General Introduction: Bhutan and its geology
The Himalayan Kingdom of Bhutan is a small land-locked country with a population of 733,004 (2013 projected figure1) and a geographic area of 38,394 km2. The country is almost entirely mountainous dissected by an intricate system of several rivers, rivulets, and streams, with nearly 95 percent of the country being above 600 meters altitude2. The topography is rugged and steep, with elevation rising from under 200 m to above 7,500 m within a short south-north distance of some 170 kilometres (km). The country can be distinguished into three broad physiographic zones: the southern belt made up of the Himalayan foothills adjacent to the belt of flatland along the Indian border; the inner Himalayas consisting of main river valleys and steep mountains; and the high Himalayas featuring alpine meadows and snow-capped mountains.
The geology and topography of Bhutan are shaped by the intense tectonic activity that resulted from the collision of the Indian and Eurasian continental plates, the closure of the intervening Tethys Sea, and the uplift of the Himalayas. The mountains are primarily made up of uplifted sedimentary and metamorphic rocks, which are highly fragile and sensitive to erosion due to rainfall. Its fragile geology makes Bhutan highly vulnerable to earthquakes. Bhutan is therefore one of the most disaster prone countries in the Asia-Pacific region, irrespective of the impacts of climate change. However, the current rate of climate change is significantly contributing to increased incidence of landslide and floods, mainly related to higher intensity of rainfall within a shorter duration. In terms of relative exposure to flood risks (as % of population), Bhutan ranks fourth highest in the region at 1.7% of the total population exposed to such risks. Although the direct human risks of landslides, windstorms, and forest fires are not particularly higher compared to other countries, the socio-economic repercussions from these events are thought to be high due to the higher baseline poverty prevalence as well communities’ inability to adapt to impacts of climate change. Climate change is likely to magnify the intensity and frequency of these hazards in future.
Bhutan is among the countries most vulnerable to climate change in the Asia-Pacific region because of its vulnerable mountainous terrain and volatile ecosystems. The country is exposed to multiple hazards, in particular glacial lake outburst floods (GLOF) resulting from glacial melting, flash floods, landslides, windstorms, forest fires, localized changes in rainfall patterns and increasing droughts during dry season. Climate change is projected to significantly magnify the intensity and frequency of such natural hazards, as has already been evidenced by the glacial lake outburst flood (GLOF) of Lugge Tsho in 1994 and more recently the high intensity cyclone Aila in May 2009, which caused substantial damages. The National Adaptation Programme of Action (NAPA), Second National Communication (SNC) and National Human Development Report 2011 give an account of a number of recent, climate-related disaster events that have impacted national and local economies and livelihoods.
Following request from RGOB, the UNDP in collaboration with GNHC and all the relevant stakeholders mobilized funding from GEF/LDCF to implement the project on “Addressing the risk of climate-induced disasters through enhanced national and local capacity for effective actions”. This project has been conceived with the objective to enhance national, local and community capacity to prepare for and respond to climate-induced multi-hazards to reduce potential losses of human lives, national economic infrastructure, livelihoods and livelihood assets. The project has been designed to address the immediate and urgent climate change adaptation needs prioritized through the update of the NAPA undertaken in 2012, involving review and updating of the earlier NAPA produced in 2006.
One of the outcomes of the project focuses on demonstrating effective practical measures to reduce flood and landslide risks in Phuentsholing and the adjoining industrial estate of Pasakha, which are the economic and industrial hubs of the country as well as among the most critical areas that are recurrently besieged by floods and landslides.