Trione-Annadel State Park
Trione-Annadel State Park is a state park of California in the United States. It is situated at the edge of Sonoma Valley and is adjacent to Spring Lake Regional Park in Santa Rosa. It offers many activities within its 5, 092-acre property. These lands were occupied by the Wappo and Pomo people in times, who would have primarily inhabited the riparian zones. Annadel includes what some consider the best example of undisturbed northern oak woodlands in existence. Visitors can enjoy the parks wildlife and scenery during any time of the year but are perhaps most rewarded from April through June when most wildflowers are in bloom. Plant communities include California oak woodland, riparian woodland, Douglas fir forest, grassland, the dominant plant community is the oak woodland, which has a canopy of coast live oak, Garry oak, black oak, Pacific madrone, bigleaf maple, and California laurel. Canyon live oak occurs in swales and creeks, in the oak woodlands, the dominant understory plants are native bunchgrasses, wild blackberry, coyote brush, and western poison-oak.
The latter covers nearly one quarter of the understory in the park, Douglas fir occurs in some of the steeper, cooler riparian zones and on north-facing slopes. Common animals in Annadel include black-tailed deer, western gray squirrel, skunk and mountain lion are occasionally observed. There are many species, including the California scrub jay, Stellers jay, acorn woodpecker, black phoebe. In moist areas, amphibians such as the rough-skinned newt can be found, the southern reaches of Annadel are drained by Yulupa Creek and other tributaries of Sonoma Creek, while the northern flanks are part of the Santa Rosa Creek watershed. Eastern slopes are drained by Yulupa and Sonoma Creeks, while the slopes are part of the Spring Creek watershed. Many of Annadels streams are dry in the summer, because rainfall is highly seasonal, Ledson Marsh, which drains into Yulupa Creek, retains some smaller pools of water throughout most of the year. The highest elevation in the park is the top of Bennett Mountain,1,887 feet.
The entirety of Annadel was below the floor as recently as twelve million years ago, around which time massive uplift. Elevations in Annadel range from about 360 to 1,880 feet above sea level, slopes within Annadel commonly range from 15 to 30 percent, but it is not uncommon to encounter slopes up to 70 percent on steep slopes above drainages which are covered in douglas fir forest. Typical soil depths are 35 to 50 centimetres, much of the soil type in the Yulupa Creek riparian zone consists of Laniger loam, with rhyolite outcrops, another relic of the igneous history
Pinnacles National Park
Pinnacles is managed by the National Park Service and the majority of the park is protected as wilderness. The national park is divided by the formations into East and West Divisions, connected by foot trails. The east side has shade and water, the west has high walls, the rock formations provide for spectacular pinnacles that attract rock climbers. The park features unusual talus caves that house at least thirteen species of bat, Pinnacles is most often visited in spring or fall because of the intense heat during the summer months. Park lands are prime habitat for prairie falcons, and are a site for California condors that have been hatched in captivity. Pinnacles National Monument was established in 1908 by U. S. President Theodore Roosevelt, Pinnacles National Park was created from the former Pinnacles National Monument by legislation passed by Congress in late 2012 and signed into law by President Barack Obama on January 10,2013. Native Americans in the Pinnacles region comprised the Chalon and Mutsun groups of the Ohlone people and these native people declined with the arrival of the Spanish in the 18th century, who brought novel diseases and changes to the natives way of life.
The last Chalon had died or departed from the area by 1810, from 1810 to 1865, when the first Anglo-American settlers arrived, the Pinnacles region was a wilderness without human use or habitation. The establishment of a Spanish mission at Soledad hastened the areas native depopulation through disease, archaeological surveys have found thirteen sites inhabited by Native Americans, twelve of which post-date the establishment of the missions. One site is believed to be about 2000 years old, by the 1880s the Pinnacles, known as the Palisades, were visited by picnickers from the surrounding communities who would explore the caves and camp. The first account of the Pinnacles region appeared in print in 1881, between 1889 and 1891, newspaper articles shifted from describing excursions to the Palisades to calling them the Pinnacles. Interest in the rose to the point that the Hollister Free Lance sent a reporter to the Pinnacles. Investors came from San Francisco to consider placing a hotel there. In 1894 a post office was established in Bear Valley, since there was at least one other Bear Valley in California, the post office was named Cook after Mrs.
