scholarly journals Assessing the changes in drought conditions during summer in the Republic of Moldova based on RegCM simulations

2013 ◽  
Vol 2 (3) ◽  
pp. 63 ◽  
Author(s):  
Vera Potop ◽  
Constanta Boroneant ◽  
Mihaela Caian
Keyword(s):  
Standardized Precipitation Index ◽  
Horizontal Resolution ◽  
Precipitation Index ◽  
Monthly Precipitation ◽  
Precipitation Data ◽  
Republic Of Moldova ◽  
Drought Conditions ◽  
The Republic ◽  
The Standardized Precipitation Index ◽  
Monthly Precipitation Data

We assess the changes in drought conditions during summer in the Republic of Moldova based on the Standardized Precipitation Index (SPI) calculated from monthly precipitation data simulated by the regional climatic model RegCM3. The RegCM simulations were conducted at a horizontal resolution of 10 km in the framework of EU-FP6 project -CECILIA. The domain was centered over Romania at 46°N, 25°E and included the Republic of Moldova.

Observed Changes of Drought/Wetness Episodes in the Middle and Lower Reaches of the Yangtze River, China

2012 ◽  
Vol 212-213 ◽  
pp. 765-771
Author(s):  
Yi Wei Zhang ◽  
Wei Guang Wang
Keyword(s):  
Rainy Season ◽  
Yangtze River ◽  
Standardized Precipitation Index ◽  
Aridity Index ◽  
Monthly Precipitation ◽  
Precipitation Data ◽  
The Yangtze River ◽  
Dry Conditions ◽  
The Standardized Precipitation Index ◽  
Monthly Precipitation Data

Monthly precipitation data of 76 meteorology stations over the middle and lower reaches of Yangtze river for 1961–2010 were analyzed by using the standardized precipitation index (SPI) and aridity index (I) for the rainy season (April–September) and winter (December– February). Trends of the number of wet and dry months were tested with Mann-Kendall technique. The results showed that: (1) The middle and lower reaches of the Yangtze River as a whole has become wetter during the rainy season and winter. (2) Major parts of the study area are characterized by increasing frequencies of severe and moderate wet months in the rainy season. (3) The study tries to explore the spatial and temporal changes in the wet and dry conditions across the middle and lower reaches of the Yangtze River by using SPI and I, and get the complete picture of the change of wet and dry.

scholarly journals Seasonal forecasts of droughts in African basins using the Standardized Precipitation Index

2013 ◽  
Vol 17 (6) ◽  
pp. 2359-2373 ◽  
Author(s):  
E. Dutra ◽  
F. Di Giuseppe ◽  
F. Wetterhall ◽  
F. Pappenberger
Keyword(s):  
Real Time ◽  
Lead Time ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Seasonal Forecasting ◽  
Monthly Precipitation ◽  
Seasonal Forecasts ◽  
Blue Nile ◽  
Forecasting System ◽  
The Standardized Precipitation Index

Abstract. Vast parts of Africa rely on the rainy season for livestock and agriculture. Droughts can have a severe impact in these areas, which often have a very low resilience and limited capabilities to mitigate drought impacts. This paper assesses the predictive capabilities of an integrated drought monitoring and seasonal forecasting system (up to 5 months lead time) based on the Standardized Precipitation Index (SPI). The system is constructed by extending near-real-time monthly precipitation fields (ECMWF ERA-Interim reanalysis and the Climate Anomaly Monitoring System–Outgoing Longwave Radiation Precipitation Index, CAMS-OPI) with monthly forecasted fields as provided by the ECMWF seasonal forecasting system. The forecasts were then evaluated over four basins in Africa: the Blue Nile, Limpopo, Upper Niger, and Upper Zambezi. There are significant differences in the quality of the precipitation between the datasets depending on the catchments, and a general statement regarding the best product is difficult to make. The generally low number of rain gauges and their decrease in the recent years limits the verification and monitoring of droughts in the different basins, reinforcing the need for a strong investment on climate monitoring. All the datasets show similar spatial and temporal patterns in southern and north-western Africa, while there is a low correlation in the equatorial area, which makes it difficult to define ground truth and choose an adequate product for monitoring. The seasonal forecasts have a higher reliability and skill in the Blue Nile, Limpopo and Upper Niger in comparison with the Zambezi. This skill and reliability depend strongly on the SPI timescale, and longer timescales have more skill. The ECMWF seasonal forecasts have predictive skill which is higher than using climatology for most regions. In regions where no reliable near-real-time data is available, the seasonal forecast can be used for monitoring (first month of forecast). Furthermore, poor-quality precipitation monitoring products can reduce the potential skill of SPI seasonal forecasts in 2 to 4 months lead time.

