Evaluating The Sensitivity and Applicability of Precipitation-Based and Precipitation-Evapotranspiration-Based Drought Indices To Different Record Periods

Abstract As drought indices are generally calculated based on multi-year historical data spanning periods of at least 30 years, different drought index values at certain times are therefore calculated due to different record lengths, making it difficult to accurately define dry or wet periods in a studied region or station. This investigation assessed the sensitivity and applicability of precipitation-based and precipitation-evapotranspiration-based drought indices, such as the Generalized extreme value drought index (GEVI), Homogeneity index of precipitation and temperature (HI), the K index (K), Precipitation anomaly percentage (Pa), Standardized precipitation evapotranspiration index (SPEI), Standardized precipitation index (SPI), and the China Z index (CZI), to different record lengths on monthly, seasonal and annual time scales. By using monthly, seasonal and annual precipitation and evapotranspiration data from a research station over the period 1961–2017, data over periods of 55, 50, 45, 40, 35 and 30 years were extracted. Analysis of correlation coefficient of all indices, match and non-match, and actual drought and no-drought recognition rate of the indices indicated that K, Pa and SPEI indices recorded better time stability compared to other indices at all time scales across different climatic zones in the study region; the GEVI index recorded the lowest time stability compared to other indices. Results also indicated that the majority of optimal lengths for all stations having the lowest non-match were 41–45 years, with some indices at different time scales being 36–40 years and 46–50 years. In addition, the HI index had the highest actual drought and no-drought recognition rate at almost all climate zones, followed by Pa and SPEI indices. Results from this study indicate that more priority should be given to precipitation-evapotranspiration-based indices when studying a large region; indices with concrete results should be selected when analyzing relatively small regions.

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A novel index for ecological drought monitoring based on ecological water deficit: a case study of Northwestern China

10.5194/egusphere-egu21-5439 ◽

2021 ◽

Author(s):

Tianliang Jiang ◽

Xiaoling Su

Keyword(s):

Water Deficit ◽

Time Scales ◽

Drought Index ◽

Vegetation Index ◽

Standardized Precipitation Index ◽

Northwestern China ◽

Drought Monitoring ◽

Drought Indices ◽

Drought Severity ◽

Different Time Scales

Although the concept of ecological drought was first defined by the Science for Nature and People Partnership (SNAPP) in 2016, there remains no widely accepted drought index for monitoring ecological drought. Therefore, this study constructed a new ecological drought monitoring index, the standardized ecological water deficit index (SEWDI). The SEWDI is based on the difference between ecological water requirements and consumption, referred to as the standardized precipitation index (SPI) method, which was used to monitor ecological drought in Northwestern China (NWRC). The performances of the SEWDI and four widely-used drought indices [standardized root soil moisture index (SSI), self-calibrated Palmer drought index (scPDSI), standardized precipitation-evaporation drought index (SPEI), and SPI) in monitoring ecological drought were evaluated through comparing the Pearson correlations between these indices and the standardized normalized difference vegetation index (SNDVI) under different time scales, wetness, and water use efficiencies (WUEs) of vegetation. Finally, the rotational empirical orthogonal function (REOF) was used to decompose the SEWDI at a 12-month scale in the NWRC during 1982&#8211;2015 to obtain five ecological drought regions. The characteristics of ecological drought in the NWRC, including intensity, duration, and frequency, were extracted using run theory. The results showed that the performance of the SEWDI in monitoring ecological drought was highest among the commonly-used drought indices evaluated under different time scales [average correlation coefficient values (r) between SNDVI and drought indices: SEWDI= 0.34, SSI= 0.24, scPDSI= 0.23, SPI= 0.20, SPEI= 0.18), and the 12-month-scale SEWDI was largely unaffected by wetness and WUE. In addition, the results of the monitoring indicated that serious ecological droughts in the NWRC mainly occurred in 1982&#8211;1986, 1990&#8211;1996, and 2005&#8211;2010, primarily in regions I, II, and V, regions II, and IV, and in region III, IV, and V, respectively. This study provides a robust approach for quantifying ecological drought severity across natural vegetation areas and scientific evidence for governmental decision makers.

