How Can Rain Create Conflict? Precipitation and Water Use: Crash Course Geography #11

Summary

This Crash Course Geography episode, hosted by Alizé Carrère, delves into the critical role of precipitation in shaping Earth's ecosystems and human life. It explores how precipitation varies with latitude and topography, affecting regions like Borneo and the Arctic, and how the Great Plains' unpredictable rainfall leads to challenges like drought. The episode also discusses the Colorado River's significance as a water source for the Southwest, highlighting water management issues, including the impact of dams, urban growth, and legal disputes over water rights. It raises questions about water control, rights, and the environmental costs of human water usage, emphasizing the importance of understanding precipitation patterns for geographical and geopolitical insights.

Takeaways

• 🌍 The map of world's precipitation is crucial for understanding life on Earth as it shows how water circulates between Earth systems.
• 💧 Precipitation, including rain, snow, sleet, and hail, is vital for agriculture, industry, transportation, and ecosystems.
• 🌱 Water acts as a universal solvent, dissolving and transporting nutrients and pollutants across different environments.
• 🗺 Comparing precipitation maps with population distribution reveals a pattern: where there is water, there are people.
• 🏔 Orographic precipitation occurs when air rises over mountains, cools, and forms clouds, leading to rain or snow on the windward side.
• 🌬 The Great Plains experience unpredictable precipitation due to continental effects, rain shadow from the Rocky Mountains, and atmospheric circulation.
• 🌋 The Dust Bowl, a severe drought in the 1930s, demonstrated the impact of precipitation patterns on human and environmental health.
• 🏞️ The Colorado River, a significant water source in the southwest, faces challenges in water distribution due to its reliance on a single source.
• 🏛️ Water management involves spatial problems, such as allocating water between farms, factories, towns, and maintaining ecological balance.
• 🏗️ Dams like Hoover and Glen Canyon were built to control water flow, impacting water distribution and raising questions about water rights and environmental justice.
• 🌐 Geopolitical issues related to water control are prevalent in regions like the Middle East, North Africa, South Asia, and the Western US, affecting public health and agriculture.

Q & A

Why is the map of the world's precipitation considered so important by geographers?

The map of the world's precipitation is considered important because it helps us understand all life on Earth by tracking water, which is essential for agriculture, industry, transportation, recreation, and all flora and fauna.

What is the hydrological cycle and how does precipitation fit into it?

The hydrological cycle is the process that circulates water molecules between the Earth's systems, and precipitation is the final step in this cycle, involving rain, snow, sleet, hail, or any liquid or solid that falls from clouds.

How does water's role as a universal solvent impact its movement through the water cycle?

As a universal solvent, water can dissolve more substances than any other liquid, which means as it moves through the water cycle, it transports both vital nutrients and harmful pollutants across different spaces and places.

What geographical pattern can be observed when comparing the map of precipitation with the map of population distribution?

A simple but powerful pattern observed is that where there is water, there are people, indicating a direct correlation between water availability and human settlement.

How does the continental effect influence precipitation patterns in the Great Plains?

The continental effect causes huge temperature fluctuations in the Great Plains due to its location far from oceans, leading to scorching summers and frigid winters, and affecting precipitation patterns.

What is orographic precipitation and how does it occur?

Orographic precipitation occurs when air is forced to rise over mountains, cools, and the water vapor condenses to form clouds and precipitation, such as rain or snow.

Why is the Great Plains region prone to drought?

The Great Plains is prone to drought due to a combination of factors including the continental effect, its location in the rain shadow of the Rocky Mountains, and subtropical high pressure systems in the atmosphere.

What was the Dust Bowl and how did it affect the Great Plains?

The Dust Bowl was a significant drought that ravaged the Great Plains from 1930 until 1939, causing devastation for people, animals, and plants, and changing the perception of the region.

How does the Colorado River serve as a water source for the southwestern United States?

The Colorado River is a major water source for the southwestern United States, with ninety percent of its surface water coming from snow in the Rocky Mountains that melts and flows into the river.

What challenges arise from relying on a single water source like the Colorado River?

Challenges include managing water distribution among different users who may not be located near the river, dealing with unregulated water use upstream that can leave less water for downstream users, and navigating political boundaries that don't align with the river's course.

How has the management of the Colorado River water been historically problematic and what are some proposed solutions?

Historically, the management of the Colorado River has been problematic due to overestimation of its flow, misallocation of water rights, and physical alterations like dams. Proposed solutions include privatizing water rights, which would allow market forces to determine water distribution and value.

