About Crack Sealing
How to Evaluate the Effectiveness of Asphalt Crack Sealing
The process of asphalt crack sealing is a great way to improve the appearance of your driveway or parking lot. There are several factors to consider before choosing the right type of sealant: cost, environmental impact, and quality. Listed below are some of the main factors to consider. Once you've decided which method to use, you can move forward to the next step: evaluating the quality of sealants and the effectiveness of your crack sealing project.
To determine the effectiveness of different methods of crack sealing, researchers have analyzed the performance of unsealed and sealed pavement. Most studies have focused on unsealed pavement and found that sealing improves pavement performance. However, not many studies have compared the cost-benefit of different techniques. This research aims to address this gap. In this article, we will discuss the differences and similarities between these two methods.
Although it is an important preventive maintenance strategy, pavement experts differ on which method is more cost-effective. Using literature review, a survey, and field performance data, researchers have developed a cost-effectiveness guideline for pavement crack sealing. The results from this study provide a basis for comparing the various methods. Crack sealing is also more expensive than crack filling. Despite its initial high cost, crack sealing may offer longer service. More research is needed to determine whether higher performance materials are truly beneficial.
While asphalt crack sealing may not have a negative environmental impact, it can have a detrimental impact on pavements. When applied improperly, crack sealing can cause damage to asphalt pavements due to moisture entrapment. Unlike other types of surface treatments, crack sealing prevents water from escaping upwards. In fact, crack sealing can reduce the lifespan of pavements by 1.1 to 2 years. This can lead to an increase in maintenance and rehabilitation costs.
This study shows that a crack seal technique can reduce emissions of nitrogen oxide and sulphur dioxide by 50 percent. However, the crack seal method has the lowest overall emission reduction. The researchers suggest that all methods of preventive maintenance reduce carbon dioxide emissions. They recommend that new pavement studies incorporate sustainable pavement management components and consider the environmental impact of asphalt crack sealing. The study concludes that future pavements must incorporate a comprehensive life-cycle assessment to evaluate their overall environmental impact.
Quality of sealant
When determining the quality of asphalt crack sealant, consider the following factors: Size, shape, moisture content, and repair method. Crack sealant's success depends on several factors. Generally, a crack less than 20% in crack density requires a more flexible product. In contrast, a larger crack density requires a stiffer sealant. In addition, sealant's tackiness decreases after it has been cured.
When choosing an asphalt crack filler, make sure to choose one with the right adhesive properties. Asphalt filler is not rubberized, and it might dislodge if the pavement moves. Sealant, on the other hand, expands and contracts with the pavement. If the crack filler doesn't expand and contract with the pavement, it is not the right choice. For this reason, choosing a high-quality asphalt crack filler is imperative.
About Alamo Heights, TX
Texas lies between two major cultural spheres of Pre-Columbian North America: the Southwestern and the Plains areas. Archaeologists have found that three major indigenous cultures lived in this territory, and reached their developmental peak before the first European contact. These were: the Ancestral Puebloans from the upper Rio Grande region, centered west of Texas; the Mississippian culture, also known as Mound Builders, which extended along the Mississippi River Valley east of Texas; and the civilizations of Mesoamerica, centered south of Texas. Influence of Teotihuacan in northern Mexico peaked around AD 500 and declined over the 8th to 10th centuries.
When Europeans arrived in the Texas region, several different cultures of Native peoples, divided into many smaller tribes, were living there. They were Caddoan, Atakapan, Athabaskan, Coahuiltecan, and Uto-Aztecan. The Uto-Aztecan Puebloan peoples lived neared the Rio Grande in the western portion of the state, the Athabaskan-speaking Apache tribes lived throughout the interior, the Caddoans controlled much of the Red River region and the Atakapans were mostly centered along the Gulf Coast. At least one tribe of Coahuiltecans, the Aranama, lived in southern Texas. This entire culture group, primarily centered in northeastern Mexico, is now extinct. It is difficult to say who lived in the northwestern region of the state originally. By the time the region came to be explored, it belonged to the fairly well-known Comanche, another Uto-Aztecan people who had transitioned into a powerful horse culture, but it is believed that they came later and did not live there during the 16th century. It may have been claimed by several different peoples, including Uto-Aztecans, Athabaskans, or even Dhegihan Siouans.
No culture was dominant in the present-day Texas region, and many peoples inhabited the area. Native American tribes who lived inside the boundaries of present-day Texas include the Alabama, Apache, Atakapan, Bidai, Caddo, Aranama, Comanche, Choctaw, Coushatta, Hasinai, Jumano, Karankawa, Kickapoo, Kiowa, Tonkawa, and Wichita.
The region was primarily controlled by the Spanish for the first couple centuries of contact, until the Texas Revolution. They were not particularly kind to their native populations—even less so with the Caddoans, who were not trusted as their culture was split between the Spanish and the French. When the Spanish briefly managed to conquer the Louisiana colony, they decided to switch tactics and attempt being exceedingly friendly to the Indians, which they continued even after the French took back the colony. After the 1803 Louisiana Purchase, the United States inherited this odd circumstance. The Caddoans preferred the company of Americans and almost the entire population of them migrated into the states of Louisiana and Arkansas. The Spanish felt jilted after having spent so much time and effort and began trying to lure the Caddo back, even promising them more land. Seemingly without actually knowing how they came by it, the United States (who had begun convincing tribes to self-segregate from whites by selling everything and moving west ever since they gained the Louisiana Purchase) faced an overflow of native peoples in Missouri and Arkansas and were able to negotiate with the Caddoans to allow several displaced peoples to settle on unused lands in eastern Texas. They included the Muscogee, Houma Choctaw, Lenape and Mingo Seneca, among others, who all came to view the Caddoans as saviors, making those peoples highly influential.
