and socioeconomic development has brought about significant changes in drought hazard, vulnerability, and risk within the global socioeconomic system. However, there is a prevailing lack of understanding about how these changes will manifest in an increasingly globalized economy under global warming. To address this knowledge gap, this study utilizes various climatic, geographical, and socioeconomic data from historical period and future projections to comprehensively map and assess the changes in global drought vulnerability and risk of population in the 2030s and 2050s under the SSP126, SSP245, and SSP585 scenarios. This study finds that the future population at risk of drought is projected to increase by 21.96 % - 25.95 % in the 2030s and 36.64 % - 45.40 % in the 2050s, driven by rapid population growth and substantial changes in drought hazard and vulnerability. This includes varying increases in drought hazard in approximately 58 % of global land area, alongside decreases in drought vulnerability in 50 % - 80 % of global land areas. Most arid and semi-arid regions, including Africa, Central Asia, West Asia, and Australia with less developed economies, are more susceptible to the adverse effects of climate change, leading to significant increases in future drought hazards, vulnerability, and risk, particularly under higher emission scenarios. In contrast, most humid and semi-humid regions exhibit varying degrees of drought vulnerability and risk of population across regions, despite the overall increasing drought hazard, with disproportionate impact of climate change and socioeconomic development. Specifically, projected increases in drought vulnerability and risk are observed in the Amazon, central and western U.S., while decreases are projected in the eastern part of China delimited by the Hu Line, southern India, Japan, Korea, most of Southeast Asia, northern Europe, and South America excluding the Amazon. The eastern U.S. is expected to experience reduced vulnerability but increased drought risk. This study can assist decision makers to develop targeted strategies and measures of adaptation and mitigation in an increasingly globalized economy under global warming.

Building drought classification map with landsat 8 image data in Bac Binh district, Binh Thuan province

Vietnam experiences increasing droughts throughout the dry season due to climate change, global warming,and human-caused activities like urbanization and deforestation. Drought hazard significantly impacts socioeconomic, agriculture, and the environment; it directly threatens human lives, livelihoods, food security, and environmental degradation. It is essential to have a drought assessment map to assist in developing and implementing strategies to combat drought. Space remote sensing technology development has enabled efficient and cost-effective monitoring and evaluation of droughts on a large scale, surpassing the capabilities of ground-based observations. This research uses remote sensing technology to monitor and assess the severity of the drought in the Bac Binh district, Binh Thuan province. We analyzed the Temperature Vegetation Dryness Index (TVDI) using multi-temporal Landsat 8 satellite data for the severe drought events in 2014, 2017, and 2020. The results indicate a significant increase in the percentage of land area affected by drought, from 50.74% in 2014 to 66.23% in 2020. The obtained maps provide valuable visual data to relevant agencies, assisting with planning preventative measures and mitigating future drought risks.