Drought Hazard Research Articles

Increasing Community Awareness of Natural Disasters in the Context of Disaster Mitigation in Kalinongko Hamlet, Pagerharjo, Samigaluh, Kulon Progo

Kalinongko Hamlet is a hamlet located in Pagerharjo, Kulon Progo, Special Region of Yogyakarta. Kemesu Hamlet has a geographical location in the Pagerharjo area. Pagerharjo Village has boundaries with Magelang Regency in the north, Ngargosari Village in the south, Banjarsari Village in the east, and Purworejo Regency in the west. Kulon Progo Regency including Pagerharjo Village, especially Kemesu Hamlet, is one of the districts that has the potential for disasters such as floods, tsunamis, earthquakes, landslides, droughts, and volcanic eruptions. Based on data obtained from BNPB, the Pagerharjo area has a high potential for landslides and drought. On the other hand, also based on data obtained from BNPB, the capacity to deal with landslides was in the medium and low categories in dealing with drought hazards. Therefore, efforts need to be made to increase the capacity of the community in Pagerharjo Village, especially in Kalinongko Hamlet, in dealing with potential landslides and drought disasters. This PKM KKN PPM activity seeks to increase community capacity in dealing with disasters through socialization and Discussion Group Forums (FGD). Resource persons for this activity are planned from disaster actors either from the campus or from the Regional Disaster Management Agency (BPPD). With this disaster socialization and FGD activity, it is hoped that it can increase the community's capacity to deal with potential disasters. The output of this PKM is published in the mass media, seminar forums, and activity videos.

Drought Hazard Analysis in the Jilin Province Based on a Three-Dimensional Copula Method

Based on the precipitation and potential evapotranspiration at 23 stations in the Jilin Province, the standardized precipitation evapotranspiration index (SPEI) was calculated. Based on run theory and combined with previous research in Jilin Province, we redefine the drought threshold, with three characteristics, that is, drought duration, intensity, and severity, were identified and extracted. Two- and three-dimensional copula functions were selected to fit and combine drought variables to calculate the joint recurrence period. In order to make the alternative copula model more complete, 25 representative copula functions are selected for the first time to construct the Joint probability distribution function. The Mann–Kendall test was used to examine abrupt changes in Meihekou County. SPEI trends and the joint cumulative probability of drought variables in the Changbai area were analyzed. The results show that: (1) the SPEI in the Meihekou area was unstable around 2000 and 2010, with abrupt change points; (2) the trend of the SPEI in the Changbai Mountains area indicates that the drought occurrence is similar at various timescales; the drought range and duration increase with increasing timescale; and (3) the correlation between the three drought variables is strong and the fit is good. The results of two- and three-dimensional joint recurrence period calculations are similar, with a high probability of recurrence within three years.

The spatial distribution of a comprehensive drought risk index in Java, Indonesia

Drought is a common hydro-meteorological disaster in several remote regions of Java, Indonesia, due to the limitation of supporting facilities in water supply management. However, little attention has been paid to drought preparedness, especially within drought risk assessment. Since Java is the most densely populated area in Indonesia and has been identified as a national food center, an effective drought risk assessment is needed for drought disaster mitigation. Therefore, a spatial drought risk assessment for the sub-district level was conducted for Java using a framework that considers the combined roles of drought hazard and drought vulnerability. Observed rainfall data from 1294 stations across Java for the time period 1991–2020 were used to define a drought hazard index. Furthermore, a drought vulnerability index was obtained by classifying several indicators that accommodated non-climate aspects. Based on these, an overall drought risk index was obtained by integrating the drought hazard index and drought vulnerability index. The results identified several areas of Java in need of priority government attention for drought disaster mitigation. Of these, the main priorities are regions with a high risk of drought, which were spread across five provinces as follows (percentage represents the number of high drought hazard index values in the sub-district to the total number of sub-districts): Yogyakarta (13.92%), West Java (7.26%), Banten (5.77%), Central Java (6.23%), and East Java (4.32%).

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.

