Колорадская пустыня: География, климат и биоразнообразие Калифорнии.

Subdivision of the larger Sonoran Desert, California
the desert in California

Colorado Desert is a part of the larger Sonoran Desert located in California, United States and Baja California, Mexico. It encompasses approximately 7 million acres (2,832,802 km2), including the heavily irrigated Coachella, Imperial and Mexicali valleys. It is home to many unique flora and fauna.

The Colorado Desert is a subdivision of the larger Sonoran Desert encompassing approximately 7 million acres (2,832,802 km2). The desert encompasses Imperial County and includes parts of San Diego County, Riverside County, a small part of San Bernardino County, California, United States, and the north part of the municipality of Mexicali, Mexico. Most of the Colorado Desert lies at a relatively low elevation, below 1000 feet (305 m), with the lowest point of the desert floor at 275 feet (84 m) below sea level, at the Salton Sea. Although the highest peaks of the Peninsular Ranges reach elevations of nearly 10000 feet (3048 m), most of the region's mountains do not exceed 3000 feet (914 m). In this region, the geology is dominated by the transition of the tectonic plate boundary from rift to fault. The southernmost strands of the San Andreas Fault connect to the northernmost extensions of the East Pacific Rise. Consequently, the region is subject to earthquakes, and the crust is being stretched, which will result in a sinking of the terrain over time.

The Colorado Desert's climate distinguishes it from other deserts. The region experiences greater summer daytime temperatures than higher elevation deserts and almost never experiences frost. In addition, the Colorado Desert experiences two rainy seasons per year (in the winter and late summer), especially toward the southern portion of the region; the more northerly Mojave Desert usually has only winter rains. The west coast Peninsular Ranges, or other west ranges, of Southern California–northern Baja California, block most eastern Pacific coastal air and rains, producing an arid climate. In the Colorado Desert's arid environment, aquatic and wetland habitats are limited in extent but are critically important to wildlife. Runoff from seasonal rains and groundwater springs forms desert arroyos, desert fan palm oases, freshwater marshes, brine lakes, desert washes, ephemeral and perennial streams, and desert riparian vegetation communities dominated by cottonwood, willow, and non native tamarisk. Two of the region's most significant aquatic systems are the Salton Sea and the Colorado River. While most desert wildlife depend on aquatic habitats as water sources, a number of species, such as the arroyo toad, desert pupfish, Yuma rail, and southwestern willow flycatcher, are restricted to these habitats. In some places, summer rains produce short lived seasonal pools that host uncommon species like Couch's spadefoot toad. Desert fan palm oases are rare ecological communities found only in the Colorado Desert. They occur only where permanent water sources are available, such as at springs or along fault lines, where groundwater is forced to the surface by the movement of hard impermeable rock, and can be found in the San Jacinto, Santa Rosa, and Little San Bernardino mountains, in the canyons of Anza Borrego Desert State Park, and along the San Andreas Fault in the Coachella Valley.

Some sub regions of the Colorado Desert contain endemic flora. Along the Lower Colorado River Valley, in flow side canyons, flatlands, or low to higher level elevations, at least three such flora occur: Hesperocallis undulata (desert lily), Nolina bigelovii (Bigelow's nolina), and Peucephyllum schottii (desert fir).

The Colorado Desert is one of the least populous regions in California, but human activities have had substantial impacts on the region's habitats and wildlife. Many unique communities, particularly aquatic and dune systems, are limited in distribution and separated by vast expanses of inhospitable, arid desert terrain. Even limited human disturbances can have markedly deleterious effects on the endemic and sensitive species supported by these unique regional systems. Some of the greatest human caused effects on the region have resulted from the water diversions and flood control measures along the Colorado River. These measures have dramatically altered the region's hydrology by redistributing the region's water supply to large expanses of irrigated agriculture and metropolitan coastal areas such as Los Angeles and San Diego. The once dynamic Salton Sea and Colorado River ecosystems are now controlled by human water management. Because of the scarcity of water resources in the desert environment, these alterations have had substantial impacts on regional wildlife and habitats. In addition, portions of the region are experiencing substantial growth and development pressures, most notably the Coachella Valley.