Whether a Native American tribe was friendly or warlike was critical to the fates of European explorers and settlers in that land. Friendly tribes taught newcomers how to grow indigenous crops, prepare foods, and hunt wild game. Warlike tribes made life difficult and dangerous for Europeans through their attacks and resistance to the newcomers.
During the Texas Revolution, the U.S. became heavily involved. Prior treaties with the Spanish forbade either side from militarizing its native population in any potential conflict between the two nations. At that time, several sudden outbreaks of violence between Caddoans and Texans started to spread. The Caddoans were always clueless when questioned. The Texan and American authorities in the region could never find hard evidence linking them to it and often it was so far-flung from Caddoan lands, it barely made any sense. It seems most likely that these were false-flag attacks meant to start a cascading effect to force the natives under Caddoan influence into armed conflict without breaking any treaties—preferably on the side of the Spanish. While no proof was found as to who the culprit was, those in charge of Texas at the time attempted multiple times to publicly blame and punish the Caddoans for the incidents with the U.S. government trying to keep them in check. Furthermore, the Caddoans never turned to violence because of it, excepting cases of self-defense.
By the 1830s, the U.S. had drafted the Indian Removal Act, which was used to facilitate the Trail of Tears. Fearing retribution of other native peoples, Indian Agents all over the eastern U.S. began desperately trying to convince all their native peoples to uproot and move west. This included the Caddoans of Louisiana and Arkansas. Following the Texas Revolution, the Texans chose to make peace with their Native peoples but did not honor former land claims or agreements. This began the movement of Native populations north into what would become Indian Territory—modern-day Oklahoma.
The first historical document related to Texas was a map of the Gulf Coast, created in 1519 by Spanish explorer Alonso Álvarez de Pineda. Nine years later, shipwrecked Spanish explorer Álvar Núñez Cabeza de Vaca and his cohort became the first Europeans in what is now Texas. Cabeza de Vaca reported that in 1528, when the Spanish landed in the area, "half the natives died from a disease of the bowels and blamed us." Cabeza de Vaca also made observations about the way of life of the Ignaces Natives of Texas:
Francisco Vázquez de Coronado describes his 1541 encounter:
European powers ignored the area until accidentally settling there in 1685. Miscalculations by René-Robert Cavelier de La Salle resulted in his establishing the colony of Fort Saint Louis at Matagorda Bay rather than along the Mississippi River. The colony lasted only four years before succumbing to harsh conditions and hostile natives.
In 1690 Spanish authorities, concerned that France posed a competitive threat, constructed several missions in East Texas. After Native American resistance, the Spanish missionaries returned to Mexico. When France began settling Louisiana, mostly in the southern part of the state, in 1716 Spanish authorities responded by founding a new series of missions in East Texas. Two years later, they created San Antonio as the first Spanish civilian settlement in the area.
Hostile native tribes and distance from nearby Spanish colonies discouraged settlers from moving to the area. It was one of New Spain's least populated provinces. In 1749, the Spanish peace treaty with the Lipan Apache angered many tribes, including the Comanche, Tonkawa, and Hasinai. The Comanche signed a treaty with Spain in 1785 and later helped to defeat the Lipan Apache and Karankawa tribes. With more numerous missions being established, priests led a peaceful conversion of most tribes. By the end of the 18th century only a few nomadic tribes had not converted to Christianity.
When the United States purchased Louisiana from France in 1803, American authorities insisted the agreement also included Texas. The boundary between New Spain and the United States was finally set at the Sabine River in 1819, at what is now the border between Texas and Louisiana. Eager for new land, many United States settlers refused to recognize the agreement. Several filibusters raised armies to invade the area west of the Sabine River. Marked by the War of 1812, some men who had escaped from the Spanish held (Old) Philippines had immigrated to and also passed through Texas (New Philippines) and reached Louisiana where Philippine exiles aided the United States in the defense of New Orleans against a British invasion, with Filipinos in the Saint Malo settlement assisting Jean Lafitte in the Battle of New Orleans. In 1821, the Mexican War of Independence included the Texas territory, which became part of Mexico. Due to its low population, the territory was assigned to other states and territories of Mexico; the core territory was part of the state of Coahuila y Tejas, but other parts of today's Texas were part of Tamaulipas, Chihuahua, or the Mexican Territory of Santa Fe de Nuevo México.
Hoping more settlers would reduce the near-constant Comanche raids, Mexican Texas liberalized its immigration policies to permit immigrants from outside Mexico and Spain. Under the Mexican immigration system, large swathes of land were allotted to empresarios, who recruited settlers from the United States, Europe, and the Mexican interior. The first grant, to Moses Austin, was passed to his son Stephen F. Austin after his death.
Austin's settlers, the Old Three Hundred, made places along the Brazos River in 1822. Twenty-three other empresarios brought settlers to the state, the majority of whom were from the United States. The population of Texas grew rapidly. In 1825, Texas had about 3,500 people, with most of Mexican descent. By 1834, the population had grown to about 37,800 people, with only 7,800 of Mexican descent. Most of these early settlers who arrived with Austin and soon after were persons less than fortunate in life, as Texas was devoid of the comforts found elsewhere in Mexico and the United States during that time. Early Texas settler David B. Edwards described his fellow Texans as being "banished from the pleasures of life".