Perceptional Differences on Drought Occurrence and Resilience Building Mechanisms in Kebri Dehar District, Somali Region of Ethiopia

Purpose: The aim of the research was to analyze the drought hazard occurrence, perceptional differences among residents to drought hazard occurrence, and explore the resilience mechanisms at household, community level, and institutional level to recover from drought hazards Theoretical framework: The research dealt with the theoretical aspects of how hazards occurrence can be observed through the perceptional differences of the residents in a particular area. Adoption of short- and long-term drought resilience mechanisms is inevitable to recover from drought hazards. Design/methodology/approach: This study is based on exploratory research design. Four ‘kebeles’ were selected considering drought classifications and 200 respondents were chosen. Descriptive statistics, Timeline Approach and ANOVA were used to analyze the data collected. Findings: Majority of respondents know about drought hazard occurrence, causes at their level, and experienced the effects of drought. There are significant perceptional differences among respondents across educational and marital status, and monthly income. Research, Practical & Social implications: Household and community participation is essential for adopting drought resilience mechanisms with the support of governmental and non-governmental agencies. Originality/value: This Study focused on drought hazard occurrence and resilience mechanisms at household and community level to recover drought hazards. The originality / value of the study lies with perceptional differences on drought hazards occurrence using the Timeline approach and ANOVA. The findings of this study would contribute to design and implement effective drought resilience mechanisms.

Water distribution based on SAR and optical data to improve hazard mapping

Climate projections foresee intense precipitation and long-term drought events is increasing with consequent rapid changes in surface water bodies in a short period. In areas with drastic hydrological changes, achieving accurate and rapid mapping of these phenomena in combination with hydrologic variability characteristics is a key of effective emergency management and disaster risk reduction plans. This study presents an automatic method for mapping drought and flood hazards, particularly in regions with significant hydrological changes. We use Sentinel-1/2 and Landsat data to extract surface water and classify permanent and seasonal water bodies in historical periods, which serve as the basis for identifying flood or drought areas. The water extraction method combines index-based analysis for optical data and the region-Otsu method for radar data, ensuring accurate identification of water. The effectiveness of this approach is demonstrated through comparisons with existing products in Poyang Lake (China), the Po River Plain (Italy), and the Indus River Plain (Pakistan). Findings show a high similarity between the two, and our results can provide more specific details. Our method is particularly well-suited for areas with fluctuating hydrological conditions, can also map quickly without optical data. By effectively identifying areas affected by drought and flood hazards while mitigating errors from natural hydrological dynamics, this methodology contributes valuable insights to enhance emergency management and disaster risk reduction plans.

Quantitative evaluation of drought risk related to vegetation productivity in China

Quantitative assessment of vegetation drought risk is crucial for addressing drought problems and vegetation management under global warming. In this study, we employed a framework based on long-term (2001–2019) vegetation Gross Primary Productivity (GPP) and the Standardized Precipitation Evapotranspiration Index (SPEI) to quantify drought risk, considering vegetation vulnerability, exposure, and hazard to drought. The results revealed that vegetation drought risk was influenced by drought hazard (55.15%), exposure (24.46%), and vulnerability (20.39%). Approximately 48% of study pixels experienced moderate to high drought risk, primarily concentrated in northeastern to southwestern China. In terms of vegetation types, forest suffered the highest drought risk, followed by cropland, while grassland had the mildest drought risk. Notably, croplands in northern China experienced relatively high drought risk, posing a threat to food security. Therefore, it is imperative to consider appropriate crop management practices such as irrigation and crop rotation to mitigate the impact of droughts. Temperature and precipitation are key climatic factors affecting vegetation drought risk in moderate-to-high risk areas. Warming inhibited drought risk by promoting vegetation growth, but also consumed water to promote drought risk. Meanwhile, increased rainfall in parts of northern China may be caused by extreme weather events that intensify vegetation vulnerability, thus aggravating drought risk. Our research provided scientific guidance to understand and cope with drought risk induced by climate change on vegetation.

Propagation from meteorological to hydrological drought in the Horn of Africa using both standardized and threshold-based indices

