Socioeconomic Drought Research Articles

Spatiotemporal Drought Risk Assessment Considering Resilience and Heterogeneous Vulnerability Factors: Lempa Transboundary River Basin in The Central American Dry Corridor

Drought characterization and risk assessment are of great significance due to drought’s negative impact on human health, economy, and ecosystem. This paper investigates drought characterization and risk assessment in the Lempa River basin in Central America. We applied the Standardized Evapotranspiration Deficit Index (SEDI) for drought characterization and drought hazard index (DHI) calculation. Although SEDI’s applicability is theoretically proven, it has been rarely applied. Drought risk is generally derived from the interactions between drought hazard (DHI) and vulnerability (DVI) indices but neglects resilience’s inherent impact. Accordingly, we propose incorporating DHI, DVI, and drought resilience index (DREI) to calculate drought risk index (DRI). Since system factors are not equally vulnerable, i.e., they are heterogeneous, our methodology applies the Analytic Hierarchy Process (AHP) to find the weights of the selected factors for the DVI computation. Finally, we propose a geometric mean method for DRI calculation. Results show a rise in DHI during 2006–2010 that affected DRI. We depict the applicability of SEDI via its relationship with El Nino-La Nina and El Salvador’s cereal production. This research provides a systematic drought risk assessment approach that is useful for decision-makers to allocate resources more smartly or intervene in Drought Risk Reduction (DRR). This research is also useful for those interested in socioeconomic drought.

Developing a new socio-economic drought index for monitoring drought proliferation: a case study of Upper Ewaso Ngiro River Basin in Kenya

The study focused on developing a novel socio-economic drought index (SeDI) for monitoring the severity of drought in a dry basin ecosystem dominated by nomadic pastoralists. The study utilized the domestic water deficit index, bareness index, normalized difference vegetation index, and water accessibility index as the input variables. An ensembled stochastic framework that coupled the 3D Euclidean feature space algorithm, least-squares adjustment, and iteration was used to derive the new SeDI. This approach minimized the uncertainties propagated by the stochastic nature of the input variables that has been a major bottleneck exhibited by the existing models. The regression analyses between the simulated SeDI and the observed ground river discharge registered a correlation coefficient (r) of -0.84 and a p-value of 0.02, while the correlation between the Hull's score-derived SeDI and ground river discharge registered a correlation coefficient (r) of -0.75 and a p-value of 0.05. The assessment revealed that the newly derived SeDI was more sensitive to the river discharge than the Hull's score-derived SeDI. The SeDI's classification results for the period between 1986 and 2018 revealed that only January 2009 manifested a significant slight severity level covering about 12.4% of the basin. Additionally, the results indicated that the basin exhibited a moderate severity level ranging between 85 and 96%, a severe level ranging between 2.2 and 13.3%, and an extreme level ranging between 0.73 and 1.17%. The derived SeDI would serve as an early warning tool necessary for increasing the resilience to climate-related risks and offer support in reducing the loss of life and livelihood.

Evaluation of Socio-Economic Drought Risk over Bundelkhand Region of India using Analytic Hierarchy Process (AHP) and Geo-Spatial Techniques