Many immigrants openly flouted Mexican law, especially the prohibition against slavery. Combined with United States' attempts to purchase Texas, Mexican authorities decided in 1830 to prohibit continued immigration from the United States. Illegal immigration from the United States into Mexico continued to increase the population of Texas anyway. New laws also called for the enforcement of customs duties angering native Mexican citizens (Tejanos) and recent immigrants alike.
The Anahuac Disturbances in 1832 were the first open revolt against Mexican rule, and they coincided with a revolt in Mexico against the nation's president. Texians sided with the federalists against the current government and drove all Mexican soldiers out of East Texas. They took advantage of the lack of oversight to agitate for more political freedom. Texians met at the Convention of 1832 to discuss requesting independent statehood, among other issues. The following year, Texians reiterated their demands at the Convention of 1833.
Within Mexico, tensions continued between federalists and centralists. In early 1835, wary Texians formed Committees of Correspondence and Safety. The unrest erupted into armed conflict in late 1835 at the Battle of Gonzales. This launched the Texas Revolution, and over the next two months the Texians defeated all Mexican troops in the region. Texians elected delegates to the Consultation, which created a provisional government. The provisional government soon collapsed from infighting, and Texas was without clear governance for the first two months of 1836.
During this time of political turmoil, Mexican President Antonio López de Santa Anna personally led an army to end the revolt. The Mexican expedition was initially successful. General José de Urrea defeated all the Texian resistance along the coast culminating in the Goliad massacre. Santa Anna's forces, after a thirteen-day siege, overwhelmed Texian defenders at the Battle of the Alamo. News of the defeats sparked panic among Texas settlers.
The newly elected Texian delegates to the Convention of 1836 quickly signed a declaration of independence on March 2, forming the Republic of Texas. After electing interim officers, the Convention disbanded. The new government joined the other settlers in Texas in the Runaway Scrape, fleeing from the approaching Mexican army. After several weeks of retreat, the Texian Army commanded by Sam Houston attacked and defeated Santa Anna's forces at the Battle of San Jacinto. Santa Anna was captured and forced to sign the Treaties of Velasco, ending the war. The Constitution of the Republic of Texas prohibited the government from restricting slavery or freeing slaves, and required free people of African descent to leave the country.
While Texas had won its independence, political battles raged between two factions of the new Republic. The nationalist faction, led by Mirabeau B. Lamar, advocated the continued independence of Texas, the expulsion of the Native Americans, and the expansion of the Republic to the Pacific Ocean. Their opponents, led by Sam Houston, advocated the annexation of Texas to the United States and peaceful co-existence with Native Americans. The conflict between the factions was typified by an incident known as the Texas Archive War. With wide popular support, Texas first applied for annexation to the United States in 1836, but its status as a slaveholding country caused its admission to be controversial and it was initially rebuffed. This status, and Mexican diplomacy in support of its claims to the territory, also complicated Texas's ability to form foreign alliances and trade relationships.
The Comanche Indians furnished the main Native American opposition to the Texas Republic, manifested in multiple raids on settlements. Mexico launched two small expeditions into Texas in 1842. The town of San Antonio was captured twice and Texans were defeated in battle in the Dawson massacre. Despite these successes, Mexico did not keep an occupying force in Texas, and the republic survived. The cotton price crash of the 1840s depressed the country's economy.
As early as 1837, the Republic of Texas made several attempts to negotiate annexation with the United States. Opposition within the republic from the nationalist faction, along with strong abolitionist opposition within the United States, slowed Texas's admission into the Union. Texas was finally annexed when the expansionist James K. Polk won the election of 1844. On December 29, 1845, the U.S. Congress admitted Texas to the U.S. as a constituent state of the Union.
The population of the new state was quite small at first, and there was a strong mix between the English-speaking American settlers who dominated in the state's eastern/northeastern portions and the Spanish-speaking former Mexicans (Tejanos) who dominated in the state's southern and western portions. Statehood brought many new settlers. Because of the long Spanish presence in Mexico and various failed colonization efforts by the Spanish and Mexicans in northern Mexico, there were large herds of Longhorn cattle that roamed the state. Hardy by nature, but also suitable for slaughtering and consumption, they represented an economic opportunity many entrepreneurs seized upon, thus creating the cowboy culture for which Texas is famous.
After Texas's annexation, Mexico broke diplomatic relations with the United States. While the United States claimed Texas's border stretched to the Rio Grande, Mexico claimed it was the Nueces River leaving the Rio Grande Valley under contested Texan sovereignty. While the former Republic of Texas could not enforce its border claims, the United States had the military strength and the political will to do so. President Polk ordered General Zachary Taylor south to the Rio Grande on January 13, 1846. A few months later Mexican troops routed an American cavalry patrol in the disputed area in the Thornton Affair starting the Mexican–American War. The first battles of the war were fought in Texas: the Siege of Fort Texas, Battle of Palo Alto and Battle of Resaca de la Palma. After these decisive victories, the United States invaded Mexican territory, ending the fighting in Texas.
After a series of United States victories, the Treaty of Guadalupe Hidalgo ended the two-year war. In return, for US$18,250,000, Mexico gave the U.S. undisputed control of Texas, ceded the Mexican Cession in 1848, most of which today is called the American Southwest, and Texas's borders were established at the Rio Grande.
The Compromise of 1850 set Texas's boundaries at their present form. U.S. Senator James Pearce of Maryland drafted the final proposal where Texas ceded its claims to land which later became half of present-day New Mexico, a third of Colorado, and small portions of Kansas, Oklahoma, and Wyoming to the federal government, in return for the assumption of $10 million of the old republic's debt. Post-war Texas grew rapidly as migrants poured into the cotton lands of the state.
