February 27, 2012
California Desertification: Too Dry or Not Too Dry
Desertification is defined as the deterioration of land in typically arid areas due to changes in climate and human activities. In the United States, desertification is typically caused by poor farming practices and the conversion of grazing areas to cropland. Climate change intensifies desertification in arid areas because not only are global temperatures rising and natural disasters becoming more extreme, but also the global water cycle and precipitation patterns are such that rainfall is decreasing in most areas and concentrating in a few others. Furthermore, because California is in a climactic region that can be defined as dry subtropical, the effects of climate change and agriculture has led to increased desertification. The short-term and long-term effects of this desertification are numerous and will have many repercussions for both humans and the environment.
The environmental costs of desertification are quite serious and can eventually destroy natural ecosystems. Topsoils lose their fertility and the growth and support of organic life in the pedosphere becomes much more difficult. As topsoil drys out it becomes susceptible to movement from winds, creating new natural disasters such as the Dust Bowl of the 1930’s. Furthermore, this dust can be blown out into the ocean and can affect weather patterns. In order to salvage lands affected by desertification, farmers begin to invest more in irrigation, which in turn diminishes groundwater resources and is the beginning of long-term impacts such as drought and famine. Additionally, as the topsoil becomes less nutrient rich from desertification plants become less productive and many of the ecosystem services they were providing are diminished.
Unfortunately, California becomes more susceptible to desertification there is a tendency to focus only on the immediate effects. Important long-term impacts on the environment also need to be addressed, such as the effects on the carbon cycle, biodiversity, and freshwater supply. Vegetation in arid areas stores a substantial amount of carbon (about 30 tons per hectare) and when desertification causes drought and the vegetation dies, that storage is lost. In addition, desertification dries out soil, the organic matter of which is the largest known carbon sink, resulting in increased greenhouse gas effects as that carbon is released into the atmosphere. As soils and vegetation are affected by desertification, ecosystems lose key resources that result in a loss of biodiversity. Desertification also poses a threat to freshwater resources. River flow rates decrease, leading to silt build up in estuaries, which incites saltwater intrusion into the water tables. As the demand for water increases there is a tendency to over-pump aquifers, which can result in water depletion and land compaction. For example, the San Joaquin Valley of California experienced subsidence at a maximum of 28 feet between 1925-1970 from overdrawn aquifers. Because California relies so much on agriculture, farmers exploit aquifer water for irrigation without considering these long-term issues. However, if the agricultural industry were to collapse from drought, we’d be facing the threat of famine and a huge economy crash.
Clearly there are many negative effects from the process of desertification that need to be addressed. Some of the most popular decisions to combat the effects of the land drying out include sustainable farming practices, such as drip irrigation, integrated crops, or no-till farming, and drought prevention. As stated in the 2010 California Drought Contingency Plan, “California’s water resources have been stressed by periodic drought cycles and unprecedented restrictions in water diversions from the Sacramento-San Joaquin Delta in recent years. Climate change is expected to increase extreme weather. It is not known if the current drought will abate soon or if it will persist for many years. However, it is certain that this is not the last drought that California will face.” The DCP has moved towards enhancing monitoring and early warning capabilities, assessing water shortage impacts, and creating preparedness, response, and recovery programs, which should help California to conserve water and slow down the desertification process.
Sources:
http://www.waterplan.water.ca.gov/docs/cwpu2009/0310final/v4c06a01_cwp2009.pdf
http://pubs.usgs.gov/circ/circ1182/pdf/06SanJoaquinValley.pdf
http://www.fao.org/sd/EPdirect/EPan0005.htm
http://onlinelibrary.wiley.com/doi/10.1111/j.1468-5973.2010.00633.x/full
Harriet Arnold and Divya Rao are undergraduates in the USC Dornsife College of Letters, Arts and Sciences.
