Evaluating Spatiotemporal Patterns and Trends of Drought in Japan Associated with Global Climatic Drivers

Abstract. Drought disasters, such as water scarcity and wildfires, are serious natural disasters in Japan that are also affected by climate change. However, as drought generally has widespread impacts and the duration of drought can vary considerably, it is difficult to assess the spatiotemporal characteristics and the climatic causes of drought. Therefore, to identify the drought homogeneous regions and understand climatic causes of regional drought over Japan, this study provides a spatiotemporal analysis for historical droughts patterns and teleconnections associated with global climatic drivers. The trends of meteorological elements, which are the basis of drought index calculation, was first assessed. Then, drought characterized by the Self-calibrating Palmer Drought Severity Index (scPDSI) was investigated. Trends and patterns of drought were identified through the trend-free pre-whitening Mann-Kendall test and distinct empirical orthogonal function. The continuous wavelet transform and cross wavelet transform together with wavelet coherence were utilized to depict the links between drought and global climatic drivers. The results are described as follows: (1) the trends of precipitation were insignificant. However, temperature and potential evapotranspiration increasing trends were detected over Japan; (2) the drought trend over Japan varied seasonally, increasing in spring and summer and decreasing in autumn and winter; (3) two major subregions of drought variability—the western Japan (W region) and most of the northernmost Japan near the Pacific (N region) were identified; (4) wildfires with large burned area were more likely to occur when the scPDSI was less than −1; and (5) the North Atlantic Index (NAOI) showed the strongest coherence connections with Distinguished Principle Components-1 among four climatic drivers. Additionally, Distinguished Principle Components-2 showed stronger coherence connections with NAOI and Arctic Oscillation Index. This study is the first to identify homogeneous regions with distinct drought characteristics over Japan and connect the drought in Japan with the global climatic drivers.

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Spatial and temporal characteristics of wildfires in Mississippi, USA

International Journal of Wildland Fire ◽

10.1071/wf08104 ◽

2010 ◽

Vol 19 (1) ◽

pp. 14 ◽

Cited By ~ 18

Author(s):

Katarzyna Grala ◽

William H. Cooke

Keyword(s):

Palmer Drought Severity Index ◽

Severity Index ◽

The State ◽

Anthropogenic Factors ◽

Burned Area ◽

Drought Severity ◽

Temporal Characteristics ◽

Wildfire Occurrence ◽

Spatial And Temporal Characteristics ◽

Drought Severity Index

Forests constitute a large percentage of the total land area in Mississippi and are a vital element of the state economy. Although wildfire occurrences have been considerably reduced since the 1920s, there are still ~4000 wildfires each year in Mississippi burning over 24 000 ha (60 000 acres). This study focusses on recent history and various characteristics of Mississippi wildfires to provide better understanding of spatial and temporal characteristics of wildfires in the state. Geographic information systems and Mississippi Forestry Commission wildfire occurrence data were used to examine relationships between climatic and anthropogenic factors, the incidence, burned area, wildfire cause, and socioeconomic factors. The analysis indicated that wildfires are more frequent in southern Mississippi, in counties covered mostly by pine forest, and are most prominent in the winter–spring season. Proximity to roads and cities were two anthropogenic factors that had the most statistically significant correlation with wildfire occurrence and size. In addition, the validity of the Palmer Drought Severity Index as a measure of fire activity was tested for climatic districts in Mississippi. Analysis indicated that drought influences fire numbers and size during summer and fall (autumn). The strongest relationship between the Palmer Drought Severity Index and burned area was found for the southern climatic districts for the summer–fall season.

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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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Malawi’s Shire River Fluctuations and Climate

Journal of Hydrometeorology ◽

10.1175/jhm-d-13-0195.1 ◽

2014 ◽

Vol 15 (5) ◽

pp. 2039-2049 ◽

Cited By ~ 9

Author(s):

Mark R. Jury

Keyword(s):

