In the grip of severe DROUGHT
In the following write-up, we will discuss what is drought and when and how it starts and ends.
What is drought?
Drought is a lack or insufficiency of rain for an extended period that causes a considerable hydrologic (water) imbalance and, consequently, water shortages, crop damage, stream-flow reduction, and depletion of groundwater and soil moisture. Droughts are in fact part of the natural climate cycle in many regions of the world, but they can still be extremely disruptive, especially when the impact of the drought is increased by human activities.
According to US Geological Survey, a drought is a period of drier-than-normal conditions that result in water-related problems.
The word “drought” has various meanings, depending on a person’s perspective. To a farmer, a drought is a period of moisture deficiency that affects the crops under cultivation — even two weeks without rainfall can stress many crops during certain periods of the growing cycle. To a meteorologist, a drought is a prolonged period when precipitation is less than normal. To a water manager, a drought is a deficiency in water supply that affects water availability and water quality. To a hydrologist, a drought is an extended period of decreased precipitation and stream flow.
In a simple meteorological drought, rainfall is lower than average, or lower than expected, for a period of several months. This can deepen into a hydrologic situation, in which overall water supplies are low and conflicts over water resources may emerge, in which case an agricultural drought, in which crops and livestock suffer, may also emerge.
There are a lot of factors that can contribute to drought. Some of the most common causes include lack of rain, high temperatures and evaporation.
When enough water vapour is not present in the atmosphere, it cannot produce rainfall. This can be due to a number of reasons, including low air pressure, dry air masses and high levels of atmospheric moisture.
Droughts can be accompanied with major climate changes, such as an increase in average temperatures, or unusually high winds. The hot, dry weather can contribute to desertification, and it can also lead to dust storms and wildfires. Arguments over natural resources can become extremely fraught during drought conditions, as for example, when two nations go to war over a shared water source on the border, or when people migrate en masse to find land which is not suffering from drought.
Beginning and end
The beginning of a drought is difficult to determine. Several weeks, months or even years might pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began.
The first evidence of drought is usually seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in streams and reservoirs may not be noticed for several weeks or months. Water levels in wells might not reflect a shortage of rainfall for a year or more after a drought begins.
Soaking rains are the best medicine to alleviate drought. Water that enters the soil recharges groundwater, which, in turn, sustains vegetation and feeds streams during periods when it is not raining. A single soaking rain will provide lasting relief from drought conditions, but multiple such rains over several months may be required to break a drought and return conditions to within the normal range. Even when a drought has been broken, it may not be truly over. The benefits of substantial rainfall such as from a tropical storm may last for months, but a return to normal rainfall patterns and amounts is necessary for conditions in streams, reservoirs and ground water to also return to normal.
There are four basic kinds of drought:
1. Permanent drought characterizes the driest climates. The sparse vegetation is adapted to aridity, and agriculture is impossible without continuous irrigation.
2. Seasonal drought occurs in climates that have well-defined annual rainy and dry seasons. For successful agriculture, planting must be adjusted so that the crops develop during the rainy season.
3. Unpredictable drought involves an abnormal rainfall failure. It may occur almost anywhere but is most characteristic of humid and sub-humid climates. Usually brief and irregular, it often affects only a relatively small area. However, ongoing large-scale droughts of this kind are possible, especially in drier regions with several subsequent years of inadequate rainfall or snowpack.
4. Invisible drought can also be recognized: in summer, when high temperatures induce high rates of evaporation and transpiration, even frequent showers may not supply enough water to restore the amount lost; the result is a borderline water deficiency that diminishes crop yields.
A number of changes can occur in the natural environment during a drought. Algae tends to proliferate in water sources because of the elevated temperatures and decreased water supply, and the algae blooms can choke out fish species and make animals sick. The landscape may also change radically as plants, trees and shrubs die from lack of water, and hardy opportunistic species move in to eke out a living. This can also change the animal demographics in the natural environment, with drought-sensitive animals disappearing along with fragile plants.
Droughts can have a number of negative consequences for both people and the environment. They can lead to drinking water shortages, a decrease in water levels in natural resources like rivers and lakes, lower crop yields, and increased fire risk. Wildlife may also be affected, as drought conditions can reduce food availability and increase the chances of species extinction.
Drought Emergency in Pakistan
The United Nations has listed Pakistan among 23 countries that are facing drought emergencies. According to the report released by the United Nations Convention to Combat Desertification (UNCCD), twenty-three countries including Afghanistan, Angola, Brazil, Burkina Faso, Chile, Ethiopia, Iran, Iraq, Kazakhstan, Kenya, Lesotho, Mali, Mauritania, Madagascar, Malawi, Mozambique, Niger, Somalia, South Sudan, Syria, Pakistan, the United States and Zambia, have experienced drought emergencies in the last two years. The report titled as “Global Land Outlook,” says about Pakistan that desertification Control through Sustainable Land Management Productive land is scarce in Pakistan – 80 percent of the country is arid or semi-arid. Land degradation and desertification are caused by unsustainable land management practices, coupled with increased demand for natural resources, and driven by a rapidly growing and largely rural population dependent on dry lands for their livelihoods.
To address these problems, in 2007, the Pakistani government began implementing a Sustainable Land Management program across nine dry land districts. Over eight years, 120 square kilometres of degraded rangeland were rehabilitated through reseeding and community-based grazing management, and a further 80 square kilometres under sustainable rainfed agriculture and water conservation measures.
In 2015, the project was extended and rolled out more widely, utilising water control and storage structures, creating shelter-belts and rangeland management plans, restoring degraded dry land forest (e.g., community tree nurseries and plantations for domestic fuel), and implementing sand dune stabilization measures. As a result, some 13,000 households directly or indirectly benefited from nearly 200 square kilometres of improved land health, better access to water for livestock and reduced wind erosion.
This success of the program inspired the Billion Trees Afforestation Project in Pakistan’s mountainous Khyber Pakhtunkhwa, which saw 3,500 square kilometres of forests and degraded land restored in just two years.
In 2018, the popularity of this initiative gave impetus to the world’s largest reforestation initiative — the Ten Billion Tree Tsunami Programme – as part of a suite of nature-based solutions to fight desertification and climate change in Pakistan.
In Balochistan, indigenous management techniques, known as the karez system, utilize tunnels that follow a natural gradient to deliver groundwater without employing mechanical energy.
The writer is a student at UMT, Lahore.
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