Time-Varying Meteorological Drought Index for a Changing Climate

2020 ◽  
Author(s):  
Rajendran Vinnarasi ◽  
Chandrika Thulaseedharan Dhanya
Keyword(s):  
Drought Index ◽  
Temporal Dynamics ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Time Varying ◽  
Precipitation Series ◽  
Statistical Parameters ◽  
Potential Index ◽  
Distribution Parameters ◽  
Nonstationary Climate

<p>Drought is considered as one of the most complicated natural disasters, whose adverse effects span over different domains such as agriculture, ecosystem, and economy. One of the widely used meteorological drought index is Standardized Precipitation Index (SPI), which is based on the stationary assumption (i.e., the statistical parameters does not change over time). Nevertheless, numerous studies have reported that the precipitation series has undergone remarkable changes, which emphasizes the need for developing a drought index incorporating the dynamic behavior of the precipitation. Hence, in this study, a non-stationary SPI (NSPI) is developed to capture the temporal dynamics of the precipitation and to identify the meteorological drought-prone areas over India. Before modelling, the non-stationarity in the distribution parameters of precipitation series are detected. If non-stationary is observed in any of the parameters, then that particular parameter is modelled as non-stationary, otherwise it is modelled as stationary. The proposed index provides a probability-based description of drought status and its uncertainty bounds, which are computed using Bayesian Inference. Results reveals that the traditional SPI is biased by the lowest magnitude of precipitation leading to overestimation of drought where frequent severe dry events are clustered, which is overcome by NSPI. Additionally, NSPI captured the historical drought, capturing the temporal dynamics of precipitation series in India and is more reliable than SPI. The proposed NSPI is found to be a potential index for drought monitoring in a nonstationary climate.</p>

scholarly journals Comparison of Projection in Meteorological and Hydrological Droughts in the Cheongmicheon Watershed for RCP4.5 and SSP2-4.5

2021 ◽  
Vol 13 (4) ◽  
pp. 2066
Author(s):  
Jin Hyuck Kim ◽  
Jang Hyun Sung ◽  
Eun-Sung Chung ◽  
Sang Ug Kim ◽  
Minwoo Son ◽  
...  
Keyword(s):  
General Circulation ◽  
Drought Index ◽  
Standardized Precipitation Index ◽  
Coupled Model ◽  
Meteorological Drought ◽  
General Circulation Models ◽  
Hydrological Drought ◽  
Drought Indices ◽  
Drought Period ◽  
Drought Characteristics

Due to the recent appearance of shares socioeconomic pathway (SSP) scenarios, there have been many studies that compare the results between Coupled Model Intercomparison Project (CMIP)5 and CMIP6 general circulation models (GCMs). This study attempted to project future drought characteristics in the Cheongmicheon watershed using SSP2-4.5 of Australian Community Climate and Earth System Simulator-coupled model (ACCESS-CM2) in addition to Representative Concentration Pathway (RCP) 4.5 of ACCESS 1-3 of the same institute. The historical precipitation and temperature data of ACCESS-CM2 were generated better than those of ACCESS 1-3. Two meteorological drought indices, namely, Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) were used to project meteorological drought while a hydrological drought index, Standardized Streamflow Index (SDI), was used to project the hydrological drought characteristics. The metrological data of GCMs were bias-corrected using quantile mapping method and the streamflow was obtained using Soil and Water Assessment Tool (SWAT) and bias-corrected meteorological data. As a result, there were large differences of drought occurrences and severities between RCP4.5 and SSP2-4.5 for the values of SPI, SPEI, and SDI. The differences in the minimum values of drought index between near (2021–2060) and far futures (2061–2100) were very small in SSP2-4.5, while those in RCP4.5 were very large. In addition, the longest drought period from SDI was the largest because the variation in precipitation usually affects the streamflow with a lag. Therefore, it was concluded that it is important to consider both CMIP5 and CMIP6 GCMs in establishing the drought countermeasures for the future period.

scholarly journals Application of Meteorological and Hydrological Drought Indices to Establish Drought Classification Maps of the Ba River Basin in Vietnam