Large Scale ◽

River Flow ◽

Potential Evapotranspiration ◽

Global Climate ◽

Severity Index ◽

Early Warning Systems ◽

Climatic Research Unit ◽

Climate Index ◽

Drought Severity ◽

High Pressure Cell

Abstract Hydrological fluctuations of Malawi’s Shire River and climatic drivers are studied for a range of time and space scales. The annual cycles of basin rainfall and river flow peak in summer and autumn, respectively. Satellite and model products at <50-km resolution resolve the water deficit in this narrow valley. The leading climate index fitting Shire River flow anomalies is the Climatic Research Unit (CRU) Palmer drought severity index, based on interpolated gauge rainfall minus Penman–Monteith potential evapotranspiration. Climate variables anticipate lake level changes by 2 months, while weather variables anticipate river flow surges by 2 days. Global climate patterns related to wet years include a Pacific La Niña cool phase and low pressure over northeastern Africa. Shire River floods coincide with a cyclonic looping wind pattern that amplifies the equatorial trough and draws monsoon flow from Tanzania. Hot spells are common in spring: daytime surface temperatures can reach 60°C causing rapid desiccation. An anticyclonic high pressure cell promotes evaporation losses of ~20 mm day−1 over brief periods. Flood and drought in Malawi are shown to be induced by the large-scale atmospheric circulation and rainfall in the surrounding highlands. Hence, early warning systems should consider satellite and radar coverage of the entire basin.

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Application of the cross wavelet transform and wavelet coherence to geophysical time series

Nonlinear Processes in Geophysics ◽

10.5194/npg-11-561-2004 ◽

2004 ◽

Vol 11 (5/6) ◽

pp. 561-566 ◽

Cited By ~ 2659

Author(s):

A. Grinsted ◽

J. C. Moore ◽

S. Jevrejeva

Keyword(s):

Time Series ◽

Wavelet Transform ◽

Statistical Significance ◽

Wavelet Coherence ◽

The Arctic ◽

Arctic Oscillation Index ◽

Time Frequency ◽

Cross Wavelet Transform ◽

The Cross ◽

Cross Wavelet

Abstract. Many scientists have made use of the wavelet method in analyzing time series, often using popular free software. However, at present there are no similar easy to use wavelet packages for analyzing two time series together. We discuss the cross wavelet transform and wavelet coherence for examining relationships in time frequency space between two time series. We demonstrate how phase angle statistics can be used to gain confidence in causal relationships and test mechanistic models of physical relationships between the time series. As an example of typical data where such analyses have proven useful, we apply the methods to the Arctic Oscillation index and the Baltic maximum sea ice extent record. Monte Carlo methods are used to assess the statistical significance against red noise backgrounds. A software package has been developed that allows users to perform the cross wavelet transform and wavelet coherence (www.pol.ac.uk/home/research/waveletcoherence/).

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The Magnitude and Causes of Global Drought Changes in the Twenty-First Century under a Low–Moderate Emissions Scenario

Journal of Climate ◽

10.1175/jcli-d-14-00363.1 ◽

2015 ◽

Vol 28 (11) ◽

pp. 4490-4512 ◽

Cited By ~ 110

Author(s):

Tianbao Zhao ◽

Aiguo Dai

Keyword(s):

Palmer Drought Severity Index ◽

Potential Evapotranspiration ◽

Severity Index ◽

First Century ◽

Agricultural Drought ◽

Drought Severity ◽

Drought Frequency ◽

The Mean ◽

Key Drivers ◽

Twenty First Century

Abstract Atmospheric demand for moisture and dry days are expected to increase, leading to drying over land in the twenty-first century. Here, the magnitude and key drivers of this drying are investigated using model simulations under a low–moderate scenario, RCP4.5. The self-calibrated Palmer drought severity index with the Penman–Monteith potential evapotranspiration (PET) (sc_PDSI_pm), top 10-cm soil moisture (SM), and runoff (R) from 14 models are analyzed. The change patterns are found to be comparable while the magnitude differs among these measures of drought. The frequency of the SM-based moderate (severe) agricultural drought could increase by 50%–100% (100%–200%) in a relative sense by the 2090s over most of the Americas, Europe, and southern Africa and parts of East and West Asia and Australia. Runoff-based hydrological drought frequency could also increase by 10%–50% over most land areas despite increases in mean runoff. The probability density functions (PDFs) flatten, enhancing the drought increases induced primarily by decreases in the mean. Precipitation (P) and evapotranspiration (E) changes contribute to the SM change; whereas decreases in sc_PDSI_pm result from ubiquitous PET increases of 10%–20% with contributions from decreased P over subtropical areas. Rising temperatures and vapor deficits explain most of the PET increase, which in turn explains most of the E increases over Asia and northern North America while decreased SM leads to lower E over the rest of the world. Radiation and wind speed changes have only small effects on future PET and drought. Globally, runoff ratio changes little while P, E, and R all increase by about 4%–5% in the twenty-first century.