scholarly journals Reconstructions of droughts in Germany since 1500 – combining hermeneutic information and instrumental records in historical and modern perspectives

2020 ◽  
Vol 16 (4) ◽  
pp. 1207-1222
Author(s):  
Rüdiger Glaser ◽  
Michael Kahle
Keyword(s):  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Monthly Precipitation ◽  
Historical Records ◽  
Climatic Effects ◽  
Virtual Research Environment ◽  
Humidity Index ◽  
The Standardized Precipitation Index ◽  
Instrumental Records

Abstract. The present article deals with the reconstruction of drought time series in Germany since 1500. The reconstructions are based on historical records from the virtual research environment Tambora (tambora.org, 2018) and official instrumental records. The historical records and recent data were related to each other through modern index calculations, drought categories and their historical equivalents. Historical and modern written documents are also taken into account to analyze the climatic effects and consequences on the environment and society. These pathways of effects are derived and combined with different drought categories. The derived historical precipitation index (HPI) is correlated with the standardized precipitation index (SPI). Finally, a historical drought index (HDI) and a historical wet index (HWI) are derived from the basic monthly precipitation index (PI) from 1500 onward. Both are combined for the historical humidity index (HHI). On this basis, the long-term development of dryness and drought in Germany since 1500, as well as medium-term deviations of drier and wetter periods and individual extreme events, is presented and discussed.

scholarly journals The Use Of Standardized Indicators (SPI And SPEI) In Predicting Droughts Over The Republic Of Moldova Territory

2015 ◽  
Vol 9 (2) ◽  
pp. 149-158
Author(s):  
M. Nedealcov ◽  
V. Răileanu ◽  
R. Sîrbu ◽  
R. Cojocari
Keyword(s):  
Standardized Precipitation Index ◽  
Annual Data ◽  
Standardized Precipitation Evapotranspiration Index ◽  
Republic Of Moldova ◽  
Temporal Estimation ◽  
Spatio Temporal ◽  
The Republic ◽  
Definition Of ◽  
The Standardized Precipitation Index ◽  
Calculation Software

Abstract The drought events frequent manifestation over the Republic of Moldova territory, in the context of climate change requires a scientific monitoring adjusted to international researchers. In recent years, internationally, the estimation of this phenomenon occurs through standardized indexes. The most used of these, being the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Since there is no a unified definition of drought, the World Meteorological Organization proposes to calculate the indexes, through developed calculation software. Thus, based on multi-annual data (1980-2014) a regional spatio-temporal estimation concerning drought in the Republic of Moldova was performed, thereby realizing the regional investigations framing in the international ones.

scholarly journals Changes in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013

2016 ◽  
Vol 42 (1) ◽  
pp. 145 ◽  
Author(s):  
A. M. El Kenawy ◽  
M. F. McCabe ◽  
S. M. Vicente-Serrano ◽  
J. I. López-Moreno ◽  
S. M. Robaa
Keyword(s):  
Standardized Precipitation Index ◽  
Principal Component ◽  
Research Unit ◽  
Monthly Precipitation ◽  
Precipitation Data ◽  
Policy Makers ◽  
Local Character ◽  
Afar Region ◽  
The Standardized Precipitation Index ◽  
Evidence For Policy

Here we present an analysis of drought occurrence and variability in Ethiopia, based on the monthly precipitation data from the Climate Research Unit (CRU-v3.22) over the period from 1960 to 2013. The drought events were characterized by means of the Standardized Precipitation Index (SPI) applied to precipitation data at a temporal scale of 12 months. At the national scale, the results reveal a statistically significant decrease in the severity of droughts over the 54-year period, a pattern that is mostly attributed to a statistically significant decrease in the frequency of high intensity drought episodes (i.e., extreme and very extreme droughts), compared to moderate droughts. To assess the general patterns of drought evolution, a principal component analysis (PCA) was applied to the SPI series. PCA results indicate a high spatial heterogeneity in the SPI variations over the investigated period, with ten different spatially well-defined regions identified. These PCA components accounted for 72.9% of the total variance of drought in the region. These regions also showed considerable differences in the temporal variability of drought, as most of the regions exhibited an increase in wetness conditions in recent decades. In contrast, the regions that receive less than 400 mm of annual precipitation showed a declining  trend, with the largest changes occurring over Afar region. Generally, the highly elevated regions over the central Ethiopian Highlands showed the weakest changes, compared to the lowlands. This study confirms the local character of drought evolution over Ethiopia, providing evidence for policy makers to adopt appropriate local policies to cope with the risks of drought. Over Ethiopia, the detailed spatial assessment of drought evolution is required for a better understanding of the possible impacts of recurrent drought on agriculture, food production, soil degradation, human settlements and migrations, as well as energy production and water resources management across Ethiopia.

