Drought
A drought is a period of drier-than-normal conditions.[1]: 1157 A drought can last for days, months or years. Drought often has large impacts on the ecosystems and agriculture of affected regions, and causes harm to the local economy.[2][3] Annual dry seasons in the tropics significantly increase the chances of a drought developing, with subsequent increased wildfire risks.[4] Heat waves can significantly worsen drought conditions by increasing evapotranspiration.[5] This dries out forests and other vegetation, and increases the amount of fuel for wildfires.[4][6]
Drought is a recurring feature of the climate in most parts of the world, becoming more extreme and less predictable due to
Economic impacts include disruption of water supplies for people, less agricultural productivity and therefore more expensive food production. Another impact is shortages of water for irrigation or hydropower. Social and health costs include the negative effect on the health of people directly exposed to this phenomenon (excessive heat waves), high food costs, stress caused by failed harvests, water scarcity, etc. Prolonged droughts have caused mass migrations and humanitarian crisis.[7][8]
Examples for regions with increased drought risks are the Amazon basin, Australia, the Sahel region and India. For example, in 2005, parts of the Amazon basin experienced the worst drought in 100 years.[9][10] Australia could experience more severe droughts and they could become more frequent in the future, a government-commissioned report said on July 6, 2008.[11] The long Australian Millennial drought broke in 2010. The 2020–2022 Horn of Africa drought has surpassed the horrific drought in 2010–2011 in both duration and severity.[12][13] More than 150 districts in India are drought vulnerable, mostly concentrated in the state of Rajasthan, Gujarat, Madhya Pradesh and its adjoining Chhattisgarh, Uttar Pradesh, northern Karnataka and adjoining Maharashtra of the country.[14]
Throughout history, humans have usually viewed droughts as disasters due to the impact on food availability and the rest of society. People have viewed drought as a natural disaster or as something influenced by human activity, or as a result of supernatural forces.
Definition
The IPCC Sixth Assessment Report defines a drought simply as "drier than normal conditions".[1]: 1157 This means that a drought is "a moisture deficit relative to the average water availability at a given location and season".[1]: 1157
According to National Integrated Drought Information System, a multi-agency partnership, drought is generally defined as "a deficiency of precipitation over an extended period of time (usually a season or more), resulting in a water shortage". The National Weather Service office of the NOAA defines drought as "a deficiency of moisture that results in adverse impacts on people, animals, or vegetation over a sizeable area".[15]
Drought is a complex phenomenon − relating to the absence of water − which is difficult to monitor and define.[16] By the early 1980s, over 150 definitions of "drought" had already been published.[17] The range of definitions reflects differences in regions, needs, and disciplinary approaches.
Categories
There are three major categories of drought based on where in the water cycle the moisture deficit occurs: meteorological drought, hydrological drought, and agricultural or ecological drought.[1]: 1157 A meteorological drought occurs due to lack of precipitation. A hydrological drought is related to low runoff, streamflow, and reservoir storage. An agricultural or ecological drought is causing plant stress from a combination of evaporation and low soil moisture.[1]: 1157 Some organizations add another category: socioeconomic drought occurs when the demand for an economic good exceeds supply as a result of a weather-related shortfall in water supply.[16][17] The socioeconomic drought is a similar concept to water scarcity.
The different categories of droughts have different causes but similar effects:
- Meteorological drought occurs when there is a prolonged time with less than average precipitation.[18] Meteorological drought usually precedes the other kinds of drought.[19] As a drought persists, the conditions surrounding it gradually worsen and its impact on the local population gradually increases.
- Hydrological drought is brought about when the water reserves available in sources such as aquifers, lakes and reservoirs fall below a locally significant threshold. Hydrological drought tends to show up more slowly because it involves stored water that is used but not replenished. Like an agricultural drought, this can be triggered by more than just a loss of rainfall. For instance, around 2007 Kazakhstan was awarded a large amount of money by the World Bank to restore water that had been diverted to other nations from the Aral Sea under Soviet rule.[20] Similar circumstances also place their largest lake, Balkhash, at risk of completely drying out.[21]
- Agricultural or ecological droughts affect crop production or ecosystems in general. This condition can also arise independently from any change in precipitation levels when either increased irrigation or soil conditions and erosion triggered by poorly planned agricultural endeavors cause a shortfall in water available to the crops.
