The Peruvian experience applied to similar areas in the Himalayas
Glacial water basins in Peru have suffered the impacts of landslides and violent floods whichhave destroyed villages, killed many people and changed the lives of communities in significant ways. This phenomenon, known as GLOF (Glacier Lake Outburst Floods) is considered to have occurred during periods of glacial retreatwhen environmental temperatureshave increased.
In the historical period known as the Hot Medieval Period (MWP), Optimal Medieval Climate or Medieval Climatic Anomaly, alluvial processes have occurred on the slopes of our glaciated mountains that have left clear evidence in the subsoil’s of the Huaylas Valley of Ancash, Peru such as in the area of Caraz.
After the Little Ice Age, between the fifteenth and the eighteenth century, landslides and glacial lake outburst floods occurred as evidenced in the reports of the Glaciology and Lake Security Unit of Huaraz.
However, it has only been since 1941 in the area of ??the Cordillera Blanca, when a great flood destroyed much of the city of Huaraz and killed many people that the Peruvian government began to take action by establishing an office to study dangerous lakes and implement mitigation works to reduce the risks they pose to the general population.
Consequently we can say that the fight of Peruvian man to counteract these morphogeodinámic-phenomena began in 1941, and can be divided into four distinct stages: the first stage occurred between 1940 and 1960 when studies and works were carried out based on the engineering and geological knowledge of the day. The second stage refers to a deepening of the glaciological studies following a visit of the French glaciologist Louis Lliboutry, who laid the foundations for continuous monitoring of glaciers and lakes in the Cordillera Blanca. From that time onward data was collected from representative glaciers on a regular basis until the mid-1990s. After some years of interruption this monitoring of representative glaciers continues. The third stage began following the great earthquake of 1970 in which repair workswere carried out on the security structures of dangerous lakes with approximately 40 works being completed. The fourth stageis closely related to climate change where the influence of glacial retreat on water resources is now being considered. This is the stage in which glaciological activities in Peru are now being developed.
Having continued for almost 70 years, the Peruvian experience is important as it was obtained by applying Peruviantechnology and criteria whichevolved gradually, acquiring some degree of scientific rigor both in the studies and in the projects carried out. In summary the Peruvian experience has integrated technology withits own resources.
The Himalaya Mountains of China, India, Pakistan, Nepal and Bhutan, have similar characteristics to the Peruvian Andes but on a larger scale. While in our country there are about 1500 square kilometers of glaciersin the Himalaya there is an estimated 33,000 square kilometers of glaciers, with all the characteristics and risks implied by this largerscale.
The thinning and retreat of Himalayan glaciers has also resulted in the formation of new lakes and the enlargement of others (ICIMOD * -2011). Since these lakes in many cases are unstable and subject to possible violent outbursts, as happened in Peru,they also present risks to populations, public and private property.
It is for this reason that under the auspices of the U.S. Agency for International Development (USAID) and the United Nations Development Program (UNDP) Peruvian personnel were invited to visit the valleys of the Hindu Kush and the Himalayas of Nepal en route to Mount Everest. Peru’spioneering experience with these works is considered important in terms of its applications to the Himalayas and for this reason during 2012 Peruvian personnel participated in meetings and social/technical discussions on the design of drainage projects for dangerous lakes.
In addition to the great experience of visiting this beautiful area of the world with its spiritual customs it was observed that global warming was notably influencing the Himalayanmountain ranges causing landslides and the accelerated formation of mountain lakes. 21 potentially dangerous lakes were identified with special attention now being given to Lakes TshoRolpa, ImjaTsho and Thulagi.
Lake TshoRolpahas been the subject of ongoing workswhich have lowered the water level byabout 3 meters, however this is still not considered enough. Drainage works are also being planned for LakeImja, which the author of this article has observed more closely. However the special characteristics of the moraine dam structure at Imjarequires that great care be taken in designing the project, especially because of the presence of ice within the dam body which raises questions that must be resolved before decisions can be made on how to reduce risks at this lake.
The other lake that also presents high risk conditions is Lake Thulagi, but decisions have not yet been taken on the best method of reducing risks at this site.
We hope that as Peruvians we can continue to provide a small grain of cooperation in decisions on how to resolve these serious problems in the Himalaya Mountains.
By: César Portocarrero.