Theofilos Toulkeridis

Universidad de las Fuerzas Armadas-ESPE | espe · Departamento de Ciencias de la Tierra y Construcción

Mahogany (Swietenia macrophylla King) is a species with great economic interest worldwide and is classified as vulnerable to extinction by the IUCN. Deforestation and climate change are the main hazards to this species. Therefore, it is vital to describe possible changes in distribution patterns under current and future climatic conditions, as they...

Solid waste management is a subject that still represents enormous challenges worldwide and therefore also in Ecuador. In the current study, we evaluated the environmental impacts generated by the management of solid urban waste (SUW) and the disposal in the an open waste dump of in Loreto, eastern Ecuador, regulated by the local government in orde...

The excess of salinity in soils affects a number of environments, such as soils, where excess of salts damages its structure, it repels water, and it affects also crop production. In order to study such phenomenon, while trying to counteract such problems, we have chosen to study a variety of soil profiles between the Simbocal dam and the Chone Mul...

The current study presents a methodology to monitor the behavior of embankments in addition to the development and implementation of an on-site settlementmeter in a given study area. This equipment is a portable system of easy installation, connection and operation that fulfills the specific function of monitor the vertical movement (settlement) of...

In the Portoviejo canton of the province of Manabí of coastal Ecuador, floods have historically occurred as a result of extreme rainfall events and the overflow of the Portoviejo River. Nowadays, hydrodynamic models constitute a tool that allows simulating the flow of water in hydrographic basins. The zones with the possibility of flooding at diffe...

The drinking water intake of the city of Guayaquil is located on the Daule River, supplying 2.7 million inhabitants who are affected by the turbidity of the water, even leading INERGAGUA to suspend the service with high economic losses. Given this, water erosion and the effects of land use were calculated using the Universal Soil Loss Equation (USL...

The conservation of Galapagos is a priority component in Ecuador's territorial planning and administration policy, because it is a world benchmark for biodiversity. It is also located in four different zones in the U.T.M representation (15 N, 15 S, 16 N, 16 S). In this sense, it is necessary to have a detailed and precise representation of this ter...

The development technology of Unmanned Aircraft Vehicles (UAV) allows the improvement of new applications and it may be used to obtain geo-spatial information with high precision. In this study we present the evaluation of an ortho-mosaic and a digital surface model (DSM), which both have been generated from information received by UAV flights. The...

The current research arose due to an oil spill in the Papallacta Sub-basin, in the Amazonian area of Ecuador. Hereby, we were based to implement a baseline of the corresponding waters and sediments by searching an effective and low-cost treatment for the removal of arsenic and heavy metals from the lagoon water matrix. First steps included the synt...

Hormones are a type of emerging contaminant that reach the aquatic environment through wastewater effluents and which wastewater treatment plants (WWTP) cannot eliminate. The objective of this article was to determine the best hormone abatement technique between algae and microalgae, rotating biological discs, organic adsorbents, and activated carb...

A large number of heavy metals are usually contained in mine-derived liquids, which could cause contamination of surrounding water sources. Due to the detrimental effects on the environment and health, conventional treatments have been employed to capture heavy metals in mining-polluted streams. This study shows the results of the operation of a bu...

The predominant aim of the current study was to evaluate the spatial dynamics of the riparian coverage of the area of influence of the Chambo River in the area of the river's source (middle-high basin), between 2500 and 3000 m.a.s.l. For its execution, Landsat 7 images from the year 2000, RapidEye from the year 2009, and Spot 6 from the year 2019 w...

The predominant aim of the current research has been to quantify and map the pattern of changes in land use coverage (LULC), using a variety of tools of geographic information systems. The study area comprises the southern zone of the Diversity and Life Zone (DLZ), located in the Yasuní Biosphere Reserve, within the western Amazonian lowland. The p...

The current study focused on the proposal of a comprehensive management system for domestic solid waste in the rural community of Río Blanco belonging to the indigenous Ecuadorian Kichwa nationality. In this community, the burning of domestic solid waste is the only management strategy commonly used, which has generated various environmental and he...

The global navigation satellite systems (GNSS) have become important in conjunction with the advancement of technology, in order to improve the accuracy of positioning and navigation on mobile devices. In the current project, a mobile application for navigation using the network transport of restricted test case modeling (RTCM) via internet protoco...

