Framework for Monitoring the Spatiotemporal Distribution and Clustering of Drought Characteristics in Hunan Province

Drought is a widespread phenomenon in the context of global climate change. Owing to the geographical location of Hunan Province in the middle reaches of Yangtze River and the abundance of forests area in this region with a large population, there is a need to focus on the impacts of drought for devising policies. The spatiotemporal distribution scheme of a given area must be determined to plan water management and protect ecosystems effectively. This study proposes a framework for exploring the spatiotemporal distribution model of drought using comprehensive surveys of historical meteorological stations, which consists of two parts, namely the characteristics of drought extraction in the spatiotemporal distribution and drought models discovered by the clustering method. Firstly, we utilized the run theory to extract drought characteristics, such as drought duration, drought severity, and drought intensity. Secondly, the K-means clustering method was adopted to explore the distribution patterns on the basis of the drought characteristics. Lastly, the method was applied to Hunan Province. Results show that historical drought conditions can be monitored with their characteristics of spatiotemporal variability. Three drought distribution clusters exist in this region. Cluster 1 in western Hunan tends to be a long-term, low-intensity drought, cluster 2 in the southern part tends to be a short-term, high-intensity drought, and cluster 3 in the central part is prone to severe drought. The proposed framework is flexible as it allows parameters to be adjusted and extraction methods to achieve reasonable results for a given area.

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Spatio-temporal evaluation of drought characteristics in the Dhasan basin

MAUSAM ◽

10.54302/mausam.v69i4.423 ◽

2021 ◽

Vol 69 (4) ◽

pp. 589-598

Author(s):

SASWAT KUMAR KAR ◽

R. M. SINGH ◽

T. THOMAS

Keyword(s):

Time Scale ◽

Monsoon Season ◽

Standardized Precipitation Index ◽

Rain Gauge ◽

Drought Severity ◽

Severe Drought ◽

Multiple Time ◽

Drought Duration ◽

Drought Characteristics ◽

Drought Conditions

ABSTRACT. The meteorological drought characteristics including onset, departure, duration, severity as well as intensity have been evaluated mainly for monsoon season at all the three rain gauge stations located in Dhasan basin. The Standardized Precipitation Index (SPI) has been applied to understand and quantify the drought severity on multiple time scale (1, 3, 6, 12 and 24 months). The spatiotemporal analysis of drought based on 3-month SPI has also carried out to identify drought years and the regions of the study area which is under the grip of continuous drought events. Based on the 3-month SPI, major drought events have been identified. The maximum drought severity of -11.17 occurred during November 1991 to August 1992 having the longest duration of 10 months, in the area under Sagar rain gauging station. The onset of most of the drought events in the basin take place during the beginning of Kharif season and terminate by the end of August or September, so affect the agricultural crops severely. The spatial variation indicates that during June 2002, about 55.74% of basin area was experiencing severe drought conditions, followed by 35.29% area under moderate drought condition and only 8.97% area faced mild drought conditions. The inter-relationship among the drought duration, number of drought events, drought severity and time scale have been studied.

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Projection of Future Drought Characteristics under Multiple Drought Indices

Water ◽

10.3390/w13091238 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1238

Author(s):

Muhammad Imran Khan ◽

Xingye Zhu ◽

Xiaoping Jiang ◽

Qaisar Saddique ◽

Muhammad Saifullah ◽

...

Keyword(s):