Outlines

00:00

🌍 Importance of Precipitation in Geography

This paragraph introduces the significance of the world's precipitation map in understanding life on Earth. It explains precipitation as a critical part of the hydrological cycle, affecting agriculture, industry, transportation, and ecosystems. The universal solvent properties of water and its role in transporting nutrients and pollutants are highlighted. The paragraph also discusses how precipitation maps can reveal disparities in water access, leading to geographical patterns and potential conflicts. It sets the stage for the Crash Course Geography series by Alizé Carrère, emphasizing the interplay between Earth's physical and human geography.

05:02

💧 Precipitation Patterns and Their Impact

The second paragraph delves into the geographical patterns of precipitation, influenced by Earth's spheroid shape, rotation, revolution, and tilt. It contrasts areas of high precipitation like Borneo with arid regions like the Svalbard islands, explaining the role of latitude and atmospheric conditions. The concept of orographic precipitation is introduced, detailing how mountain ranges like the Rockies influence rainfall patterns, creating 'rain shadows'. The paragraph discusses the challenges of managing water resources in regions like the Great Plains, where precipitation is unpredictable and can lead to droughts. It also touches on the historical and environmental consequences of mismanagement, such as the Dust Bowl, and the ongoing struggle for water rights among various stakeholders.

10:06

🌱 Water Management and Its Geopolitical Ramifications

The final paragraph focuses on the Colorado River as a case study for water management challenges. It discusses the river's importance as a water source for the southwest United States, the challenges of distributing water from a single source, and the historical and legal complexities of water rights. The paragraph outlines the 'prior appropriation doctrine' and the Colorado River Compact, which have led to over-allocation and legal disputes. It also addresses the impact of urban growth on water demand and the proposed privatization of water rights. The paragraph concludes by emphasizing the broader geopolitical issues related to water control and the need for geographers to continue exploring these challenges.

Keywords

💡Precipitation

Precipitation refers to any form of water that falls from clouds in the atmosphere, including rain, snow, sleet, and hail. It is a critical component of the Earth's water cycle, linking the hydrological cycle to various Earth systems. In the video, precipitation is highlighted as the most important map for understanding life on Earth, as it directly impacts agriculture, industry, and ecosystems. The script discusses how different regions receive varying amounts of precipitation, influencing human settlement and the potential for conflict over water resources.

💡Hydrological Cycle

The hydrological cycle is the continuous movement of water on, above, and below the Earth's surface. It involves the processes of evaporation, condensation, precipitation, and collection. The video underscores the importance of the hydrological cycle in distributing water, which is essential for life. Precipitation is depicted as the final phase of this cycle, where water returns to the Earth's surface, completing the circulation and making it available for various uses.

💡Universal Solvent

Water is often referred to as the 'universal solvent' due to its ability to dissolve more substances than any other liquid. This property is crucial as it allows water to transport nutrients and pollutants, as mentioned in the script. The concept is integral to understanding how water, through its journey in the hydrological cycle, can carry and distribute essential elements for life and potentially harmful substances.

💡Orographic Precipitation

Orographic precipitation occurs when air masses are forced to rise over mountains, cool, and condense, forming clouds and precipitation on the windward side. The video uses the example of the Rocky Mountains to explain how this phenomenon creates a rain shadow effect on the leeward side, such as the Great Plains, leading to a semi-arid climate. This concept is central to understanding regional climate differences and the distribution of water resources.

💡Rain Shadow

A rain shadow is a dry area on the leeward side of a mountain range, where the mountain blocks the path of moist air, leading to less precipitation. The script mentions the Great Plains as being in the rain shadow of the Rocky Mountains, which contributes to its semi-arid climate. This term is vital for comprehending how topography influences local climates and water availability.

💡Continental Effect

The continental effect refers to the significant temperature fluctuations in continental interiors, far from the moderating influence of large bodies of water. The video describes how the Great Plains experience extreme seasonal temperature changes due to this effect, contributing to its unpredictable precipitation patterns. Understanding the continental effect is key to analyzing climate variations within large landmasses.

💡Drought

Drought is an extended period of abnormally low precipitation, leading to water shortages that can adversely affect agriculture, ecosystems, and human activities. The script recounts the Dust Bowl, a severe drought that devastated the Great Plains, to illustrate the impact of droughts on the environment and human livelihoods. Drought is a significant concern in the context of the video's discussion on water scarcity and its implications.

💡Water Rights

Water rights are the legal rights or claims to use water from a particular source. The video discusses the historical and ongoing disputes over water rights in the Colorado River Basin, emphasizing the complexity of managing shared water resources. The concept of water rights is central to the video's exploration of how water allocation decisions can lead to conflicts and the need for equitable water management.