The global COVID-19 pandemic has shocked the world. Since the virus gave rise to health problems and often ended in deaths, the count of the contagion and the deceased has been an open issue. Such statistics are vital for every nation and even every city or district and suburb as these numbers decide the level of intervention and the subsequent red...

In the high altitude (>3000 m asl) grasslands of northern Ecuador, the Páramo ecosystem, soils generally formed on recent volcanic ashes being <10,000 years old in the northern and central part of the cordilleras. With time these soils evolved in to non-allophanic Andisols with hydric properties such as evidenced in profiles from the Cajas massif l...

In this contribution we report the first systematic study of zircon U-Pb geochronology and δ18O-εHf(t) isotope geochemistry from ten islands of the hot-spot related Galapagos Archipelago. The data extracted from the zircons allow them to be grouped into three types: 1) young zircons (0 – ~4 Ma) with εHf(t) (~5 – 13) and δ18O (~4 – 7) isotopic mantl...

Illegal gold mining is on the rise in the tropical Andes. The Santiago-Cayapas watershed is located in the north of the Pacific basin of Ecuador, in the Chocó biogeographical region It is recognized for its high biodiversity, as 62 fish species have been described in the area, and because it contains two of the largest protected areas in the Pacifi...

The current study is based on the analysis and adaptation of a Federal Emergency Management Agency guide, FEMA P-1000, from the USA to improve school safety against natural hazards by applying the guide to the infrastructure of Ecuadorian schools, focusing primarily on seismic risk. By considering the technical foundations of structuring and managi...

The current study presents the evaluation of the mechanical behavior of an asphalt mixture using the alternative aggregate boiler coke ash, an element that originates in nickel processing. Hereby, we have focused the research on the runways for military purposes, which marks a great difference to the existing commercial runways in the Western Brazi...

Understanding physical phenomena such as blast shock waves produced by controlled explosions are relevant for issues appearing in the fields of military and civilian activities. The current study analyzes detonations of cylindrical and 3D cone-shaped charges through experimental trials and numerical simulations. In order to accomplish such goals, t...

The increase in livestock production in the Ecuadorian Amazon Region has caused an increase in deforestation and the advance of the agricultural frontier. The aim of the current study was to conduct a socioeconomic and productive characterization in Andean-Amazonian livestock systems in Ecuador. The study area was part of the Sumaco Biosphere Reser...

There are a number of unusual tsunamis, which occur within the continents rather than in the oceans, named inland tsunamis. One of these rare occasions occurred in the morning of the Friday the 13th October 2000 in a volcanic glacial lake of the horseshoe shaped extinct El Altar volcano in central Ecuador. A detailed mapping of available air photos...

The city of Chone, being situated on the Ecuadorian coast, was affected due to the close-by epicenter of the earthquake of 16 April 2016, which reached a magnitude of Mw 7.8. This catastrophic event presented settlements in the ground, sand boils and land subsidence, being the most damaging in a variety of civil works among these several buildings....

The dyeing processes of the textile industry generate waste products such as unfixed dyes, phenolic surfactants and heavy metals. These constitute an environmental problem for the bodies receiving their wastewater due to the interruption of the lighting in the aquatic environment and the release of toxic molecules by the decomposition of the dyes....

Currently, DEMs are inputs in multiple geoscience applications. Ecuador presents three regions with topographic characteristics that influence the performance of the DEM on altimetric precision. The main objective has been to analyze the precision of five global models and the official local model of the country, using GPS points to determine the l...

Personal care products (PCPs) enter wastewater primarily through greywater. Treatment plants have not been able to remove this type of contaminant, although PCP abatement techniques have been developed in recent years. The objective of the current study has been to encounter the sustainable technique that keeps the optimal balance between the crite...

One of the main factors of air contamination within urban areas is burning gasoline by cars, light trucks and motorcycles. Gasoline burning liberates pollution gases such as Nitrogen dioxide, Sulfur dioxide, Carbon monoxide, benzene, besides others. Among these, Nitrogen dioxide (NOx) is the one that stands out for the people’s awareness of such co...