Indices and monitoring
Several indices have been defined to quantify and monitor drought at different spatial and temporal scales. A key property of drought indices is their spatial comparability, and they must be statistically robust.[22] Drought indices include:[22]
- Palmer drought index (sometimes called the Palmer drought severity index (PDSI)): a regional drought index commonly used for monitoring drought events and studying areal extent and severity of drought episodes.[23] The index uses precipitation and temperature data to study moisture supply and demand using a simple water balance model.[23][24][25]
- meteorological factors.[26]
- Standardized precipitation index (SPI): It is computed based on precipitation, which makes it a simple and easy-to-apply indicator for monitoring and prediction of droughts in different parts of the world. The World Meteorological Organization recommends this index for identifying and monitoring meteorological droughts in different climates and time periods.[22]
- Standardized Precipitation Evapotranspiration Index (SPEI): a multiscalar drought index based on climatic data. The SPEI accounts also for the role of the increased atmospheric evaporative demand on drought severity.[22] Evaporative demand is particularly dominant during periods of precipitation deficit. The SPEI calculation requires long-term and high-quality precipitation and atmospheric evaporative demand datasets. These can be obtained from ground stations or gridded data based on reanalysis as well as satellite and multi-source datasets.[22]
- Indices related to vegetation: root-zone soil moisture, vegetation condition index (VDI) and vegetation health index (VHI). The VCI and VHI are computed based on vegetation indices such as the normalized difference vegetation index (NDVI) and temperature datasets.[22]
- Deciles index
- Standardized runoff index
High-resolution drought information helps to better assess the spatial and temporal changes and variability in drought duration, severity, and magnitude at a much finer scale. This supports the development of site-specific adaptation measures.[22]
The application of multiple indices using different datasets helps to better manage and monitor droughts than using a single dataset, This is particularly the case in regions of the world where not enough data is available such as Africa and South America. Using a single dataset can be limiting, as it may not capture the full spectrum of drought characteristics and impacts.[22]
Careful monitoring of moisture levels can also help predict increased risk for wildfires.
Causes
General precipitation deficiency
Mechanisms of producing precipitation include
Precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice.
Droughts occur mainly in areas where normal levels of rainfall are, in themselves, low. If these factors do not support precipitation volumes sufficiently to reach the surface over a sufficient time, the result is a drought. Drought can be triggered by a high level of reflected sunlight and above average prevalence of high
Dry season
Within the tropics, distinct,
El Niño–Southern Oscillation (ENSO)
The
Conversely, during El Niño events, drier and hotter weather occurs in parts of the
Climate change
Globally, the occurrence of droughts has increased as a result of the increase in temperature and atmospheric evaporative demand. In addition, increased climate variability has increased the frequency and severity of drought events. Moreover, the occurrence and impact of droughts are aggravated by anthropogenic activities such as land use change and water management and demand.[22]
The IPCC Sixth Assessment Report also pointed out that "Warming over land drives an increase in atmospheric evaporative demand and in the severity of drought events"[43]: 1057 and "Increased atmospheric evaporative demand increases plant water stress, leading to agricultural and ecological drought".[44]: 578
There is a rise of compound warm-season droughts in Europe that are concurrent with an increase in potential evapotranspiration.[45]
Higher temperatures increase evaporation. This dries the soil and increases plant stress. Agriculture suffers as a result. This means even regions where overall rainfall is expected to remain relatively stable will experience these impacts.[48]: 1157 These regions include central and northern Europe. Without climate change mitigation, around one third of land areas are likely to experience moderate or more severe drought by 2100.[48]: 1157 Due to global warming droughts are more frequent and intense than in the past.[49]
Several impacts make their impacts worse. These are increased water demand, population growth and urban expansion in many areas.[50] Land restoration can help reduce the impact of droughts. One example of this is agroforestry.[51]Erosion and human activities
Human activity can directly trigger exacerbating factors such as over-farming, excessive irrigation,[52] deforestation, and erosion adversely impact the ability of the land to capture and hold water.[53] In arid climates, the main source of erosion is wind.[54] Erosion can be the result of material movement by the wind. The wind can cause small particles to be lifted and therefore moved to another region (deflation). Suspended particles within the wind may impact on solid objects causing erosion by abrasion (ecological succession). Wind erosion generally occurs in areas with little or no vegetation, often in areas where there is insufficient rainfall to support vegetation.[55]
Impacts
Drought is one of the most complex and major
One can divide the impacts of droughts and water shortages into three groups: environmental, economic and social (including health).
