Spatial Analysis of Accidental Oil Spills Using Heterogeneous Data: A Case Study from the North-Eastern Ecuadorian Amazon

Abstract

Accidental oil spills were assessed in the north-eastern Ecuadorian Amazon, a rich biodiversity and cultural heritage area. Institutional reports were used to estimate oil spill volumes over the period 2001–2011. However, we had to make with heterogeneous and incomplete data. After statistically discriminating well- and poorly-documented oil blocks, some spill factors were derived from the former to spatially allocate oil spills where fragmentary data were available. Spatial prediction accuracy was assessed using similarity metrics in a cross-validation approach. Results showed 464 spill events (42.2/year), accounting for 10,000.2 t of crude oil, equivalent to annual discharges of 909.1 (±SD = 1219.5) t. Total spill volumes increased by 54.8% when spill factors were used to perform allocation to poorly-documented blocks. Resulting maps displayed pollution ‘hotspots’ in Dayuma and Joya de Los Sachas, with the highest inputs averaging 13.8 t km−2 year−1. The accuracy of spatial prediction ranged from 32 to 97%, depending on the metric and the weight given to double-zeros. Simulated situations showed that estimation accuracy depends on variabilities in incident occurrences and in spill volumes per incident. Our method is suitable for mapping hazards and risks in sensitive ecosystems, particularly in areas where incomplete data hinder this process.

Estimating persistent oil contamination in tropical region using vegetation indices and random forest regression

“…Along with its development during the last century, oil and gas industry has become a major source of contamination in the environment (Barraza et al, 2018;Durango-Cordero et al, 2018;Ogri, 2001;Romero et al, 2017). Crude oil and by-products (e.g.…”

Landslide and Environmental Risk from Oil Spill due to the Rupture of SOTE and OCP Pipelines, San Rafael Falls, Amazon Basin, Ecuador

“…If this event constantly occurs, it could cause adverse damage to the benthic and epibentic organisms of the river [1], [55]- [57]. Similarly, in the section of the Quijos -Coca river basin through which the SOTE and OCP transfer lines pass, there is a lack of information that the state has inventoried the previous spills that have occurred due to the rupture of the SOTE transfer lines and OCP, which does not happen in the case of the environmental risks generated in the hydrocarbon activities [15], [58], [59]. The spills caused are inventoried by the Environmental and Social Repair Program PRAS, where it monitors the comprehensive repair plan of the Amazon district with a percentage of 39% compliance up to the year 2017.…”

“…Indeed, Ecuador is one of the countries in the world with the highest exposure to natural risks [10]- [13], particularly in protected areas that represent immense economic value to the world [6], [14], [15]. For instance, the factors that have caused damage to the abiotic, biotic and social components in the Ecuadorian Amazon are the contamination of rivers and estuaries (94.91% to the soil, 80.46% to the soil and animals and 95.71% to animals, soil and properties), pipeline spills (81.95% to soil, 70.18% to soil and animals, 87.14% to soil, animals and property), pool breakdown (65.05% to the ground, 55.57% to the ground and animals, 72.14% to the ground, animals and properties), seismic activity (46.25% to the soil, 37.77% to soil and animals, 65% to soil, animals and properties), oil facilities (51.46% soil, 43.27% soil and animals, 62.85% soil, animals and property), and road construction (30.24% to the ground, 25.18% to the ground and animals 30% to the ground, animals and properties) [16]- [19].…”

Estimation of Biogas Generated in Two Landfills in South-Central Ecuador

“…As a result of the degradation of organic waste in sanitary landfills, it gives rise to the production of biogas composed of methane gases CH 4 50-60%, carbon dioxide CO 2 40-50%, carbon monoxide CO traces, nitrogen N 2 2-3%, hydrogen sulfide H 2 S 1-2%, Hydrogen H 2 < 1, oxygen O 2 < 1, ammonia NH 3 traces, aromatic and cyclic hydrocarbons and volatile organic compounds [18][19][20][21]. CH 4 and CO 2 are the main components of biogas, and most of Ecuador's sanitary landfills lack a biogas recovery system, therefore, causes a serious problem for the environment.…”