INDEXING OF METEOROLOGICAL DROUGHT

Author(s):  
K. Kaverina ◽  
I. Kostyrko ◽  
R. Oliynyk

Drought is a serious extreme climatic event that negatively affects the physical environment and water systems causing disruptions in the hydrological cycle of the region. This is a stochastic natural hazard caused by persistent rainfall scarcity. The life cycle of the drought begins with a meteorological phenomenon, and further influence is realized throughout the hydrological cycle. Adequate measures are needed to respond and mitigate the various effects of drought. Developing and implementing drought mitigation and response strategies requires understanding the various indicators used to study drought. Drought characteristics are an important condition that allows both retrospective analysis and forward planning – risk assessment. Thus, it is necessary to objectively identify the events of drought by time, duration, scale and severity of manifestation. This can be implemented with integrated indicators that involve the main characteristics of the drought. More than 150 drought indices have now been proposed, some of which are perceived as operational information used to characterize drought through maps at regional and national levels. By quantifying the level of severity and announcing the onset and end of drought, drought indices are now assisting in a variety of operations, including early warning, drought monitoring and contingency planning. Despite their diversity and continuous development, it is important to provide a comprehensive overview of the available weather indicators, which highlights their differences and studies their trends and which can be used in a special given manner regional climate.

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Roman Hohl ◽  
Ze Jiang ◽  
Minh Tue Vu ◽  
Srivatsan Vijayaraghavan ◽  
Shie-Yui Liong

PurposeExamine the usability of rainfall and temperature outputs of a regional climate model (RCM) and meteorological drought indices to develop a macro-level risk transfer product to compensate the government of Central Java, Indonesia, for drought-related disaster payments to rice farmers.Design/methodology/approachBased on 0.5° gridded rainfall and temperature data (1960–2015) and projections of the WRF-RCM (2016–2040), the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) are calculated for Central Java over different time spans. The drought indices are correlated to annual and seasonal rice production, based on which a weather index insurance structure is developed.FindingsThe six-month SPI correlates best with the wet season rice production, which generates most output in Central Java. The SPI time series reveals that drought severity increases in future years (2016–2040) and leads to higher payouts from the weather index structure compared to the historical period (1960–2015).Practical implicationsThe developed methodology in using SPI for historical and projected periods allows the development of weather index insurance in other regions which have a clear link between rainfall deficit and agricultural production volatility.Originality/valueMeteorological drought indices are a viable alternative for weather index insurance, which is usually based on rainfall amounts. RCM outputs provide valuable insights into future climate variability and drought risk and prolong the time series, which should result in more robust weather index insurance products.


2018 ◽  
Author(s):  
Aurelia Baca ◽  
Joel Larsen ◽  
Emrys Treasure ◽  
Michael Gavazzi ◽  
Nathan Walker ◽  
...  

The USDA Forest Service hosted a two-day drought adaptation workshop in Atlanta, Georgia in January 2017 to share state-of-science information on drought and climate effects in the region and to develop management response strategies. The workshop was attended by regional experts from the Forest Service Southern Region, Southern Research Station, and Office of Sustainability and Climate; the USDA Southeast Regional Climate Hub; and state and federal climate offices. They met to address challenges, cultivate opportunities, and develop and expand the collective understanding of the most effective management strategies to adapt to and mitigate the effects of drought in the region. The workshop focused on the effects of, and management responses to drought in forest, riparian, and aquatic ecosystems. This fact sheet is a synopsis of the workshop.


2021 ◽  
Vol 21 (1) ◽  
pp. 39-51
Author(s):  
Buruk Kitachew Wossenyeleh ◽  
Kaleb Asnake Worku ◽  
Boud Verbeiren ◽  
Marijke Huysmans

