shifting of rocks in higher places, resulting in the rock- and landslide.”
Lost Horizon
Maoxian County, in northern Sichuan, is famous for its charming
natural scenery and diverse ethnic culture. For generations the ances-
tors of 17 ethnic groups including Tibetan and Qiang have lived in
the county’s mountainous regions.
Aerial photography of Xinmo Village before the landslide circu-
lated online after the disaster showed off the remote village’s previous
beauty and tranquility. Netizens lamented the impermanence of the
place as news of the landslide spread through the country.
According to Professor Liu Chun of Tongji University, Shanghai,
an expert in remote sensing and geoinformatics, from a technical
point of view, monitoring and early warning systems were not precise
and did not issue alerts in time in the case of the Maoxian landslide.
Additionally, “from the point of view of disaster management, local
villagers’ lack of risk awareness also contributed to the disastrous re-
sults,” said Liu.
Geologically, Maoxian is located at the Longmenshan Mountain
fracture zone, and according to Professor Liu Chun, a drive along
mountain roads in the valley area often involves an encounter with
falling rocks from the slopes above. Liu and his team’s area of study
focuses on this part of Sichuan where historical records indicate that
landslides have occurred before in Maoxian itself. An earthquake
measuring 7.5 on the Richter scale struck Maoxian in 1933, leaving a
barrier lake still visible today.
A landslide is complicated geological activity – some happen quick-
ly while others shift only slowly. Most landslides occur due to earth-
quakes, rainfall or construction projects. The 2008 earthquake in
Sichuan Province damaged the geological stability of the mountains
in the wider region. The frequent heavy rain and extreme weather
conditions in recent years, coupled with intensive infrastructure con-
struction involved in the building of dams, roads and tunnels have all
had an impact on the internal geological structure of the entire region.
The frequency of landslides has increased significantly in recent
years, making it impossible for technicians to make precise forecasts
for small-scale landslides.
“This time, it is due to the special geographical situation and techni-
cal limitations, that no effective forecasts could be made in advance,”
Liu explained to our reporter, “The landslide took place at a height of
3,400 metres above sea level, some 1,250 metres above Xinmo village.
The spot was an uninhabited area and the precipitously steep slope
made it hard for humans to access. Thus it would not be possible for
geologists to conduct regular visits and monitoring.”
Additionally, the density of mountain forests can impair the satel-
lite imaging and remote sensing used to detect changes to mountain
slopes. “Considering the vastness of the whole region, it is not pos-
sible for monitoring to be 100 percent accurate,” added Liu to the
reporter.
Despite the previous occurrence of some small-scale landslides in
the same region, as Liu explained, local villagers had not foreseen the
potentially serious dangers that might result from a large slide. In such
circumstances where prevention measures are of no help, the reloca-
tion of the local population is the only option.Effective Contrast
A national research programme on landslide forecast data collec-
tion and early warning systems has been underway in Sichuan for
years. Professor Liu’s team has concentrated its efforts on monitor-
ing landslides of all scales in the province. Some effective preventative
measures have since been taken in some locations.
According to a local media report, Jiaju Tibetan Village of Danba,
located in western Sichuan Province, ranked first on the list of the
“Six Most Beautiful Ancient Towns in China” category of “The Most
Beautiful Places in China” in 2005. Danba is one of the main tourist
destinations in all of Sichuan. Over 140 Jiarong Tibetan households
(a subbranch of the Tibetan ethnicity) live on its terraced mountain
slopes. “If this place had landslides, this beautiful village would disap-
pear,” said Liu Chun. Fortunately, scientists and researchers detected
the high possibility of danger and have started to delve into more
support for the village, both financially and technically, to improve
the site’s geological stability. In previous years, according to Liu Chun,
once scientists noticed any warning signs of possible landslides, ac-
tions would be taken to begin reinforcement construction works on
the slope immediately. This has proved to be effective in containing
the impact of geological disasters. “Through such initiatives, landslides
have not occurred in Danba so far,” explained Liu to ChinaReport.
Liu Chun also reiterated that apart from professional technical
monitoring, effective forecasting for landslides also depends on the
joint efforts of disaster prevention teams. “The joint efforts include
government, technicians as well as local communities,” explained Liu,
“that can effectively form an intact monitoring network for geological
disaster.” Liu added that even with such preparation, due to the large
size of the region, there might be gaps, which could result in unavoid-
able landslides.High-tech Solution
The normal process for determining the possible position for a
landslide first of all requires technicians to recognise the overall situa-
tion of an area through remote sensing. The second step is to send an
unmanned aerial vehicle to the location identified as a danger zone for
further inspection to determine whether there are any cracks in the