The answer to this question will be dependent on the local factor, rather then being universal.
For example, a frequent problem in urban areas are flush flooding following heavy rains. These tend to be associated with over urbanisation, absence of green spaces, outdated drainage infrastructure, and climate change. This can be mitigated by increasing green areas, introducing 'green' or 'blue' roofs, implementing sustainable drainage systems that would capture, temporarily retain and delay the discharge of the rain water into the public drainage network and by doing so reduced the adverse impact associated with flush flooding.
Other example, may be related to the protection of flooding from rivers, etc. This can be done by building flooding defenses, implementing measures to protect existing buildings from flooding, taking into consideration the flood risk and build buildings above the flood risk level, or designing the new building with flood protection in mind.
Introducing parks with trees and water features can help manage carbon emission and pollution whilst moderating temperatures in the area, etc.
It is complex and depends on so many regional variables. But Generally, control of urban heat is the mechanism. for that, you may do several pecausions. Instance, increasing urban greenery is an adaptation and mitigation measure while using more renewable energy and using renewable materials for buildings are some mitigation measures. Most importantly, there are so many measures that can be accounted for because urban areas are one of the major indirect GHG emitters.
Aregbesola Busayo Gbemisola, Adaptation and mitigation mechanisms in urban areas often extended along and are interconnected. Examples include, (1). Climate resilient buildings, Energy Infrastructural Resilience etc.
(2) Climate Change Adaptation: such as flood management is a major one here. Others may include, Urban planning and Land Use. This will depend on the land use act in the region. Note that, all of these can be is as a result of the over population and increase in the population density, which leads to increase in energy consumption and so on.