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Tracking Interannual Streamflow Variability with Drought Indices in the U.S. Pacific Northwest

Journal of Hydrometeorology ◽

10.1175/jhm-d-13-0167.1 ◽

2014 ◽

Vol 15 (5) ◽

pp. 1900-1912 ◽

Cited By ~ 32

Author(s):

John T. Abatzoglou ◽

Renaud Barbero ◽

Jacob W. Wolf ◽

Zachary A. Holden

Keyword(s):

Pacific Northwest ◽

Potential Evapotranspiration ◽

Standardized Precipitation Index ◽

Severity Index ◽

The United States ◽

Drought Indices ◽

Drought Severity ◽

Climate Data ◽

Mountain Watersheds ◽

Streamflow Variability

Abstract Drought indices are often used for monitoring interannual variability in macroscale hydrology. However, the diversity of drought indices raises several issues: 1) which indices perform best and where; 2) does the incorporation of potential evapotranspiration (PET) in indices strengthen relationships, and how sensitive is the choice of PET methods to such results; 3) what additional value is added by using higher-spatial-resolution gridded climate layers; and 4) how have observed relationships changed through time. Standardized precipitation index, standardized precipitation evapotranspiration index (SPEI), Palmer drought severity index, and water balance runoff (WBR) model output were correlated to water-year runoff for 21 unregulated drainage basins in the Pacific Northwest of the United States. SPEI and WBR with time scales encompassing the primary precipitation season maximized the explained variance in water-year runoff in most basins. Slightly stronger correlations were found using PET estimates from the Penman–Monteith method over the Thornthwaite method, particularly for time periods that incorporated the spring and summer months in basins that receive appreciable precipitation during the growing season. Indices computed using high-resolution climate surfaces explained over 10% more variability than metrics derived from coarser-resolution datasets. Increased correlation in the latter half of the study period was partially attributable to increased streamflow variability in recent decades as well as to improved climate data quality across the interior mountain watersheds.

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EVALUATION OF DROUGHT IN IRAQ USING DSI. BY REMOTE SENSING

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v49i6.152 ◽

2018 ◽

Vol 49 (6) ◽

Author(s):

Jawad &et al.

Keyword(s):

Arid Zone ◽

Potential Evapotranspiration ◽

Severity Index ◽

Precipitation Anomaly ◽

Drought Severity ◽

Simulation Group ◽

Precipitation Anomalies ◽

Desert Zone ◽

Semi Arid ◽

Run Theory

Evaluation of drought patterns in Iraq and determining the most susceptible areas of this phenomenon were analyzed, using the remotely-sensed Drought Severity Index (DSI) through analysis the daily and annual DSI for three zones over Iraq, also have been analyzed DSI time series using run theory to evaluate the characteristics of drought in Iraq. The efficiency of DSI for drought monitoring was examined from compared with Percentage of Precipitation Anomaly (PPA) for three zones (Arid and Semi-Arid, Steppes and Desert), and compared with drought indicators (Evapotranspiration (ET), Potential evapotranspiration (PET) and total annual precipitation (PRE)) for the period 2000-2011, were derived from the Numerical Terradynamic Simulation Group (NTSG). The spatial interpolation techniques in Geographic Information System (GIS) 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 drier year is 2008, the wetter years are 2001 in Desert zone and 2003 in steppes and Arid and Semi-Arid Zone zones. The results also showed a significant fluctuation in precipitation from the average, especially at Arid and Semi-Arid Zone when compared with other zones. The values of standard deviation of precipitation were compared with precipitation anomalies for each zone, Arid and Semi-Arid is the drier zone in 2007-2008, the wetter zone is also Arid and Semi-Arid in 2002-2003. Using run theory, the drier Zone is Arid and Semi-Arid and the wetter Zone is steppes during study period.

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Mapping environmental and climate variations by GMT: A case of Zambia, Central Africa

Zemljiste i biljka ◽

10.5937/zembilj2101117l ◽

2021 ◽

Vol 70 (1) ◽

pp. 117-136

Author(s):

Polina Lemenkova

Keyword(s):