💡Prior Appropriation Doctrine

The prior appropriation doctrine is a legal principle used in water law that allocates water rights based on the order in which claims were initiated, favoring those who first put the water to beneficial use. The video explains how this doctrine has historically disadvantaged Native American tribes and led to disputes over water allocation in the Colorado River Basin. This doctrine is crucial for understanding the historical context of water rights and the ongoing challenges in water resource management.

💡Cyclonic Systems

Cyclonic systems are large-scale weather patterns characterized by low pressure and rotating winds. The video hints at cyclonic systems as a topic for future discussion, suggesting their impact on weather and spatial implications for human activities, such as where people choose to live and build. Cyclonic systems are important for understanding regional weather patterns and their influence on human settlement and infrastructure.

💡Indigenous Peoples

Indigenous peoples are the original inhabitants of a particular region, with deep historical and cultural ties to the land. The video acknowledges the importance of recognizing Indigenous peoples' relationships with the land and their traditional knowledge of geographical elements. This acknowledgment is essential for understanding the cultural and historical context of geographical studies and the need for inclusive and respectful approaches to geography.

Highlights

The map of world's precipitation is crucial for understanding life on Earth.

Precipitation is a critical part of the hydrological cycle, affecting all Earth systems.

Water is essential for agriculture, industry, transportation, and ecosystems.

Water acts as a universal solvent, transporting nutrients and pollutants.

Precipitation maps can reveal disparities in water access and potential conflicts.

Population distribution often correlates with areas of high precipitation.

The Great Plains experience extreme temperature fluctuations due to the continental effect.

Orographic precipitation occurs when air rises and cools, forming clouds and precipitation on mountain slopes.

The rain shadow effect creates dry areas on the leeward side of mountains.

The Great Plains have a semi-arid climate, prone to unpredictable rainfall and drought.

The Dust Bowl was a significant drought that devastated the Great Plains in the 1930s.

The Colorado River is a critical water source for the Southwest, with challenges in distribution and management.

Water rights and management are complex, involving legal battles and political boundaries.

The Colorado River Compact was an attempt to divide water resources among states, but it overlooked variability.

Dams like Hoover and Glen Canyon were built to store water, impacting water distribution and ecosystems.

Urban growth has increased water demand, affecting rural communities and agriculture.

Privatizing water rights is a proposed solution, potentially changing water distribution and access.

Native American tribes are still fighting for water rights, highlighting ongoing struggles for resource control.

Precipitation patterns and water management are key to understanding geographical and geopolitical issues.

Water shortages can impact public health, agriculture, and ecological systems.

Geographers continue to explore the stories and patterns of Earth, including cyclonic systems and their impacts.

Acknowledging Indigenous peoples' relationships with land is important in understanding geography.

Transcripts

Even though lots of maps help us understand  our geographical space, there’s one map  

that some geographers would say is the most  important to understand all life on Earth:  

the map of the world’s precipitation. 

We can think of precipitation as the final  flourish in the hydrological cycle that  

circulates water molecules between the  four Earth systems. It’s all the rain,  

snow, sleet, hail or any liquid or solid  that falls from clouds in the atmosphere. 

And we need water for so many parts  of our lives: agriculture, industry,  

transportation, recreation, and not least  for all the flora and fauna that live here. 

Water is the universal solvent, which  means it can dissolve more substances  

than any other liquid and we almost  never find completely pure water.  

That's pretty important, because as  water moves through the water cycle,  

it transports both vital nutrients and  harmful pollutants across spaces and places.

So using a map of precipitation helps us  track water on Earth and reveals potential  

consequences of differing access to water.  Like if we compare our precipitation map with the  

map of population distribution, we can understand  a simple but powerful pattern of human geography:   

where there is water, there are people. 

But it gets a little more complicated than  that, because where there are people and  

limited resources, there's often conflict  and bigger geographical questions at stake. 

I’m Alizé Carrère and this  is Crash Course Geography.

[INTRO]

We started our journey into physical  geography by looking at the big,  

big picture to reveal the geographic  patterns and processes that create  

Earth’s environments and  support all living things. 

And we’ve learned that the spheroid shape,  

rotation, revolution, and tilt of the Earth  cause insolation, air temperature, pressure,  

and wind to form worldwide patterns  that strongly depend on latitude.

Ultimately, precipitation comes  from clouds in the atmosphere,  

which are complex structures that  change based on many of those patterns.  