Hydrology ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 49 ◽  
Author(s):  
Doan Quang Tri ◽  
Tran Tho Dat ◽  
Dinh Duc Truong
Keyword(s):  
River Basin ◽  
Drought Index ◽  
Assessment Tool ◽  
Swat Model ◽  
Standardized Precipitation Index ◽  
Aridity Index ◽  
Meteorological Drought ◽  
Hydrological Drought ◽  
Drought Indices ◽  
Calibration And Validation

The objective of this study was to establish drought classification maps to simulate and calculate the lack of discharge in the Ba River basin in Vietnam. The maps were established using three meteorological drought indices (the Standardized Precipitation Index (SPI), the Drought Index (J), and the Ped Index (Ped)), the Soil and Water Assessment Tool (SWAT) model, and the hydrological drought index (KDrought). The results from the calculation of the SPI, Aridity Index (AI), and Ped at three stations (An Khe, Ayunpa, and MDrak) showed that the J index was suitable for the study area. Based on the J index, an extreme drought was predicted to occur at the Ayunpa, An Khe, and MDrak stations. During the calibration process, the SWAT Calibration Uncertainties Program (SWAT-CUP) model, with automatic algorithms, was used to select the parameters to optimize the SWAT model. For the calibration and validation, the observed discharge at two hydrology stations, An Khe and Cung Son, from the periods 1981–1991 and 1992–2002, respectively, were used. The simulated discharge was found to be acceptable, with the Nash–Sutcliffe efficiency (NSE), Percent bias (PBIAS), and R2 reaching good levels in both calibration and validation. The results from the calculation of the drought index (KDrought), and the established drought classification maps in 2016, showed that the most affected areas were the communes of the Gia Lai and Dak Lak provinces. The results from the simulation and calculations were found to be consistent with the situation that occurred in practice. The application of meteorological and hydrological drought indices, as well as the hydrological model, to support impact assessments of drought classification in space and time, as well as the establishment of forecasting and warning maps, will help managers to effectively plan policy responses to drought.

scholarly journals Mediterranean-Scale Drought: Regional Datasets for Exceptional Meteorological Drought Events during 1975–2019

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 941
Author(s):  
Shifa Mathbout ◽  
Joan Albert Lopez-Bustins ◽  
Dominic Royé ◽  
Javier Martin-Vide
Keyword(s):  
Drought Index ◽  
Standardized Precipitation Index ◽  
Principal Component ◽  
Meteorological Drought ◽  
Western Mediterranean ◽  
Drought Indices ◽  
Drought Event ◽  
Evaporative Demand ◽  
Atmospheric Circulation Patterns ◽  
Dry Conditions

Drought is one of the most complex climate-related phenomena and is expected to progressively affect our lives by causing very serious environmental and socioeconomic damage by the end of the 21st century. In this study, we have extracted a dataset of exceptional meteorological drought events between 1975 and 2019 at the country and subregional scales. Each drought event was described by its start and end date, intensity, severity, duration, areal extent, peak month and peak area. To define such drought events and their characteristics, separate analyses based on three drought indices were performed at 12-month timescale: the Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), and the Reconnaissance Drought Index (RDI). A multivariate combined drought index (DXI) was developed by merging the previous three indices for more understanding of droughts’ features at the country and subregional levels. Principal component analysis (PCA) was used to identify five different drought subregions based on DXI-12 values for 312 Mediterranean stations and a new special score was defined to classify the multi-subregional exceptional drought events across the Mediterranean Basin (MED). The results indicated that extensive drought events occurred more frequently since the late 1990s, showing several drought hotspots in the last decades in the southeastern Mediterranean and northwest Africa. In addition, the results showed that the most severe events were more detected when more than single drought index was used. The highest percentage area under drought was also observed through combining the variations of three drought indices. Furthermore, the drought area in both dry and humid areas in the MED has also experienced a remarkable increase since the late 1990s. Based on a comparison of the drought events during the two periods—1975–1996 and 1997–2019—we find that the current dry conditions in the MED are more severe, intense, and frequent than the earlier period; moreover, the strongest dry conditions occurred in last two decades. The SPEI-12 and RDI-12 have a higher capacity in providing a more comprehensive description of the dry conditions because of the inclusion of temperature or atmospheric evaporative demand in their scheme. A complex range of atmospheric circulation patterns, particularly the Western Mediterranean Oscillation (WeMO) and East Atlantic/West Russia (EATL/WRUS), appear to play an important role in severe, intense and region-wide droughts, including the two most severe droughts, 1999–2001 and 2007–2012, with lesser influence of the NAO, ULMO and SCAND.