Soil Moisture ◽

Potential Evapotranspiration ◽

Central Africa ◽

Environmental Parameters ◽

Severity Index ◽

Shortwave Radiation ◽

Balance Model ◽

Drought Severity ◽

Negative Effects ◽

Environmental Threats

Zambia recently experienced several environmental threats from climate change such as droughts, temperature rise and occasional flooding and they all affect agricultural sustainability and people wellbeing through negative effects on plants and growing crops. This paper is aimed at showing variations in several climate and environmental parameters in Zambia showing spatial variability and trends in different regions of Zambia's key environmental areas (Zambezi River and tributaries), Livingstone near the Victoria Falls and central region with Muchinga Mountains. A series of 10 maps was plotted using data from TerraClimate dataset: precipitation, soil moisture, Palmer Drought Severity Index (PDSI), downward surface shortwave radiation, vapor pressure deficit and anomalies, potential and actual evapotranspiration and wind speed with relation to the topographic distribution of elevations in Zambia plotted using GEBCO/SRTM data. The data range of the PDSI according to the index values ranged from minimum at -5.7 to the maximum at 16.6 and mean at 7.169, with standard deviation at 4.278. The PDSI is effective in quantifying drought in long-term period. Because PDSI index applies temperature data and water balance model, it indicates the effect of climate warming on drought by correlation with potential evapotranspiration. The maximum values for soil moisture of Zambia show minimum at 1 mm/m, maximum at 413 mm/m, mean at 173 mm/m. This study is technically based on using the Generic Mapping Tools (GMT) as cartographic scripting toolset. The paper contributes to the environmental monitoring of Zambia by presenting a series of climate and environmental maps that are beneficial for agricultural mapping of Zambia.

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CMIP6 Model-projected Hydroclimatic and Drought Changes and Their Causes in the 21st Century

Journal of Climate ◽

10.1175/jcli-d-21-0442.1 ◽

2021 ◽

pp. 1-58

Author(s):

Tianbao Zhao ◽

Aiguo Dai

Keyword(s):

Palmer Drought Severity Index ◽

Potential Evapotranspiration ◽

Coupled Model ◽

Severity Index ◽

Distribution Functions ◽

Drought Severity ◽

Drought Duration ◽

Probability Distribution Functions ◽

Underlying Causes ◽

The Mean

AbstractDrought is projected to become more severe and widespread as global warming continues in the 21st century, but hydroclimatic changes and their drivers are not well examined in the latest projections from the Phase Six of the Coupled Model Inetercomparison Project (CMIP6). Here, precipitation (P), evapotranspiration (E), soil moisture (SM), and runoff (R) from 25 CMIP6 models, together with self-calibrated Palmer Drought Severity Index with Penman-Monteith potential evapotranspiration (scPDSIpm), are analyzed to quantify hydroclimatic and drought changes in the 21st century and the underlying causes. Results confirm consistent drying in these hydroclimatic metrics across most of the Americas (including the Amazon), Europe and the Mediterranean region, southern Africa, and Australia; although the drying magnitude differs, with the drying being more severe and widespread in surface SM than in total SM. Global drought frequency based on surface SM and scPDSIpm increases by ~25%–100% (50%–200%) under the SSP2-4.5 (SSP5-8.5) scenario in the 21st century together with large increases in drought duration and areas, which result from a decrease in the mean and flattening of the probability distribution functions of SM and scPDSIpm; while the R-based drought changes are relatively small. Changes in both P and E contribute to the SM change, whereas scPDSIpm decreases result from ubiquitous PET increases and P decreases over subtropical areas. The R changes are determined primarily by P changes, while the PET change explains most of the E increase. Inter-model spreads in surface SM and R changes are large, leading to large uncertainties in the drought projections.

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Revisiting drought trend over China during 1948-2016: a multivariate perspective

10.5194/egusphere-egu2020-4555 ◽

2020 ◽

Author(s):

Liliang Ren

Keyword(s):

Drought Index ◽

Potential Evapotranspiration ◽

Severity Index ◽

Northeastern China ◽

Trend Detection ◽

Drought Indices ◽

Drought Severity ◽

Main Driver ◽

Land Data Assimilation System ◽

The Individual

How drought changes in the context of global warming is a concerning issue that influences the strategies of drought mitigation and drought management. Based on the simulations of the version 2 of Global Land Data Assimilation System (GLDAS-2.0) during 1948-2016, we revisited the drought trend over China and analyzed the individual contributions of precipitation and potential evapotranspiration (PET) on varied drought patterns. Four composite drought indices including the Aggregate Drought Index (ADI), Joint Drought Deficit Index (JDI), self-calibrating Palmer Drought Severity Index (scPDSI) and Standardized Palmer Drought Index (SPDI) were employed for trend detection. Results showed that all four composite drought indices suggested a significant drying belt spreads from northeastern China to southwestern China, and a significant wetting trend in the &#8220;Three river sources&#8221; areas. Controversial patterns were mainly located in the northwestern China, Xinjiang districts, and the middle and lower reaches of the Yangtze River, where the SPDI and JDI respectively, overestimated and underestimated the moisture conditions at varying degrees. According to the change point tests, it is found that the drying pattern in the northeastern China occurred since 1970s, where precipitation deficits and expanded PET jointly aggravated the drying process, while for the &#8220;Three river sources&#8221; areas, the increased precipitation since 2000s is the main driver for the wetting pattern.

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