So precipitation varies a lot between different  places, especially different latitudes. 

Looking at our map, there are  areas with a lot of precipitation,  

like the island we call Borneo. The air here near  the equator is hotter and has a higher dew point,  

the temperature when the air is saturated with  water vapor and condensation is imminent. 

But areas like what we call the Svalbard  islands in the Arctic Ocean get very  

little precipitation because the air  at those latitudes is cold and dry. 

A different kind of precipitation variability  can happen within a place that spans similar  

latitudes. Like there's a region that makes  up a large chunk of the continental interior  

of the US and Canada, often called  the Great Plains or the Prairies. 

Because the Great Plains sit  deep within the interior,  

far from oceans, a phenomenon  called the continental effect causes  

huge temperature fluctuations with  scorching summers and frigid winters. 

In addition, the Rocky Mountains, which are west  of the Great Plains, form a barrier to the warm,  

moist winds blowing in from the Pacific.  Basically, as the winds hit the side of the  

mountains, the air is forced to rise.  As it rises, the air expands and cools  

enough that the water vapor molecules can  condense to form clouds and precipitation. 

  The resulting rain or snow (or fog or whatever!)  

is called orographic precipitation, which got its  name from “oros” -- a Greek word for mountain.

Then, as the air descends the  other side of the mountains,  

it gets warmer as the air molecules are  compressed together, and any leftover water  

droplets evaporate. So we say the side of the  mountains not facing the winds -- like where  

the Great Plains are -- is in a warm, dry area  called the rain shadow of the Rocky Mountains. 

Orographic precipitation patterns  can be found on mountains worldwide.  

In Argentina, the Patagonia desert lies  in the rain shadow of the Andes Mountains,  

while the Trans-Himalayan region of Tibet  and Central Asia lies in the rain shadow  

of the Himalaya Mountains. The Great Plains straddle the  

98th meridian. So there’s precipitation  sometimes... it's just unpredictable. 

The result is a steppe or semi-arid  climate which is too dry to support forest,  

but too moist to be a desert., 

The dryness can be linked to some combination of  the continental effect, the rain shadow location,  

and subtropical high pressure systems in  the atmosphere. The unpredictability comes  

from local conditions and the constantly flowing  atmospheric and ocean circulation. So, basically,  

rainfall amounts can change dramatically from  one year or season or month to the next. 

A year with lots of rain could be followed by  several years of below average precipitation.  

So drought can be a major, recurring  problem for people, animals, and plants.

In fact, at one point the Great Plains  was called the Great American Desert,  

even though it’s technically a stretch  of grasslands between forests to the  

east and deserts to the west. By  thinking about the physical space,  

we learn more about how our perception  of the perceived space has changed. 

It wasn’t until the inventions  of barbed wire, the steel plow,  

well-drilling techniques, and  the railroad solved the region’s  

unique spatial problems that it became  a place where European people settled. 

Over long periods of time, grasslands produce  excellent soils, making them extremely productive  

farmlands -- but also prone to severe soil  erosion from overfarming and overgrazing. 

So the combination of mass settling and  farming, unpredictable precipitation,  

and high temperatures led to  devastation in this physical space.  

One of the most significant droughts in the last  century was the Dust Bowl, which ravaged the  

Great Plains for nearly a decade from 1930 until  the fall of 1939, when the rains finally came. 

So now our idea of the Great Plains as a place  is forever tied to hardship and even lack of  

opportunity, not just precipitation patterns  like the rainfall effect. All because of the  

physical geography of the space layered with the  human geography of our lived experiences there. 

On the other side of the Rockies  and east of the Sierra Nevadas,  

there are also vast stretches of semi-arid  regions, with some true deserts in the southwest.  

Like in the Great Plains, precipitation is  rather unevenly distributed, so the Colorado  

River is actually the region’s largest water  source, dubbed the "lifeline of the southwest." 

Actually ninety percent of the surface water in  

the Colorado River comes from  snow in the Rocky Mountains,  

which melts, flows down a network of smaller  tributary streams, and reaches the main river. 

The challenges of relying on water  from one source like a river,  

instead of from widespread rainfall,  involve both who needs the water and  

where they are relative to the source.  Managing water resources is a spatial problem. 

For example, the biggest water-users are farms,  factories, and towns, but they aren't all on  

the riverbanks, so they have to find ways to  transport the water they need.And those that  

live near the upstream parts of the Colorado  River can use a ton of water if unregulated,  

leaving less for anyone who lives downstream. 