The Bundelkhand region situated in the central part of India has a long history of droughts. Although recurrent drought events in this region are controlled by the climatic variables, its unique soil, and physiography, the adversities associated with this devastating hazard largely depend upon the coping capacity of the local communities. Hence, estimating the socio-economic vulnerability of drought is necessary for adopting specific mitigation strategies to reduce the adverse impacts of drought. In this study, we explored the potentiality of geographical information system (GIS)-based analytic hierarchy process (AHP) for assessing drought risk in the Bundelkhand region from socio-economic perspective. The 10-day composite Satellite Pour l'Observation de la Terre Vegetation (SPOT-VGT) Normalized Difference Vegetation Index (NDVI) (1998–2013) dataset was used for computing the Vegetation Condition Index (VCI), a satellite-derived agricultural drought index for monitoring spatio-temporal dynamics of drought. NDVI maps of each year were assessed for mapping drought frequency. On the other hand, the socio-economic vulnerability of drought was estimated using five relevant parameters, viz. population density, marginalized population, cultivators, agricultural labours, and literacy rate, with employing AHP in a GIS platform. The pairwise comparison method was used for estimating the weights of each criterion. Most of the districts under hot semi-arid agro-climatic zone located in the Uttar Pradesh (UP) part of Bundelkhand are highly vulnerable to socio-economic drought, mainly due to high density of population and extensive agricultural activities. Out of the total area under highly vulnerable zone (27.8%), about 20% fall under semi-arid agro-ecological zone covering a large part of UP. The Madhya Pradesh (MP) part of Bundelkhand, located under the hot sub-humid agro-ecological zone, is comparatively less vulnerable to socio-economic drought. A substantial portion of this area is covered by forest, and the percentage of the total population involved in agricultural activities is relatively less. The study reveals that near about half of the total area is under threat to high (20.1%) and very high (29.1%) risk of socio-economic drought. Most of this drought risk zone falls under UP part of Bundelkhand. It is a matter of deep concern as this extensive fertile plain produces various cash crops, as well as cereals; therefore, high drought risk over this region needs a suitable strategy to mitigate the adversities of the hazard.

A multi-scale daily SPEI dataset for drought characterization at observation stations over mainland China from 1961 to 2018

Abstract. The monthly standardized precipitation evapotranspiration index (SPEI) can be used to monitor and assess drought characteristics with 1-month or longer drought duration. Based on data from 1961 to 2018 at 427 meteorological stations across mainland China, we developed a daily SPEI dataset to overcome the shortcoming of the coarse temporal scale of monthly SPEI. Our dataset not only can be used to identify the start and end dates of drought events, but also can be used to investigate the meteorological, agricultural, hydrological, and socioeconomic droughts with a different timescales. In the present study, the SPEI data with 3-month (about 90 d) timescale were taken as a demonstration example to analyze spatial distribution and temporal changes in drought conditions for mainland China. The SPEI data with a 3-month (about 90 d) timescale showed no obvious intensifying trends in terms of severity, duration, and frequency of drought events from 1961 to 2018. Our drought dataset serves as a unique resource with daily resolution to a variety of research communities including meteorology, geography, and natural hazard studies. The daily SPEI dataset developed is free, open, and publicly available from this study. The dataset with daily SPEI is publicly available via the figshare portal (Wang et al., 2020c), with https://doi.org/10.6084/m9.figshare.12568280.Highlights. A multi-scale daily SPEI dataset was developed across mainland China from 1961 to 2018. The daily SPEI dataset can be used to identify the start and end days of the drought event. The developed daily SPEI dataset in this study is free, open, and publicly available.

Socioeconomic Drought in a Mexican Semi-arid City: Monterrey Metropolitan Area, a Case Study

The Monterrey Metropolitan Area (MMA) is located in northeastern Mexico in a semi-arid region. As in other areas of the world, prolonged and severe meteorological droughts are recurrent. Meteorological droughts affect the level of dam reservoirs, rivers, and groundwater (aquifers) in the region to the extent they become hydrological droughts which in turn may contribute to socioeconomic droughts. The recent dry event (2011–2013) in northern Mexico severely affected various socioeconomic sectors and may serve as an example of future climatic and hydrologic conditions in this region. Meteorological droughts in northeastern Mexico, mostly induced by anomalously intense subsidence, frequently result in hydrological droughts and intense pressure in the water resources services of the Monterrey Metropolitan Area (MMA), one of the largest cities in Mexico. Landfalling tropical cyclones entering northeastern Mexico historically have alleviated water crises during prolonged droughts. In 2013, the rains from tropical cyclone Ingrid helped to recover water levels in the system of dam reservoirs that provides water to the MMA. However, water management is only one part of a complex socioeconomic system that must respond to the growing demands for water in a region where aquifers are already overexploited. Trends in the atmospheric circulation indicate that droughts in the region may become more severe in the coming decades. Improved water management programs and protocols should be considered in addition to closer reviews of the hydraulic infrastructure. Water transfers from one region to another should be carefully planned because solving a problem in one place may adversely affect another. The use of climate information may be critical to avoidance of water conflicts in the future.