Abstract. There have been numerous drought propagation studies in data-rich countries, but not much has been done for data-poor regions (such as the Horn of Africa, HOA). In this study, we characterize meteorological, soil moisture and hydrological drought and the propagation from one to the other for 318 catchments in the HOA to improve understanding of the spatial variability in the drought hazard. We calculate the standardized precipitation index (SPI), standardized soil moisture index (SSMI) and standardized streamflow index (SSI). In addition, we use the variable threshold method to calculate the duration of drought below a predefined percentile threshold for precipitation, soil moisture and discharge. The relationship between meteorological and soil moisture drought is investigated by finding the SPI accumulation period that has the highest correlation between SPI and SSMI, and the relationship between meteorological and hydrological drought is analysed by the SPI accumulation period that has the highest correlation between SPI and SSI time series. Additionally, we calculated these relationships with the ratio between the threshold-based meteorological-drought duration and soil moisture drought duration and the relation between threshold-based meteorological-drought duration and streamflow drought duration. Finally, we investigate the influence of climate and catchment characteristics on these propagation metrics. The results show that (1) the propagation from SPI to SSMI and the mean drought duration ratio of meteorological to soil moisture drought (P / SM) are mainly influenced by soil properties and vegetation, with the short accumulation periods (1 to 4 months) of SPI in catchments with arable land, high mean annual precipitation, and low sand and silt content, while longer accumulations (5 to 7 months) are in catchments with low mean annual upstream precipitation and shrub vegetation; (2) the propagation from SPI to SSI and precipitation-to-streamflow duration ratio are highly influenced by the climate and catchment control, i.e. geology, elevation and land cover, with the short accumulation times in catchments with high annual precipitation, volcanic permeable geology and cropland and the longer accumulations in catchments with low annual precipitation, sedimentary rocks and shrubland; and (3) the influence of mean annual upstream precipitation is more important for the propagation from SPI to SSI than from SPI to SSMI. Additionally, precipitation accumulation periods of approximately 1 to 4 months in wet western areas of the HOA and of approximately 5 to 7 months in the dryland regions are found. This can guide forecasting and management efforts as different drought metrics are thus of importance in different regions.

Spatial analysis of flash flood and Drought impact from Climate Change in Phongsaly District, Phogsaly Province, by using Geo-Informatics Technology and Modelling

A method for predicting the water resource in the region in the future to be used as a basis for mitigating the consequences is to study how climate change affects hydrology. The purpose of this study is to i). choose a global climate model that is suitable for the area, ii). rainfall run-off modelling, iii). drought and flood hazard index map. The SSP-126, SSP-245, and SSP-585 scenarios were chosen as the most appropriate global climate model among the four institutes, with efficiency criteria using the coefficient of Nash-Sutcliffe and Kling-Gupta and then calibrate the data with the Bias Correction Linear Scaling method which divides the analysis period into 2 periods for Near-Future and Far-Future from analyzing Rainfall Run-off Modeling from Rainfall Concentration 1-hours, 3-hours and 6-hours. It was found that the SSP-585 scenario in the Rainfall Concentration 1-hours model has the most dangerous area for very high risk until the end of the 21st century. For the analysis of drought indices SPI_1, SPI_3 and SPI_6 in Near-Future, it was found that the frequency of droughts is increasing according to the worst scenario, the scenario with the most drought is SSP-585 and in the Far-Future, the frequency of drought is decreasing according to the worst scenario, the scenario with the most drought is SSP-126.

Drought hazard and annual precipitation predicted to increase in the Sirppujoki river basin, Finland

Droughts pose a critical global risk that affect vast land areas and threaten almost all nations. Yet the impacts of droughts are most concretely felt at the local scale. Here, we assess drought indices in a Finnish basin with limited observations under current and future climate conditions in order to support local drought management. Long time series are needed for deriving drought indices, yet the available data is often a constraint. To increase the sample size available for analysis, we generated a thousand years of weather data with a stochastic weather generator based on observations and Regional Climate Model (RCM) data. The generated meteorological variables were fed into a hydrological model to simulate a large sample of hydrological variables. These large samples of simulated meteorological and hydrological variables were then used to analyse drought events and their characteristics in a past (1990–2019) and a future (2040–2069) time period. The results support the ongoing drought management work being done in South-Western Finland and specifically the Sirppujoki basin. Our results indicate that drought events will most likely become more frequent, especially during the growing season. Such changes would affect particularly the agricultural sector of Finland.

Characterization and outlook of climatic hazards in an agricultural area of Pakistan

Many dimensions of human life and the environment are vulnerable to anthropogenic climate change and the hazards associated with it. There are several indices and metrics to quantify climate hazards that can inform preparedness and planning at different levels e.g., global, regional, national, and local. This study uses biased corrected climate projections of temperature and precipitation to compute characteristics of potential climate hazards that are pronounced in the Gomal Zam Dam Command Area (GZDCA)— an irrigated agricultural area in Khyber Pakhtunkhwa province of Pakistan. The results answer the question of what the future holds in the GZDCA regarding climate hazards of heatwaves, heavy precipitation, and agricultural drought. The results of heatwaves and agricultural drought present an alarming future and call for immediate actions for preparedness and adaptation. The magnitude of drought indices for the future is correlated with the crop yield response based on AquaCrop model simulations with observed climate data being used as input. This correlation provides insight into the suitability of various drought indices for agricultural drought characterization. The results elaborate on how the yield of wheat crop grown in a typical setting common in the South Asian region respond to the magnitude of drought indices. The findings of this study inform the planning process for changing climate and expected climate hazards in the GZDCA. Analyzing climate hazards for the future at the local level (administrative districts or contiguous agricultural areas) might be a more efficient approach for climate resilience due to its specificity and enhanced focus on the context.