Series Data ◽

Natural Phenomenon ◽

Drought Indices ◽

Drought Severity ◽

Severe Drought ◽

Drought Analysis ◽

Songhua River ◽

Drought Intensity ◽

Drought Characteristics ◽

Rcp 8.5

Drought is a natural phenomenon caused by the variability of climate. This study was conducted in the Songhua River Basin of China. The drought events were estimated by using the Reconnaissance Drought Index (RDI) and Standardized Precipitation Index (SPI) which are based on precipitation (P) and potential evapotranspiration (PET) data. Furthermore, drought characteristics were identified for the assessment of drought trends in the study area. Short term (3 months) and long term (12 months) projected meteorological droughts were identified by using these drought indices. Future climate precipitation and temperature time series data (2021–2099) of various Representative Concentration Pathways (RCPs) were estimated by using outputs of the Global Circulation Model downscaled with a statistical methodology. The results showed that RCP 4.5 have a greater number of moderate drought events as compared to RCP 2.6 and RCP 8.5. Moreover, it was also noted that RCP 8.5 (40 events) and RCP 4.5 (38 events) showed a higher number of severe droughts on 12-month drought analysis in the study area. A severe drought conditions projected between 2073 and 2076 with drought severity (DS-1.66) and drought intensity (DI-0.42) while extreme drying trends were projected between 2097 and 2099 with drought severity (DS-1.85) and drought intensity (DI-0.62). It was also observed that Precipitation Decile predicted a greater number of years under deficit conditions under RCP 2.6. Overall results revealed that more severe droughts are expected to occur during the late phase (2050–2099) by using RDI and SPI. A comparative analysis of 3- and 12-month drying trends showed that RDI is prevailing during the 12-month drought analysis while almost both drought indices (RDI and SPI) indicated same behavior of drought identification at 3-month drought analysis between 2021 and 2099 in the research area. The results of study will help to evaluate the risk of future drought in the study area and be beneficial for the researcher to make an appropriate mitigation strategy.

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Elucidating Diverse Drought Characteristics from Two Meteorological Drought Indices (SPI and SPEI) in China

Journal of Hydrometeorology ◽

10.1175/jhm-d-19-0290.1 ◽

2020 ◽

Vol 21 (7) ◽

pp. 1513-1530 ◽

Cited By ~ 3

Author(s):

Lingcheng Li ◽

Dunxian She ◽

Hui Zheng ◽

Peirong Lin ◽

Zong-Liang Yang

Keyword(s):

Clustering Algorithm ◽

Potential Evapotranspiration ◽

Standardized Precipitation Index ◽

Three Dimensional ◽

Meteorological Drought ◽

Drought Indices ◽

Drought Severity ◽

Severe Drought ◽

Small Areas ◽

Drought Characteristics

AbstractThis study elucidates drought characteristics in China during 1980–2015 using two commonly used meteorological drought indices: standardized precipitation index (SPI) and standardized precipitation–evapotranspiration index (SPEI). The results show that SPEI characterizes an overall increase in drought severity, area, and frequency during 1998–2015 compared with those during 1980–97, mainly due to the increasing potential evapotranspiration. By contrast, SPI does not reveal this phenomenon since precipitation does not exhibit a significant change overall. We further identify individual drought events using the three-dimensional (i.e., longitude, latitude, and time) clustering algorithm and apply the severity–area–duration (SAD) method to examine the drought spatiotemporal dynamics. Compared to SPI, SPEI identifies a lower drought frequency but with larger total drought areas overall. Additionally, SPEI identifies a greater number of severe drought events but a smaller number of slight drought events than the SPI. Approximately 30% of SPI-detected drought grids are not identified as drought by SPEI, and 40% of SPEI-detected drought grids are not recognized as drought by SPI. Both indices can roughly capture the major drought events, but SPEI-detected drought events are overall more severe than SPI. From the SAD analysis, SPI tends to identify drought as more severe over small areas within 1 million km2 and short durations less than 2 months, whereas SPEI tends to delineate drought as more severe across expansive areas larger than 3 million km2 and periods longer than 3 months. Given the fact that potential evapotranspiration increases in a warming climate, this study suggests SPEI may be more suitable than SPI in monitoring droughts under climate change.