Understanding farmers' risk perception to drought vulnerability in Balochistan, Pakistan

Frequent occurrence of drought is a major challenge to the farmers in the drought prone district of Balochistan province, Pakistan. The agricultural communities are facing threat to agricultural production and livestock due to socio-economic drought in the study area. The Socio-economic drought refers to the conditions in which water supply flops sustaining water demand, resulting in adverse effects on society, economy and environment. The intensity of drought impacts is normally analyzed through meteorological, agricultural and hydrological indices. However, this paper presents a study based on interviews to analyze farmer's risk perceptions, attitude and awareness towards socio-economic drought and risks associated with it. The study relies on a survey of 265 farm households, following a structured questionnaire, focus group discussions and key informant interviews. Results of the study revealed that farmers perceived a continuous variability in climate for the last two decades and identified drought as the most prevalent disaster in the region. Economic reliance on agriculture and livestock, abolishment of surface water resources, depletion of groundwater and insufficient supply of electricity has further increased their vulnerability to drought. Reduction in agriculture and livestock production as well as loss of employment were the immediate economic impacts of the socio-economic drought in the study area. Social impacts such as migration to other places, increase in social crimes, drop out of schoolchildren and impacts on health and festivals were also reported. The environmental impacts included constant increase in temperature, decrease in rainfall intensity and non-climatic factors. Understanding of farmer's risk perception to drought vulnerability may contribute in assisting policy makers for the most appropriate intervention strategies.

Spatial and Temporal Analysis of Dry and Wet Spells in Upper Awash River Basin, Ethiopia

This study aimed to analyze the probability of the occurrence of dry/wet spell rainfall using the Markov chain model in the Upper Awash River Basin, Ethiopia. The rainfall analysis was conducted in the short rainy (Belg) and long rainy (Kiremt) seasons on a dekadal (10–day) scale over a 30-year period. In the Belg season, continuous, three-dekad dry spells were prevalent at all stations. Persistent dry spells might result in meteorological, hydrological, and socio-economic drought (in that order) and merge with the Kiremt season. The consecutive wet dekads of the Kiremt season indicate a higher probability of wet dekads at all stations, except Metehara. This station experienced a short duration (dekads 20–23) of wet spells, in which precipitation is more than 50% likely. Nevertheless, surplus rainwater may be recorded at Debrezeit and Wonji only in the Kiremt season because of a higher probability of wet spells in most dekads (dekads 19–24). At these stations, rainfall can be harvested for better water management practices to supply irrigation during the dry season, to conserve moisture, and to reduce erosion. This reduces the vulnerability of the farmers around the river basin, particularly in areas where dry spell dekads are dominant.

Socioeconomic Drought Under Growing Population and Changing Climate: A New Index Considering the Resilience of a Regional Water Resources System

AbstractSocioeconomic drought occurs when water supply from a regional water resources system cannot meet the water demands. Even if a socioeconomic drought ends, the antecedent water deficit may continue to have impacts for some time, thus influencing the resilience of a regional water resources system. To take this into account, especially under growing population and changing climate, this study develops a new method through integrating a new index, Water Resources System Resilience Index (WRSRI), into socioeconomic drought event identification. The new index represents the percentage of the antecedent water deficit for a socioeconomic drought that can be recovered from the excess water during subsequent periods through analyzing records of a historical drought event. The methodology, implemented on the East River Basin in South China, involves three major steps: (1) calculation of WRSRI value; (2) analysis of key features of identified future socioeconomic drought events, that is, total number, longest duration (LD), and percentage on different drought levels; and (3) sensitivity analysis of WRSRI based on a total of 52 streamflow data sets generated from General Circulation Model outputs and using a macroscale hydrologic model. The results indicate that, for each data set, the total number decreases with an increase in WRSRI but the LD increases; moreover, for most data sets, the LD is less sensitive within the WRSRI range of [0, 0.6]. The outcomes of this study can enhance our capability in more effectively assessing the resilience of a regional water resources system, especially under changing future socioeconomic and environmental conditions.

