Types of droughts pdf

Usually, hydrological droughts are further divided into streamflow droughts and groundwater droughts depending on which type of water body is observed fleig, 2004. The dyk is a suite of notes that attempt to explain or clarify complex climate phenomena, climate monitoring products and methodologies, and climate system insights. Farmers will have to contend with spending huge sums of money for irrigation and watering animals. Socioeconomic definitions of drought associate the supply and demand of some economic good with elements of meteorological, hydrological, and agricultural drought. Droughts pdf download types of droughts and factors the distribution of water on the earths surface is not even. S droughts pdf download types of droughts and factors. Drought is often hard to categorize since various countries, and even regions, have different definitions based on their impact. There are many definitions and classifications of drought, including that of the national commission on agriculture quoted. In addition, droughts can lead to other hazards, such as. A drought usually refers to a period of lowerthanaverage precipitation leading to sustained periods of low water supply and the resultant negative effects of such an event. Meteorological drought is caused by the lack of rains and dry weather is the main factor for this type of natural calamity. The primary thing you can be sure of is that all of them hurt. Well, these are the typical earth conditions that define drought in layman terms. Sep 14, 2018 droughts caused due to meteorological factors are most common in nature and usually precede other types of droughts.

Droughts pdf download types of droughts and factors the term drought in simple words is the absence of water for a long period of time, at a place where it is considered abnormal as compared to its usual conditions. Understanding droughts national geographic society. Many indices and indicators are available to assist in the quantitative assessment of drought severity. Dry weather patterns dominate the area experiencing a climatological drought. Some arid areas of africa suffered from sustained reduction of rainfall over several decades of the late twentieth century, and recurring droughts. Meteorological drought is caused by persistent anomalies e. Meteorological drought is defined on the basis of the degree of dryness, in comparison to a normal or average amount, and the duration of the dry period. Economic effects of droughts usually involve loss of money by governments, enterprises, families or individuals. There are cases when drought develops relatively quickly and lasts a very short period of time, exacerbated by extreme heat andor wind, and there are other cases when drought spans multiple years, or even decades. There are meteorological droughts caused by changes in the weather such as wind patterns, changing sea temperatures or air temperatures.

Different people pay more attention to certain types of drought than to others. These definitions of drought bring us to the main types of droughts, which include. Agricultural droughts affect crop production or the ecology of the range. Such an event is caused by a prolonged period of low precipitation. These three categories help determine the economic, environmental, and social impacts of droughts on communities. Types there are three conditions that are generally referred to as drought. Agricultural, meteorological, hydrological and socioeconomic types of water droughts are there. Many watersheds experience depleted amounts of available water. Zolotokrylin encyclopedia of life support systems eolss precipitation over the land mostly outside arid areas.

Drought facts, drought, drought mitigation, drought. Some of the worst droughts witnessed in subsaharan africa have been associated with global warming and climate change. There are cases when drought develops relatively quickly and lasts a very short period of time, exacerbated by extreme heat andor wind, and there are other cases when. While this certainly can initiate drought conditions, oftentimes the onset of a drought is less noticeable. Droughts and desertification key concepts you must know, or be able to do the following. It describes a situation where there is a reduction in rainfall for a specific period days, months, seasons or year. Unfortunately, though, it is hard to get kids really pumped about learning the causes, effects and mitigation of drought. Hydrologists define drought as an extended period of less precipitation and stream flow. This is the reason droughts have been occurring for several hundreds of years, and still, keep occurring in different parts of the world. Day 1 drought concepts and how they are represented in the. Droughts have different physical characteristics society is dynamic so each drought event is superimposed onto societyimpacts reflect changing vulnerabilities does your country have a monitoring system for recording drought impacts. They were tasked with exploring each model and using their packets to help them compare and contrast the two types of phenomena.

The farms themselves can also cause droughts to happen as the soil is depleted and therefore cannot absorb as much water, but they can be impacted by natural droughts as well. The distribution of water on the earths surface is not even. Meteorological droughtthis type of drought all about the weather and occurs when there is a prolonged period of below average precipitation, which creates a natural shortage of available water. Causes because drought is defined as a deficit in water supply, it can be caused by a number of factors. It is due to the below normal rainfall and water shortage due to that. Meteorological drought is based on the degree of dryness or rainfall deficit and the length of the dry period hydrological drought is based on the impact of rainfall deficits on the water supply such as stream flow, reservoir and lake levels, and ground water table decline. Most people define drought as a deficiency in precipitation that persist for an extended period of time. Theyre all slightly different, some are worse than others, and its possible to get more than one at a time. Meteorological drought, agricultural drought, hydrological drought and socialeconomic drought 9. As intelligence agencies worldwide have pointed out, water scarcity and drought are global concerns. Types, causes and effects of droughts earth eclipse. Common types of drought meteorological drought meteorological drought is based on the degree of dryness rainfall deficit and the.