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Comparison of the Entropy- and Copula-based Precipitation-Streamflow Drought Indices for Assessing Agricultural Drought in Arid and Semi-arid Coastal Areas of Southern Iran

10.21203/rs.3.rs-943371/v1 ◽

2021 ◽

Author(s):

Javad Bazrafshan ◽

Zahra Azhdari

Keyword(s):

Drought Index ◽

Standardized Precipitation Index ◽

Agricultural Drought ◽

Drought Indices ◽

Drought Severity ◽

Study Region ◽

Southern Iran ◽

Hydrological Droughts ◽

Semi Arid ◽

Meteorological Droughts

Abstract In arid and semi-arid regions, precipitation and seasonal streamflow are the two major sources of water for vegetation. The scarcity of these water sources has a detrimental effect on vegetation cover degradation. The purpose of this research is to study the effect of meteorological and hydrological droughts, and also their combined effects, on vegetation changes in seven coastal sub-basins in southern Iran (part of the Bandar-Sedij and Kol-Mehran catchment). To track meteorological and hydrological droughts, the Standardized Precipitation Index (SPI) and the Streamflow Drought Index (SDI) were used. The copula function and the entropy approach (which is developed in this research) were used to blend individual meteorological and hydrological drought indices, yielding hybrid indices called the Copula-based Drought Index and the Entropy-based Drought Index (EnDI). The single (i.e., SPI and SDI) and hybrid drought indices (CoDI and EnDI) were compared in terms of temporal behavior, drought severity and duration characteristics, drought frequency, and a bivariate analysis of the drought severity-duration return period. The results indicated that the rank correlation (\({r}_{s}\)) between SPI and SDI ranged between 0.327 and 0.726 in the studied sub-basins. However, the two hybrid indices CoDI and EnDI had extremely high correlations (\({r}_{s}\ge 0.9\)). Despite the fact that meteorological droughts benefited both hybrid drought indices more than hydrological droughts, the contribution of meteorological droughts to EnDI was greater than that of CoDI. Over the study region, CoDI reported droughts that were both longer and more severe than those recorded by EnDI. EnDI showed stronger associations with the Normalized Vegetation Difference Index (NDVI) in nearly all the sub-basins, possibly because precipitation has a greater effect on EnDI than it does on CoDI. EnDI was therefore recommended as a superior index for estimating vegetation droughts throughout the research region.

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Hydrological response to different time scales of climatological drought: an evaluation of the Standardized Precipitation Index in a mountainous Mediterranean basin

Hydrology and Earth System Sciences ◽

10.5194/hess-9-523-2005 ◽

2005 ◽

Vol 9 (5) ◽

pp. 523-533 ◽

Cited By ~ 156

Author(s):

S. M. Vicente-Serrano ◽

J. I. López-Moreno

Keyword(s):

Time Scales ◽

Hydrological Cycle ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Drought Indices ◽

Long Time ◽

The Standardized Precipitation Index ◽

Hydrological Droughts ◽

Different Time Scales

Abstract. At present, the Standardized Precipitation Index (SPI) is the most widely used drought index to provide good estimations about the intensity, magnitude and spatial extent of droughts. The main advantage of the SPI in comparison with other indices is the fact that the SPI enables both determination of drought conditions at different time scales and monitoring of different drought types. It is widely accepted that SPI time scales affect different sub-systems in the hydrological cycle due to the fact that the response of the different water usable sources to precipitation shortages can be very different. The long time scales of SPI are related to hydrological droughts (river flows and reservoir storages). Nevertheless, few analyses empirically verify these statements or the usefulness of the SPI time scales to monitor drought. In this paper, the SPI at different time scales is compared with surface hydrological variables in a big closed basin located in the central Spanish Pyrenees. We provide evidence about the way in which the longer (>12 months) SPI time scales may not be useful for drought quantification in this area. In general, the surface flows respond to short SPI time scales whereas the reservoir storages respond to longer time scales (7–10 months). Nevertheless, important seasonal differences can be identified in the SPI-usable water sources relationships. This suggests that it is necessary to test the drought indices and time scales in relation to their usefulness for monitoring different drought types under different environmental conditions and water demand situations.

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The Evaporative Demand Drought Index. Part II: CONUS-Wide Assessment against Common Drought Indicators

Journal of Hydrometeorology ◽

10.1175/jhm-d-15-0122.1 ◽

2016 ◽

Vol 17 (6) ◽

pp. 1763-1779 ◽

Cited By ~ 48

Author(s):

Daniel J. McEvoy ◽

Justin L. Huntington ◽

Michael T. Hobbins ◽

Andrew Wood ◽

Charles Morton ◽

...