Winter Wheat Drought Risk Assessment by Coupling Improved Moisture-Sensitive Crop Model and Gridded Vulnerability Curve

The crop drought risk assessment is an important basis for mitigating the effects of drought on crops. The study of drought using crop growth models is an integral part of agricultural drought risk research. The current Decision Support System for Agrotechnology Transfer (DSSAT) model is not sufficiently sensitive to moisture parameters when performing simulations, and most studies that conduct different scenario simulations to assess crop drought vulnerability are based on the site-scale. In this paper, we improved the moisture sensitivity of the Crop Environment Resource Synthesis System (CERES)-Wheat to improve the simulation accuracy of winter wheat under water stress, and then we assessed the drought intensity in the Beijing-Tianjin-Hebei region and constructed a gridded vulnerability curve. The grid vulnerability curves (1 km × 1 km) were quantitatively characterized using key points, and the drought risk distribution and zoning of winter wheat were evaluated under different return periods. The results show that the stress mechanism of coupled water and photosynthetic behavior improved the CERES-Wheat model. The accuracy of the modified model improved in terms of the above-ground biomass and yield compared with that before the modification, with increases of 20.39% and 11.45% in accuracy, respectively. The drought hazard intensity index of winter wheat in the study area from 1970 to 2019 exhibited a trend of high in the southwest and low in the southeast. The range of the multi-year average drought hazard intensity across the region was 0.29–0.61. There were some differences in the shape and characteristic covariates of the drought vulnerability curves among the different sub-zones. In terms of the cumulative loss rates, almost the entire region had a cumulative drought loss rate of 49.00–54.00%. Overall, the drought risk index decreased from west to east and from north to south under different return periods. This quantitative evaluation of the drought hazard intensity index provides a reference for agricultural drought risk evaluation.

Joint modeling of drought and dust hazards using copula- based model over Iran from 1988 to 2018

Joint modeling of drought and dust hazards using copula- based model over Iran from 1988 to 2018

Analyzing the informative value of alternative hazard indicators for monitoring drought hazard for human water supply and river ecosystems at the global scale

Abstract. Streamflow drought hazard indicators (SDHIs) are mostly lacking in large-scale drought early warning systems (DEWSs). This paper presents a new systematic approach for selecting and computing SDHIs for monitoring drought for human water supply from surface water and for river ecosystems. We recommend considering the habituation of the system at risk (e.g., a drinking water supplier or small-scale farmers in a specific region) to the streamflow regime when selecting indicators; i.e., users of the DEWSs should determine which type of deviation from normal (e.g., a certain interannual variability or a certain relative reduction of streamflow) the risk system of interest has become used to and adapted to. Distinguishing four indicator types, we classify indicators of drought magnitude (water anomaly during a predefined period) and severity (cumulated magnitude since the onset of the drought event) and specify the many relevant decisions that need to be made when computing SDHIs. Using the global hydrological model WaterGAP 2.2d, we quantify eight existing and three new SDHIs globally. For large-scale DEWSs based on the output of hydrological models, we recommend specific SDHIs that are suitable for assessing the drought hazard for (1) river ecosystems, (2) water users without access to large reservoirs, and (3) water users with access to large reservoirs, as well as being suitable for informing reservoir managers. These SDHIs include both drought magnitude and severity indicators that differ by the temporal averaging period and the habituation of the risk system to reduced water availability. Depending on the habituation of the risk system, drought magnitude is best quantified either by the relative deviation from the mean or by the return period of the streamflow value that is based on the frequency of non-exceedance. To compute the return period, we favor empirical percentiles over the standardized streamflow indicator as the former do not entail uncertainties due to the fitting of a probability distribution and can be computed for all streamflow time series. Drought severity should be assessed with indicators that imply habituation to a certain degree of interannual variability, to a certain reduction from mean streamflow, and to the ability to fulfill human water demand and environmental flows. Reservoir managers are best informed by the SDHIs of the grid cell that represents inflow into the reservoir. The DEWSs must provide comprehensive and clear explanations about the suitability of the provided indicators for specific risk systems.