Jul 28, 2016 according to the national climatic data center, droughts are the second most severe weatherrelated phenomena that can damage the economy in the united states. Types of drought include meteorological, hydrological, and agricultural. Lack of water in river systems and reservoirs can impact hydroelectric power companies, farmers, wildlife, and communities. How do you incorporate impacts into a drought early warning system. Meteorological drought this type of drought all about the weather and occurs when there is a prolonged period of below average precipitation, which creates a natural shortage of available water. It is mainly caused by low precipitation and high evaporation rates, but in regions. What is drought, its types, causes and effects natural.

Sequence of drought occurrence and impacts for commonly accepted drought types. Drought impacts are a key indicator of vulnerability. Drought concepts and how they are represented in the lafdm. The frequency of occurrence of extreme droughts fig. Article about what drought is, its types, causes and effects. While droughts can be defined in many ways, three main drought types are commonly discussed. Droughts are the most costly catastrophic event or natural disasters in the world. Below is an outline of the main economic impacts of droughts.

Droughts pdf download types of droughts and factors. However, a comprehensive analysis of droughts, including their evolution, complexity, social implications. In order to combat drought we first need to understand it. Table 1 presents definitions for these different types of drought. Jan 23, 2020 the farms themselves can also cause droughts to happen as the soil is depleted and therefore cannot absorb as much water, but they can be impacted by natural droughts as well. Definitions of meteorological drought must be regionspecific, since the atmospheric conditions that result in. A drought index is often a single number characterising the general drought behaviour at a measurement site, whereas a drought event definition is applied to select drought events in a time series including the beginning and end of the droughts. The input variables for drought forecasting depend upon different types of droughts mishra and singh, 2010 to be forecasted.

Drought is a creeping phenomenon with no universal definitiondefinitions are region and application impact specific. The north and northwest parts, however, do show severe droughts during kiremt timescale fig. Hydrological drought is based on the impact of rainfall deficits on the water supply such as stream flow. In the early 1970s, more than 100,000 people died and millions of people were forced to migrate. The objective of this study is to provide a description of the background of the definition and the available methods characterizing point and regional droughts. Projected future aridity is presented based on recent studies and our analysis of model simulations. Put simply, a drought is a failure of rain, leading to moisture stress, that in turn leads to agricultural losses and other forms of social and economic hardship. Drought introduction slide 3 moisture imbalance and drought drought is when crops need more water than is availablerecharge of aquifers, lakes, and reservoirs is insufficient to provide irrigation waterprecipitation is too low at critical timesprecipitation or snow pack is. Meteorological drought occurs when there is a prolonged time with less than average precipitation. For example, farmers typically are concerned about agricultural and hydrological drought, urban planners and water managers about hydrological drought, and ranchers about ecological drought. It differs from the aforementioned types of drought because its occurrence depends on the time and space processes of supply and demand to identify or classify droughts.

During dry and hot weather periods, it is common to find dry and cracked earth without even a single shed of water or wet areas. Introduction drought is a sustained and regionally extensive occurrence of below average natural water availability. Roughly 30 percent of the worlds population live in dry areas affected by scarce natural resources, land degradation and frequent droughts, and whose living conditions are expected to decline due to. Drought is one of the natural disasters that can be reverted by nature itself. Droughts are a constant threat to mankind creating famine, war, fires and pestilence just like the four horsemen of the apocalypse rolled into one. Droughts are one of the most complex of all natural hazards, as it is difficult to determine their precise beginning or end. The terms drought event definition and drought index are frequently being confused. Thus droughts are difficult to identify and characterize, they impact in non. The effects of drought are widespread and have devastating effects on the environment and the society as a whole. Droughts that occur in the developing world can cause even greater devastation. Oct 15, 2014 droughts are a constant threat to mankind creating famine, war, fires and pestilence just like the four horsemen of the apocalypse rolled into one. A drought can be broken down into three main categories that physically define the phenomena. If youre seeing rain or snow, but are seeing it in lighter amounts a drizzle here and flurries there, rather than steady rain or snow showers this can also signal a drought inthemaking. Its impact results from the relation between a natural event and demands on the water supply, and it is often exacerbated by human activities.

The variables and associated types of drought include. This packet was created to go along with an inquiry lesson where students were shown models of both floods and droughts. East africa ea has been the primary focus for various drought studies in recent years. The sahel region in africa, which includes eight countries, endured a series of droughts in the 1970s and 1980s where annual rainfall dropped by about 40 percent. Assess which areas would be prone to droughts and desertification on both a global, regional and local scale. This kind of drought takes places when dry weather patterns outweigh other climatic conditions. But unlike the first place hurricanes, droughts have more than one definition. Mar 18, 2017 droughts, climate events caused by low precipitation over an extended period of time, are defined. Sep 28, 2018 droughts occur in nearly all types of climate. Recently the us has experienced major droughts that have impacted a large part of the country.