Assessing future socioeconomic drought events under a changing climate over the Pearl River basin in South China

Study regionPearl River basin (PRB) in South China. Study focusThis study aims to assess future socioeconomic drought events under a changing climate over the study region. Variable Infiltration Capacity (VIC) model is used to simulate the streamflow in the PRB during the period of 2020–2099, and 48 projected precipitation datasets from General Circulation Models (GCMs) are selected to drive the VIC model at 0.5° × 0.5° spatial resolution and daily temporal resolution. Then, the minimum in-stream water requirement (MIWR) of the PRB is determined, and trend analysis of the simulated streamflow is conducted. Socioeconomic drought index (SEDI) is used to detect the occurrence of socioeconomic drought event, and further, the impact of the reservoirs in the PRB on drought analysis is evaluated. New hydrological insights for the regionBased on any dataset, nearly one hundred socioeconomic drought events at different severity levels can be identified in the PRB; however, most of them, especially those at severe and extreme levels, can be mitigated through reservoir operation, i.e., reserving at least 40 % of the total manageable storage capacity (TMSC) in the reservoirs. Overall, this study can improve the recognition of future socioeconomic drought events, which is of great value for our society to effectively assess the impacts of climate change and water projects on sustainable water resources utilization in such river basins.

A Probabilistic Approach for Characterization of Sub-Annual Socioeconomic Drought Intensity-Duration-Frequency (IDF) Relationships in a Changing Environment

Changes in climate, land use, and population can increase annual and interannual variability of socioeconomic droughts in water-scarce regions. This study develops a probabilistic approach to improve characterization of sub-annual socioeconomic drought intensity-duration-frequency (IDF) relationships under shifts in water supply and demand conditions. A mixture Gamma-Generalized Pareto (Gamma-GPD) model is proposed to enhance characterization of both the non-extreme and extreme socioeconomic droughts. Subsequently, the mixture model is used to determine sub-annual socioeconomic drought intensity-duration-frequency (IDF) relationships, return period, amplification factor, and drought risk. The application of the framework is demonstrated for the City of Fort Collins (Colorado, USA) water supply system. The water demand and supply time series for the 1985–2065 are estimated using the Integrated Urban water Model (IUWM) and the Soil and Water Assessment Tool (SWAT), respectively, with climate forcing from statistically downscaled CMIP5 projections. The results from the case study indicate that the mixture model leads to enhanced estimation of sub-annual socioeconomic drought frequencies, particularly for extreme events. The probabilistic approach presented in this study provides a procedure to update sub-annual socioeconomic drought IDF curves while taking into account changes in water supply and demand conditions.

Large-Scale Linkages of Socioeconomic Drought with Climate Variability and Its Evolution Characteristics in Northwest China

Socioeconomic drought is one of the most frequent natural disasters in the world and is closely related to human life. The main cause of socioeconomic drought is the contradiction between water supply and demand; hence, as local reservoirs play a major role in improving water supply and coping with extreme climate, it is reasonable to estimate socioeconomic drought based on reservoir operations. The multivariate standardized reliability and resilience index (MSRRI) is utilized to evaluate socioeconomic drought, considering the characteristics of reservoir management and storage water resources. Therefore, with the MSRRI, this study takes the Heihe River Basin in northwestern China, which is controlled by two reservoirs dominating the upstream and downstream regions, as a case study to reveal the evolution characteristics of socioeconomic drought in the basin and the external impacts of climate variability. The results showed that (1) the drought intensity in the up-midstream region is stronger than that in the downstream region; in view of the hysteresis in the downstream region, the occurrence of drought in the up-midstream region could be regarded as an early warning to implement preventive measures in the downstream region; (2) an increasing trend in socioeconomic drought throughout the basin exists on both monthly and annual scales, which indicates that the increasing possibility of drought should be effectively addressed; (3) cross wavelet analysis indicated that the large-scale climate indices contribute to the variations in the socioeconomic droughts throughout the basin, indicating that climate variability may provide a reference for managers to deal with socioeconomic drought in the HRB.