Environmental and economic impacts
Environmental effects of droughts include: lower surface and subterranean water-levels, lower flow-levels (with a decrease below the minimum leading to direct danger for amphibian life), increased pollution of surface water, the drying out of wetlands, more and larger wildfires, higher deflation intensity, loss of biodiversity, worse health of trees and the appearance of pests and dendroid diseases.[56][6]
Economic losses as a result of droughts include lower agricultural, forests, game and fishing output, higher food-production costs, lower energy-production levels in hydro plants, losses caused by depleted water tourism and transport revenue, problems with water supply for the energy sector and for technological processes in metallurgy, mining, the chemical, paper, wood, foodstuff industries etc., disruption of water supplies for municipal economies.
Further examples of common environmental and economic consequences of drought include:
- Alteration of diversity of plant communities, which can have an impact on net primary production and other ecosystem services.[57]
- Australian bushfires and wildfires in the United States, become more common during times of drought and may cause human deaths.[58]
- Dust Bowls, themselves a sign of erosion, which further erode the landscape
- Dust storms, when drought hits an area suffering from desertification and erosion
- Snake migration, which results in snake-bites[60]
- Reduced
- Shortages of water for
Agricultural impacts
Droughts can cause land degradation and loss of soil moisture, resulting in the destruction of cropland productivity.[64] This can result in diminished crop growth or yield productions and carrying capacity for livestock. Drought in combination with high levels of grazing pressure can function as the tipping point for an ecosystem, causing woody encroachment.[65]
Water stress affects plant development and quality in a variety of ways: firstly drought can cause poor germination and impaired seedling development.[66] At the same time plant growth relies on cellular division, cell enlargement, and differentiation. Drought stress impairs mitosis and cell elongation via loss of turgor pressure which results in poor growth.[67] Development of leaves is also dependent upon turgor pressure, concentration of nutrients, and carbon assimilates[clarification needed] all of which are reduced by drought conditions, thus drought stress lead to a decrease in leaf size and number.[67] Plant height, biomass, leaf size and stem girth has been shown to decrease in maize under water limiting conditions.[67] Crop yield is also negatively effected by drought stress, the reduction in crop yield results from a decrease in photosynthetic rate, changes in leaf development, and altered allocation of resources all due to drought stress.[67] Crop plants exposed to drought stress suffer from reductions in leaf water potential and transpiration rate. Water-use efficiency increases in crops such as wheat while decreasing in others, such as potatoes.[68][69][67]
Plants need water for the uptake of nutrients from the soil, and for the transport of nutrients throughout the plant: drought conditions limit these functions leading to stunted growth. Drought stress also causes a decrease in photosynthetic activity in plants due to the reduction of photosynthetic tissues, stomatal closure, and reduced performance of photosynthetic machinery. This reduction in photosynthetic activity contributes to the reduction in plant growth and yields.[67] Another factor influencing reduced plant growth and yields include the allocation of resources; following drought stress plants will allocate more resources to roots to aid in water uptake increasing root growth and reducing the growth of other plant parts while decreasing yields.[67]
Social and health impacts
The most negative impacts of drought for humans include
There are negative effects on the health of people who are directly exposed to this phenomenon (excessive heat waves). Droughts can also cause limitations of water supplies, increased water pollution levels, high food-costs, stress caused by failed harvests, water scarcity, etc. Reduced water quality can occur because lower water-flows reduce dilution of pollutants and increase contamination of remaining water sources.[70][71]
This explains why droughts and water scarcity operate as a factor which increases the gap between developed and developing countries.[72]
Effects vary according to vulnerability. For example, subsistence farmers are more likely to migrate during drought because they do not have alternative food-sources. Areas with populations that depend on water sources as a major food-source are more vulnerable to famine.
Further examples of social and health consequences include:
- Water scarcity, crop failure, famine[73] and hunger – drought provides too little water to support food crops; malnutrition, dehydration and related diseases
- Mass migration, resulting in internal displacement and international refugees
- Social unrest
- War over natural resources, including water and food
- Cyanotoxin accumulation within food chains and water supply (some of which are among the most potent toxins known to science) can cause cancer with low exposure over the long term.[74] High levels of microcystin appeared in San Francisco Bay Area salt-water shellfish and fresh-water supplies throughout the state of California in 2016.