Abstract. Drought can be described as a temporary decrease in water availability over a significant period that affects both surface and groundwater resources. Droughts propagate through the hydrological cycle and may impact vulnerable ecosystems. This paper investigates drought propagation in the hydrological cycle, focusing on assessing its impact on a groundwater-fed wetland ecosystem. Meteorological drought indices were used to analyze meteorological drought severity. Moreover, a method for assessing groundwater drought and its propagation in the aquifer was developed and applied. Groundwater drought was analyzed using the variable threshold method. Furthermore, meteorological drought and groundwater drought on recharge were compared to investigate drought propagation in the hydrological cycle. This research is carried out in the Doode Bemde wetland in central Belgium. The results of this research show that droughts are attenuated in the groundwater system. The number and severity of drought events on groundwater discharge were smaller than for groundwater recharge. However, the onset of both drought events occurred at the same time, indicating a quick response of the groundwater system to hydrological stresses. In addition, drought propagation in the hydrological cycle indicated that not all meteorological droughts result in groundwater drought. Furthermore, this drought propagation effect was observed in the wetland.


2020 ◽  
Author(s):  
Buruk Kitachew Wossenyeleh ◽  
Kaleb Asnake Worku ◽  
Boud Verbeiren ◽  
Marijke Huysmans

Abstract. Drought can be described as a temporary decrease in water availability over a significant period and affects both surface and groundwater resources. Droughts propagate through the hydrological cycle and may impact vulnerable ecosystems. This paper investigates drought propagation in the hydrological cycle, focusing on assessing its impact on a groundwater-fed wetland ecosystem. Meteorological drought indices were used to analyze meteorological drought severity. Besides, a method for assessing groundwater drought and its propagation in the aquifer was developed and applied. Groundwater drought was analyzed using the variable threshold method. Furthermore, meteorological drought and groundwater drought on recharge were compared to investigate drought propagation in the hydrological. This research is carried out in the Doode Bemde wetland in central Belgium. The results of this research show that droughts are strongly attenuated in the groundwater system. The number and severity of groundwater discharge drought events were smaller than for groundwater recharge drought. However, the onset of both drought events occurred at the same time, indicating a quick response of the groundwater system to hydrological stresses. In addition, drought propagation in the hydrological cycle indicated that not all meteorological droughts result in groundwater drought. Furthermore, this drought propagation effect was observed in the wetland.


2017 ◽  
Author(s):  
Niko Wanders ◽  
Anne F. Van Loon ◽  
Henny A. J. Van Lanen

Abstract. Drought is an abnormal and prolonged deficit in available water. Possible drought impacts are crop losses, famine, fatalities, power blackouts and degraded ecosystems. These severe socio-economic and environmental impacts show the need to carefully monitor drought conditions using a suitable index. Our objective is to provide an intercomparison of frequently used physical drought indices to show to which degree they are interchangeable for monitoring drought in precipitation, soil moisture, groundwater and streamflow. Physical indices are commonly introduced to predict drought impacts, because appropriate drought impact indices are still missing. Correlations (R) between frequently used indices for different drought types were calculated at the global scale. We have made the index timeseries available to the community for future studies. Precipitation drought indices show low to intermediate correlations (ranging from R = 0.1 to 0.75), soil moisture drought indices show an even lower similarity (R = 0.25). Indices for streamflow drought show the highest correlation (R = 0.5 to 0.95). Additionally, meteorological drought indices do not capture the soil moisture drought correctly (R = 0.0 to 0.6) nor streamflow drought (R = 0.0 to 0.7). These findings have implications for drought monitoring systems: (i) for each drought type, a different index should carefully be identified; (ii) drought indices that are designed to monitor the same drought type show large discrepancies in their anomalies and hence drought detection; (iii) there is no single superior physical drought index that is capable of accurately capturing the diverse set of drought impacts in all parts of the hydrological cycle.