scholarly journals COMBINATION OF METEOROLOGICAL INDICES AND SATELLITE DATA FOR DROUGHT MONITORING IN TWO DIFFERENT ENVIRONMENTS IN IRAN

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 197-200
Author(s):  
M. Behifar ◽  
A. A. Kakroodi ◽  
M. Kiavarz ◽  
F. Amiraslani
Keyword(s):  
Satellite Data ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Precipitation Index ◽  
Drought Monitoring ◽  
Spatial Characteristic ◽  
Drought Indices ◽  
Precipitation Data ◽  
Spi Index ◽  
The Standardized Precipitation Index

Abstract. The main problem using meteorological drought indices include inappropriate distribution of meteorological stations. Satellite data have reliable spatial and temporal resolution and provide valuable information used in many different applications. The Standardized precipitation index has several advantages. The SPI is based on rainfall data alone and has a variable time scale and is thus conducive to describing drought conditions for different application.This study aims to calculate SPI using satellite precipitation data and compare the results with traditional methods. To do this, satellite-based precipitation data were assessed against station data and then the standardized precipitation index was calculated. The results have indicated that satellite-based SPI could illustrate drought spatial characteristic more accurate than station-based index. Also, the standardized property of the SPI index allows comparisons between different locations, which is one of the remote sensing drought indices limitations.

scholarly journals Spatiotemporal Characteristics of Meteorological Drought for the Island of Crete

2011 ◽  
Vol 12 (2) ◽  
pp. 206-226 ◽  
Author(s):  
Aristeidis G. Koutroulis ◽  
Aggeliki-Eleni K. Vrohidou ◽  
Ioannis K. Tsanis
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Climate Models ◽  
Regional Climate ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Drought Severity ◽  
Monthly Precipitation ◽  
Drought Conditions ◽  
First Time

Abstract A modified drought index, named the spatially normalized–standardized precipitation index (SN-SPI), has been developed for assessing meteorological droughts. The SN–SPI is a variant index to the standardized precipitation index and is based on the probability of precipitation at different time scales, but it is spatially normalized for improved assessment of drought severity. Results of this index incorporate the spatial distribution of precipitation and produce improved drought warnings. This index is applied in the island of Crete, Greece, and the drought results are compared to the ones of SPI. A 30-year-long average monthly precipitation dataset from 130 watersheds of the island is used by the above indices for drought classification in terms of its duration and intensity. Bias-adjusted monthly precipitation estimates from an ensemble of 10 regional climate models were used to quantify the influence of global warming to drought conditions over the period 2010–2100. Results based on both indices (calculated for three time scales of 12, 24, and 48 months) from 3 basins in west, central, and east parts of the island show that 1) the extreme drought periods are the same (reaching 7% of time) but the intensities based on SN–SPI are lower; 2) the area covered by extreme droughts is 3% (first time scale), 16% (second time scale), and 25% (third time scale), and 96% (first time scale), 95% (second time scale), and 80% (third time scale) based on the SN–SPI and SPI, respectively; 3) concerning the longest time scale (48 months), more than half of the area of Crete is about to experience drought conditions during 28%, 69%, and 97% for 2010–40, 2040–70, and 2070–2100, respectively; and 4) extremely dry conditions will cover 52%, 33%, and 25% of the island for the future 90-year period using 12-, 24-, and 48-month SN–SPI, respectively.

Drought and Flood Distribution Variation Based on SPI in Nanjing, China

2013 ◽  
Vol 295-298 ◽  
pp. 2116-2120
Author(s):  
Jian Fen Liu ◽  
Xing Nan Zhang ◽  
Hui Min Wang
Keyword(s):  
Time Series ◽  
Time Scales ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Precipitation Data ◽  
Temporal Scales ◽  
Drought And Flood ◽  
Three Stages ◽  
The Standardized Precipitation Index

Many drought and flood indices have been developed, the Standardized Precipitation Index (SPI) is one which has various temporal scales together to form an overall judgment of drought and flood and can be applied easily to different locations to identify and monitor drought and flood. Take Nanjing, China in the study as an example to analysis drought and flood variation by computing SPI values of four time scales including 3-months, 6-months, 12-months and 24-months, applying precipitation data from 1946-2000 of the study area. The results demonstrated SPI can be appropriate to analyze drought and flood variation of Nanjing, while the precipitation data were divided into three stages(1946-1963,1964-1981,1982-2000), the frequencies of various drought and flood classes from various time scales are different, particularly 12-months and 24-months. The time series is longer, the frequencies are more reliable and the differences more little.

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