Loss of fertile soils
Wind erosion is much more severe in arid areas and during times of drought. For example, in the Great Plains, it is estimated that soil loss due to wind erosion can be as much as 6100 times greater in drought years than in wet years.[75]
Regions particularly affected
Amazon basin
In 2005, parts of the
Australia
The 1997–2009 Millennium Drought in Australia led to a water supply crisis across much of the country. As a result, many desalination plants were built for the first time (see list).
By far the largest part of
East Africa and Sahel
In 2012, a severe drought struck the western Sahel. More than 10 million people in the region were at risk of famine due to a month-long heat wave that was hovering over Niger, Mali, Mauritania and Burkina Faso.[92]
Himalayan river basins
Approximately 2.4 billion people live in the drainage basin of the Himalayan rivers.[93] India, China, Pakistan, Bangladesh, Nepal and Myanmar could experience floods followed by droughts in coming decades. More than 150 districts in India are drought vulnerable, mostly concentrated in the state of Rajasthan, Gujarat, Madhya Pradesh and its adjoining Chhattisgarh, Uttar Pradesh, northern Karnataka and adjoining Maharashtra of the country.[14] Drought in India affecting the Ganges is of particular concern, as it provides drinking water and agricultural irrigation for more than 500 million people.[94][95][96]
North America
The west coast of
By country or region
Droughts in particular countries:
See also:
- Droughts and famines in Russia and USSR
- Droughts in California
- 2021 Madagascar food crisis
- 2010 China drought and dust storms
- Cape Town water crisis in 2015–2018
Protection, mitigation and relief
Agriculturally, people can effectively mitigate much of the impact of drought through irrigation and crop rotation. Failure to develop adequate drought mitigation strategies carries a grave human cost in the modern era, exacerbated by ever-increasing population densities.
Strategies for drought protection or mitigation include:
- Dams – many dams and their associated reservoirs supply additional water in times of drought.[99]
- United States National Research Council released a report in 2004 stating that to date, there is still no convincing scientific proof of the efficacy of intentional weather modification.[101]
- Land use – Carefully planned crop rotation can help to minimize erosion and allow farmers to plant less water-dependent crops in drier years.
- Transvasement – Building canals or redirecting rivers as massive attempts at irrigationin drought-prone areas.
When water is scarce due to droughts, there are a range of options for people to access other sources of water, such as wastewater reuse, rainwater harvesting and stormwater recovery, or seawater desalination.
History
Throughout history, humans have usually viewed droughts as
Droughts can be scientifically explained in terms of physical mechanisms, which underlie
Historically, rituals have been used in an attempt to prevent or avert drought. Rainmaking rituals have ranged from dances to scapegoating to human sacrifices. Many ancient practices are now a matter of folklore while others may still be practiced.[109]
In areas where people have limited understanding of the scientific basis of drought, beliefs about drought continue to reflect indigenous beliefs in the power of spirits and Christian philosophies that see drought as a divine punishment. Such beliefs can influence people's thinking and affect their resilience and ability to adapt to stress and respond to crises.[106] In the case of Creationism, curricula sometimes give religious explanations of natural phenomena rather than scientific ones. Teaching explicitly denies evolution, that human agency is affecting climate, and that climate change is occurring.[110]
Some historical droughts include:
- The longest drought in recorded history started 400 years ago in the Atacama Desert in Chile and still continues.[111]
- Drought might have been a contributing factor to Classic Maya collapse between the 7th and 9th centuries
- 1540 Central Europe, said to be the "worst drought of the millennium" with eleven months without rain and temperatures of 5–7 °C above the average of the 20th century[112][113]
- 1900 India killing between 250,000 and 3.25 million.
- 1921–22 Soviet Union in which over 5 million perished from starvation due to drought.
- 1928–30 Northwest China resulting in over 3 million deaths by famine.
- 1936 and 1941 Sichuan Province China resulting in 5 million and 2.5 million deaths respectively.
See also
- Aridity index
- Drought refuge
- Flash drought
- Food security
- Leaf Sensor
- List of droughts
- Permanent wilting point
- United Nations Convention to Combat Desertification
- Water security
References
- ^ a b c d e Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021: Water Cycle Changes Archived 2022-09-29 at the Wayback Machine. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1055–1210, doi:10.1017/9781009157896.010.