Hains maiden name. In 1924 the post office was renamed Pinnacles, Schuyler Hain was a homesteader who arrived in the Pinnacles area in 1891 from Michigan, following his parents and eight siblings to Bear Valley. White, was a student at Stanford University, and White brought one of his professors to see the Pinnacles in 1893, dr. Gilbert was impressed by the scenery, and his comments inspired Hain to publicize the region. Hain led tours to Bear Valley and through the caves, advocating the preservation of the Pinnacles, Hains efforts resulted in a 1904 visit by Stanford president David Starr Jordan, who contacted Fresno Congressman James C. Jordan and Needham in turn influenced Gifford Pinchot to advocate the establishment of the Pinnacles Forest Reserve to President Theodore Roosevelt, Roosevelt proclaimed the establishment on July 8,1906
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism. The term typically refers to the zone in which the organism lives and it is the natural environment in which an organism lives, or the physical environment that surrounds a species population. Every organism has certain habitat needs for the conditions in which it will thrive, habitat types include polar, temperate and tropical. The terrestrial vegetation type may be forest, grassland, the word habitat has been in use since about 1755 and derives from the Latin third-person singular present indicative of habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the environment of an organism. It is similar in meaning to a biotope, an area of environmental conditions associated with a particular community of plants. Generally speaking, animal communities are reliant on specific types of plant communities, some plants and animals are generalists, and their habitat requirements are met in a wide range of locations.
The small white butterfly for example is found on all the continents of the world apart from Antarctica and its larvae feed on a wide range of Brassicas and various other plant species, and it thrives in any open location with diverse plant associations. Disturbance is important in the creation of biodiverse habitats, in the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. Similarly coastal habitats can become dominated by kelp until the seabed is disturbed by a storm, another cause of disturbance is when an area may be overwhelmed by an invasive introduced species which is not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands and deserts, within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils and vegetation types.
Many of these habitats grade into each other and each one has its own communities of plants. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities, freshwater habitats include rivers, lakes, ponds and bogs. Although some organisms are found across most of these habitats, the majority have more specific requirements, aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marine habitats include brackish water, bays, the sea, the intertidal zone. Further variations include rock pools, sand banks, brackish lagoons and pebbly beaches, the benthic zone or seabed provides a home for both static organisms, anchored to the substrate, and for a large range of organisms crawling on or burrowing into the surface. A desert is not the kind of habitat that favours the presence of amphibians, with their requirement for water to keep their skins moist, some frogs live in deserts, creating moist habitats underground and hibernating while conditions are adverse
Channel Islands National Park
Channel Islands National Park is a United States national park that consists of five of the eight Channel Islands off the coast of the U. S. state of California, in the Pacific Ocean. Although the islands are close to the shore of densely populated Southern California, the park covers 249,561 acres of which 79,019 acres are owned by the federal government. The Nature Conservancy owns and manages 76% of Santa Cruz Island, Channel Islands National Park is home to a wide variety of significant natural and cultural resources. It was designated a U. S. National Monument on April 26,1938, and it was promoted to a National Park on March 5,1980. Channel Islands National Marine Sanctuary encompasses the waters six nautical miles around Channel Islands National Park, the Channel Islands were originally discovered in 1542 by the explorer Juan Rodríguez Cabrillo. In 1938 the Santa Barbara and Anacapa islands were designated a national monument, San Miguel, Santa Rosa and Santa Cruz islands were combined with the monument in 1980 to form modern-day Channel Islands National Park.
On January 28,1969 an oil rig belonging to Union Oil experienced a blow-out 6 miles off the coast of California, the resulting spill was, at the time, the largest oil spill to occur in United States territorial waters. Following the spill, tides carried the oil onto the beaches of the Anacapa, San Miguel, Santa Rosa and this spill had a large impact on native wildlife of the Channel Islands. Much of the seabird population was affected, with over an estimated 3,600 avians killed. Meanwhile, seals and other sea life died and washed ashore on both the islands and the mainland and this spill is the third largest oil spill in the United States, only surpassed by the Deepwater Horizon and the Exxon Valdez oil spills. It resulted in a 34,000 acres expansion of the Department of the Interior buffer zone in the channel, the islands within the park extend along the Southern California coast from Point Conception near Santa Barbara to San Pedro, a neighborhood of Los Angeles. Park headquarters and the Robert J.
