In April 2017, Peru awoke from a prolonged nightmare: one of the strongest El Niño episodes recorded in recent decades. For four months, the country experienced intense rains, floods and huaicos, a Quechua term referring to a flash flood caused by heavy rains and because they originate high in the Andean mountains, they carry rocks, mud and logs down to rivers, causing them to overflow.
This episode has had significant consequences on the country’s infrastructure, especially on its road network. Sixty thousand kilometers of roads were affected, corresponding to 37% of the total network. Access to various rural areas and small cities was limited or impossible for several months. This complicated the supply of goods and services to these areas and their ability to market their products.
Climate change will cause an increase in the frequency and intensity of these events in the future. This fact highlights the need for more resilient designs and maintenance of transport infrastructure.
This is not an easy challenge in Peru: the country’s road network comprises over 139,000 kilometers under municipal management. Its development and maintenance are limited by the budgets of these entities and the high costs in mountain and rainforest regions. Nevertheless,
A guide for building resilience
For these reasons,The guide can help national or local operators to identify higher-priority investments through a risk-analysis methodology for rural roads, based on the prioritization of risk indicators at critical points.
This guide also includes a section on contingency plans and early warnings to reduce Peru’s exposure to climate events, and offers tools for monitoring and evaluation in order to determine whether or not the implemented resilience measures had an effect on road conditions. It also provides general recommendations on improving the technical design and management of climate events during the construction of new roads.
This document was prepared through a participatory consultation process with local road-management stakeholders, including: Provías Descentralizado (PVD); the National Center for Estimation, Prevention and Reduction of Disasters (CENEPRED); the National Commission on Climate Change (CNCC) of the Ministry of the Environment (MINAM); the Fund for Economic Inclusion in Rural Areas (FONIE); the National Civil Defense Institute (INDECI); the Geological Institute for Mining and Metallurgy (INGEMMET); the Ministry of the Environment (MINAM); the Authority for Reconstruction with Changes (ARCC); and the National Meteorology and Hydrology Service of Peru (SENAMHI).
The risk assessment methodology was applied to nine rural roads in diverse regions of the country, with a selection of adequate technical measures. The guide includes the lessons learned from these experiences. These nine roads are in the process of rehabilitation and improvement under the framework of the Support to the Subnational Transport Project (PATS), also co-financed by the World Bank.
Methodology for Risk Analysis
As for the risk analysis, the methodology is based on the one developed by the Intergovernmental Panel on Climate Change (IPCC) in its Fifth report, and considers the three main threats to rural roads in Peru:
- Rapid floods, huaicos and ravines.
- Slow floods and river erosion.
- Mass movements, such as landslides and other erosive processes.
The data collected make it possible to identify critical points and assess their status for each of the indicators established in an MS Excel tool developed for the guide. This includes innovative indicators based on Peru’s future climate projections. The tool enables the calculation of a global risk indicator for the sites considered, based on weightings adapted to the Peruvian context.
From the risk analysis, and depending on the type of identified critical point and geographical zone (coast, mountain, rainforest), the tools included in the guide enable the choice of relevant technical measures in terms of cost/resilience for the design of rehabilitation and maintenance works. Measures are included for drainage, erosion control, maintenance and prevention, and embankment stabilization. In general, the maintenance and prevention measures have the best cost/resilience values.
and thus ensure the accessibility of rural communities to markets and services.
Although this guide is an initial step toward improving the resilience of rural roads in Peru, the technical standards for road designs still need to be reviewed in order to include resilience measures for rural roads and for the road network as a whole. A similar process could be developed in other countries, based on the same methodology, by adjusting the tools to local geographic contexts.