Development and application of SPI generator using open source for analyzing drought at a varying time scale

The Standardized Precipitation Index (SPI) is a probability index that gives a belier representation of abnormal wetness and dryness than any other drought indices. The primary objective of the current study is to develop a comprehensive tool to compute SPI on a spatial basis and analyze spa!iotemporal variability of drought in North West Indian region during 1951-2007 using APHRODITE waler resource data at 0.25-degree resolution. This tool was developed using the python programming language, and the site-packages such as Numpy, Scipy, Ma!plo!lib, Ne!CDF, PyQt were used. The result showed Iha! the SPI time series showed significant inter-annual and multi-decadal variations. In the whole data period, three consecutive droughts have occurred only once, 1999-2002. This prolonged drought hurt the agricultural and water resources sectors over the study area. The computed SPI for the year2002 showed an extreme dry spell over the study area signifying the major drought over India in the same year with a 56% deficit of rainfall in July. The computed 12-month SPI for the year 1996 shows a wet period over the northwestern part of India, especially over Haryana signifying medium to heavy rainfall, conforming 1996 flood. The developed SPI tool, portray a realistic picture of drought scenario over the Northwest region and improve the timely identification of emerging drought conditions that can trigger appropriate responses by the decision makers.

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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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Análisis comparativo de índices de sequía en Andalucía para el periodo 1901-2012

Cuadernos de Investigación Geográfica ◽

10.18172/cig.2946 ◽

2016 ◽

Vol 42 (1) ◽

pp. 67 ◽

Cited By ~ 7

Author(s):

M. Peña-Gallardo ◽

S. R. Gámiz-Fortís ◽

Y. Castro-Diez ◽

M. J. Esteban-Parra

Keyword(s):

Time Windows ◽

Initial Period ◽

Climatic Variability ◽

Standardized Precipitation Index ◽

Meteorological Drought ◽

Precipitation Index ◽

Drought Indices ◽

Global Evaluation ◽

Temporal Behaviour ◽

The Standardized Precipitation Index

The aim of this paper is the analysis of the detection and evolution of droughts occurred in Andalusia for the period 1901-2012, by applying three different drought indices: the Standardized Precipitation Index (SPI), the Standardized Precipitation and Evapotranspiration Index (SPEI) and the Standardized Drought-Precipitation Index (IESP), computed for three time windows from the initial period 1901-2012. This analysis has been carried out after a preliminary study of precipitation trends with the intention of understanding the precipitation behaviour, because this climatic variable is one of the most important in the study of extreme events. The specific objectives of this study are: (1) to investigate and characterize the meteorological drought events, mainly the most important episodes in Andalusia; (2) to provide a global evaluation of the capacities of the three different considered indices in order to characterize the drought in a heterogeneous climatically territory; and (3) to describe the temporal behaviour of precipitation and drought indices series in order to establish the general characteristics of their evolution in Andalusia. The results have shown that not all the indices respond similarly identifying the intensity and duration of dry periods in this kind of region where geographical and climatic variability is one of the main elements to be considered.

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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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Long-Term, Gridded Standardized Precipitation Index for Hawai‘i

Data ◽

10.3390/data5040109 ◽

2020 ◽

Vol 5 (4) ◽

pp. 109

Author(s):

Matthew P. Lucas ◽

Clay Trauernicht ◽

Abby G. Frazier ◽

Tomoaki Miura

Keyword(s):

High Spatial Resolution ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Drought Indices ◽

Drought Severity ◽

Spatially Explicit ◽

Historical Period ◽

The Standardized Precipitation Index ◽

Climatic Information

Spatially explicit, wall-to-wall rainfall data provide foundational climatic information but alone are inadequate for characterizing meteorological, hydrological, agricultural, or ecological drought. The Standardized Precipitation Index (SPI) is one of the most widely used indicators of drought and defines localized conditions of both drought and excess rainfall based on period-specific (e.g., 1-month, 6-month, 12-month) accumulated precipitation relative to multi-year averages. A 93-year (1920–2012), high-resolution (250 m) gridded dataset of monthly rainfall available for the State of Hawai‘i was used to derive gridded, monthly SPI values for 1-, 3-, 6-, 9-, 12-, 24-, 36-, 48-, and 60-month intervals. Gridded SPI data were validated against independent, station-based calculations of SPI provided by the National Weather Service. The gridded SPI product was also compared with the U.S. Drought Monitor during the overlapping period. This SPI product provides several advantages over currently available drought indices for Hawai‘i in that it has statewide coverage over a long historical period at high spatial resolution to capture fine-scale climatic gradients and monitor changes in local drought severity.

