Extreme weather 

Damage caused by extreme weather events during 2009 and 2010 in Central America mean that climate change is now a high-level policy priority, especially for the government of El Salvador. The President of El Salvador, last year on July 20th, in an extraordinary meeting of presidents that was convened in San Salvador, launched the intervention process. Climate Change was put as the number one issue for the region. The government of El Salvador's position, which mirrors that of other Central American countries like Nicaragua, Guatemala, and Honduras, is due to the fact that anthropogenic (human caused) climate change is impacting the planet more than ever, and scientists expect it to worsen. El Salvador, has been dramatically affected by severe weather events including extreme rain events and flooding from tropical storms and hurricanes that are increasing in both frequency and intensity. Congressman Valencia is also calling for all institutions of the government to incorporate their policies and laws towards addressing issues of adaptation to climate change so that government resources can be invested into the functions of adapting. In Central America, there is a very close linkage between climate change and security. If These problems are not addressed and not seriously put into action, the losses, the diversion of resources simply to attend to emergencies, will become so large that these countries won’t have any resources to invest in health, education, and so on.

http://www.aljazeera.com/indepth/features/2011/03/201132141536987194.html
http://cdkn.org/project/el-salvador-national-climate-change-strategy/

Sinkholes

Every website I searched for sinkholes in El Salvador, the feed was all about Guatemala. I found this article which is somewhat connected to El Salvador. Sinkholes are natural depressions that can form when water-saturated soil and other particles become too heavy and cause rooks of existing voids in the soil to collapse. A storm sewer may have been slowly saturating the surrounding soil for a long time before tropical storm Agatha added to the inundation. Honduras and El Salvador were other countries affected by this storm taking the death toll to over 175.

This is the sinkhole in Guatemala caused by the storm that also affected El Salvador. 

http://prasoondiwakar.com/wordpress/news/hole-in-the-earth-guatemala-sinkhole

Landslides

Rainfalls and earthquakes have shown to be important triggers for landslides in El Salvador. The combination of these factors are critical in trigger thresholds and in controlling mechanisms. On January 13 and February 13 of the year 2001, the earthquakes that happened in El Salvador left around 1,000 death due to the landslides induced. The landslides induced during these events were associated with susceptible slopes highly intervened by anthropogenic activities. Rainfall intensity and earthquake magnitude alone doens't reflect the effects on landslide characteristics. Slop susceptibility also controls both spatial and temporal distribution of slides. Slope susceptibility to failure is what influences landslide characteristics.Material related to landslides in El Salvador is volcanic and residual soils. Natural slopes in volcanic soils are commonly nearly vertical and can reach several meter in height. Earthquake and rainfall landslides in El Salvador start as disrupted slides and falls in residual, alluvial, volcanic-ash, and volcanic-rock deposits. El Salvador is regularly affected by extreme natural events such as flooding, landslides, earthquakes, and volcanic eruptions. There is reconstruction and disaster prevention in El Salvador. This includes measures taken to protect infrastructure, measures for organizational development and training and equipping village emergency committees. They have reduced their vulnerability to threats caused by extreme natural phenomena such as flooding and landslides. 

References: 

• http://dc.engconfintl.org/cgi/viewcontent.cgi?article=1026&context=geohazards
• https://www.giz.de/en/worldwide/21495.html