- ^ Living With Drought Archived 2007-02-18 at the Wayback Machine
- ^ Australian Drought and Climate Change Archived 2018-07-26 at the Wayback Machine, retrieved on June 7th 2007.
- ^ ISSN 0084-6597.
- ^ Merzdorf, Jessica (July 9, 2019). "A Drier Future Sets the Stage for More Wildfires". Climate Change: Vital Signs of the Planet. NASA.
- ^ ISSN 1543-5008.
- PMID 23787891.
- PMC 7659048.
- ^ a b "Amazon Drought Worst in 100 Years". www.ens-newswire.com. Archived from the original on 2019-11-15. Retrieved 5 November 2017.
- ^ a b Drought Threatens Amazon Basin - Extreme conditions felt for second year running Archived May 27, 2013, at the Wayback Machine
- ^ a b Australia faces worse, more frequent droughts: study Archived 2021-02-03 at the Wayback Machine, Reuters
- ^ a b Dunne, Daisy (2022-10-26). "Analysis: Africa's unreported extreme weather in 2022 and climate change". Carbon Brief. Retrieved 2022-10-29.
- ^ a b "Horn of Africa Drought: Regional Humanitarian Overview & Call to Action". reliefweb.int. 2022-09-21. Retrieved 2022-10-29.
- ^ a b Nandy, S.N. (2021) Analysis of drought vulnerability indices of Indian districts using Fuzzy logic approach. International Water Resources Association Journal (IWRA - India), 10(2): 11-17. https://www.indianjournals.com/ijor.aspx?target=ijor:iwra&volume=10&issue=2&article=002
- ^ "Drought Basics". Drought.gov. NOAA National Integrated Drought Information System. Retrieved 2022-09-16.
- ^ a b "Definition of Drought". www.ncei.noaa.gov. NOAA | National Centers for Environmental Information (NCEI). Retrieved 2022-09-16.
- ^ a b "Types of Drought". drought.unl.edu. National Drought Mitigation Center. Retrieved 2022-09-16.
- S2CID 26920225.
- ^ "What is a Drought?" (PDF). National Oceanic and Atmospheric Administration. August 2006. Archived (PDF) from the original on 2022-10-09. Retrieved 2007-04-10.
- ^ "BBC NEWS - Asia-Pacific - Dam project aims to save Aral Sea". BBC. 2007-04-09.
- ^ "BBC NEWS - Asia-Pacific - Kazakh lake 'could dry up'". BBC. 2004-01-15.
- ^ ISSN 1866-3516. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
- ^ .
- .
- ISSN 1436-3240.
- ^ Keetch, John J.; Byram, George M. (1968). "A Drought Index for Forest Fire Control". Res. Pap. Se-38. Asheville, Nc: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 35 P. 038. USDA Forest Service Southern Research Station. Retrieved August 11, 2016.
(Date: 1968) Res. Paper SE-38. 32 pp. Asheville, NC: U.S. Department of Agriculture, Forest Service
- .
- .
- ISBN 978-0-12-548035-2. Retrieved 2009-01-02.
- OCLC 427392836.
- ISBN 978-0792310174.
- ISBN 978-1573563789.
- ISBN 978-3540406105.
- ISBN 978-0198036784.
- ^ "Wet & Dry Seasons". Archived from the original on 2012-03-20. Retrieved 2018-12-23.
- ^ Alistair B. Fraser (1994-11-27). "Bad Meteorology: The reason clouds form when air cools is because cold air cannot hold as much water vapor as warm air". Archived from the original on 2015-03-16. Retrieved 2015-02-17.
- ^ Cooperative Extension Service (January 2014). Home Vegetable Gardening in Kentucky (PDF). University of Kentucky. p. 19. Archived (PDF) from the original on 2022-10-09. Retrieved 2015-02-18.
- ^ North Carolina State University (2013-08-09). "Evapotranspiration". Archived from the original on 2015-02-19. Retrieved 2015-02-18.
- ^ National Oceanic and Atmospheric Administration (2002-05-16). "Warm Temperatures and Severe Drought Continued in April Throughout Parts of the United States; Global Temperature For April Second Warmest on Record". Archived from the original on Feb 19, 2015. Retrieved 2015-02-18.
- ^ Seth Borenstein (May 28, 2022). "Weather's unwanted guest: Nasty La Niña keeps popping up". 9news.com. Archived from the original on 6 Dec 2023. Retrieved June 4, 2022.