February 8, 2012
The Sierra Snowpack: Here Today, Gone Tomorrow
It’s no secret that California’s relationship with water is a precarious one. Historically, the Golden State—especially its thirsty southern metropolis, Los Angeles—has grappled with the realities of an arid climate and long distances to sufficient water sources. With the development of a complex system of dams, reservoirs, and aqueducts to feed California’s inhabitants and huge agricultural sector came a dependence on the water from the Sierra snowpack, the layers of snow that typically form from December through March in the high mountains to then slowly melt over the spring and summer. But at a time when up to 60% of California’s fresh water supply comes from the Sierra snowpack, large fluctuations in seasonal snowfall are raising concerns about the stability and reliability of a system that so heavily depends on such unpredictable factors. Even in individual years when there is enough water, the erratic changes in precipitation from year to year make for an ongoing problems of water shortage and allotments for different consumers. If we continue to place the same demands on the snowpack going forward, the only way to stabilize the water supply from the Sierras will be to increase the efficiency of water usage on the consumers’ end.
The size fluctuations of California’s snowpack have been drastic in recent years. Following several years of drought, the Sierras received record amounts of snow during the 2010-2011 winter season, leading the state’s two largest reservoirs to nearly reach capacity. Many farmers and water managers rejoiced; for the first time in a while it appeared that California would have ample water for the entire year. But as of January 2012, snow at high Sierra peaks is disturbingly thin: data collection is painting a picture of snowpack water content of at 23% of the normal season total. While reservoirs still hold a large amount of water from the 2011 season, this water cannot fill the place of the gradual summertime snow melt that is responsible for replenishing the water supply and sustaining the state through the drier months. Water suppliers have requested 4 million acre-feet of water this year, and the Department of Water Resources has estimated that it will be able to supply 60% of this amount—down from the 80% promised last year.
Scientists are attributing the wild fluctuations in snowfall to the La Niña phenomenon, in which cooler than normal surface water temperatures in the Pacific cause changes in global weather patterns, resulting in dry conditions in California. While this phenomenon is occurs naturally every few years, some researchers are concerned that increased frequency and intensity of La Niña and shifting weather patterns could be evidence of climate change. Warmer winters in the future could mean precipitation falling as water instead of snow, something that California’s current water infrastructure of dams and reservoirs is not designed to handle and could mean potential flooding. Irregularity in mountain snowfall—whether extremely high or low—also poses threats to California ecosystems, as they may not be able to deal with such drastic changes precipitation.
Whether the city populations and farmers want to hear it or not, though, the truth of the matter is that California’s natural water systems were never designed to support this many people, and that there will be years when the Sierras simply cannot provide the water citizens would ideally like. Aqueducts from the Eastern Sierras pump in 430 million gallons of water per day to Los Angeles alone. Better water management will mean certain sacrifices from all players, but wise consumption of water and preservation of surpluses for the future will be key in permitting California to thrive.
Links:
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2010/12/28/BAG11H0GOF.DTL
http://articles.latimes.com/2011/jun/12/local/la-me-snowpack-20110608
http://www.water.ca.gov/news/newsreleases/2012/020112snow.pdf
http://www.ucsusa.org/assets/documents/global_warming/ucs-ca-water.pdf
http://www.water-ed.org/watersources/community.asp?rid=9&cid=562age
Brittany Cheng and Kali Staniec are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.
Will You Go Thirsty in the Future?
California is currently experiencing a water crisis. Many believe that the state is safe after Governor Brown officially declared the three-year drought to be over on March 30, 2011. The reality is simple—California is not safe and the water issue has not gone away.
History has shown that California easily slips back and forth between times of water scarcity and water abundance. California has been able to cope with these drought patterns before, but as time progresses California will not be able to quench the thirst of citizens who overuse water resources. Thus, the government and citizens alike must begin taking steps to prepare for years of little rainfall, because who knows if there will be enough water in the future.
Southern California’s demand for water is rarely met with sufficient supply. Many regulations and laws have been implemented in the past couple of years in response to Southern California drought conditions, but different counties have different laws. The overall goal is the same: consume less water and penalize those who waste it. In 2009, Orange County faced a severe drought that spawned a series of regulations that helped the county through tough times. The city of Santa Ana raised its water rates three times within a two-year span in order to make people think twice before leaving faucet running or taking a long shower. Yorba Linda, Anaheim, Placentia, and other cities within the Yorba Linda water district even restricted residents from watering their lawns between 9am and 6pm.