Keyword(s):

United States ◽

Soil Moisture ◽

Time Scales ◽

Drought Index ◽

Standardized Precipitation Index ◽

Stress Index ◽

Multiple Time Scales ◽

Multiple Time ◽

Evaporative Demand ◽

Hydrologic Drought

Abstract Precipitation, soil moisture, and air temperature are the most commonly used climate variables to monitor drought; however, other climatic factors such as solar radiation, wind speed, and humidity can be important drivers in the depletion of soil moisture and evolution and persistence of drought. This work assesses the Evaporative Demand Drought Index (EDDI) at multiple time scales for several hydroclimates as the second part of a two-part study. EDDI and individual evaporative demand components were examined as they relate to the dynamic evolution of flash drought over the central United States, characterization of hydrologic drought over the western United States, and comparison to commonly used drought metrics of the U.S. Drought Monitor (USDM), Standardized Precipitation Index (SPI), Standardized Soil Moisture Index (SSI), and the evaporative stress index (ESI). Two main advantages of EDDI over other drought indices are that it is independent of precipitation (similar to ESI) and it can be decomposed to identify the role individual evaporative drivers have on drought onset and persistence. At short time scales, spatial distributions and time series results illustrate that EDDI often indicates drought onset well in advance of the USDM, SPI, and SSI. Results illustrate the benefits of physically based evaporative demand estimates and demonstrate EDDI’s utility and effectiveness in an easy-to-implement agricultural early warning and long-term hydrologic drought–monitoring tool with potential applications in seasonal forecasting and fire-weather monitoring.

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Dynamical delimitation of the Central American Dry Corridor (CADC) using drought indices and aridity values

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133319860224 ◽

2019 ◽

Vol 43 (5) ◽

pp. 627-642 ◽

Cited By ~ 4

Author(s):

Luis Eduardo Quesada-Hernández ◽

Oscar David Calvo-Solano ◽

Hugo G Hidalgo ◽

Paula M Pérez-Briceño ◽

Eric J Alfaro

Keyword(s):

Drought Index ◽

Pacific Coast ◽

Potential Evapotranspiration ◽

Standardized Precipitation Index ◽

Severity Index ◽

Rainfall Anomaly ◽

Central American ◽

Drought Indices ◽

Drought Severity ◽

Southern Mexico

The Central American Dry Corridor (CADC) is a sub-region in the isthmus that is relatively drier than the rest of the territory. Traditional delineations of the CADC’s boundaries start at the Pacific coast of southern Mexico, stretching south through Central America’s Pacific coast down to northwestern Costa Rica (Guanacaste province). Using drought indices (Standardized Precipitation Index, Modified Rainfall Anomaly Index, Palmer Drought Severity Index, Palmer Hydrological Drought Index, Palmer Drought Z-Index and the Reconnaissance Drought Index) along with a definition of aridity as the ratio of potential evapotranspiration (representing demand of water from the atmosphere) over precipitation (representing the supply of water), we proposed a CADC delineation that changes for normal, dry and wet years. The identification of areas that change their classification during extremely dry conditions is important because these areas may indicate the location of future expansion of aridity associated with climate change. In the same way, the delineation of the CADC during wet extremes allows the identification of locations that remain part of the CADC even during the wettest years and that may require special attention from the authorities.

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Using integrated meteorological and hydrological indices to assess drought characteristics in southern Taiwan

Hydrology Research ◽

10.2166/nh.2019.120 ◽

2019 ◽

Vol 50 (3) ◽

pp. 901-914 ◽

Cited By ~ 3

Author(s):

Hsin-Fu Yeh

Keyword(s):