They also brought or purchased enslaved African Americans, whose numbers tripled in the state from 1850 to 1860, from 58,000 to 182,566.
Texas was at war again after the election of 1860. At this time, blacks comprised 30 percent of the state's population, and they were overwhelmingly enslaved. When Abraham Lincoln was elected, South Carolina seceded from the Union. Five other Deep South states quickly followed. A state convention considering secession opened in Austin on January 28, 1861. On February 1, by a vote of 166–8, the convention adopted an Ordinance of Secession from the United States. Texas voters approved this Ordinance on February 23, 1861. Texas joined the newly created Confederate States of America on March 4, 1861, ratifying the permanent C.S. Constitution on March 23.
Not all Texans favored secession initially, although many of the same would later support the Southern cause. Texas's most notable Unionist was the state Governor, Sam Houston. Not wanting to aggravate the situation, Houston refused two offers from President Lincoln for Union troops to keep him in office. After refusing to swear an oath of allegiance to the Confederacy, Houston was deposed as governor. Around 2,000 Texans served in the Union Army, with a large contingent of recent German immigrants in Texas Hill Country being a Unionist stronghold.
While far from the major battlefields of the American Civil War, Texas contributed large numbers of men and equipment to the rest of the Confederacy. Union troops briefly occupied the state's primary port, Galveston. Texas's border with Mexico was known as the "backdoor of the Confederacy" because trade occurred at the border, bypassing the Union blockade. The Confederacy repulsed all Union attempts to shut down this route, but Texas's role as a supply state was marginalized in mid-1863 after the Union capture of the Mississippi River. The final battle of the Civil War was fought at Palmito Ranch, near Brownsville, Texas, and saw a Confederate victory.
Texas descended into anarchy for two months between the surrender of the Army of Northern Virginia and the assumption of authority by Union General Gordon Granger. Violence marked the early months of Reconstruction. Juneteenth commemorates the announcement of the Emancipation Proclamation in Galveston by General Gordon Granger, almost two and a half years after the original announcement. President Johnson, in 1866, declared the civilian government restored in Texas. Despite not meeting reconstruction requirements, Congress resumed allowing elected Texas representatives into the federal government in 1870. Social volatility continued as the state struggled with agricultural depression and labor issues.
Like most of the South, the Texas economy was devastated by the War. However, since the state had not been as dependent on slaves as other parts of the South, it was able to recover more quickly. The culture in Texas during the later 19th century exhibited many facets of a frontier territory. The state became notorious as a haven for people from other parts of the country who wanted to escape debt, war tensions, or other problems. Indeed, "Gone to Texas" was a common expression for those fleeing the law in other states. Nevertheless, the state also attracted many businessmen and other settlers with more legitimate interests as well.
The cattle industry continued to thrive, though it gradually became less profitable. Cotton and lumber became major industries creating new economic booms in various regions of the state. Railroad networks grew rapidly as did the port at Galveston as commerce between Texas and the rest of the U.S. (and the rest of the world) expanded. As with some other states before, the lumber industry quickly expanded in Texas and was its largest industry before the beginning of the 20th century.
In 1900, Texas suffered the deadliest natural disaster in U.S. history during the Galveston hurricane. On January 10, 1901, the first major oil well in Texas, Spindletop, was found south of Beaumont. Other fields were later discovered nearby in East Texas, West Texas, and under the Gulf of Mexico. The resulting "oil boom" transformed Texas. Oil production eventually averaged three million barrels per day at its peak in 1972.
In 1901, the Democratic-dominated state legislature passed a bill requiring payment of a poll tax for voting, which effectively disenfranchised most blacks and many poor whites and Latinos. In addition, the legislature established white primaries, ensuring minorities were excluded from the formal political process. The number of voters dropped dramatically, and the Democrats crushed competition from the Republican and Populist parties. The Socialist Party became the second-largest party in Texas after 1912, coinciding with a large socialist upsurge in the United States during fierce battles in the labor movement and the popularity of national heroes like Eugene V. Debs. The socialists' popularity soon waned after their vilification by the United States government for their opposition to U.S. involvement in World War I.
The Great Depression and the Dust Bowl dealt a double blow to the state's economy, which had significantly improved since the Civil War. Migrants abandoned the worst-hit sections of Texas during the Dust Bowl years. Especially from this period on, blacks left Texas in the Great Migration to get work in the Northern United States or California and to escape the oppression of segregation. In 1940, Texas was 74% Anglo, 14.4% black, and 11.5% Hispanic.
World War II had a dramatic impact on Texas, as federal money poured in to build military bases, munitions factories, POW detention camps and Army hospitals; 750,000 young men left for service; the cities exploded with new industry; the colleges took on new roles; and hundreds of thousands of poor farmers left the fields for much better-paying war jobs, never to return to agriculture. Texas manufactured 3.1 percent of total United States military armaments produced during World War II, ranking eleventh among the 48 states.
Texas modernized and expanded its system of higher education through the 1960s. The state created a comprehensive plan for higher education, funded in large part by oil revenues, and a central state apparatus designed to manage state institutions more efficiently. These changes helped Texas universities receive federal research funds.
Beginning around the mid-20th century, Texas began to transform from a rural and agricultural state to one urban and industrialized. The state's population grew quickly during this period, with large levels of migration from outside the state. As a part of the Sun Belt, Texas experienced strong economic growth, particularly during the 1970s and early 1980s. Texas's economy diversified, lessening its reliance on the petroleum industry. By 1990, Hispanics and Latino Americans overtook blacks to become the largest traditional minority group in the state. Texas has the largest Black and African American population with over 3.9 million.
