The so-called El Trébol is a critical road interchange in Quito connecting the north and south regions of the city. In addition, it connects Quito with the highly populated Los Chillos Valley, one of the most traveled zones in the Ecuadorian capital. El Trébol was constructed in the late 1960s in order to resolve the traffic jams of the capital city and for that purpose the Machángara River was rerouted through an underground concrete box tunnel. In March 2008, the tunnel contained a high amount of discarded furniture that had been impacting the top portion of the tunnel, compromising the structural integrity. On 31 March 2008 after a heavy rainfall a sinkhole of great proportions formed in the Trébol traffic hub. In the first few minutes, the sinkhole reached an initial diameter of 30 m. The collapse continued to grow in the following days until the final dimensions of 120 m in diameter and some 40 m of depth, revealing the Machángara River at the base of the sinkhole.A state of emergency was declared. The cause of the sinkhole was a result of the lack of monitoring of the older subterranean infrastructure where trash had accumulated and damaged the concrete tunnel that channelized the Machángara River until it was worn away for a length of some 20 m, leaving behind the sinkhole and the fear of recurrence in populated areas.With the intent to understand the causes and consequences of this sinkhole event, rainfall data are shown together with hydrogeological characteristics and a view back to the recent history of sinkhole lineation or arrangement of the city of Quito. The economic impact is also emphasized, where the direct costs of the damage and the reconstruction are presented and compared to indirect costs associated with this socio-natural disaster. These analyses suggest that the costs of indirect financial damage, like time loss or delay, and subsequent higher expenses for different types of vehicles, are equivalent to many times the costs of the reconstruction of El Trébol.

Air pollution is one of the hazardous effects of urbanization. Hereby, one the most polluted cities in Ecuador is the Metropolitan District of Quito (DMQ). This study attempts to determine the marginal willingness to pay for a cleaner air in the DMQ using the impact of air pollutants on price properties. Spatial interpolation techniques visualized pollutant concentrations in the DMQ. Additionally, a hedonic price model estimated air pollution impact on properties. Results demonstrated hazard levels for at least three pollutants, being Particulate Matter PM _2.5 , Nitrogen Dioxide NO ₂ , and Sulfur Dioxide SO ₂ . Subsequently, the economic impact on the house market was statistically significant with a decrease in property value between 1.1% and 2.8%. These drop of value between 1,846.20 up to 4,984.74 US$ (United States Dollars) represents a substantial loss in property value for the DMQ and loss of revenues for the city.

The recent awakening of the Cotopaxi volcano in Ecuador set the conditions to estimate and verify the possible effects of potential lahars on residential housing unit prices. About 300,000 people live in the Los Chillos valley, which is the northern natural drainage of Cotopaxi’s lahars; therefore, the effects on house values can be significant. We have used housing information from 2016 of 240 properties to settle a hedonic price model within and outside of the lahar’s area. The regression model has a significant R² value of about 0.723. The variable that determined the effects of potential lahar on the hedonic model demonstrates that the value of a residence house unit will increase its price by 41.99 USD for each meter away from the lahar path. Our study suggests that environmental disamenities generated by natural hazards will have a negative effect on residential house unit prices and we infer that consumers would be willing to pay a higher price in order to avoid such potential disamenities.

Better knowledge of solar energy potential helps to further exploit this renewable resource. Our study consisted the estimation of the solar energy potential incident in Ecuador applying the mathematical model of Angstrom, using information available from 27 meteorological stations in the period of 2004 to 2014. The data obtained from the stations recorded heliofany, of which the analysis has been performed in two ways, being by region and by altitude. As the average value of the estimated solar energy potential for the 2004-2014 series has been 4,378 (kW - h/m ² day). The highest solar radiation estimated in the country occurred in the Highland region, due to its Altitude. There, the solar rays that incur in the surface are less distorted by ozone, cloudiness or other atmospheric gases, allowing the total solar radiation to be higher.