Scientists are noticing that in the past 25 years the world seems to be getting more La Niñas than it used to…
- ^ Chan, Joanne (3 March 2010). "February 2010 is driest month for S'pore since records began in 1869". channelnewsasia.com. Archived from the original on 3 March 2010. Retrieved 5 November 2017.
- ^ "Climate Change 2021 / The Physical Science Basis / Working Group I contribution to the WGI Sixth Assessment Report of the Intergovernmental Panel on Climate Change / Summary for Policymakers" (PDF). Intergovernmental Panel on Climate Change. 9 August 2021. p. SPM-23. Archived (PDF) from the original on 4 November 2021. Fig. SPM.6
- ^ Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021: Chapter 8: Water Cycle Changes. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1055–1210, doi:10.1017/9781009157896.010.
- ^ Caretta, M.A., A. Mukherji, M. Arfanuzzaman, R.A. Betts, A. Gelfan, Y. Hirabayashi, T.K. Lissner, J. Liu, E. Lopez Gunn, R. Morgan, S. Mwanga, and S. Supratid, 2022: Chapter 4: Water. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 551–712, doi:10.1017/9781009325844.006.
- PMID 33536204.
- ^ Irina Ivanova (2 June 2022). "California is rationing water amid its worst drought in 1,200 years". CBS News. Retrieved 2 June 2022.
- S2CID 53624756.
- ^
- ^ "Scientists confirm global floods and droughts worsened by climate change". PBS NewsHour. 2023-03-13. Retrieved 2023-05-01.
- .
- ^ Daniel Tsegai, Miriam Medel, Patrick Augenstein, Zhuojing Huang (2022) Drought in Numbers 2022 - restoration for readiness and resilience, United Nations Convention to Combat Desertification (UNCCD)
- ^ "A biblical tragedy as Sea of Galilee faces drought". BelfastTelegraph.co.uk.
- ^ "Kenya: Deforestation exacerbates droughts, floods". forests.org. Archived from the original on 2011-09-27. Retrieved 2008-05-24.
- ^ a b Vern Hofman; Dave Franzen (1997). "Emergency Tillage to Control Wind Erosion". North Dakota State University Extension Service. Retrieved 2009-03-21.
- ^ United States Geological Survey (2004). "Dunes – Getting Started". Archived from the original on 2012-04-27. Retrieved 2009-03-21.
- .
- ISSN 0022-0477.
- ^ "TFS Article". tamu.edu. Archived from the original on 11 July 2003.
- ^ C.Michael Hogan. 2010. Abiotic factor. Ed. Emily Monosson. Encyclopedia of Earth. National Council for Science and the Environment, Washington DC Archived June 8, 2013, at the Wayback Machine
- ^ "BBC NEWS - Asia-Pacific - Australians face snake invasion". bbc.co.uk. 2007-01-20.
- ^ Drought affecting US hydroelectric production | Daily Estimate Archived October 2, 2011, at the Wayback Machine
- ^ "Parched village sues to shut tap at Coke / Drought-hit Indians say plant draining groundwater". SFGate. 2005-03-06.
- ^ "Sweden closes nuclear plants over safety fears". Greenpeace International. Archived from the original on 2009-01-10. Retrieved 2016-02-06.
- S2CID 252713722.
- S2CID 253299539.
- S2CID 12066792.
- ^ PMID 28706531.
- PMID 30584094.
- .
- .
- ^ 10. Mosley LM, Zammit B, Leyden E, Heneker TM, Hipsey MR, Skinner D, and Aldridge KT (2012). The Impact of Extreme Low Flows on the Water Quality of the Lower Murray River and Lakes (South Australia). Water Resources Management 26: 3923–3946.
- ^ Prokurat, Sergiusz (2015). "Drought and water shortages in Asia as a threat and economic problem" (PDF). Journal of Modern Science. 26 (3). Archived (PDF) from the original on 2022-10-09. Retrieved 4 August 2016.
- ISBN 9781483189666.
- ^ "Toxins from freshwater algae found in San Francisco Bay shellfish". Retrieved 5 November 2017.
- ISBN 978-0-470-71076-0.
- S2CID 131245730.
- ISBN 978-3-540-27951-8.
- ISBN 978-0-697-38506-2.