And the Colorado River is well, a river. So  as it winds from its source to its mouth,  

it's unaware of any political boundaries, like  those from counties, Native American tribal land,  

or even international boundaries. But the  humans that have made this semi-arid region  

their home generally use all these political  boundaries for decision making about water.

Understanding why precipitation is unevenly  distributed, how drought can change seasonally,  

and how people use water are key parts of  geography. And the intersection between  

these physical geography processes and  human geography decision-making can be  

the source of a lot of tension -- especially  when it comes to environmental policies.

For example, Native Americans have used  the Colorado River’s water and managed  

its resources for thousands of years.  But the modern legal doctrine that governs  

water rights in the West -- which goes back  to the Gold Rush of the 1840s and 50s in some  

places -- is the “prior appropriation doctrine.”  This doctrine allocates rights based on who  

started using the water first...except  traditional Native American claims. 

Then in 1922 the seven states  of the Colorado River Basin  

drew up the Colorado River Compact  on how to divide the waters, because  

seasonal precipitation alone wouldn't provide  enough water for everyone that lived there. 

But they overestimated the flow of the  river and didn’t account for how the  

amount of water varies year-to-year. So  each state was allocated more water than  

actually exists -- a problem that’s led  to intense legal battles between states. 

Like California is a downstream  user but also a very powerful state,  

and for decades was using more water  than it was allocated. So in 2003,  

after threats that their water would be cut  off, California agreed to reduce its use of  

Colorado River water over the next 14 years  to allow the upstream states their share. 

The other big problem was that the river's  natural flow had to be physically moved to  

suit certain human wants and needs,  which made things even less fair. 

Like two huge dams -- the Hoover dam on the  Arizona-Nevada border and the Glen Canyon dam  

in Arizona --  were built in the 1930s and 60s  to store and hold back water in reservoirs. 

Lake Mead, the reservoir for the Hoover dam,  supplies water to 25 million people in California,  

Arizona, and Nevada, and generates  hydroelectricity for the region.  

But all that water still has to be  divided between different needs. 

And since the 1950s, explosive  urban growth in upstream states,  

like the growth of cities like Phoenix  and Las Vegas, meant skyrocketing demand  

for water there -- and, as a consequence, less  water for farmers and other rural communities.

Basically, early miscalculations and  mismanagement has created a water  

crisis that affects 40 million people  and 5.5 million acres of farmland.

As of 2021, privatizing water rights is being  proposed as a new solution. Private investors  

would buy water rights, and cities, states,  and individual farms could buy water from them,  

even across state lines. This way the market  would decide whether water was more valuable  

serving urban or rural populations, redefining  the century-old rules for sharing the river. 

So yes, this would turn the river water into  a commodity that could be bought and sold.  

Private investors would redraw the map of water  distribution in the West and make a profit.

But while water management enters a new phase  with big players from Wall Street staking a claim,  

Native American tribes are still working to obtain  

their water rights that they  were finally awarded in 1908.

There is no substitute for water. Today we  mainly focused on one region with one kind  

of precipitation pattern, but we still saw how  studying precipitation opens up lots of deeper  

questions in geography, from what makes a region  habitable to political struggles over resources. 

Some of the most serious geopolitical  issues in the Middle East, North Africa,  

South Asia, and the Western US  relate to control over water.

Like water shortages affect public health,  reduce agricultural productivity, and  

damage ecological systems on which we depend.   So, really, that map of the Earth's precipitation,  

and where and how much water falls from  the sky, is the foundation of a bunch  

of big geographical questions: who should  control water? Is water a basic human right?  

And how have humans altered the environment  to get the water we need -- and at what cost?  

As geographers, we’ll keep looking for new  answers in the stories and patterns of the Earth.

Like next time when we’ll look at cyclonic  systems that bring dramatic weather and spatial  

implications affecting human activities like  where we build our homes and choose to live.

Many maps and borders represent modern  geopolitical divisions that have often  

been decided without the consultation, permission,  or recognition of the land's original inhabitants.  

Many geographical place names also don't reflect  the Indigenous or Aboriginal peoples languages.  

So we at Crash Course want to acknowledge these  peoples’ traditional and ongoing relationship  

with that land and all the physical  and human geographical elements of it.

We encourage you to learn about  the history of the place you call  

home through resources like native-land.ca  and by engaging with your local Indigenous  

and Aboriginal nations through the  websites and resources they provide.

Thanks for watching this episode of Crash  Course Geography which is filmed at the  

Team Sandoval Pierce Studio and was made with  the help of all these nice people. If you want  

to help keep all Crash Course free for everyone,  forever, you can join our community on Patreon.