Lagomarsino Visitor Center are located in the city of Ventura, only three mammals are endemic to the islands, one of which is the deer mouse which is known to carry the sin nombre hantavirus. The spotted skunk and Channel Islands fox are endemic, the island fence lizard is endemic to the Channel Islands. One hundred and forty-five of these species are unique to the islands, Marine life ranges from microscopic plankton to the endangered blue whale, the largest animal on earth. Archeological and cultural resources span a period of more than 10,000 years, the average annual visitation to the parks mainland visitor center was around 300,000 in the period from 2007 to 2016, with 364,807 visiting in 2016. The visitor center is located in the Ventura Harbor Village, the visitor center contains several exhibits that provide information regarding all five islands, native vegetation, marine life and cultural history. Also, visitors can enjoy a film, free of charge. The visitor center is open day, except Thanksgiving and Christmas, from 8, 30AM–5
Devils Postpile National Monument
Devils Postpile National Monument is located near Mammoth Mountain in eastern California. The national monument protects Devils Postpile, a rock formation of columnar basalt. In addition, the John Muir Trail and Pacific Crest Trail merge into one trail as they pass through the monument, excluding a small developed area containing the monument headquarters, visitor center and a campground, the National Monument lies within the borders of the Ansel Adams Wilderness. The monument was once part of Yosemite National Park, but discovery of gold in 1905 near Mammoth Lakes prompted a change that left the Postpile on adjacent public land. Later, a proposal to build a dam called for blasting the Postpile into the river. Influential Californians, including John Muir, persuaded the government to stop the demolition and, in 1911. The flora and fauna at Devils Postpile are typical of the Sierra Nevada, dark-eyed juncos and white-crowned sparrows are common in the summer. The name Devils Postpile refers to a cliff of columnar basalt.
Radiometric dating indicates the formation was created by a flow at some time less than 100,000 years ago. Estimates of the thickness range from 400 feet to 600 feet. The lava that now makes up the Postpile was near the bottom of this mass, because of its great thickness, much of the mass of pooled lava cooled slowly and evenly, which is why the columns are so long and so symmetrical. Columnar jointing occurs when certain types of contract while cooling. A glacier removed much of this mass of rock and left a surface on top of the columns with very noticeable glacial striations. The Postpiles columns average 2 feet in diameter, the largest being 3.5 feet, together they look like tall posts stacked in a pile, hence the features name. If the lava had cooled perfectly evenly, all of the columns would be expected to be hexagonal, but some of the columns have different polygonal cross-sections due to variations in cooling. A survey of 400 of the Postpiles columns found that 44. 5% were 6-sided,37. 5% 5-sided,9. 5% 4-sided,8.
0% 7-sided, compared with other examples of columnar jointing, the Postpile has more hexagonal columns. Another feature that places the Postpile in a category is the lack of horizontal jointing. Several stones from the Devils Postpile can be seen at the entrance to the United States Geological Survey headquarters lot in Reston, although the basaltic columns are impressive, they are not unique
Anza-Borrego Desert State Park
Anza-Borrego Desert State Park is a state park located within the Colorado Desert of southern California, United States. The park takes its name from 18th century Spanish explorer Juan Bautista de Anza and borrego, the Spanish word for bighorn sheep. With 600,000 acres that includes one-fifth of San Diego County, ABDSP is the largest state park in California and, after New Yorks Adirondack Park, the second largest in the contiguous United States. The park occupies eastern San Diego County and reaches into Imperial and Riverside counties, ABDSP is around a two-hour drive northeast from San Diego, southeast from Riverside or Irvine, and south from Palm Springs. The park is an anchor in the Mojave and Colorado Deserts Biosphere Reserve, Park information and maps, interpretive events and displays and listening devices for the hearing impaired are all available in the Visitor Center. ABDSP has Wi-Fi access to the Internet in various sections of the park, many visitors approach ABDSP from the east-Coachella Valley side via California County Route S22 and S78.
These highways climb from the coast to 2,400 ft above sea level, the great bowl of the surrounding desert is surrounded by mountains, with the Vallecito Mountains to the south and the highest Santa Rosa Mountains to the north. They are in the wilderness area, without paved roads. In January of 2017 Anza-Borrego Desert State Park was named the best state park in California, the habitats of ABDSP are primarily within the Colorado Desert ecosystem of the Sonoran Desert ecoregion. The higher extreme northern and eastern sections in the Peninsular Ranges are in the California montane chaparral, the park features and desert washes, rock formations and colorful badlands, vast arid landscapes, and dramatic mountains. The bajadas are predominantly creosote bush-bur sage with creosote bush and the palo verde-cactus shrub ecosystems with the palo verde tree, cacti, in the washes, Colorado/Sonoran microphylla woodlands can be found. These woodlands include such plants as tree, velvet mesquite. ABDSP has natural springs and oases, with the only native palm.