During the late 20th century, the Republican Party replaced the Democratic Party as the dominant party in the state. Beginning in the early 21st century, metropolitan areas including Dallas–Fort Worth and Greater Austin became centers for the Texas Democratic Party in statewide and national elections as liberal policies became more accepted in urban areas.
From the mid-2000s to 2019, Texas gained an influx of business relocations and regional headquarters from companies in California. Texas became a major destination for migration during the early 21st century and was named the most popular state to move for three consecutive years. Another study in 2019 determined Texas's growth rate at 1,000 people per day.
During the COVID-19 pandemic in the United States, the first confirmed case of the virus in Texas was announced on March 4, 2020. On April 27, 2020, Governor Greg Abbott announced phase one of re-opening the economy. Amid a rise in COVID-19 cases in autumn 2020, Abbott and other U.S. governors refused to enact further lockdowns. In November 2020, Texas was selected as one of four states to test Pfizer's COVID-19 vaccine distribution. As of February 2, 2021, there had been over 2.4 million confirmed cases in Texas, with at least 37,417 deaths.
During February 13–17, 2021, the state faced a major weather emergency as Winter Storm Uri hit the state, as well as most of the Southeastern and Midwestern United States. Historically high power usage across the state caused the state's power grid to become overworked and ERCOT (the main operator of the Texas Interconnection grid) declared an emergency and began to implement rolling blackouts across Texas, causing a power crisis. Over 3 million Texans were without power and over 4 million were under boil notices.
Texas is the second-largest U.S. state, after Alaska, with an area of 268,820 square miles (696,200 km). Though 10% larger than France, almost twice as large as Germany or Japan, and more than twice the size of the United Kingdom, it ranks only 27th worldwide amongst country subdivisions by size. If it were an independent country, Texas would be the 39th-largest.
Texas is in the south central part of the United States of America. Three of its borders are defined by rivers. The Rio Grande forms a natural border with the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south. The Red River forms a natural border with Oklahoma and Arkansas to the north. The Sabine River forms a natural border with Louisiana to the east. The Texas Panhandle has an eastern border with Oklahoma at 100° W, a northern border with Oklahoma at 36°30' N and a western border with New Mexico at 103° W. El Paso lies on the state's western tip at 32° N and the Rio Grande.
With 10 climatic regions, 14 soil regions and 11 distinct ecological regions, regional classification becomes problematic with differences in soils, topography, geology, rainfall, and plant and animal communities. One classification system divides Texas, in order from southeast to west, into the following: Gulf Coastal Plains, Interior Lowlands, Great Plains, and Basin and Range Province.
The Gulf Coastal Plains region wraps around the Gulf of Mexico on the southeast section of the state. Vegetation in this region consists of thick piney woods. The Interior Lowlands region consists of gently rolling to hilly forested land and is part of a larger pine-hardwood forest. The Cross Timbers region and Caprock Escarpment are part of the Interior Lowlands.
The Great Plains region in Central Texas spans through the state's panhandle and Llano Estacado to the state's hill country near Lago Vista and Austin. This region is dominated by prairie and steppe. "Far West Texas" or the "Trans-Pecos" region is the state's Basin and Range Province. The most varied of the regions, this area includes Sand Hills, the Stockton Plateau, desert valleys, wooded mountain slopes and desert grasslands.
Texas has 3,700 named streams and 15 major rivers, with the Rio Grande as the largest. Other major rivers include the Pecos, the Brazos, Colorado, and Red River. While Texas has few natural lakes, Texans have built more than a hundred artificial reservoirs.
The size and unique history of Texas make its regional affiliation debatable; it can be fairly considered a Southern or a Southwestern state, or both. The vast geographic, economic, and cultural diversity within the state itself prohibits easy categorization of the whole state into a recognized region of the United States. Notable extremes range from East Texas which is often considered an extension of the Deep South, to Far West Texas which is generally acknowledged to be part of the interior Southwest.
Texas is the southernmost part of the Great Plains, which ends in the south against the folded Sierra Madre Occidental of Mexico. The continental crust forms a stable Mesoproterozoic craton which changes across a broad continental margin and transitional crust into true oceanic crust of the Gulf of Mexico. The oldest rocks in Texas date from the Mesoproterozoic and are about 1,600 million years old.
These Precambrian igneous and metamorphic rocks underlie most of the state, and are exposed in three places: Llano uplift, Van Horn, and the Franklin Mountains, near El Paso. Sedimentary rocks overlay most of these ancient rocks. The oldest sediments were deposited on the flanks of a rifted continental margin, or passive margin that developed during Cambrian time.
This margin existed until Laurasia and Gondwana collided in the Pennsylvanian subperiod to form Pangea. This is the buried crest of the Appalachian Mountains–Ouachita Mountains zone of Pennsylvanian continental collision. This orogenic crest is today buried beneath the Dallas–Waco–Austin–San Antonio trend.
The late Paleozoic mountains collapsed as rifting in the Jurassic period began to open the Gulf of Mexico. Pangea began to break up in the Triassic, but seafloor spreading to form the Gulf of Mexico occurred only in the mid- and late Jurassic. The shoreline shifted again to the eastern margin of the state and the Gulf of Mexico's passive margin began to form. Today 9 to 12 miles (14 to 19 km) of sediments are buried beneath the Texas continental shelf and a large proportion of remaining US oil reserves are here. At the start of its formation, the incipient Gulf of Mexico basin was restricted and seawater often evaporated completely to form thick evaporite deposits of Jurassic age. These salt deposits formed salt dome diapirs, and are found in East Texas along the Gulf coast.