A system of fines and penalties is common amongst different regions of Southern California. Los Angeles restricted its water usage to twice a week in 2009. The citywide restriction was imposed after Mayor Villaregosa called the drought “a crisis that we have not seen in decades.” A tiered system was also instituted, and residents were charged based on their water usage. The two tiers were based on water usage in cubic feet, where the base rate for Tier I was $2.92 per 100 cubic feet and $2.98 for Tier II. Residents that abused their water consumption, wasting more than the average for Tier II usage, were heavily fined and penalized. Some believe these strict regulations helped California escape from its three-year drought. Regardless, though, conservation is still an issue.
Citizens cannot leave it up to the government to save them from this water crisis. Government restrictions are not enough; instead, people must take it upon themselves to ration the amount of water they use on a day-to-day basis. The average California household consumes between one half-acre foot to one acre-foot of water each year, which is somewhere between 163,000 and 326,000 gallons! A family may consume 300 gallons per person each day if they are not water conscious, while those who are more aware may consume as little as 50 gallons per person each day. It is simply not enough for some to conserve water while others do not, especially when all it takes is turning the water off as you brush your teeth or purchasing more drought resistant plants.
The severity of outside factors on the California water crisis is increasing over time. Issues like population growth and global warming only complicate the water debate and intensify concerns over future water levels. As the population grows, Californians must monitor current water usage to ensure people in the future do not go thirsty. Nature itself must be taken into consideration, because issues such as global warming attribute to inconsistent precipitation levels that can strain water reserves. In order to solve this issue, one must think of the broader impact water has on the state. Water is not just necessary for life but an integral part of the economy and politics as well. Without taking proper precautions, California leaves itself susceptible to a mega-drought where citizens may be facing a modern American Dust Bowl.
Connor Schroeder and Albert Perez are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.
September 19, 2011
Desertification in California
The Central Valley of California is a fertile bed of over 350 diverse species of agricultural crops, some of the major cash crops being rice, grapes, cotton, and almonds. California’s agricultural industry makes up 15% of the entire nation’s crops and made a profit of $37 billion in the year 2009.
Despite these numbers, desertification is an increasingly major problem.
Between 1998 and 2000, 10,000 acres of farmland were lost every year in Central Valley from urbanization alone—this doesn’t account for the acres of fertile farmland lost due to overgrazing, climate change, or poor farming practices. Currently, California is losing 178 km2 of arable, fertile land each year. Southern California especially, being a very arid and drought-inclined region to begin with, has a problem with increasing salinity and compound minerals in the soil, caused by overdrawing ground water (United States Geological Survey).
Desertification is not only the result of human activity. The UN Convention to Combat Desertification identifies the other major cause of desertification to be climatic variations—for example, erosion, drought and irregular rainfall, and violent winds. Essentially it renders the soil infertile, not only for planting and agriculture but for any organic life. Desertification occurs on a global scale, particularly through deforestation and drought. Areas around the Amazons, for example, have undergone desertification because the trees are being harvested for wood and cleared for farmland, and much of the space lies fallow. Similarly, in California, trees are cleared using the “slash and burn” method to open fields for cheap soybean and livestock cultivation.
Desertification is a challenge for California because it is a desert environment supporting an increasingly large population on limited water imports. The situation becomes more dire when the effects of global warming are considered, which dramatically expedite desertification. Owens Valley, California, for example, became a desert when all of the natural water resources were diverted to Southern California for drinking water and crop irrigation. The San Joaquin Valley is a region that has undergone natural desertification due to climate change, a result of surface crusting, salinization and waterlogging problems.
Most popularly considered solutions to desertification involve addressing problems of drought. Every 5 years in California a new Drought Contingency Plan (DCP) is released. In 2008, the last DCP, tactics included aggressive conservation, new groundwater and surface water storage facilities, and environmental restoration. GMOs also offer the possibility of growing crops that are resistant to drought, thus using less of the precious water resources to yield the same or greater amount of agriculture.