Seasonal wildflower displays can be stunning in any plant community association throughout the park, the high-country to the north and east has closed-cone pine forests and oak woodlands. The oases are prolific with all types of fauna, especially for bird-watching, in the reptile class, desert iguanas and the red diamond rattlesnakes can be seen — with caution. ===Desert bighorn sheep=== Some areas of ABDSP are habitat for the Peninsular bighorn sheep, few park visitors see them, and the sheep are justly wary. A patient few observers each year see and count this endangered species to study the population, the expanses of ABDSPs eroded badlands provide a different view into the regions long-vanished tropical past. The inland of southeastern California was not always a desert, the study of the fossilized remains of ancient life, is the key to understanding this prehistoric world
Sonora, officially the Free and Sovereign State of Sonora, is one of 31 states that, with Mexico City, comprise the 32 federal entities of Mexico. It is divided into 72 municipalities, the city is Hermosillo. Sonora is located in Northwest Mexico, bordered by the states of Chihuahua to the east, Baja California to the northwest and Sinaloa to the south. To the north, it shares the U. S. –Mexico border with the states of Arizona and New Mexico, and on the west has a significant share of the coastline of the Gulf of California. Sonoras natural geography is divided into three parts, the Sierra Madre Occidental in the east of the state and rolling hills in the center, and the coast on the Gulf of California. It is primarily arid or semiarid deserts and grasslands, with only the highest elevations having sufficient rainfall to support other types of vegetation, Sonora is home to eight indigenous peoples, including the Mayo, the Yaqui, and Seri. It has been important for its agriculture and mining since the colonial period.
With the Gadsden Purchase, Sonora lost more than a quarter of its territory, from the 20th century to the present, industry and agribusiness have dominated the economy, attracting migration from other parts of Mexico. Several theories exist as to the origin of the name Sonora and they encountered the Opata, who could not pronounce Señora, instead saying Senora or Sonora. A third theory, written by Father Cristóbal de Cañas in 1730, states that the name comes from the word for a water well, sonot. The first record of the name Sonora comes from explorer Francisco Vásquez de Coronado, Francisco de Ibarra traveled through the area in 1567 and referred to the Valles de Señora. Evidence of human existence in the dates back over 10,000 years. The first humans were hunter gatherers who used tools made from stones, seashells. During much of the period, the environmental conditions were less severe than they are today, with similar. The oldest Clovis culture site in North America is believed to be El Fin del Mundo in northwestern Sonora and it was discovered during a 2007 survey.
It features occupation dating around 13,390 calibrated years BP, in 2011, remains of Gomphothere were found, the evidence suggests that humans did in fact kill two of them here. Agriculture first appeared around 400 BCE and 200 CE in the river valleys, the lowland central coast, seems never truly to have adopted agriculture. Because Sonora and much of the northwest does not share many of the traits of that area
Fort Point, San Francisco
Fort Point is a masonry seacoast fortification located at the southern side of the Golden Gate at the entrance to San Francisco Bay. This fort was completed just before the American Civil War by the United States Army, the fort is now protected as Fort Point National Historic Site, a United States National Historic Site administered by the National Park Service as a unit of the Golden Gate National Recreation Area. In 1769 Spain occupied the San Francisco area and by 1776 had established the areas first European settlement, with a mission and a presidio. To protect against encroachment by the British and Russians, Spain fortified the high white cliff at the narrowest part of the bays entrance, the Castillo de San Joaquin, built in 1794, was an adobe structure housing nine to thirteen cannons. Mexico won independence from Spain in 1821, gaining control of the region and the fort, following the United States victory in 1848, California was annexed by the U. S. and became a state in 1850. The gold rush of 1849 had caused rapid settlement of the area, military officials soon recommended a series of fortifications to secure San Francisco Bay.