Spatio-temporal characterisation of droughts using selected indices in Upper Tana River watershed, Kenya

Monitoring and assessment of drought is key to modelling, impact assessment, mitigation and prediction of occurrence. The Upper Tana River watershed hosts two of Kenya's main water towers, Mt. Kenya and Aberdare Ranges, and is increasingly under threat from reduced water levels in the river basins due to unsustainable anthropogenic activities. The occurrence of drought in the region often exacerbates the impact of such activities on the natural resource-base. The study evaluated temporal and spatial characteristics of meteorological drought in Upper Tana Watershed using remotely sensed data from 1981 to 2018. Climate Hazard Group InfraRed Precipitation with Station (CHIRPS) and Modern-Era Retro-Analysis for Research and Applications-Assimilation Model (MERRA) products provided precipitation and temperature data via Google Earth Engine platform. GeoClim was used in the retrieval of Standardised Precipitation Index (SPI), while Standardised Precipitation and Evapotranspiration Index (SPEI) data were downloaded from SPEI Global Drought Monitor. Values for these datasets were plotted against time to facilitate temporal analysis of the drought. Spatially, the most intense meteorological drought period was from 2007 to 2009 in that the years were hit by severe drought for three consecutive years that covered the entire watershed. Temporally, drought incidences were observed in 1982, 1989, 1994, 2000, 2006, and 2011 and 2017. Both SPI and SPEI indices showed similar drought years. Drought mitigation measures should be implemented across the watershed. The findings provide insights that can be used by natural resource management practitioners in; drought forecasting, early warning systems, and in planning and management of water resources within the watershed. We recommend characterisation of the other types of droughts, agricultural and socio-economic droughts, for a holistic understanding of their spatial-temporal manifestations and the impact on the livelihoods of the watershed.

پایش مکانی و زمانی خشکسالی کشاورزی در اراضی تحت کشت گندم با استفاده از شاخص بارش استاندارد‌شده (مطالعه موردی غرب استان گلستان)