Similarly, Air-to-Water harvesters are a new technology that essentially takes the humidity in the air and convert it to usable water. This can slow desertification significantly.
From a more bottom-up perspective, education and conservation initiatives will also drastically reduce the human contribution to desertification. Programs teaching grey-water usage, water conservation, and the transformation of lawns into food forests can save a lot of water if it is implemented locally and broadly. Natural forests and wetlands need to be protected rather than cleared, farmed, and abandoned.
While desertification is in and of itself a natural process, the human factors can and must be reduced, especially in California, if we are to live harmoniously with the land and reap the benefits of its yield.
About the authors: Xueyou Wang and Kayla Duarte are undergraduate students in the USC Dana and David Dornsife College of Letters, Arts and Sciences.
September 5, 2011
California Drought: It’s Not Over Yet
Image: USDA; http://droughtmonitor.unl.edu/
Though Governor Jerry Brown officially declared the three-year California drought to be over on March 30, 2011, water scarcity is still a huge issue for Californians. The drought was declared over because after three very dry winters, this winter resulted in 159% of normal Sierra Nevada snowpack for that time of year. The Sierra Nevada snowpack is a critical source of California water, as “almost two-thirds of the water used to irrigate millions of acres of farmland” and “water supply for 38.8 million people is contained in the Sierra snowpack.” Governor Brown states though, “while this season’s surplus of rain and strong snowpack has clearly ended the dry spell for now, it is critical that Californians continue to conserve water.” If the state of California does not begin to conserve water in this time of dryness, water sources will dry up and agriculture, industry, and residents will all be seriously affected.
In 2008, “Governor Schwarzenegger declared the first statewide drought in seventeen years,” a drought being defined as a prolonged period of abnormally low precipitation resulting in a shortage of water. In this state of emergency, solutions were proposed to alleviate the matter such as rationing of water and huge cutbacks. The drought lasted for three years until the Sierras had above-average snowpack in 2011. In this image, which shows the severity of drought in 2007 across the nation, it is clear that California is one of the most affected regions by drought, ranking in the “extreme category” in much of southern California. The entire state was experiencing dryness to some degree, though the southern half was hardest hit.
California residents on average use 80 to 100 gallons of water each day, and as a state, California was ranked number one, responsible for 11% of all the freshwater use in the United States. These numbers are just simply too high to be sustainable with the limited water resources that California has. “California produces more than half of the nations fruits, vegetables, and nuts” and growing these requires a huge amount of water. This accounts for a major portion of the water use in California. A water shortage would affect all state of the state from the economy with unemployment and overall revenue. There are already many lawsuits in place over distribution of water and water rights by many local farmers.
In 2009, most of California’s major water reservoirs remained below 50% capacity. Lake Shasta, California’s largest reservoir remained at an extreme low of 30% (Dept. CA Water Resources). California’s reservoirs are rapidly draining and are not having enough time to be replenished. We are beginning to see the same situations as the Owen’s and Mono Lake misfortune at many of California’s major reservoirs, where the growing Los Angeles population diverted too much water for expansion and ended up draining the entire reservoir. Not only does this water shortage from drought have a damaging affect on the people, but also the land is becoming more susceptible to dangerous wildfires, which are becoming “some of the costliest and most damaging in U.S. history” (Dept. CA Water Resources).
Even though the drought is officially classified as over, we still need to work hard and find new strategies and technologies for conserving water due to the yearly fluctuations of snowpack and precipitation. Water is one of the most important aspects of life, especially in California where millions of crops are being grown to supply food for the rest of the country. If the water were to decline suddenly, there would be major conflicts within the state. Therefore, we should live using water sparingly in case of another major drought.
About the authors: Sara Bethel and Megan Won are working towards their bachelor’s degrees in Environmental Studies and Biological Sciences, respectively, at USC Dana and David Dornsife College of Letters, Arts and Sciences.