Landslides in Developing Nations Latin America Near Quito

Landslides in Developing Nations Latin America

Near Quito, Ecuador Date: March 11, 2004 Type of mass wasting: Landslide Cause: unknown Result: rupture of the Transecuadorean Pipeline (14 th major spill since 1998) Oil is Ecuador’s leading export & second largest source of government income.

Santa Tecla, El Salvador Date: January 2001 Type of mass wasting: Landslide/earthflow Cause: 13 Jan. , 2001, El Salvador Earthquake (M=7. 6) Result: numerous landslides in volcanic rocks, Pan. American Highway closed in two places 265 - 450 people reported dead

Santa Tecla, El Salvado Problem: battle between real-estate developers versus city officials, environmentalists and local residents Claimed area was over-developed “inherently geologically unstable” – local geologist deforestation

Oblique aerial view of landslide that buried Colonia Las Colinas (Photograph by Edwin L. Harp, U. S. Geological Survey )

The Jan. 13 earthquake that hit El Salvador triggered this landslide from the Balsamo Ridge over Las Colinas. Edwin Harp (http: //www. geotimes. org/mar 01/geophen. html)

View of headscarp of Las Colinas landslide showing fractures in Balsamo ridge behind the scarp. Note the white tephra at the base of the steepest part of the headscarp. (Photograph by Edwin L. Harp, U. S. Geological Survey )

Nicaragua Date: October 1988 Type of mass wasting: Lahar Cause: Hurricane Mitch Stalled off the Honduras & Nicaragua coast 25 -75” of rain fell over three days Result: 2000 killed when a crater lake overflowed and created a lahar

Cerro Musun, Nicaragua Date: June 29, 2004 Type of mass wasting: mudslide Cause: storms / deforestation Result: 52 mudslides in Cerro Musun region (ecological preserve & rainforest) 29 known dead 18 known injured 5, 751 people affected

Cerro Musun, Nicaragua Why was there so much damage? Deforestation & improper agriculture techniques ~ 1, 200 sq. kilometers of forest disappear every year in Nicaragua • 1983 - 76, 668 sq. km of forests • 2000 - 55, 977 sq. km of forests

Cerro Musun, Nicaragua Analysis of the Ministry of the Environment (Marena) relation between activity and productivity in the forest is unsustainable reduces the potential for hydroelectric production creates a need for major state investment in accessing water for human consumption raises the poverty level in the rural areas and increases migration and colonization on the agricultural frontier.

Vargas, Venezuela Date: December 1999 Type of mass wasting: Debris Flow Cause: unusually heavy rains Result: catastrophic landslides and flooding along a 40 -km coastal strip north of Caracas from La Guaira to Naiguita, in the northern coastal state of Vargas, Venezuela

Daily rainfall (mm) for December 1 -18, 1999 at Maiquetia (Urbani, 2000).

Vargas, Venezuela 8000 individual residences, and 700 apartment buildings were destroyed or damaged Roads, telephones, electricity, etc cut off. Total economic losses ~ $1. 79 Billion

Vargas, Venezuela Original population ~300, 000 Death toll ~30, 000 or 10% of the population Only 1000 bodies were recovered Buried in mud Swept out to sea

Vargas, Venezuela Why was there so much damage? Cities were built on alluvial fans Older homes not built on fans

Debris-Flow Deposits and Contours of Maximum Boulder Size on the Caraballeda Fan, Venezuela (http: //pubs. usgs. gov/of/2001/ofr-01 -0144/plates/plate 2. html)

Debris-Flow and Flood Deposit Thickness for December, 1999 Storm on the Caraballeda Fan, Venezuela (http: //pubs. usgs. gov/of/2001/ofr-01 -0144/plates/plate 3. html)

Aerial view of debris-flow deposition resulting in widespread destruction on the Caraballeda fan of the Quebrada San Julián. Avulsion of the main channel (left side of photo) resulted in deposits up to 6 -m in thickness and totaling about 1. 8 million cubic meters of bouldery debris. Secondary new flood channels are visible through center of fan to the lower right of photo (Photo by Lawson Smith, US ACE). http: //pubs. usgs. gov/of/2001/ofr-01 -0144/