مدیریت منطقی برای مقابله با خشکسالی، ایجاد نظام مدیریتی و ارائه اطلاعات صحیح در مقیاس‏های زمانی مختلف امری لازم و ضروری است. شاخص­های خشکسالی از طریق ارزیابی ساده و کمی این پدیده، ابزار کارآمدی برای تحلیل خشکسالی هستند. این مطالعه با هدف پایش مکانی و زمانی خشکسالی کشاورزی در اراضی گندم با استفاده از شاخص بارش استاندارد­شده (SPI) در غرب استان گلستان انجام شد. برای این منظور، در سال‏های 1379 تا 1395 شهرستان­های آق‌قلا، علی‏آباد کتول، گرگان، بندر‏ گز، بندر ‏ترکمن و کردکوی از آمار بارندگی 15 ایستگاه با طول دوره آماری (30 ساله) مشترک از سال 1363 تا 1395 استفاده شد. پس از محاسبه شاخص بارش استاندارد­شده و همبستگی بهتر شاخص SPI سه ماهه منتهی به اردیبهشت‏ماه با میانگین عملکرد گندم، نقشه این شاخص با روش درون­یابی‏ کریجینگ معمولی تهیه و پهنه­بندی شد و سپس به ارزیابی و بررسی خشکسالی پرداخته شد. برای تهیه نقشه ریسک خشکسالی ابتدا نقشه‌های شاخص SPI3 منتهی به اردیبهشت‏ماه طی یک دوره 17 ساله (1379 تا 1395) به‌صورت دودویی (بولین) طبقه‏بندی شدند. سپس از ترکیب نقشه­های بولینی به‌دست آمده نقشه فراوانی وقوع خشکسالی تهیه شد. با استفاده از نقشه­های احتمال فراوانی خشکسالی شاخص­ SPI، نقشه ریسک خشکسالی کشاورزی نهایی تولید شد. با بررسی نقشه‏های شدت خشکسالی و ریسک خشکسالی در این مطالعه، شاخص SPI سه‌ماهه جهت بررسی الگوهای خشکسالی در ابعاد زمانی و مکانی مختلف و شدت آن در دوره‏های خشکسالی و مرطوب مؤثر شناخته شد. هم‌چنین، نتایج نشان داد که شش شهرستان مورد مطالعه در استان گلستان به دو منطقه خطرپذیر از نظر خشکسالی (شامل خطر شدید و خیلی شدید) طبقه‏بندی شده‏است. نقشه ریسک نشان می‏دهد که در دوره آماری 1379 تا 1395 بخش گسترده‏ای از منطقه مطالعاتی (حدود 98 درصد) در معرض خطر خشکسالی شدید قرار گرفته ‏است. هم‌چنین بخش کوچکی از شمال شهرستان بندر ترکمن (حدود دو درصد از کل منطقه) خطر خشکسالی بسیار شدید را تجربه کرده‏است. در واقع دامنه نوسانات خشکسالی در این منطقه به‌دلیل هم­جواری با صحرای ترکمنستان و وضعیت آب‌وهوایی خشک و نیمه­خشک بیش‌تر بوده و این مناطق دارای پتانسیل حساسیت به خشکسالی می‏باشند. نتایج نشان داد عملکرد گندم در شهرستان‏های آق‏قلا، علی‏آباد کتول، بندر‏گز، گرگان و کردکوی همبستگی مثبت و معنی­داری با مقادیر SPI3 منتهی به اردیبهشت ماه داشت. این رابطه می­تواند هشداری برای تأثیر خشکسالی هواشناسی (به‌خصوص در مناطق مستعد خشکسالی) بر تولید محصولات کشاورزی باشد و نشان می­دهد که SPI3 می­تواند به پیش­بینی کاهش تولید ناشی از خشکسالی کمک کند.

The extreme drought of 1842 in Europe as described by both documentary data and instrumental measurements

Abstract. Extreme droughts are weather phenomena of considerable importance, involving significant environmental and societal impacts. While those that have occurred in the comparatively recent period of instrumental measurement are identified and dated on the basis of systematic, machine-standardized meteorological and hydrological observations, droughts that took place in the pre-instrumental period are usually described only through the medium of documentary evidence. The extreme drought of 1842 in Europe presents a case in which information from documentary data can be combined with systematic instrumental observations. Seasonal, gridded European precipitation totals are used herein to describe general DJF, MAM, and JJA precipitation patterns. Annual variations in monthly temperatures and precipitation at individual stations are expressed with respect to a 1961–1990 reference period, supplemented by calculation of selected drought indices (Standardized Precipitation Index, SPI; Standardized Precipitation Evapotranspiration Index, SPEI; and Palmer Z index). The mean circulation patterns during the driest months are elucidated by means of sea-level pressure (SLP) maps, the North Atlantic Oscillation Index (NAOI), and the Central European Zonal Index (CEZI). Generally drier patterns in 1842 prevailed in January–February and at various intensities between April and August. The driest patterns in 1842 occurred in a broad zonal belt extending from France to eastern central Europe. A range of documentary data is used to describe the peculiarities of agricultural, hydrological, and socio-economic droughts, with particular attention to environmental and societal impacts and human responses to them. Although overall grain yields were not very strongly influenced, a particularly bad hay harvest, no aftermath (hay from a second cut), and low potato yields led to severe problems, especially for those who raised cattle. Finally, the 1842 drought is discussed in terms of long-term drought variability, European tree-ring-based scPDSI (self-calibrated Palmer Drought Severity Index) reconstruction, and the broader context of societal impacts.