River Basin ◽

Drought Index ◽

Standardized Precipitation Index ◽

Assessment Method ◽

Drought Indices ◽

Trend Test ◽

Integrated Analysis ◽

Drought Assessment ◽

Southern Taiwan ◽

The Standardized Precipitation Index

Abstract Numerous drought index assessment methods have been developed to investigate droughts. This study proposes a more comprehensive assessment method integrating two drought indices. The Standardized Precipitation Index (SPI) and the Streamflow Drought Index (SDI) are employed to establish an integrated drought assessment method to study the trends and characteristics of droughts in southern Taiwan. The overall SPI and SDI values and the spatial and temporal distributions of droughts within a given year (November to October) revealed consistent general trends. Major droughts occurred in the periods of 1979–1980, 1992–1993, 1994–1995, and 2001–2003. According to the results of the Mann–Kendall trend test and the Theil–Sen estimator analysis, the streamflow data from the Sandimen gauging station in the Ailiao River Basin showed a 30% decrease, suggesting increasing aridity between 1964 and 2003. Hence, in terms of water resources management, special attention should be given to the Ailiao River Basin. The integrated analysis showed different types of droughts occurring in different seasons, and the results are in good agreement with the climatic characteristics of southern Taiwan. This study suggests that droughts cannot be explained fully by the application of a single drought index. Integrated analysis using multiple indices is required.

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Assessment of spatiotemporal characteristics of agro-meteorological drought events based on comparing Standardized Soil Moisture Index, Standardized Precipitation Index and Multivariate Standardized Drought Index

Journal of Water and Climate Change ◽

10.2166/wcc.2020.280 ◽

2020 ◽

Vol 11 (S1) ◽

pp. 1-17 ◽

Cited By ~ 1

Author(s):

Muhammad Imran Khan ◽

Xingye Zhu ◽

Muhammad Arshad ◽

Muhammad Zaman ◽

Yasir Niaz ◽

...

Keyword(s):

Soil Moisture ◽

Drought Index ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Drought Indices ◽

Moisture Index ◽

Drought Characteristics ◽

Soil Moisture Index ◽

The Impact ◽

Standardized Drought Index

Abstract Drought indices that compute drought events by their statistical properties are essential stratagems for the estimation of the impact of drought events on a region. This research presents a quantitative investigation of drought events by analyzing drought characteristics, considering agro-meteorological aspects in the Heilongjiang Province of China during 1980 to 2015. To examine these aspects, the Standardized Soil Moisture Index (SSI), Standardized Precipitation Index (SPI), and Multivariate Standardized Drought Index (MSDI) were used to evaluate the drought characteristics. The results showed that almost half of the extreme and exceptional drought events occurred during 1990–92 and 2004–05. The spatiotemporal analysis of drought characteristics assisted in the estimation of the annual drought frequency (ADF, 1.20–2.70), long-term mean drought duration (MDD, 5–11 months), mean drought severity (MDS, −0.9 to −2.9), and mild conditions of mean drought intensity (MDI, −0.2 to −0.80) over the study area. The results obtained by MSDI reveal the drought onset and termination based on the combination of SPI and SSI, with onset being dominated by SPI and drought persistence being more similar to SSI behavior. The results of this study provide valuable information and can prove to be a reference framework to guide agricultural production in the region.

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Commonly Used Drought Indices as Indicators of Soil Moisture in China

Journal of Hydrometeorology ◽

10.1175/jhm-d-14-0076.1 ◽

2015 ◽

Vol 16 (3) ◽

pp. 1397-1408 ◽

Cited By ~ 43

Author(s):

Hongshuo Wang ◽

Jeffrey C. Rogers ◽

Darla K. Munroe

Keyword(s):

Soil Moisture ◽

Time Scales ◽

Standardized Precipitation Index ◽

Meteorological Drought ◽

Severity Index ◽

Agricultural Drought ◽

Weather Data ◽

Drought Indices ◽

Drought Severity ◽

Better Than

Abstract Soil moisture shortages adversely affecting agriculture are significantly associated with meteorological drought. Because of limited soil moisture observations with which to monitor agricultural drought, characterizing soil moisture using drought indices is of great significance. The relationship between commonly used drought indices and soil moisture is examined here using Chinese surface weather data and calculated station-based drought indices. Outside of northeastern China, surface soil moisture is more affected by drought indices having shorter time scales while deep-layer soil moisture is more related on longer index time scales. Multiscalar drought indices work better than drought indices from two-layer bucket models. The standardized precipitation evapotranspiration index (SPEI) works similarly or better than the standardized precipitation index (SPI) in characterizing soil moisture at different soil layers. In most stations in China, the Z index has a higher correlation with soil moisture at 0–5 cm than the Palmer drought severity index (PDSI), which in turn has a higher correlation with soil moisture at 90–100-cm depth than the Z index. Soil bulk density and soil organic carbon density are the two main soil properties affecting the spatial variations of the soil moisture–drought indices relationship. The study may facilitate agriculture drought monitoring with commonly used drought indices calculated from weather station data.