Coastal defenses were built at Alcatraz Island, Fort Mason, the U. S. Army Corps of Engineers began work on Fort Point in 1853. Plans specified that the lowest tier of artillery be as close as possible to water level so cannonballs could ricochet across the surface to hit enemy ships at the water-line. Workers blasted the 90-foot cliff down to 15 feet above sea level, the structure featured seven-foot-thick walls and multi-tiered casemated construction typical of Third System forts. It was sited to defend the maximum amount of harbor area, while there were more than 30 such forts on the East Coast, Fort Point was the only one on the West Coast. In 1854 Inspector General Joseph K. Mansfield declared this point as the key to the whole Pacific Coast. a crew of 200, many unemployed miners, labored for eight years on the fort. In 1861, with war looming, the army mounted the forts first cannon, colonel Albert Sidney Johnston, commander of the Department of the Pacific, prepared Bay Area defenses and ordered in the first troops to the fort.
Kentucky-born Johnston resigned his commission to join the Confederate Army, throughout the Civil War, artillerymen at Fort Point stood guard for an enemy that never came. Troops soon moved out of Fort Point, and it was never again occupied by the army. The fort was important enough to receive protection from the elements. In 1869 a granite seawall was completed, the following year, some of the forts cannon were moved to Battery East on the bluffs nearby, where they were more protected. In 1882 Fort Point was officially named Fort Winfield Scott after the hero from the war against Mexico. The name never caught on and was applied to an artillery post at the Presidio
Lassen Volcanic National Park
Lassen Volcanic National Park is a United States National Park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world, Lassen Volcanic National Park started as two separate national monuments designated by President Theodore Roosevelt in 1907, Cinder Cone National Monument and Lassen Peak National Monument. The source of heat for volcanism in the Lassen area is subduction off the Northern California coast of the Gorda Plate diving below the North American Plate, the area surrounding Lassen Peak is still active with boiling mud pots, stinking fumaroles, and churning hot springs. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found, the park is accessible via State Routes SR89 and SR44. SR89 passes north-south through the park, beginning at SR36 to the south, SR89 passes immediately adjacent the base of Lassen Peak. A large lodge with concession facilities was located near the south-west entrance, a new, full-service visitor center was constructed in the same location, and opened to the public in 2008.
Near the old location was located Lassen Ski Area. Native Americans have inhabited the area long before white settlers first saw Lassen. The natives knew that the peak was full of fire and water, White immigrants in the mid-19th century used Lassen Peak as a landmark on their trek to the fertile Sacramento Valley. One of the guides to these immigrants was a Danish blacksmith named Peter Lassen, Lassen Peak was named after him. Nobles Emigrant Trail was cut through the area and passed Cinder Cone. Inconsistent newspaper accounts reported by witnesses from 1850 to 1851 described seeing fire thrown to a terrible height, as late as 1859, a witness reported seeing fire in the sky from a distance, attributing it to an eruption. Early geologists and volcanologists who studied the Cinder Cone concluded the last eruption occurred between 1675 and 1700, after the 1980 eruption of Mount St. Helens, the United States Geological Survey began reassessing the potential risk of other active volcanic areas in the Cascade Range.
Further study of Cinder Cone estimated the last eruption occurred between 1630 and 1670, recent tree-ring analysis has placed the date at 1666. The Lassen area was first protected by being designated as the Lassen Peak Forest Preserve, Lassen Peak and Cinder Cone were declared as U. S. National Monuments in May 1907 by President Theodore Roosevelt. Starting in May 1914 and lasting until 1921, a series of minor to major eruptions occurred on Lassen and these events created a new crater, and released lava and a great deal of ash. Fortunately, because of warnings, no one was killed, because of the eruptive activity, which continued through 1917, and the areas stark volcanic beauty, Lassen Peak, Cinder Cone and the area surrounding were declared a National Park on August 9,1916. The 29-mile Main Park Road was constructed between 1925 and 1931, just 10 years after Lassen Peak erupted, near Lassen Peak the road reaches 8,512 feet, making it the highest road in the Cascade Mountains
Located at the foot of the Sierra Nevada in Californias Owens Valley between the towns of Lone Pine to the south and Independence to the north, it is approximately 230 miles north of Los Angeles. Long before the first incarcerees arrived in March 1942, Manzanar was home to Native Americans and miners formally established the town of Manzanar in 1910, but abandoned the town by 1929 after the City of Los Angeles purchased the water rights to virtually the entire area. As different as these groups were, their histories displayed a common thread of forced relocation, the primary focus is the Japanese American incarceration era, as specified in the legislation that created the Manzanar National Historic Site. The site interprets the former town of Manzanar, the days, the settlement by the Owens Valley Paiute. Let us review the main points of the debate, over 120,000 residents of the U. S. A. two thirds of whom were American citizens, were incarcerated under armed guard. There were no crimes committed, no trials, and no convictions, to detain American citizens in a site under armed guard surely constitutes a concentration camp.