scholarly journals ANALYSIS OF METEOROLOGICAL DATA AND DROUGHT IN THE LOWER NORTHERN PART OF THAILAND

2021 ◽  
Vol 9 (2) ◽  
pp. 467-476
Author(s):  
Daniel Derajew Demmsie, Et. al.
Keyword(s):  
Drought Index ◽  
Meteorological Data ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Rain Gauge ◽  
Northern Region ◽  
Environmental Conservation ◽  
Annual Rainfall ◽  
Dry Conditions ◽  
The Standardized Precipitation Index

The study areas include Phitsanulok, Nakhon Sawan and Khamphang Phet. The meteorological data between 1986 and 2015, was collected from the meteorological rain gauge stations situated in the Lower Northern part of Thailand. This study involves the analysis of the meteorological data and drought trends in the northern region of Thailand from 1986 to 2015. The study used the Meteorological Drought Monitor software (MDM) to analyze the drought trends through the Standardized Precipitation Index (SPI). From this analysis, we then presented the results through graphs representing the trends in meteorological parameters and drought index.  The results showed that, the annual rainfall measurement of the regions analyzed continues to reduce consistently as the temperature increase. The drought trends in these provinces observed to considerably lean towards dry conditions. Nakhon Sawan, for instance, experienced extreme drought in 1977(SPI =-2.5) and moderate wetness in 2013. Kampheang Phet recorded moderately wet conditions (SPI =1.5) in 2013 and 2014 years, and near normal conditions (SPI = -1.1) in 1996. Lastly, Phitsanulok was majorly comprised of moderately dry and severely dry, especially for 2015(SPI =-22). From the findings, awareness should be created to foster the need for environmental conservation, besides to improve environmental protection and the levels of precipitation.                       

scholarly journals Meteorological Drought Analysis with Different Indices for the Betwa River Basin, India

2021 ◽  
Author(s):  
Uttam Singh ◽  
Pooja Agarwal ◽  
Pramod Kumar Sharma
Keyword(s):  
River Basin ◽  
Drought Index ◽  
Meteorological Data ◽  
Groundwater Resources ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Drought Indices ◽  
Trend Test ◽  
Time Step ◽  
Drought Assessment

Abstract Climate change is adversely affecting the development, management, and planning of surface and groundwater resources. The meteorological drought becomes a severe natural problem, and it can occur in any climatic region of the world. So, monitoring and minimizing drought is a crucial stage for analyzing and predicting drought impacts. A single drought index can't assess each aspect of the meteorological drought. In this study, we considered seven drought indices such as the Standardized Precipitation Index (SPI), China Z Index (CZI), Modified China Z Index (MCZI), Percent Normal drought index (PNI), Deciles Index (DI), Rainfall Anomaly Index (RAI), and Z-score index (ZSI). The drought was analyzed for 3, 6, 9, and 12 months’ time-step, and drought classification and threshold values were estimated. SPI showed maximum correlation values 0.389, 0.412, 0.560,and 0.996 for 3, 6, 9,and 12-month time steps compared to the other drought indices. The value of correlation is increased with the increase in time step for all drought indices; therefore, the accuracy of drought assessment also increases with an increase in time step. The Mann-Kendall's trend test was analyzed at a 5% level of significance for drought assessments. The drought magnitude and severity of the Betwa river basin were estimated based on the meteorological data (Rainfall) for the year between 1970 to 2014.

scholarly journals Probabilistic hydrological drought index forecasting based on meteorological drought index using Archimedean copulas

2019 ◽  
Vol 50 (5) ◽  
pp. 1230-1250 ◽  
Author(s):  
Majid Dehghani ◽  
Bahram Saghafian ◽  
Mansoor Zargar
Keyword(s):  
Drought Index ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Hydrological Drought ◽  
Dependence Structure ◽  
Monthly Precipitation ◽  
Drought Condition ◽  
Copula Functions ◽  
Hydrological Droughts ◽  
Hydrological Drought Index

