This report begins with a general overview of the Malaita Road Network, including the East Road and its overall locus within and impact on the geography, economy, and social experience of Malaita. The background also describes three proposed alternatives for road upgrading and a set of probable rainfall events likely to impact the road over its functional lifetime. Thereafter, the report details the mathematical approach to operationalizing the resilience concept in the context of the East Road and follows with the data and methodologies used to construct relevant resilience indicators for each of the three proposed upgrading options and baseline (status quo) scenarios. Following the documentation and analysis of results, the report concludes with a discussion of this case study's implications for more general efforts to structure resilience considerations in infrastructure decision-making as well as its limitations.

# II. Background

The Solomon Islands is the Pacific's largest archipelagic nation, consisting of nearly 1,000 islands extending across 1,500 km from east to west. The country has enjoyed steady economic development over the past few decades, with annual average GDP growth of 2.8% annually between 2000 to 2009, and 4.7% annually between 2010 and 2016. GDP is expected to continue to grow by an average 2.9% each year over the period of 2019 to 2023 (IMF, 2018). Key drivers of economic progress have been growth in services, as well as development of the forestry and logging sectors.

Major threats to development, however, include the expected losses and damages associated with natural disasters and climate change. Solomon Islands is highly vulnerable to tropical cyclones, floods and droughts, landslides, volcanic eruptions, earthquakes, and tsunamis.<sup>21</sup> The country has been ranked among the 10 countries with the highest vulnerability and exposure to natural disaster risks.<sup>22</sup> In fact, seven major natural disasters over the past 30 years have caused significant losses of life and major economic damages. A 2014 flash flood in Guadalcanal, for example, displaced an approximate 10,000 people and caused damages and losses equivalent to 9% of the country's GDP. GFDRR estimates that natural hazards and climate change will cause average annual losses of US$20.5 million (3% of GDP) over the next half century.<sup>23</sup> Moreover, road infrastructure remains a key area of development for the country and an important factor limiting trade and transport. The road network in Solomon Islands is publicly owned and operated. It is made up of approximately 1,500 km of roads: some 625 km (42%) are classified as main roads, 523 km (35%) are feeder roads, and 346 km (23%) as access roads. Three-quarters of the road network (including all the sealed roads) are in just three provinces: Guadalcanal (including the Capital Territory of Honiara), Malaita and Western Province. Only 184 km (29%) of the main road network (comprising 12% of the overall network) is sealed. Overall, 15% of the network is in fair to good condition, comprising 56% (104 km) of the sealed network and 11% (146 km) of the unsealed (gravel road) network.<sup>24</sup> The country's road network extends 1,694 km across 30 islands. Most roads (66% of the network) are concentrated in only two provinces – Guadalcanal and Malaita. Only approximately 126 km (7.5% of the network) all located in Guadalcanal and Malaita are sealed with bitumen/asphalt, concrete, or tar, while the rest are unsealed coral, gravel, or dirt roads. Much of the road network is deteriorated due to natural disasters and conflict-related damage. Mountainous terrain presents an additional construction challenge.

> 21 GFDRR, 2019. Building community resilience in the Solomon Islands: Helping communities manage disaster and climate risk. <u>https://www.gfdrr.org/sites/default/files/publication/FINAL%20-%20Results%20in%20Resilience%20-</u> - <u>%20Building%20Community%20Resilience%20in%20the%20Solomon%20Islands%20 %207.9.18.pdf</u>

> 22 World Risk Index, World Risk Report. 2016. <u>http://collections.unu.edu/view/UNU:5763</u> 23 GDFRR, ibid.

> 24 World Bank. 2019. Project Appraisal Document: Solomon Islands Roads and Aviation Project.

> <u>http://documents.worldbank.org/curated/en/621001554084042298/pdf/Solomon-Islands-Roads-and-Aviation-Project.pdf</u>

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