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Evaluation of Drought Characteristics in Iraq using SC-PDSI

Science Journal of University of Zakho ◽

10.25271/sjuoz.2018.6.4.547 ◽

2018 ◽

Vol 6 (4) ◽

pp. 177-182

Author(s):

Thaer K. Jawad ◽

Osama T. Al-Taai ◽

Yaseen K. Al-Timimi

Keyword(s):

Severity Index ◽

Climatic Research Unit ◽

Drought Severity ◽

Arid Zones ◽

Severe Drought ◽

Drought Characteristics ◽

Dry Spell ◽

Desert Zone ◽

Semi Arid ◽

Run Theory

Evaluation of drought characteristics in Iraq by analysis annual growing season of Self-Calibrating Palmer Drought Severity Index (SC-PDSI) for three climatic zones using run theory method. The efficiency of SC-PDSI for drought monitoring was examined from compared with Rainfall Departure from the mean (RD) for three zones (Arid and Semi-Arid, Steppes and Desert) for the period 1981-2015, were derived from Climatic Research Unit (CRU). The spatial interpolation techniques in ArcGIS package has been used, to cover the whole extent of country and extracting the zones. Statistical methods were applied to compute the probability of drought events at every zone. The results showed the years 1999, 2000, 2008 and 2009 experienced droughts in all zones except the desert zone where was experienced severe drought in 2012, while the years 1982 and 1988 experienced received precipitation above-average in all zones. The values of standard deviation of precipitation were compared with precipitation anomalies for each zone, the drier seasons are (2007-2008) and (1998-1999) in all Zones. The wetter seasons are (1987-1988) in Arid and Semi-Arid and Steppes zone, (1994-1995) and (1997-1998) are wetter seasons in Desert zone. Using run theory, the steppes zone have experienced more severe droughts than other zones evaluated in this study and the most susceptible areas to dry spell are steppes and Arid and Semi-Arid Zones during study period. While the desert zone experienced less droughts.

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Spatiotemporal Analysis of Drought Characteristics in Song-Liao River Basin in China

Advances in Meteorology ◽

10.1155/2017/3484363 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 3

Author(s):

Xiaojing Shen ◽

Xu Wu ◽

Xinmin Xie ◽

Zhenzhen Ma ◽

Meijian Yang

Keyword(s):

River Basin ◽

Abrupt Change ◽

Spatiotemporal Analysis ◽

Drought Severity ◽

Drought Duration ◽

Affected Area ◽

Average Temperature ◽

Drought Characteristics ◽

Long Term Trends ◽

Drought Occurrence

The monthly accumulated precipitation and monthly average temperature of 117 meteorological stations in Song-Liao River Basin (SLRB) were used to calculate the Standardized Precipitation Evapotranspiration Indices (SPEI) to analyze the drought characteristics, including long-term trends, drought affected area, climate abrupt change, intensive drought occurrence regions, and drought durations during 1964–2013 with the support of GIS. The Area Drought Severity (ADS), a comprehensive index, is proposed to assess both the variations of drought degree and the extent of the drought affected area. The results revealed that (1) the drought happening probability and degree are rising and the affected areas of all degrees of drought have an increasing trend during the last 50 years; (2) there is a climate abrupt change which occurred in around 1994, and the area with declining SPEI is larger than that with declining SPI, which could be due to the rising temperature after the climate abrupt change; (3) all degrees of drought occurrence probability increased, and the intensive drought occurrence regions altered from the northern SLRB to the southwestern SLRB after the climate abrupt change; (4) the drought duration increased from 1994, and the increased drought durations occurred in most parts of SLRB.

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Spatiotemporal Variation of Drought Characteristics Based on Standardized Precipitation Index in Central Java over 1990-2010

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/893/1/012022 ◽

2021 ◽

Vol 893 (1) ◽

pp. 012022

Author(s):

Misnawati ◽

R Boer ◽

F Ramdhani

Keyword(s):

