  After about a decade of research in this domain, what is missing is a
systematic overview of the research agenda across different infrastructures and
hazards. It is now imperative to evaluate the current progress and gaps. This
paper presents a systematic review of equity literature on disrupted
infrastructure during a natural hazard event. Following a systematic review
protocol, we collected, screened, and evaluated almost 3,000 studies. Our
analysis focuses on the intersection within the dimensions of the
eight-dimensional assessment framework that distinguishes focus of the study,
methodological approaches, and equity dimensions (distributional-demographic,
distributional-spatial, procedural, and capacity equity). To conceptualize the
intersection of the different dimensions of equity, we refer to pathways, which
identify how equity is constructed, analyzed, and used. Significant findings
show that (1) the interest in equity in infrastructure resilience has
exponentially increased, (2) the majority of studies are in the US and by
extension in the global north, (3) most data collection use descriptive and
open-data and none of the international studies use location-intelligence data.
The most prominent equity conceptualization is distributional equity, such as
the disproportionate impacts to vulnerable populations and spaces. The most
common pathways to study equity connect distributional equity to the
infrastructure's power, water, and transportation in response to flooding and
hurricane storms. Other equity concepts or pathways, such as connections of
equity to decision-making and building household capacity, remain understudied.
Future research directions include quantifying the social costs of
infrastructure disruptions and better integration of equity into resilience
decision-making.