But what were the used by the government officials who were involved in the process. Raymond Okamura provides us with a detailed list of terms, lets consider three such euphemisms, evacuation and non-aliens. Earthquake and flood victims are evacuated and relocated, the words refer to moving people in order to rescue and protect them from danger. The official government policy makers consistently used evacuation to refer to the removal of the Japanese Americans. These are euphemisms as the terms do not imply forced removal nor incarceration in enclosures patrolled by armed guards. Hirabayashi went on to describe the harm done by the use of such euphemisms, the harm in continuing to use the governments euphemisms is that it disguises or softens the reality which subsequently has been legally recognized as a grave error. The actions abrogated some fundamental principles underlying the Constitution, the document under which we govern ourselves. This erosion of fundamental rights has consequences for all citizens of our society, some have argued that the Nazi Germany camps during the Holocaust were concentration camps and to refer to the Japanese American camps likewise would be an affront to the Jews.
It is certainly true that the Japanese Americans did not suffer the fate of the Jews in the terrible concentration camps or death camps where Nazi Germany practiced a policy of genocide. Although the loss of life was minimal in Americas concentration camps and Walter Weglyns research concerning Nazi Germanys euphemisms for their concentration camps revealed such phrases as protective custody camps, reception centers, and transit camps. Ironically, two Nazi euphemisms were identical to our governments usage, assembly centers and relocation centers and it might be well to point out, that the Nazis were not operating under the U. S. Constitution. Comparisons usually neglect to point out that Hitler was operating under the rules of the Third Reich
An alluvial fan is a fan- or cone-shaped deposit of sediment crossed and built up by streams. If a fan is built up by debris flows it is called a debris cone or colluvial fan. These flows come from a point source at the apex of the fan. Fans are typically found where a canyon draining from mountainous terrain emerges out onto a flatter plain, a convergence of neighboring alluvial fans into a single apron of deposits against a slope is called a bajada, or compound alluvial fan. As a streams gradient decreases, it drops coarse-grained material and this reduces the capacity of the channel and forces it to change direction and gradually build up a slightly mounded or shallow conical fan shape. The deposits are poorly sorted. There will be iso-transport energy lines forming concentric arcs about the point at the apex of the fan. Thus the material will tend to be deposited equally about these lines, Alluvial fans are often found in desert areas subject to periodic flash floods from nearby thunderstorms in local hills.
The typical watercourse in an arid climate has a large, funnel-shaped basin at the top, leading to a narrow defile, multiple braided streams are usually present and active during water flows. Phreatophytes are plants that are concentrated at the base of alluvial fans. They have long tap roots 30 to 50 feet to water that has seeped through the fan and hit an impermeable layer, sometimes collecting in springs. These stands of shrubs cling to the soil at their bases, Alluvial fans develop in wetter climates. Along the upper Koshi tributaries, tectonic forces elevate the Himalayas several millimeters annually, uplift is approximately in equilibrium with erosion, so the river annually carries some 100 million cubic meters of sediment as it exits the mountains. Deposition of this magnitude over millions of years is more than sufficient to account for the megafan, despite overpopulation on the plains, this bhabar zone is highly malarial and has remained largely uninhabited. In North America, streams flowing into Californias Central Valley have deposited smaller, such as that of the Kings River flowing out of the Sierra Nevada creates a low divide, turning the south end of the San Joaquin Valley into an endorheic basin without a connection to the ocean.
Alluvial fans are subject to flooding and can be more dangerous than the upstream canyons that feed them. Their slightly convex perpendicular surfaces cause water to spread widely until there is no zone of refuge, if the gradient is steep, active transport of materials down the fan creates a moving substrate that is inhospitable to travel on foot or wheels. But as the gradient diminishes downslope, water comes down from above faster than it can flow away downstream, in the case of the Koshi River, the huge sediment load and megafans slightly convex transverse surface conspire against engineering efforts to contain peak flows inside manmade embankments