Drought and flood hazards management for agricultural water users in Central Java, Indonesia

Central Java has a huge population and is the food production area for Indonesia. Due to its geographical complexity and the human factor, it is very vulnerable to drought and flood hazards. This study aimed to analyse drought and flood events in Central Java and their impact on economic, environmental, and social aspects, as well as to evaluate the multi-hazard management in Central Java related to agriculture. Drought and flood monitoring were conducted by SPI and SPEI. Those hazard forecasting were done by correlating the selected drought index to MEI. The drought vulnerability of five municipalities in Central Java was evaluated by DVI. Proposed mitigation strategies were offered after evaluating the results and current disaster management. This study showed that SPEI-3 was the best method to determine dry and wet periods in Central Java during 1980-2010, and its correlation to MEI was relatively higher than other indices (R2=0.3612). Karanganyar is the least vulnerable region to drought (DVI=0.36) and Rembang has the highest DVI (0.59). Since numerous stakeholders are responsible for managing water availability for different sectors, then proposed improvements for current agricultural mitigation strategies are focused on government, farmers, public water supplier, and coastal residents and their particular measures.

Multi-Hazard Analysis in Gunungkidul Regency Using Spatial Multi-Criteria Evaluation

This study has two aims: to determine the spatial distribution of multi-hazard levels and to discover the interactions, interdependencies, and effects that cascade among hazards in Gunungkidul Regency, Special Region of Yogyakarta. A multi-hazard map was created with a scale of 1:250,000 and modelled using SMCE (Spatial Multi-Criteria Evaluation). The conditioning factors used included slope, rainfall, historical data, river distance, geomorphology, land cover, lithology, and fault distance. The selected conditioning factors for each hazard were then weighted using weighted overlay analysis. The results showed that the area of Gunungkidul can be included in the high-risk category for floods, since the probability of flooding is 56.72%, the probability of landslides is 9.14%, that of drought is 48.86%, and that of seismic disturbance is 20.83%. (Multi-hazard maps are created by overlaying flood, landslide, seismic, and drought hazard maps.) After these risk factors were calculated, the regions on the multi-hazard map were re-categorized into five hazard classes. All areas in Gunungkidul Regency have multiple hazards, with risk factors of different magnitudes. The interaction between hazards can generate new hazards that are called cascading hazards. The cascading hazards in the study area are most likely to occur in the north of Gunungkidul Regency with its very high seismic and landslide hazard risk factors, due to the geological and geomorphological conditions of the Baturagung Structural Hills.

Future drought risks in the Yellow River Basin and suggestions for targeted response

Drought risk has posed severe challenges to social development and human security in the Yellow River Basin (YRB), which is vulnerable to water scarcity. When dealing with drought, the insufficient coordination among various departments caused by the uncertainty of the comprehensive drought risk under climate change could lead to water conflict. Therefore, in this study, the drought risk changes in the YRB under shared socioeconomic pathway (SSP) scenario 5–8.5 were assessed by integrating the temporally dynamic hazard with the static vulnerability and exposure. Then, suggestions for drought risk management were developed according to the spatial differentiation of the drought risk characteristics. The results show that the drought hazard may increase as the standardized precipitation evapotranspiration index (SPEI) decreases from the baseline (1985–2014; −0.04 ± 0.26) to the mid-term period (2041–2070; −0.09 ± 0.21), and may decrease as the SPEI increases (0.14/10 yr) significantly (p < 0.01) during the long-term period (2071–2100). As a result, the drought risk in the upstream, midstream, and downstream areas may change by 0.26 ± 0.56, −0.05 ± 0.49, and −0.86 ± 0.38 levels in the long term, respectively, compared with the baseline. To reduce the drought risk, it is suggested that agricultural technology be further developed in the southwestern upstream, central upstream, and northern midstream areas; the water management be strengthened in the Hetao Plain and Ordos Plateau; the scale of exposure be controlled in the provincial capitals, southeastern midstream, and downstream areas; and the drought disaster research and early warning system be improved in the areas between 105°E and 110°E. Detailed suggestions for drought risk response were developed for each specific region.