The predominant aim of the current study was to synthesize the nanofertilizer nanoparti-cles ZnO_MnO-NPs and FeO_ZnO-NPs using Andean blueberry extract and determine the effect of NPs in the growth promotion of cabbage (Brassica oleracea var. capitata) and Andean lupin (Lupinus mutabilis sweet) crops. The nanoparticles were analyzed by visible spec...

METHs are drugs that enter wastewater through the feces and urine of users. Conventional wastewater treatment plants are not capable of removing this type of emerging contaminant, but, in recent years, techniques have been developed to abate drugs of abuse. The present investigation focused on obtaining the technique that keeps the best balance bet...

Combatir la actividad criminal representa un desafió para el sistema de seguridad. El perfil geográfico permite ubicar, con un grado de pertenencia, la zona más probable donde se pueda encontrar un agresor. Sin embargo, actualmente se carece de una metodología definida o estandarizada. El sistema de información geográfica (SIG) es una poderosa herr...

The network of lava tubes is one of the most unexploited natural wonders of the Galapagos Islands. Here, we provide the first morphological, mineralogical, and biogeochemical assessment of speleothems from volcanic caves of the Galapagos to understand their structure, composition, and origin, as well as to identify organic molecules preserved in sp...

Cemeteries are a source of environmental contamination, as they hold hundreds of human corpses in different stages of decomposition. Therefore, the current research developed a new tool, which is easily applied, to determine the potential environmental contamination generated by current cemeteries within their ecosystems. The linear equations devel...

The current study describes the development and evaluation of hollow concrete blocks using recycled polymers and a waterproof, resistance improver nanoadditive together with cement, sand, and pumice to search for an ecological building material capable of reducing the environmental pollution. Three phases were performed; in which the first, we char...

The Sustainable Development Goals (SDG) of 2015 identify poverty, growth, and inequality as three key areas of intervention towards the UN 2030 Agenda for human well-being and sustainability. Herein, the predominant objectives are: (a) To determine the poverty groups by quintiles through the cattle income in households of small milk producers; (b)...

Determining the altitude of mountains is one of the most fundamental challenges for humankind. Therefore, the main objective of the study is to determine the altitudes of the three main summits in Ecuador through GNSS positioning, referring to the official vertical datum of Ecuador and the geopotential surface (Wo). The three peaks are active volca...

The city of Portoviejo in coastal Ecuador was severely affected during the April 16, 2016, Pedernales earthquake (Mw 7.8). Various co-seismic liquefaction phenomena occurred, inducing lateral spreading, sand boils, ground subsidence, and sinkholes in soils with poor geotechnical quality in the alluvial and alluvial–colluvial sedimentary environment...

The Hunga Tonga-Hunga Ha'apai submarine volcano erupted on Saturday 15, 2022 leading to a VEI 5 eruption at 17.27 local time, shaking the earth with a M5.8. As result of this explosion a tsunami was triggered. The reasons of the tsunami may have been by a complex magma-water interaction or by repeated submarine mass movements. However, this tsunami...

In Yunguilla, in the northern part of Ecuador, a study of sustainable development has been conducted based on economic thinking and focused on the three conceptual dimensions, being economic, social and environmental. With this base, its scope was delimited and its drawbacks identified. We considered factors such as the availability of resources, t...

The current study presents a design and implementation of a prediction model that prevents phishing attacks on emails using data mining techniques. Hereby, we collected appropriate data sets in order to identify the characteristics of the infected emails, which allow a phishing attack to be successful from three significant sources, being Monkey.or...

The global COVID-19 pandemic has shocked the world. Since the virus gave rise to health problems and often ended in deaths, the count of the contagion and the deceased has been an open issue. Such statistics are vital for every nation and even every city or district and suburb as these numbers decide the level of intervention and the subsequent red...

The main aim of the current research has been to quantify and map the pattern of changes in land use coverage (LULC), using free data. The study area has been the northern area of the Diversity and Life Strip, located in the Yasuní Biosphere Reserve, considered to be a biodiversity hotspot. The processes performed in order to apply LULC on the Dive...

Landslides are the most recurrent natural hazards in the Metropolitan District of Quito (DMQ), affecting sometimes lives but extremely frequently and severely the traffic and associated infrastructure. The present research proposes the calculation of the landslide susceptibility cartographic model in the city of Quito and its main highway, the Simó...