Analyses of the Spatial Pattern of Drought Risk in Tigray Region, Northern Ethiopia

Drought risk index uses the meteorological drought hazard index and the socioeconomic drought vulnerability aspects to assess the level of drought risk in an area. This study examined the extent and spatial pattern of drought risk in, Tigray region, one of the recurrently drought-affected areas in Ethiopia. Monthly Gridded Climatic Research Unit (CRU) Time-series (TS) data version 4.01 data on twelve selected stations, was used to calculate the Standard Precipitation and Evapotranspiration Index (SPEI). Additionally, socioeconomic data collected from various sources were also used to assess drought vulnerability. Drought risk levels of each district were, then calculated based on the drought hazard and drought vulnerability indices. The results indicated that about 44.1% of districts were categorized under high to very high drought risk levels. However, the test of variation, using one-way ANOVA, has shown no significant variation in drought risk between districts at p < 0.05. The results of spatial autocorrelation test also indicated the presence of clustered pattern of drought risk. The study has also revealed high and very high drought risk levels largely clustered in the western, eastern and southern zones of the study area. Overall, the study has demonstrated the importance of integrating socioeconomic and climate data for comprehensive drought risk characterization, which can be used as an input for drought management planning.Keywords: Drought, Vulnerability, Risk, Spatial-pattern

Copulas-based bivariate socioeconomic drought dynamic risk assessment in a changing environment

As the only unnatural phenomenon among the four drought types, socioeconomic drought exerts direct negative impacts on socioeconomic system. Socioeconomic drought is closely related to regional sustainable development, which however is received the least attention. Therefore, this study aims to construct a practical framework to fully assess socioeconomic drought dynamic risk. Based on an improved Multivariate Standardized Reliability and Resilience Index (IMSRRI) and copulas function, the joint return periods of different grades drought were calculated to assess the drought risk from a macro perspective, while three drought risk indicators (resilience, vulnerability, and exposure) were adopted for drought risk assessment from a micro perspective. In addition, a 30-year sliding window was applied on the IMSRRI series to explore the dynamic drought risk in a changing environment. Furthermore, the linkages between drought risk indicators and teleconnection factors (Arctic Oscillation (AO), El Niño Southern Oscillation (ENSO), and Pacific Decadal Oscillation (PDO)) were explored. The upper Yellow River Basin (UYRB) was selected as a case study, and the study period is from 1959 to 2010. Results indicate that: (1) the ‘∩’ joint return periods of the moderate, severe and extreme drought in the UYRB were 5.03, 11.7, and 40.78 years, respectively, and the resilience, vulnerability and exposure values of socioeconomic drought were 0.11, 14.38, and 0.37, respectively; (2) the year of 1995 was the turning point of socioeconomic drought risk (before 1995, socioeconomic drought risk was decreasing, after 1995, socioeconomic drought risk was increasing), which corresponds well to that of the IMSRRI series; and (3) socioeconomic drought risk is significantly associated with teleconnection factors, with the descending correlation order of PDO > ENSO > AO. This study sheds new insights into socioeconomic drought dynamic risk assessment in a changing environment.

Socio-economic drought assessment in Lake Mead, USA, based on a multivariate standardized water-scarcity index

ABSTRACT Drought events are increasing worldwide. Socio-economic drought is the least investigated type of drought, and is the only type for which water demand is taken into consideration. In this research, socio-economic drought was studied in Lake Mead, USA, using a multivariate standardized water-scarcity index (MSWSI) over the period 1990–2014, combining two water-scarcity indices based on time series of inflow, outflow, reservoir storage, and water demand. The inflow and outflow were determined from streamgage data, and reservoir storage from lake level data; demand was based on water pumped by the Southern Nevada Water Authority. Missing observations in input streamgage data were filled through regression modeling. The results indicate that Lake Mead has been in socio-economic drought since 2000, with the most severe drought occurring between 2006 and 2012, and the highest intensity drought in April–July 2014. The Lake Mead droughts revealed through the MSWSI are consistent with those reported in US Drought Monitor (USDM) products. The temporal behavior of MSWSI provides an insight into the socio-economic effects of droughts not captured by USDM products.