Apartment in Caraballeda extensively damaged by passage of debris-flow front at least 3. 5 m in height, leaving boulders (> 1 m) on second floor of structure. http: //pubs. usgs. gov/of/2001/ofr-01 -0144/

Excavated channel of the Quebrada San Julián on the eastern portion of Caraballeda fan. Debris flow and flood waters overflowed channel at this point midway on the fan. Concrete base of channel (left) dates to post-1951 flood recovery efforts. Channel was probably partially refilled with sediment príor to the events of December 1999. Note bulldozer in channel for scale. http: //pubs. usgs. gov/of/2001/ofr-01 -0144/

Roof of a one-story residence buried by debris flow in center of Caraballeda fan. View eastward across area inundated by bouldery debris flow. http: //pubs. usgs. gov/of/2001/ofr-01 -0144/

Relatively small landslide above Quebrada Seca that local residents said was responsible for killing 13 people climbing hillside to seek safety http: //pubs. usgs. gov/of/2001/ofr-01 -0144/

Vargas, Venezuela Date: Feb 10, 2005 Type of mass wasting: Debris Flow/mudslide Cause: unusually heavy rains Result: 13 – 53 dead and 20, 000+ homeless in the La Guaira region, Vargas, Venezuela Government & people better prepared

Source: Relief. Web. com

Vargas, Venezuela Clearing roads REUTERS/ Christian Veron REF: CAR 06 D Coastal waters discolored by mud from runoff & landslides REUTERS/ Howard Yanes REF: CAR 10 D Evacuation by the Venezuelan Navy REUTERS/ Ho REF: VEN 05 D Relief efforts REUTERS/ Handout REF: VEN 06 Dr

Landslides in Developing Nations Asia

Ho Chi Minh City, Viet Nam Date: June 2, 2004 Type of mass wasting: Landslide Cause: river erosion & rains Result: 1, 000 resident & 200 homes evacuated, one tennis court destroyed Many return to the same place to rebuild

Ho Chi Minh City, Viet Nam Landslides have plagued the Thanh Da peninsula for 15 years Annual events Causes 100 ha of land lost & VND 100 million (US$6, 000) in property damage Solution? Government building dikes

China Economic Losses Yunnan Province - one billion yuan (US$120. 8 million) Chongqing Municipality - 420 million yuan (US$50. 7 million) Total losses caused by geologic disasters dropped by 50% in 2004 • implementation of the Regulations on the Prevention of Geological Disasters

Yunnan Province, China Geographical location The most southwestern province in China, with the Tropic of Cancer running through its southern part. Natural Resources Lots of rain Tropical to Subtropical More than 150 kinds of minerals

Xinping county, China Date: August 2002 Type of mass wasting: rock & mudslides Cause: Heavy rains & deforestation Result: Several landslides in addition to flooding Over 100 people dead

Xinping county, China Problem: Deforestation Since the 1960 s, landslides have damaged 2, 100 hectares of farmland killed 187 people. Hillsides cleared to plant tobacco, tea & coffee

Xinping county, China Solution: Central and local governments have spent more than 10 million yuan in landslide control projects each year Three measures: • stabilizing mountain slopes through re-forestation • constructing levees to block mud and rocks • building troughs to channel mud and rocks to safe places.

Guangxi Province, China Geographical location Located in south China; a coastal province. Natural Resources Lots of rivers Tropical to Subtropical Coastal

Zuojiaying, Nayong County, China Date: December 2004 Type of mass wasting: landslide/rockslide Cause: Heavy rains & deforestation Result: damaged 25 homes "affected" 108 people 65 people missing

Zuojiaying, Nayong County, China Source: People's Daily Online

Chongqing Province, China Geographical location: On the upper reaches of the Yangtze River in southwest of China, bordering provinces of Hubei, Hunan, Guizhou, Sichuan and Shaanxi. Natural resources: Lots of rivers 38 kinds of mineral deposits Three Gorges River Dam

Chongqing Province, China Date: June 8, 2004 Type of mass wasting: Debris Flow Cause: Heavy rains Result: About 200, 000 m 3 of rubble from a hill and gangue deposit slid 500 meters 24 farmers from 14 homes nearby buried (source: China Economic Net)

~ End ~