2019 ◽  
Vol 11 (2) ◽  
pp. 120 ◽  
Author(s):  
Gonca Okay Ahi ◽  
Shuanggen Jin

Water is arguably our most precious resource, which is related to the hydrological cycle, climate change, regional drought events, and water resource management. In Turkey, besides traditional hydrological studies, Terrestrial Water Storage (TWS) is poorly investigated at a continental scale, with limited and sparse observations. Moreover, TWS is a key parameter for studying drought events through the analysis of its variation. In this paper, TWS variation, and thus drought analysis, spatial mass distribution, long-term mass change, and impact on TWS variation from the parameter scale (e.g., precipitation, rainfall rate, evapotranspiration, soil moisture) to the climatic change perspective are investigated. GRACE (Gravity Recovery and Climate Experiment) Level 3 (Release05-RL05) monthly land mass data of the Centre for Space Research (CSR) processing center covering the period from April 2002 to January 2016, Global Land Data Assimilation System (GLDAS: Mosaic (MOS), NOAH, Variable Infiltration Capacity (VIC)), and Tropical Rainfall Measuring Mission (TRMM-3B43) models and drought indices such as self-calibrating Palmer Drought Severity (SCPDSI), El Niño–Southern Oscillation (ENSO), and North Atlantic Oscillation (NAO) are used for this purpose. Turkey experienced serious drought events interpreted with a significant decrease in the TWS signal during the studied time period. GRACE can help to better predict the possible drought nine months before in terms of a decreasing trend compared to previous studies, which do not take satellite gravity data into account. Moreover, the GRACE signal is more sensitive to agricultural and hydrological drought compared to meteorological drought. Precipitation is an important parameter affecting the spatial pattern of the mass distribution and also the spatial change by inducing an acceleration signal from the eastern side to the western side. In Turkey, the La Nina effect probably has an important role in the meteorological drought turning into agricultural and hydrological drought.


2005 ◽  
Vol 9 (5) ◽  
pp. 523-533 ◽  
Author(s):  
S. M. Vicente-Serrano ◽  
J. I. López-Moreno

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.


2011 ◽  
Vol 24 (8) ◽  
pp. 2025-2044 ◽  
Author(s):  
Martha C. Anderson ◽  
Christopher Hain ◽  
Brian Wardlow ◽  
Agustin Pimstein ◽  
John R. Mecikalski ◽  
...  

Abstract The reliability of standard meteorological drought indices based on measurements of precipitation is limited by the spatial distribution and quality of currently available rainfall data. Furthermore, they reflect only one component of the surface hydrologic cycle, and they cannot readily capture nonprecipitation-based moisture inputs to the land surface system (e.g., irrigation) that may temper drought impacts or variable rates of water consumption across a landscape. This study assesses the value of a new drought index based on remote sensing of evapotranspiration (ET). The evaporative stress index (ESI) quantifies anomalies in the ratio of actual to potential ET (PET), mapped using thermal band imagery from geostationary satellites. The study investigates the behavior and response time scales of the ESI through a retrospective comparison with the standardized precipitation indices and Palmer drought index suite, and with drought classifications recorded in the U.S. Drought Monitor for the 2000–09 growing seasons. Spatial and temporal correlation analyses suggest that the ESI performs similarly to short-term (up to 6 months) precipitation-based indices but can be produced at higher spatial resolution and without requiring any precipitation data. Unique behavior is observed in the ESI in regions where the evaporative flux is enhanced by moisture sources decoupled from local rainfall: for example, in areas of intense irrigation or shallow water table. Normalization by PET serves to isolate the ET signal component responding to soil moisture variability from variations due to the radiation load. This study suggests that the ESI is a useful complement to the current suite of drought indicators, with particular added value in parts of the world where rainfall data are sparse or unreliable.


Author(s):  
Vinícius Machado Rocha ◽  
Francis Wagner Silva Correia ◽  
Prakki Satyamurty ◽  
Saulo Ribeiro De Freitas ◽  
Demerval Soares Moreira ◽  
...  

2018 ◽  
Vol 176 ◽  
pp. 05040
Author(s):  
Guangyao Dai ◽  
Songhua Wu ◽  
Xiaoquan Song ◽  
Xiaochun Zhai

Cirrus clouds affect the energy budget and hydrological cycle of the earth’s atmosphere. The Tibetan Plateau (TP) plays a significant role in the global and regional climate. Optical and geometrical properties of cirrus clouds in the TP were measured in July-August 2014 by lidar and radiosonde. The statistics and temperature dependences of the corresponding properties are analyzed. The cirrus cloud formations are discussed with respect to temperature deviation and dynamic processes.


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