Use of meteorological data for identification of drought

ABSTRACT Drought is called a creeping disaster because of the way it develops. It can be categorized as meteorological, hydrological, agriculture and socioeconomic drought. In the present study, meteorological data in terms of monthly rainfall for 45 years (from 1971 to 2016) were used for identification of drought in Anantapur district of Andhra Pradesh in India. Different drought indices like percentage of departure (), percent of normal, decile and Standardized Precipitation Index (SPI) were derived. Percentage of departure ( is identified based on rate deviation of yearly precipitation from the long-term yearly mean precipitation. Percent of normal is obtained by dividing the precipitation by normal precipitation for the time being considered. It interprets the deficient of rainfall from wet season to dry season and vice versa as precipitation deviation from the normal annual precipitation. Decile is calculated by interpolation technique based on ranking given to the rainfall distribution. SPI values were generated based on gamma distribution of precipitation data. Compared with other indices, SPI shows better variation with small change in precipitation because of its statistical nature. Therefore, it is suggested that SPI as a stand-alone indicator needs to be interpreted with caution to assess the intensity of drought.

Assessing socio-economic drought evolution characteristics and their possible meteorological driving force

Droughts are among the most damaging environmental disasters that may have destructive damages on societal properties and lives. Generally, socio-economic drought occurs when water resources systems could not fulfil the water demand. Additionally, it is not to be overlooked the role of local reservoirs in modifying uneven distribution of water and coping with climatic extremes. This study examined the evolution characteristics of the socio-economic droughts via applying a Multivariate Standardized Reliability and Resilience Index (MSRRI). Furthermore, the influences of anomalous atmospheric circulation on the socio-economic droughts were explored through adopting the cross wavelet analysis to investigate the meteorological driving force behind the socio-economic droughts. Results mainly indicated that (1) the MSRRI has proven to be effective in evaluating socio-economic droughts for its integration of inflow-demand reliability and water storage resilience indexes; (2) the MSRRI series in Datong River Basin (DRB) has a non-significant increasing trend at annual scale with apparent periods (17 and 22 years) and (3) the comprehensive effects of ENSO, EASM and PNA contribute to the socio-economic drought variations, and the ENSO has strongest impacts than others. The findings in this study benefit local socioeconomic drought mitigation and water resources planning and management.

Assessing socioeconomic drought based on an improved Multivariate Standardized Reliability and Resilience Index

Among the four types of drought, socioeconomic drought, which has a direct impact on human production and daily life, is the least understood. The current socioeconomic drought index proposed by Mehran et al. (2015) is the Multivariate Standardized Reliability and Resilience Index (MSRRI), which combines information on inflow-demand reliability and water storage resilience. The MSRRI resolves the problem of difficult quantification of socioeconomic drought. However, the MSRRI also has some flaws such as ignoring reservoir dispatching regulations and the relationship between water supply and water demand. Therefore, this study aims to improve the MSRRI through combining reservoir operation processes and actual water supply and demand and proposing an improved MSRRI (IMSRRI). The upper Yellow River Basin (UYRB) was selected as a case study, and comparison between the MSRRI and IMSRRI was conducted. The evolution characteristics of the IMSRRI series in the UYRB were examined. Additionally, cross-wavelet analysis was utilized to reveal the associations between the IMSRRI series and climate factors. Results indicated that: (1) compared with the MSRRI, the IMSRRI could capture the onset and termination of socioeconomic drought more accurately and reasonably due to the fusion of reservoir scheduling characteristics at a smaller timescale; (2) the socioeconomic drought in the UYRB had dramatically changed during the past few decades (the IMSRRI series showed a significantly decreasing trend and two change points (1995 and 1975) were captured); and (3) the El Niño Southern Oscillation (ENSO) and the Atlantic Oscillation (AO) showed significant influences on the short period (the influences of ENSO were stronger than AO), while sunspots had the strongest impacts on the long period.