- ^ Amazon rainforest 'could become a desert' Archived 2017-08-25 at the Wayback Machine, The Independent, July 23, 2006. Retrieved September 28, 2006.
- ^ Dying Forest: One year to save the Amazon Archived 2017-08-25 at the Wayback Machine, The Independent, July 23, 2006. Retrieved September 28, 2006.
- ^ Climate change a threat to Amazon rainforest, warns WWF, World Wide Fund for Nature, March 9, 2996. Retrieved September 28, 2006.
- ^ Sensitivity of the Australian Monsoon to insolation and vegetation: Implications for human impact on continental moisture balance Archived 2010-06-15 at the Wayback Machine, Geological Society of America
- ^ Australian rivers 'face disaster' Archived 2021-08-13 at the Wayback Machine, BBC News
- ^ Metropolis strives to meet its thirst Archived 2021-09-06 at the Wayback Machine, BBC News
- ^ "Plan B Updates - 47: Disappearing Lakes, Shrinking Seas - EPI". earth-policy.org.
- ^ "Shrinking African Lake Offers Lesson on Finite Resources". nationalgeographic.com. Archived from the original on April 30, 2001.
- ^ Sara Pantuliano and Sara Pavanello (2004) Taking drought into account Addressing chronic vulnerability among pastoralists in the Horn of Africa Archived March 7, 2012, at the Wayback Machine Overseas Development Institute
- ^ "Fatal Failure: Did Aid Agencies Let Up To 100,000 Somalis Die in 2011? Archived 2013-12-25 at the Wayback Machine". Time. January 18, 2012.
- ^ Warah, Rasna (2 October 2011). "Manufacturing a famine: How Somalia crisis became a fund-raising opportunity". The East African. Archived from the original on 24 October 2012. Retrieved 16 March 2013.
- ^ a b Gettleman, Jeffrey (3 February 2012). "U.N. Says Somalia Famine Has Ended, but Crisis Isn't Over". The New York Times. Retrieved 5 November 2017.
- ^ "Thomson Reuters Foundation". alertnet.org. Archived from the original on 2007-12-13. Retrieved 2007-07-31.
- ^ "Methodists make appeal for famine threatened West Africa - Ekklesia". ekklesia.co.uk. 2010-07-06.
- ^ "People & the Planet > climate change > newsfile > big melt threatens millions, says un". peopleandplanet.net. Archived from the original on 19 August 2007.
- ^ "Ganges, Indus may not survive: climatologists". rediff.com.
- ^ "People's Daily Online - Glaciers melting at alarming speed". peopledaily.com.cn.
- ^ "BBC NEWS - Science/Nature - Himalaya glaciers melt unnoticed". BBC. 2004-11-10.
- ^ "Glaciers Are Melting Faster Than Expected, UN Reports". ScienceDaily.
- ^ Water shortage worst in decades, official says Archived 2011-02-19 at the Wayback Machine, Los Angeles Times
- ^ Matt Weiser; Jeremy B. White (2014-06-01). "Should California build dams, reservoirs to help with future droughts?". Fresno Bee. Archived from the original on 2015-03-20. Retrieved 2015-02-18.
- ^ "Cloud seeding helps alleviate drought". chinadaily.com.cn.
- ISBN 978-0-309-09053-7.
- ^ "BBC - Weather Centre - Features - History and Religion - Weather in the Bible - Drought and Famine". Archived from the original on 10 January 2004. Retrieved 5 November 2017.
- ^ "Ancient Chile Migration Mystery Tied to Drought". nationalgeographic.com. Archived from the original on October 28, 2002.
- ^ Drought pushed ancient African immigration [permanent dead link]
- ISSN 1757-7780.
- ^ ISSN 1572-8366.
- ^ Wrethman, Emily (4 April 2023). "How societies use supernatural forces to explain earthly events". Faculty of Medicine, Dentistry and Health Sciences.
- ISSN 2397-3374.
- ISBN 978-3-030-62316-6.
- ISSN 1871-1510.
- ^ "Driest Place: Atacama Desert, Chile". Extreme Science. Retrieved September 25, 2016..
- Climatic Change, June 2014, doi:10.1007/s10584-014-1184-2
- ^ Andreas Frey (2018-08-04). "Elf Monate ohne Regen: Die Angst vor der Megadürre des Jahres 1540 geht um". Neue Zürcher Zeitung (in German). Retrieved 2018-08-06.