Earthquake

The two major cyclones are cyclone of November (14-20) 1977 and May (3-11) 1990. These cyclones caused heavy loss of property, affected severely the telecommunications and power supply along with severe damage of various infrastructures. (USAID; UNDP, 2015). For lower return periods (5 to 50 years), lower wind speed extents are limited to areas over the western wards whereas the relatively higher wind speeds cover a large extent of the eastern part of Vijayawada.

Earthquake

Vijayawada city lies in Zone III which refers to moderate damage risk zone. The liquefaction during an earthquake may pose more significant risk, given the high groundwater table across this fertile region in coastal district particularly in the Capital Region Development Area in Krishna and Guntur districts. The number of high liquefaction vulnerable zones should be reduced by avoiding huge constructions and structures.

Figure 17.11: Andhra Pradesh state map showing seismic zone of Vijayawada There are around 22 seismic sources (faults) in and around Vijayawada within a radius of 300 km and among them, the prominent active fault is the Gundlakamma fault (The Earthquake Engineering Research Centre of IIIT). Since 1861 to 2015, more than 170 quakes/tremors with minor and medium incidents have occurred on the Richter scale in the range of 3-6 as shown in Table 1.3. Several areas to the south of the Krishna River near Mangalgiri, and east towards Poranki have been classified as hazardous.