East Texas outcrops consist of Cretaceous and Paleogene sediments which contain important deposits of Eocene lignite. The Mississippian and Pennsylvanian sediments in the north; Permian sediments in the west; and Cretaceous sediments in the east, along the Gulf coast and out on the Texas continental shelf contain oil. Oligocene volcanic rocks are found in far west Texas in the Big Bend area. A blanket of Miocene sediments known as the Ogallala formation in the western high plains region is an important aquifer. Located far from an active plate tectonic boundary, Texas has no volcanoes and few earthquakes.
A wide range of animals and insects live in Texas. It is the home to 65 species of mammals, 213 species of reptiles and amphibians, and the greatest diversity of bird life in the United States—590 native species in all. At least 12 species have been introduced and now reproduce freely in Texas.
Texas plays host to several species of wasps, including an abundance of Polistes exclamans, and is an important ground for the study of Polistes annularis.
During the spring Texas wildflowers such as the state flower, the bluebonnet, line highways throughout Texas. During the Johnson Administration the first lady, Lady Bird Johnson, worked to draw attention to Texas wildflowers.
The large size of Texas and its location at the intersection of multiple climate zones gives the state highly variable weather. The Panhandle of the state has colder winters than North Texas, while the Gulf Coast has mild winters. Texas has wide variations in precipitation patterns. El Paso, on the western end of the state, averages 8.7 inches (220 mm) of annual rainfall, while parts of southeast Texas average as much as 64 inches (1,600 mm) per year. Dallas in the North Central region averages a more moderate 37 inches (940 mm) per year.
Snow falls multiple times each winter in the Panhandle and mountainous areas of West Texas, once or twice a year in North Texas, and once every few years in Central and East Texas. Snow falls south of San Antonio or on the coast only in rare circumstances. Of note is the 2004 Christmas Eve snowstorm, when 6 inches (150 mm) of snow fell as far south as Kingsville, where the average high temperature in December is 65 °F.
Maximum temperatures in the summer months average from the 80s °F (26 °C) in the mountains of West Texas and on Galveston Island to around 100 °F (38 °C) in the Rio Grande Valley, but most areas of Texas see consistent summer high temperatures in the 90 °F (32 °C) range.
Night-time summer temperatures range from the upper 50s °F (14 °C) in the West Texas mountains to 80 °F (27 °C) in Galveston.
The table below consists of averages for August (generally the warmest month) and January (generally the coldest) in selected cities in various regions of the state.
Thunderstorms strike Texas often, especially the eastern and northern portions of the state. Tornado Alley covers the northern section of Texas. The state experiences the most tornadoes in the United States, an average of 139 a year. These strike most frequently in North Texas and the Panhandle. Tornadoes in Texas generally occur in the months of April, May, and June.
Some of the most destructive hurricanes in U.S. history have impacted Texas. A hurricane in 1875 killed about 400 people in Indianola, followed by another hurricane in 1886 that destroyed the town. These events allowed Galveston to take over as the chief port city. The 1900 Galveston hurricane subsequently devastated that city, killing about 8,000 people or possibly as many as 12,000. This makes it the deadliest natural disaster in U.S. history. In 2017, Hurricane Harvey made landfall in Rockport as a Category 4 Hurricane, causing significant damage there. The storm stalled over land for a very long time, allowing it to drop unprecedented amounts of rain over the Greater Houston area and surrounding counties. The result was widespread and catastrophic flooding that inundated hundreds of thousands of homes. Harvey ultimately became the costliest hurricane worldwide, causing an estimated $198.6 billion in damage, surpassing the cost of Hurricane Katrina.
Other devastating Texas hurricanes include the 1915 Galveston hurricane, Hurricane Audrey in 1957 which killed more than 600 people, Hurricane Carla in 1961, Hurricane Beulah in 1967, Hurricane Alicia in 1983, Hurricane Rita in 2005, and Hurricane Ike in 2008. Tropical storms have also caused their share of damage: Allison in 1989 and again during 2001, Claudette in 1979, and Tropical Storm Imelda in 2019.
There is no substantial physical barrier between Texas and the polar region. Although it is unusual, it is possible for arctic or polar air masses to penetrate Texas, as occurred during the February 13–17, 2021 North American winter storm. Usually, prevailing winds in North America will push polar air masses to the southeast before they reach Texas. Because such intrusions are rare, and, perhaps, unexpected, they may result in crises such as the 2021 Texas power crisis.
As of 2017, Texas emitted the most greenhouse gases in the U.S., almost twice the amount of California, the second-most polluting state. As of 2017 the state emits about 1,600 billion pounds (707 million metric tons) of carbon dioxide annually. As an independent state, Texas would rank as the world's seventh-largest producer of greenhouse gases. Causes of the state's vast greenhouse gas emissions include the state's large number of coal power plants and the state's refining and manufacturing industries. In 2010, there were 2,553 "emission events" which poured 44.6 million pounds (20,200 metric tons) of contaminants into the Texas sky.