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An Evaluation of Multiscalar Drought Indices in Nevada and Eastern California

Earth Interactions ◽

10.1175/2012ei000447.1 ◽

2012 ◽

Vol 16 (18) ◽

pp. 1-18 ◽

Cited By ~ 71

Author(s):

Daniel J. McEvoy ◽

Justin L. Huntington ◽

John T. Abatzoglou ◽

Laura M. Edwards

Keyword(s):

Great Basin ◽

Arid Regions ◽

Standardized Precipitation Index ◽

The United States ◽

Drought Indices ◽

Reservoir Water ◽

Mountainous Regions ◽

Simple Term ◽

The Standardized Precipitation Index ◽

Hydrologic Drought

Abstract Nevada and eastern California are home to some of the driest and warmest climates, most mountainous regions, and fastest growing metropolitan areas of the United States. Throughout Nevada and eastern California, snow-dominated watersheds provide most of the water supply for both human and environmental demands. Increasing demands on finite water supplies have resulted in the need to better monitor drought and its associated hydrologic and agricultural impacts. Two multiscalar drought indices, the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI), are evaluated over Nevada and eastern California regions of the Great Basin using standardized streamflow, lake, and reservoir water surface stages to quantify wet and dry periods. Results show that both metrics are significantly correlated to surface water availability, with SPEI showing slightly higher correlations over SPI, suggesting that the inclusion of a simple term for atmospheric demand in SPEI is useful for characterizing hydrologic drought in arid regions. These results also highlight the utility of multiscalar drought indices as a proxy for summer groundwater discharge and baseflow periods.

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Finescale Evaluation of Drought in a Tropical Setting: Case Study in Sri Lanka

Journal of Applied Meteorology and Climatology ◽

10.1175/2008jamc1767.1 ◽

2009 ◽

Vol 48 (1) ◽

pp. 77-88 ◽

Cited By ~ 10

Author(s):

Bradfield Lyon ◽

Lareef Zubair ◽

Vidhura Ralapanawe ◽

Zeenas Yahiya

Keyword(s):

Sri Lanka ◽

Standardized Precipitation Index ◽

Meteorological Drought ◽

Drought Indices ◽

Drought Risk ◽

Mitigation And Adaptation ◽

Wide Range ◽

Drought Relief ◽

Drought Indicators ◽

The Standardized Precipitation Index

Abstract In regions of climatic heterogeneity, finescale assessment of drought risk is needed for policy making and drought management, mitigation, and adaptation. The relationship between drought relief payments (a proxy for drought risk) and meteorological drought indicators is examined through a retrospective analysis for Sri Lanka (1960–2000) based on records of district-level drought relief payments and a dense network of 284 rainfall stations. The standardized precipitation index and a percent-of-annual-average index for rainfall accumulated over 3, 6, 9, and 12 months were used, gridded to a spatial resolution of 10 km. An encouraging correspondence was identified between the spatial distribution of meteorological drought occurrence and historical drought relief payments at the district scale. Time series of drought indices averaged roughly over the four main climatic zones of Sri Lanka showed statistically significant (p < 0.01) relationships with the occurrence of drought relief. The 9-month cumulative drought index provided the strongest relationships overall, although 6- and 12-month indicators provided generally similar results. Some cases of appreciable drought without corresponding relief payments could be attributed to fiscal pressures, as during the 1970s. Statistically significant relationships between drought indicators and relief payments point to the potential utility of meteorological drought assessments for disaster risk management. In addition, the study provides an empirical approach to testing which meteorological drought indicators bear a statistically significant relationship to drought relief across a wide range of tropical climates.

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Evaluating Uncertainties in the Projection of Future Drought

Journal of Hydrometeorology ◽

10.1175/2007jhm929.1 ◽

2008 ◽

Vol 9 (2) ◽

pp. 292-299 ◽

Cited By ~ 163

Author(s):

Eleanor J. Burke ◽

Simon J. Brown

Keyword(s):

Land Surface ◽

Climate Model ◽

Climate Modeling ◽

Standardized Precipitation Index ◽

Severity Index ◽

Ensemble Member ◽

Drought Indices ◽

Drought Severity ◽

Hadley Centre ◽

The Standardized Precipitation Index

Abstract The uncertainty in the projection of future drought occurrence was explored for four different drought indices using two model ensembles. The first ensemble expresses uncertainty in the parameter space of the third Hadley Centre climate model, and the second is a multimodel ensemble that additionally expresses structural uncertainty in the climate modeling process. The standardized precipitation index (SPI), the precipitation and potential evaporation anomaly (PPEA), the Palmer drought severity index (PDSI), and the soil moisture anomaly (SMA) were derived for both a single CO2 (1×CO2) and a double CO2 (2×CO2) climate. The change in moderate drought, defined by the 20th percentile of the relevant 1×CO2 distribution, was calculated. SPI, based solely on precipitation, shows little change in the proportion of the land surface in drought. All the other indices, which include a measure of the atmospheric demand for moisture, show a significant increase with an additional 5%–45% of the land surface in drought. There are large uncertainties in regional changes in drought. Regions where the precipitation decreases show a reproducible increase in drought across ensemble members and indices. In other regions the sign and magnitude of the change in drought is dependent on index definition and ensemble member, suggesting that the selection of appropriate drought indices is important for impact studies.

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Rogation ceremonies: a key to understanding past drought variability in northeastern Spain since 1650

Climate of the Past ◽

10.5194/cp-15-1647-2019 ◽

2019 ◽

Vol 15 (5) ◽

pp. 1647-1664 ◽

Cited By ~ 6

Author(s):

Ernesto Tejedor ◽

Martín de Luis ◽

Mariano Barriendos ◽

José María Cuadrat ◽

Jürg Luterbacher ◽

...