Standardized Precipitation Index ◽

Rain Gauge ◽

Precipitation Index ◽

Extreme Drought ◽

Drought Severity ◽

Severe Drought ◽

Drought Event ◽

Drought Characteristics ◽

Central Java ◽

Moderate Drought

Abstract Drought is a natural hazard that results from a deficiency of precipitation, leading to low soil moisture and river flows, reduced storage in reservoirs, and less groundwater recharge. This study investigates the spatial variations of drought characteristics (drought event frequency, duration, severity, and intensity). This study using the Standardized Precipitation Index (SPI) to analyse the drought characteristics in Central Java during 1990-2010. The rain gauge station data and CHIRPS rainfall data over Central Java is used to calculate the SPI index. The SPI was calculated at multiple timescales (1-, 3-, 6-, 12-, 24- and 48-month), the run theory was used for identification and characterization of drought events. Analysis of drought characteristics by SPI from 1990 to 2010 shows the longest drought event is four months, the maximum drought severity is 6.06, and the maximum drought intensity is 2.02. El Nino year probability drought occurrence reached 100% in August for moderate drought, severe drought, and extreme drought category, whereas the probability drought occurrences in the Normal and La Nina year range 0-70% for moderate drought, 0-50% for severe drought category and 0-40% for extreme drought category. The results of this study may help inform researchers and local policymakers to develop strategies for managing drought.

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Global Warming Impacts on Severe Drought Characteristics in Asia Monsoon Region

Water ◽

10.3390/w12051360 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1360 ◽

Cited By ~ 2

Author(s):

Jeong-Bae Kim ◽

Jae-Min So ◽

Deg-Hyo Bae

Keyword(s):

Global Warming ◽

Standardized Precipitation Index ◽

Global Climate Models ◽

Cold Climate ◽

Drought Severity ◽

Severe Drought ◽

Monsoon Region ◽

Climate Zones ◽

Drought Characteristics ◽

Dry Spell

Climate change influences the changes in drought features. This study assesses the changes in severe drought characteristics over the Asian monsoon region responding to 1.5 and 2.0 °C of global average temperature increases above preindustrial levels. Based on the selected 5 global climate models, the drought characteristics are analyzed according to different regional climate zones using the standardized precipitation index. Under global warming, the severity and frequency of severe drought (i.e., SPI <−1.5) are modulated by the changes in seasonal and regional precipitation features regardless of the region. Due to the different regional change trends, global warming is likely to aggravate (or alleviate) severe drought in warm (or dry/cold) climate zones. For seasonal analysis, the ranges of changes in drought severity (and frequency) are −11.5%~6.1% (and −57.1%~23.2%) under 1.5 and 2.0 °C of warming compared to reference condition. The significant decreases in drought frequency are indicated in all climate zones due to the increasing precipitation tendency. In general, drought features under global warming closely tend to be affected by the changes in the amount of precipitation as well as the changes in dry spell length. As the warming enhanced, the spatial variation of drought severity will be increased across climate zones, which can lead to increased water stress over Asia. This study demonstrates that precipitation characteristic changes can explicitly modulate severe regional drought features.

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Drought assessment in the Dongliao River basin: traditional approaches vs. generalized drought assessment index based on water resources systems

Natural Hazards and Earth System Science ◽

10.5194/nhess-15-1889-2015 ◽

2015 ◽

Vol 15 (8) ◽

pp. 1889-1906 ◽

Cited By ~ 3

Author(s):

B. S. Weng ◽

D. H. Yan ◽

H. Wang ◽

J. H. Liu ◽

Z. Y. Yang ◽

...

Keyword(s):

