The first case study reviewed involves dam construction and management along the Zambezi River. Recent developments of dams and hydroelectricity facilities have caused problems for residents of the region that are exacerbated by changes in climate. The two large dams that were most recently constructed have been the source of false comfort by local residents as they have moved into regions that are susceptible to periodic floods. The goal of the dams was to harness the power of hydroelectricity by using river water to power the facilities. An unintended consequence of the construction includes a lowering of the levels of the floodplains. This leads to two types of problems for the region. First, elimination of the floodplains means less area for fisheries, wildlife, and agriculture. The second consequence is that residents have migrated closer to the rivers as a result of a perceived lower risk of flooding. Instead of relying on larger dams that are likely to fail in extreme weather, local officials propose reinforcing smaller existing dams to use water for hydroelectricity projects and provide better flood management.
The second of the case studies involves transportation avenues and issues related to traffic under conditions of rising water in Mobile, Alabama. The main concerns in Mobile involve an increased flow of traffic, aging infrastructure, and effects brought about by current and future changes in climate. To address these concerns, the local operations and management departments of the state government have commissioned studies intended to gauge the risks to the transportation infrastructure and steps that can be taken to alleviate the effects of a variety of stressors. Among the plans to solve the issue are initiatives to repair roadways and traffic signals to operate better in times of heavy traffic and extreme weather. These initiatives involve evaluating planned and on-demand circumstances affecting conditions on the transportation routes. Planned circumstances are routine and include preventative measures while on-demand circumstances involve reactive or corrective steps that can be taken.
The two cases relate to my hometown (Pittsburgh, PA) because of our continuing concerns about water levels, traffic, and use of waterways at the confluence of the three rivers (Allegheny, Monongahela, and Ohio rivers). The three rivers of Pittsburgh provide transportation routes for cargo and passengers, are the sources of drinking water for Western Pennsylvania residents and others, and pose a risk to homes, businesses, and roadways along the rivers. Dams and locks along the rivers have provided a measure of security for residents who seek riverfront living and places to locate their businesses, but as is the case in Mozambique, those various structures have shown over the years to be insufficient to safeguard from the damage severe weather can inflict. Similarly, the erosion of land at or near the river banks is an on-going concern as higher water levels can compromise the integrity of the land nearest to the river; putting structures and roadways at risk of damage or making transportation routes impassable during a severe weather event.