Keyword(s):

18Th Century ◽

Standardized Precipitation Index ◽

Extreme Drought ◽

Drought Indices ◽

Independent Evidence ◽

Superposed Epoch Analysis ◽

Drought Variability ◽

Instrumental Period ◽

Epoch Analysis ◽

The Standardized Precipitation Index

Abstract. In the northeast of the Iberian Peninsula, few studies have reconstructed drought occurrence and variability for the pre-instrumental period using documentary evidence and natural proxies. In this study, we compiled a unique dataset of rogation ceremonies – religious acts asking God for rain – from 13 cities in the northeast of Spain and investigated the annual drought variability from 1650 to 1899 CE. Three regionally different coherent areas (Mediterranean, Ebro Valley, and Mountain) were detected. Both the Barcelona and the regional Mediterranean drought indices were compared with the instrumental series of Barcelona for the overlapping period (1787–1899), where we discovered a highly significant and stable correlation with the Standardized Precipitation Index of May with a 4-month lag (r=-0.46 and r=-0.53; p<0.001, respectively). We found common periods with prolonged droughts (during the mid and late 18th century) and extreme drought years (1775, 1798, 1753, 1691, and 1817) associated with more atmospheric blocking situations. A superposed epoch analysis (SEA) was performed showing a significant decrease in drought events 1 year after the volcanic events, which might be explained by the decrease in evapotranspiration due to reduction in surface temperatures and, consequently, the higher availability of water that increases soil moisture. In addition, we discovered a common and significant drought response in the three regional drought indices 2 years after the Tambora volcanic eruption. Our study suggests that documented information on rogation ceremonies contains important independent evidence to reconstruct extreme drought events in areas and periods for which instrumental information and other proxies are scarce. However, drought index for the mountainous areas (denoted Mountain later in the text) presents various limitations and its interpretation must be treated with caution.

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Analyzing the Dependence of Major Tanks in the Headwaters of the Aruvi Aru Catchment on Precipitation. Applying Drought Indices to Meteorological and Hydrological Data

Water ◽

10.3390/w12102941 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2941

Author(s):

Robin Saase ◽

Brigitta Schütt ◽

Wiebke Bebermeier

Keyword(s):

Water Level ◽

Management Practices ◽

Standardized Precipitation Index ◽

Drought Indices ◽

Strong Positive Correlation ◽

Level Data ◽

Water Level Data ◽

Dry Zone ◽

Catchment Size ◽

The Standardized Precipitation Index

This study aims to analyze the dependence of reservoirs (locally called tanks or wewas) in the headwaters of the Aruvi Aru catchment on precipitation and thus to evaluate their efficiency. The Aruvi Aru is located in the Dry Zone of Sri Lanka, and numerous human made reservoirs characterize the study area. The methodology is based on the application and correlation of climatic and hydrological drought indices. The Standardized Precipitation Index (SPI) is applied to precipitation data at different time scales and the Standardized Water-Level Index (SWLI) is applied to water-level data of five major tanks in the catchment. The results show that near normal present-day average precipitation is appropriate to fill the investigated tanks. The precipitation of the previous 6–12 months has the highest impact on water-level changes. A moderate to strong positive correlation between SWLI and SPI point to other factors besides precipitation affecting the water level of the tanks. These are: (i) catchment size together with the buffering capacity of the upstream catchment and (ii) management practices. As the overall conclusion of our study shows, the tanks functioned efficiently within their system boundaries.

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Drought Frequency Analysis Based on the Development of a Two-Variate Standardized Index (Rainfall-Runoff)

Water ◽

10.3390/w12092599 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2599 ◽

Cited By ~ 1

Author(s):

Gholamreza Nikravesh ◽

Mohammad Aghababaei ◽

Mohammad Nazari-Sharabian ◽

Moses Karakouzian

Keyword(s):

Standardized Precipitation Index ◽

Drought Indices ◽

Flow Index ◽

Severe Drought ◽

Drought Event ◽

Rainfall Runoff ◽

Drought Duration ◽

Novel Approach ◽

Standardized Index ◽

The Standardized Precipitation Index

Drought is one of the most drastic events, which has imposed irreparable damages on human societies and may occur in any climate regime. To define drought, given its properties of multidimensionality and randomity, one cannot rely on a single variable/index (e.g., precipitation, soil moisture, and runoff). Accordingly, implementing a novel approach, this study investigated drought events in two basins with different climatic regimes, using multivariate frequency analyses of drought duration, severity, and severity peak, based on developing a Two-variate Standardized Index (TSI). The index was developed based on the concept of copula, by applying rainfall-runoff data (1974–2019) and comparing them with two popular drought indices, the Standardized Precipitation Index (SPI) and Standardized Stream Flow Index (SSFI), in terms of derived drought characteristics. The results show that TSI determined more severe drought conditions with fewer return periods than SPI and SSFI in a specific drought event. This implies that the disadvantages of SPI and SSFI might not be found in TSI. The developed index can be employed by policymakers and planners to protect water resources from drought.

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