Spatial and Temporal Assessment of Drought Hazard, Vulnerability and Risk in Three Different Climatic Zones in Algeria Using Two Commonly Used Meteorological Indices

Drought is considered a natural hazard and has become a recurrent phenomenon in Algeria since the 1970s. Algeria is characterized by three different climates, namely, sub-humid, semi-arid and arid climates. In this study, we aimed to spatiotemporally assess drought hazard, vulnerability and risk in the three climates of three sub-basins, namely, the Seybouse Maritime, Wadi Djelfa-Hadjia and Wadi M’Zi sub-basins. To this end, the standardized precipitation index (SPI) and the reconnaissance drought index (RDI) were used to evaluate drought physical characteristics on a 12-month timescale, based on precipitation and temperature monthly data covering the period of 1979–2019. High values of the coefficient of determination (R2) (0.76–0.99) confirmed by low values of the root-mean-square error (RMSE) (0.08–0.49) proved that the drought indices displayed a high correlation. Drought hazard and vulnerability were evaluated based on physical characteristics and socioeconomic aspects, respectively. The results led to the determination of a high correlation between the two indices used; the determination of the main drought events; and the mapping of the drought hazard, vulnerability and risk using a geographic information system (GIS). These findings suggest that the SPI provided the highest intensities, while the longest periods and the strongest magnitudes were given by the RDI. The spatiotemporal drought distributions varied with time from station to station and from sub-basin to sub-basin. Risk maps revealed that vulnerability based on socioeconomic factors controls drought risk.

Correlation analysis of agricultural drought risk on wet farming crop and meteorological drought index in the tropical-humid region

In the tropical-humid region, wet farming crops (e.g., paddy) are a common agricultural commodity with a high-water requirement. Usually planted in the Asia monsoon region with a high precipitation rate, these crops are divided into the wet cropping season and the dry cropping season. During the dry cropping season, they are particularly vulnerable to agricultural drought caused by the decrease in precipitation. This study used Indonesia as a case study and is aimed at assessing the agricultural drought risk on a wet farming crop during the dry cropping season by examining the correlation between the drought hazard and its risk. For hazard assessment, Standardized Precipitation Index (SPI) was used to assess the agricultural drought, by using the Global Satellite Mapping of Precipitation (GSMaP) which has 0.1° × 0.1° spatial resolution. The result of correlation analysis between the SPI and drought-affected areas on a city scale showed that SPI-3 in August is the most suitable timescale to assess the agricultural drought in Indonesia. The agricultural drought risk assessment was conducted on the grid scale, where the crop yield estimation model was developed with the help of Normalized Difference Vegetation Index (NDVI). Based on the correlation analysis between SPI-3 and the detrended crop yield as drought risk indicators, the higher yield loss was found in the area above the threshold value (r-value ≤ 0.6) indicating that those areas were more vulnerable to drought, while the area below the threshold value has lower crop yield loss even in the area that was hit by the most severe drought, because the existing irrigation system was able to resist the drought’s impact on crop yield loss.

Quantifying hazard of drought and heat compound extreme events during maize (Zea mays L.) growing season using Magnitude Index and Copula

Hazard assessment is the basic work in the field of disaster risk. For the agricultural field which is seriously affected by extreme events, it is necessary to carry out hazard assessment of compound extreme events (CEEs) to increase the accuracy of risk assessment. First, in this study, the SMDI and TCI were used to characterize the spatial and temporal distribution patterns of agricultural drought and heat, respectively, and the drought and heat compound extreme events (DHCEEs) were identified by characterizing the drought and heat events based on runs theory. Then, the compound event magnitude index (CEMI) was constructed by fitting the non-transcendent probabilities. next, the optimal copula function of severity and duration of DHCEEs was screened, and the fitted probabilities were used in the hazard assessment. The hazard assessment model of DHCEEs is constructed by considering the occurrence probability, severity, and duration. We evaluated the hazard of all DHCEEs identified in the Songliao Plain from 1990 to 2020. The results show that the whole study area is affected by agricultural drought, and heat mainly affects the western region. CEMI can effectively determine the severity of DHCEEs. In the study area, 46.51% of the DHCEEs have a hazard less than 0.1, and 2.71% have a hazard greater than 0.5. The event that had the biggest hazard occurred in 2001, and the proportion of high hazard compound events gradually increased after 2000. Similar compound extreme events are gaining attention in important food-producing regions around the world, and the hazard assessment model constructed in this study can be used to assess crop damage from compound extreme events in real-time, increasing the relevance and accuracy of risk assessment.