Abstract Hydrological drought forecasting is considered a key component in water resources risk management. As sustained meteorological drought may lead to hydrological drought over time, it is conceptually feasible to capitalize on the dependency between the meteorological and hydrological droughts while trying to forecast the latter. As such, copula functions are powerful tools to study the propagation of meteorological droughts into hydrological droughts. In this research, monthly precipitation and discharge time series were used to determine Standardized Precipitation Index (SPI) and Standardized Hydrological Drought Index (SHDI) at different time scales which quantify the state of meteorological and hydrological droughts, respectively. Five Archimedean copula functions were adopted to model the dependence structure between meteorological/hydrological drought indices. The Clayton copula was identified for further investigation based on the p-value. Next, the conditional probability and the matrix of forecasted class transitions were calculated. Results indicated that the next month's SHDI class forecasting is promising with less than 10% error. Moreover, extreme and severe meteorological drought classes lead to hydrological drought condition with a more than 70% probability. Other classes of meteorological drought/wet conditions lead to normal hydrological (drought) condition with less than 50% probability and to wet hydrological condition with over 20% probability.

scholarly journals Evaluation of Extreme Cold and Drought over the Mongolian Plateau

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 74 ◽  
Author(s):  
Zhaofei Liu ◽  
Zhijun Yao ◽  
Heqing Huang ◽  
Batbuyan Batjav ◽  
Rui Wang
Keyword(s):  
Drought Index ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Drought Indices ◽  
Mongolian Plateau ◽  
The Past ◽  
Extreme Cold ◽  
Two Indices ◽  
High Consistency ◽  
The Standardized Precipitation Index

Extreme cold and meteorological drought in the Mongolian Plateau (MP) were investigated during 1969–2017. Several drought indices were evaluated by analyzing recorded historical drought data in the Chinese region of the MP. The evaluated drought indices were then applied to detect drought characteristics in the entire MP. The trends of extreme cold indices showed that the climate of the MP has warmed during the past 49 years; however, the frequency of cold day/night has increased in the Mongolian region. The climate of Mongolia has also become colder in the spring season. The comprehensive meteorological drought index (CMDI) and the standardized precipitation index with a six-month scale (SPI6) exhibited better performances, showing high consistency between the spatial patterns of the two indices. However, drought represented by the SPI6 was enhanced greater than that expressed by the CMDI. Drought in the MP has been enhanced during the past 49 years, particularly in the Ordos and Alashan plateaus and the Xiliao River basin in China. Moreover, drought has been enhanced from August to October, particularly in the Mongolian region. However, spring drought has shown a weakening trend, which has been beneficial for agriculture and husbandry sectors in some regions of the MP.

scholarly journals Different Agricultural Responses to Extreme Drought Events in Neighboring Counties of South and North Korea

2019 ◽  
Vol 11 (15) ◽  
pp. 1773 ◽  
Author(s):  
Jae-Hyun Ryu ◽  
Kyung-Soo Han ◽  
Yang-Won Lee ◽  
No-Wook Park ◽  
Sungwook Hong ◽  
...  
Keyword(s):  
North Korea ◽  
Drought Index ◽  
Management Practices ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Condition Index ◽  
Agricultural Management ◽  
Agricultural Drought ◽  
Extreme Drought ◽  
Drought Indices

Satellite-based remote sensing techniques have been widely used to monitor droughts spanning large areas. Various agricultural drought indices have been developed to assess the intensity of agricultural drought and to detect damaged crop areas. However, to better understand the responses of agricultural drought to meteorological drought, agricultural management practices should be taken into consideration. This study aims to evaluate the responses to drought under different forms of agricultural management for the extreme drought that occurred on the Korean Peninsula in 2014 and 2015. The 3-month standardized precipitation index (SPI3) and the 3-month vegetation health index (VHI3) were selected as a meteorological drought index and an agricultural drought index, respectively. VHI3, which comprises the 3-month temperature condition index (TCI3) and the 3-month vegetation condition index (VCI3), differed significantly in the study area during the extreme drought. VCI3 had a different response to the lack of precipitation in South and North Korea because it was affected by irrigation. However, the time series of TCI3 were similar in South and North Korea. These results meant that each drought index has different characteristics and should be utilized with caution. Our results are expected to help comprehend the responses of the agricultural drought index on meteorological drought depending on agricultural management.

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