The state has three cities with populations exceeding one million: Houston, San Antonio, and Dallas. These three rank among the 10 most populous cities of the United States. As of 2020, six Texas cities had populations greater than 600,000 people. Austin, Fort Worth, and El Paso are among the 20 largest U.S. cities. Texas has four metropolitan areas with populations greater than a million: Dallas–Fort Worth–Arlington, Houston–Sugar Land–The Woodlands, San Antonio–New Braunfels, and Austin–Round Rock–San Marcos. The Dallas–Fort Worth and Houston metropolitan areas number about 7.5 million and 7 million residents as of 2019, respectively.
Three interstate highways—I-35 to the west (Dallas–Fort Worth to San Antonio, with Austin in between), I-45 to the east (Dallas to Houston), and I-10 to the south (San Antonio to Houston) define the Texas Urban Triangle region. The region of 60,000 square miles (160,000 km) contains most of the state's largest cities and metropolitan areas as well as 17 million people, nearly 75 percent of Texas's total population. Houston and Dallas have been recognized as world cities. These cities are spread out amongst the state.
In contrast to the cities, unincorporated rural settlements known as colonias often lack basic infrastructure and are marked by poverty. The office of the Texas Attorney General stated, in 2011, that Texas had about 2,294 colonias, and estimates about 500,000 lived in the colonias. Hidalgo County, as of 2011, has the largest number of colonias. Texas has the largest number of people living in colonias of all states.
Texas has 254 counties, which is more than any other state by 95 (Georgia). Each county runs on Commissioners' Court system consisting of four elected commissioners (one from each of four precincts in the county, roughly divided according to population) and a county judge elected at large from the entire county. County government runs similar to a "weak" mayor-council system; the county judge has no veto authority, but votes along with the other commissioners.
Although Texas permits cities and counties to enter "interlocal agreements" to share services, the state does not allow consolidated city-county governments, nor does it have metropolitan governments. Counties are not granted home rule status; their powers are strictly defined by state law. The state does not have townships—areas within a county are either incorporated or unincorporated. Incorporated areas are part of a municipality. The county provides limited services to unincorporated areas and to some smaller incorporated areas. Municipalities are classified either "general law" cities or "home rule". A municipality may elect home rule status once it exceeds 5,000 population with voter approval.
Texas also permits the creation of "special districts", which provide limited services. The most common is the school district, but can also include hospital districts, community college districts, and utility districts (one utility district near Austin was the plaintiff in a landmark Supreme Court case involving the Voting Rights Act). Municipal, school district, and special district elections are nonpartisan, though the party affiliation of a candidate may be well-known. County and state elections are partisan.
The United States Census Bureau determined the resident population of Texas was 29,145,505 at the 2020 U.S census, a 15.9% increase since the 2010 United States census. At the 2020 census, the apportioned population of Texas stood at 29,183,290. The 2015 Texas Population Estimate program estimated the population was 27,469,114 on July 1, 2015. In 2010, Texas had a census population of 25,145,561. Texas is the second-most populous state in the United States after California.
In 2015, Texas had 4.7 million foreign-born residents, about 17% of the population and 21.6% of the state workforce. The major countries of origin for Texan immigrants were Mexico (55.1% of immigrants), India (5%), El Salvador (4.3%), Vietnam (3.7%), and China (2.3%). Of immigrant residents, some 35.8 percent were naturalized U.S. citizens. As of 2018, the population increased to 4.9 million foreign-born residents or 17.2% of the state population, up from 2,899,642 in 2000.
In 2014, there were an estimated 1.7 million undocumented immigrants in Texas, making up 35% of the total Texas immigrant population and 6.1% of the total state population. In addition to the state's foreign-born population, an additional 4.1 million Texans (15% of the state's population) were born in the United States and had at least one immigrant parent. According to the American Community Survey's 2019 estimates, 1,739,000 residents were undocumented immigrants, a decrease of 103,000 since 2014 and increase of 142,000 since 2016. Of the undocumented immigrant population, 951,000 have resided in Texas from less than 5 up to 14 years. An estimated 788,000 lived in Texas from 15 to 19 and 20 years or more.
Texas's Rio Grande Valley has seen significant migration from across the U.S.–Mexico border. During the 2014 crisis, many Central Americans, including unaccompanied minors traveling alone from Guatemala, Honduras, and El Salvador, reached the state, overwhelming Border Patrol resources for a time. Many sought asylum in the United States.
Texas's population density as of 2010 is 96.3 people per square mile (34.9/km) which is slightly higher than the average population density of the U.S. as a whole, at 87.4 people per square mile (31.1/km2). In contrast, while Texas and France are similarly sized geographically, the European country has a population density of 301.8 people per square mile (116.5/km). Of its dense population, two-thirds of all Texans live in major metropolitan areas such as Houston. The Dallas–Fort Worth metropolitan area is the largest in Texas. While Houston is the largest city in Texas and the fourth-largest city in the United States by population, the Dallas–Fort Worth metropolitan area is larger than the city and metropolitan area of Houston.
In 2019, non-Hispanic whites represented 41.2% of Texas's population, reflecting a national demographic shift. Blacks or African Americans made up 12.9%, American Indians and Alaska Natives 1.0%, Asian Americans 5.2%, Native Hawaiians and other Pacific Islanders 0.1%, some other race 0.2%, and two or more races 1.8%. Hispanics or Latino Americans of any race made up 39.7% of the estimated population. At the 2020 census, the racial and ethnic composition of the state was 42.5% white (39.7% non-Hispanic white), 11.8% Black or African American, 5.4% Asian, 0.3% American Indian and Alaska Native, 0.1% Native Hawaiian and other Pacific Islander, 13.6% some other race, 17.6% two or more races, and 39.3% Hispanic and Latino American of any race.
