Drought Impacts on Navigation and Transportation
During drought conditions that result in low water levels on rivers and other waterways, port and water-borne transportation operations may be limited due to a reduction in available routes and cargo-carrying capacity, resulting in increased transportation costs. For example, the 2012 Great Plains drought closed the Mississippi River at least three times, costing an estimated $300 million per day that the river was closed to traffic.
Any increased shipping costs may be passed on to consumers, resulting in higher retail prices for goods. Alternative modes of transportation (such as rail or truck) may be available for some products, but it would be impractical to shift products such as Midwest grain to these modes of transportation.
Drought conditions can affect more than just waterways. Higher temperatures that often coexist with drought can impact pavement, requiring state departments of transportation to allocate resources for repair. Airport runways are also vulnerable to extreme heat, which can cause asphalt to soften and deteriorate. Some airplanes themselves cannot fly in extremely high temperatures. While larger planes are able to operate in a wide range of temperature conditions, many smaller, regional aircraft cannot fly safely if temperatures exceed 118℉. Extreme heat can also cause rail lines to buckle (called “sun kinks”), causing derailments. When water supplies are depleted in drought, subsidence (the sinking of the ground) can occur as more groundwater is removed. This affects infrastructure, including roads, buildings, and water pipes, and can lead to the formation of sinkholes.
Drought also increases the risk of wildfire, the smoke from which can severely affect visibility and result in road and airport closures.