To what extent can preparedness and planning lessen the effects of volcanic hazards?

Volcanic hazards have many effects that can be split into two catagories: those affecting people and those affecting the environment. Volcanoes can be made through both constructive and destructive fault lines, occuring when the tectonic plates collide, forcing with great energy the opposing plate up or down. In order to assess how preparedness and planning for volcanic hazards may reduce the consequences, it is important to note that many volcanoes occur in highly populated areas. Due to the rich and fertile volcanic soil often volcanoes occur in densely populated areas, such as the Philipines which has 53 active volcanoes and is also the location of the most densely populated city in the world, Manila. 

Detection and communication technology (mostly available in MEDCs) is a form of preparation that can dramatically reduce the death toll of volcanic explosions. In 2000 the eruption of Popocatepetl in Mexico was detected and over 550,000 were able to be evacuated. Evacuation from such hazards saves thousands of lives, however, infrastructures, homes and sanitation systems are still destroyed. The channelling of lava flows is a form of planing in order to reduce risk to life and settlements. These are very expensive schemes and would not necessarily withstand a violent eruption. Due to enormous scale and power of volcanic hazards it is nearly impossible to reduce the environmental impacts. Toxic fumes, such as sulphur dioxide, are released in many cases causing acid rain. Large scale plumes of gas can even contribute to global climate change. To conclude, preparedness and planning has the potential to decrease the death toll, however, the volcano's affect on the environment cannot be controlled.