In 2010, 49% of all births were Hispanics; 35% were non-Hispanic whites; 11.5% were non-Hispanic blacks, and 4.3% were Asians/Pacific Islanders. Based on U.S. Census Bureau data released in February 2011, for the first time in recent history, Texas's white population is below 50% (45%) and Hispanics grew to 38%. Between 2000 and 2010, the total population grew by 20.6%, but Hispanics and Latino Americans grew by 65%, whereas non-Hispanic whites grew by only 4.2%. Texas has the fifth highest rate of teenage births in the nation and a plurality of these are to Hispanics or Latinos. Following continued population growth among people of color since the 2020 census alongside the 2022 Buffalo, NY mass shooting, concerns about racial and ethnic tensions were highlighted in some Texas newspapers regarding the extremist Great Replacement theory.
The most common accent or dialect spoken by natives throughout Texas is sometimes referred to as Texan English, which itself is a sub-variety of a broader category of American English known as Southern American English. Creole language is spoken in some parts of East Texas. In some areas of the state—particularly in the large cities—Western American English and General American English, is increasingly common. Chicano English—due to a growing Hispanic population—is widespread in South Texas, while African-American English is especially notable in historically minority areas of urban Texas.
At the 2019 American Community Survey's estimates, 64.4% of the population spoke only English, and 35.6% spoke a language other than English. Roughly 30% of the total population spoke Spanish. Approximately 50,742 Texans spoke French or a French-creole language. German and other West Germanic languages were spoken by 47,098 residents; Russian, Polish, and other Slavic languages by 27,956; Korean by 31,581; Chinese 22,616; Vietnamese 81,022; Tagalog 43,360; and Arabic by 26,281 Texans.
At the census of 2010, 65.8% (14,740,304) of Texas residents age 5 and older spoke only English at home, while 29.2% (6,543,702) spoke Spanish, 0.8 percent (168,886) Vietnamese, and Chinese (which includes Cantonese and Mandarin) was spoken by 0.6% (122,921) of the population over five. Other languages spoken include German (including Texas German) by 0.3% (73,137), Tagalog with 0.3% (64,272) speakers, and French (including Cajun French) was spoken by 0.3% (55,773) of Texans. Reportedly, Cherokee is the most widely spoken Native American language in Texas. In total, 34.2% (7,660,406) of Texas's population aged five and older spoke a language at home other than English as of 2006.
The majority of Texas's population have been and remain predominantly Christian, influenced by Spanish Catholic and American Protestant colonialism and missionary work (75.5%). Texas's large Christian population is also influenced due to its location within the Bible Belt. The following largest groups were the irreligious (20%), Judaism (1%), Islam (1%), Buddhism (1%) and Hinduism, and other religions at less than 1 percent each.
The largest Christian denomination as of 2014 has been the Catholic Church, per the Pew Research Center at 23% of the population, though Protestants altogether made up 50% of the Christian population in 2014; in another study by the Public Religion Research Institute in 2020, the Catholic Church's membership increased to encompassing 28% of the population identifying with a religious or spiritual belief. The largest Catholic jurisdictions in Texas are the Archdiocese of Galveston-Houston—the first and oldest Latin Church diocese in Texas—the dioceses of Dallas, Fort Worth, and the Archdiocese of San Antonio.
Among Protestant Christians, which as a whole declined to 47% of the population in a separate study by the Public Religion Research Institute, predominantly-white Evangelical Protestantism declined to 14% of the Protestant Christian population. Mainline Protestants in contrast made up 15% of Protestant Texas. Hispanic or Latino American-dominated Protestant churches and historically Black or African American Protestantism grew to a collective 13% of the Protestant population.
In contrast, Evangelical Protestants altogether were 31% of the population at the Pew Research Center's 2014 study, and Baptists were the largest Evangelical tradition (14%); per the 2014 study, they made up the second largest Mainline Protestant group behind Methodists (4%). Nondenominational and interdenominational Christians were the second largest Evangelical group (7%) followed by Pentecostals (4%). The largest Evangelical Baptists in the state were the Southern Baptist Convention (9%) and independent Baptists (3%). The Assemblies of God made the largest Evangelical Pentecostal denomination in 2014. Among Mainline Protestants, the United Methodist Church was the largest denomination (4%) and the American Baptist Churches USA comprised the second largest Mainline Protestant group (2%).
According to the Pew Research Center in 2014, the largest historically African American Christian denominations were the National Baptist Convention (USA) and the Church of God in Christ. Black Methodists and other Christians made up less than 1 percent each of the Christian demographic. Other Christians made up 1 percent of the total Christian population, and the Eastern and Oriental Orthodox formed less than 1 percent of the statewide Christian populace. The Church of Jesus Christ of Latter-Day Saints is the largest nontrinitarian Christian group in Texas alongside the Jehovah's Witnesses.
Non-Christian faiths accounted for 4% of the religious population in 2014, and 5% in 2020 per the Pew Research Center and Public Religion Research Institute. Adherents of many other religions reside predominantly in the urban centers of Texas. Judaism, Islam, and Buddhism were tied as the second largest religion as of 2014 and 2020. In 1990, the Islamic population was about 140,000 with more recent figures putting the current number of Muslims between 350,000 and 400,000 as of 2012. The Jewish population was around 128,000 in 2008. In 2020, the Jewish population grew to over 176,000. Around 146,000 adherents of religions such as Hinduism and Sikhism lived in Texas as of 2004. Texas is the fifth-largest Muslim-populated state in the country. Of the unaffiliated, an estimated 2% were atheists and 3% agnostic.