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A Study on the Estimation of the Occurrence Frequency of Mega-drought by the Characteristics of Drought Damage

10.5194/egusphere-egu2020-11927 ◽

2020 ◽

Author(s):

Song Youngseok ◽

Kim Jinbok ◽

Park Jongun ◽

Park Moojong

Keyword(s):

Drought Index ◽

Standardized Precipitation Index ◽

Development Program ◽

Agricultural Drought ◽

Drought Indices ◽

The Past ◽

Short Period ◽

Recent Climate ◽

The World ◽

Drought Damage

Unlike natural disasters such as typhoons, torrential rains and floods, drought is a disaster caused by long-term effects as well as short-term effects. The effect of drought is caused by damage from a short period of weeks to a long period of years, which causes extensive and enormous damage to agriculture, life, society and economy. In addition, the recent climate change has affected the frequency and scale of rainfall in the global temperature, so it is necessary to prepare measures against it.The past studies on drought have been conducted using drought indexes such as agricultural, meteorological, and hydrological methods to evaluate drought. The representative drought indexes for each drought are Palmer Drought Severity Index (PDSI), Standardized Precipitation Index (SPI), Agricultural drought is Crop Moisture Index (CMI), Crop Specific Drought Index (CSDI), Hydrological drought is Surface Drought Water Supply Index (SWSI), Reclamation Drought Index (RDI) and so on are used. However, these drought indices are only used as a method of predicting the depth of drought, and do not give the actual number of drought occurrences.In this study, we want to determine the frequency of Mega-drought occurrences in consideration of the drought damage characteristics that occurred worldwide from 1900 to 2018. The drought damages in the world were used by EM-DAT (the Emergency Events Database) which manages disaster data in CRED (Centre for Research on the Epidemiology of Disasters). Drought damages occurred in the world from 1900 to 2018 occurred more than once/years in 146 countries. The duration of drought persistence occurred in the country continuously for at least one to 17 years. The purpose of this study is to propose the criteria for mega drought by using the past victim data in connection with the incidence frequency.Acknowledges : This research was supported by a grant(2019-MOIS31-010) from Fundamental Technology Development Program for Extreme Disaster Response funded by Korean Ministry of Interior and Safety(MOIS).<div>&#160;</div>

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Comparison of Meteorological Drought using SPI and SPEI

Civil Engineering Journal ◽

10.28991/cej-2021-03091783 ◽

2021 ◽

Vol 7 (12) ◽

pp. 2130-2149

Author(s):

Shashi Shankar Ojha ◽

Vivekanand Singh ◽

Thendiyath Roshni

Keyword(s):

River Basin ◽

Potential Evapotranspiration ◽

Standardized Precipitation Index ◽

Meteorological Drought ◽

Drought Indices ◽

Resources Management ◽

Drought Assessment ◽

Time Period ◽

Almost All ◽

Effective Water

Drought assessment is crucial for effective water resources management in a river basin. Drought frequency has increased worldwide in recent years due to global warming. In this paper, an attempt is made to assess the meteorological drought in the Punpun river basin, India using two globally accepted drought indices namely, Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). The SPI and SPEI at 1-, 3-, 6-, 9-, and 12-month timescale were obtained to analyze the temporal variability of different drought levels. Correlation analysis of available observed data and gridded data has been carried out and the correlation coefficient was found to be 0.956. Hence gridded rainfall data from the year 1991 to 2020 is used for further analysis. Potential evapotranspiration (PET) used in the calculation of SPEI was computed by the Thornthwaite method. Water deficit was observed throughout as there is a decrease in rainfall and an increase in PET during the selected period. The results show that the period 2004 to 2006 and 2009 to 2010 years are observed as drought periods by both indices for almost all timescale. The intensity and duration of drought have increased after 2004. A negative trend of both the indices have been observed in all seasons on all timescale, which clearly shows a transition from near normal to moderately dry during the selected time period. The highest correlation between both the indices is for the 12-month scale with R² value 0.92 and the RMSE value 0.28. The main outcome of this study is that both SPI and SPEI show a strong correlation on same time scales adopted in this study. The dependency of SPEI on temperature is also observed in this study. Doi: 10.28991/cej-2021-03091783 Full Text: PDF

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