Water Resources ◽

River Basin ◽

Drought Severity ◽

Severe Drought ◽

Drought Duration ◽

Assessment Index ◽

Drought Assessment ◽

Water Resources Systems ◽

Traditional Approaches ◽

The Impact

Abstract. Drought is firstly a resource issue, and with its development it evolves into a disaster issue. Drought events usually occur in a determinate but a random manner. Drought has become one of the major factors to affect sustainable socioeconomic development. In this paper, we propose the generalized drought assessment index (GDAI) based on water resources systems for assessing drought events. The GDAI considers water supply and water demand using a distributed hydrological model. We demonstrate the use of the proposed index in the Dongliao River basin in northeastern China. The results simulated by the GDAI are compared to observed drought disaster records in the Dongliao River basin. In addition, the temporal distribution of drought events and the spatial distribution of drought frequency from the GDAI are compared with the traditional approaches in general (i.e., standard precipitation index, Palmer drought severity index and rate of water deficit index). Then, generalized drought times, generalized drought duration, and generalized drought severity were calculated by theory of runs. Application of said runs at various drought levels (i.e., mild drought, moderate drought, severe drought, and extreme drought) during the period 1960–2010 shows that the centers of gravity of them all distribute in the middle reaches of Dongliao River basin, and change with time. The proposed methodology may help water managers in water-stressed regions to quantify the impact of drought, and consequently, to make decisions for coping with drought.

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Drought Risk Assessment in Central Asia Using a Probabilistic Copula Function Approach

Water ◽

10.3390/w12020421 ◽

2020 ◽

Vol 12 (2) ◽

pp. 421 ◽

Cited By ~ 3

Author(s):

Leyuan Zhang ◽

Yi Wang ◽

Yaning Chen ◽

Yifei Bai ◽

Qifei Zhang

Keyword(s):

Central Asia ◽

Three Dimensional ◽

Joint Probability ◽

Copula Function ◽

Drought Severity ◽

Drought Risk ◽

Severe Drought ◽

Drought Event ◽

Drought Duration ◽

Climate Conditions

The aim of this research is to adopt the Standardized Precipitation Evapotranspiration Index (SPEI) with three-month timescale (SPEI-3) to analyze drought risk in Central Asia. Based on SPEI-3, a drought event is defined through Run Theory. The multidimensional Copula function based on drought risk is then comprehensively assessed through the multivariable joint probability of drought duration, drought severity, and drought peak. Results indicate as follows: (1) the climate conditions were relatively stable from 1961–1974 and 1979–1995, while they varied from 1974 to 1979 and from 1995 to 2017, during which the study areas experienced recurrent drought. (2) The drought characteristics show noticeable spatial variability, and the severity of drought is larger in the west than in the east in Central Asia; the duration of drought contrasts with the severity of drought spatially. (3) The drought risk in the three-dimensional joint distribution is similar to the analysis using the two-dimensional distributions, and the study area has gone through the process from moderate to slight and then to severe drought risk from 1961 to 2017; the return period studied in this paper was calculated to be 80% probability in about two years.

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Uncertainties in runoff projection and hydrological drought assessment over Gharesu basin under CMIP5 RCP scenarios

Journal of Water and Climate Change ◽

10.2166/wcc.2020.088 ◽

2020 ◽

Vol 11 (S1) ◽

pp. 145-163 ◽

Cited By ~ 1

Author(s):

S. M. Ashrafi ◽

H. Gholami ◽

M. R. Najafi

Keyword(s):

River Basin ◽

General Circulation ◽

General Circulation Models ◽

Hydrological Drought ◽

Drought Severity ◽

Historical Period ◽

Drought Duration ◽

Rcp Scenarios ◽

Drought Assessment ◽

Drought Characteristics

Abstract Hydrological drought plays an important role in planning and managing water resources systems to meet increasing water demands due to population growth. In this study, the effects of climate change on the hydrological drought characteristics of the Gharasu basin, as one of the major sub-basins of the Karkheh river basin, are investigated. This river basin has experienced severe droughts, and floods, in recent years. The uncertainties in projected drought conditions are characterized based on a suite of 34 general circulation models (GCMs). Based on hydrological simulations over the historical period, 12 GCMs are selected to estimate projected runoff values and the corresponding streamflow drought index (SDI) in the future period. The ‘run theory’ is applied to evaluate the drought characteristics under Representative Concentration Pathways (RCPs) 4.5 and 8.5 emission scenarios. Results show that uncertainties of drought projection under RCP8.5 are higher than under RCP4.5, where among different drought characteristics, the maximum uncertainty is detected for drought severity and maximum drought duration. Moreover, the uncertainty of drought projection in wet periods is greater than that in dry periods.

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