The Cotopaxi Volcano is one of the most dangerous volcanoes world- wide due to its potential of the generation of voluminous lahars of dozens of mil- lions of cubic meters capable of destroying infrastructure and endangering a lot of people living near major river drainages of this volcano. Our study describes such circumstances in the northern sid...

Cemeteries are sites for the final disposal of human bodies that constitute a source of contamination of soil and water as a result of the cadaveric decomposition generated. The current research performed an initial study on the contamination of soil and water due to the influence of cemeteries and verified compliance with the legislation regulatin...

The current study is about the elaboration of concrete mortars composed of recycled sanitary ceramic waste, cement, silica gel in different percentages and sizes, with the purpose of reducing environmental pollution by creating an ecological material for the construction industry. Therefore, two phases were performed, which consisted of a bibliogra...

Due to the increasing population growth and subsequently the number of corpses, it is fundamental to consider the degree of pollution of the cemeteries. Otherwise, the cemeteries become sources of pollution, inasmuch as they are their final separation and contaminants can infiltrate the soil and affect water sources. This research identifies enviro...

In the coastal area of Ecuador and especially in the Province of Manabí, there are permanent floods due to the high winter rainfall in that area, generating a permanent risk for the population. In the present work, by means of hydraulic modeling with the HEC-Ras software and a detailed hydrological study of the upper and middle zone of the Portovie...

In the city of Ibarra, comprehensive scientific studies are limited to those that are analyzed in the territory from the physical point of view. Based on the problem of expansion due to population growth, this study analyzes the physical variables of the soil based on the photo-interpretation of the geoforms, which is the basic unit of analysis. Th...

This research zonifies territorial inequalities in Latacunga (Ecuador), considered one of the cities with high global vulnerability to risks due to its geo-graphic location. Based on the information generated by the former Ecuadorian Space Institute, through the project “Generation of geospatial information at a scale of 1: 5 000 for the determinat...

The city of Esmeraldas exposes several vulnerabilities to natural disasters, health deficiencies, as well as inaccessibility to basic services and education. Therefore, it appears the need to identify the relationships between its socio-economic status and the corresponding territorial conditions. The current study aims to identify spatial relation...

The current study has been performed in the San José de Chilibulo suburb in the south of the Metropolitan District of Quito, which aimed to zone the subsidence through the geological mapping of the Quaternary units combined with the subsurface studies, in order to elaborate a conceptual model that explains the dynamics of the area. In the sector, t...

The current study analyzed the effects of adding silica gel absorbent water in concrete, performing a verification of performance of the mixture according to the compressive strength and bending. An initial pattern mix has been developed and used as a basis for the development of different mixtures, adding an additive silica gel in various concentr...

Fighting criminal activity represents a challenge for the security system. The Geographic Profile allows locating with a degree of belonging the most probable area where an aggressor can be found. However, a defined or standardized methodology is currently lacking. The geographic information system (GIS) is a powerful tool for analysis and decision...

Geospatial technologies are presented as an alternative for the monitoring and control of crops, as demonstrated through the analysis of spectral responses (SR) of each species. In this study, it was intended to determine the effects of the application of nanonutrients (Zn and Mn) in cabbage (Brassica oleracea var. capitate L.) by analyzing the rel...

The Amazon Region of Ecuador (ARE) hosts a great variety of biodiversity and ecosystems. These hotspots are internationally recognized for presenting unique fauna and flora found nowhere else in the world. Within the ARE, there is the Yasuní National Park (YNP), a recognized Biosphere Reserve located in the sub-basins of various rivers. The study a...

There are hundreds of volcanic lakes around the world that represent an important hazard due to the potential occurrence of phreatomagmatic or limnic eruptions. Variations in geochemical and geophysical parameters could help to identify potential risks for these events. Cuicocha and Quilota volcanic lakes, located at the North Andean Volcanic Zone...

The current study is a pioneer work of an improved technical risk assessment, where alternative solutions are proposed of how lives may be better saved during a potential tsunami impact in the coastal cities of Manta and Salinas in the central coast of Ecuador. As Ecuador has been already the target of several tsunamis during recorded history, furt...

We validated the GPS leveling as an alternative to the traditional geometric leveling method. Validation compares the geometric slopes derived from the GNSS positioning technique, heights resulting from geometric leveling campaigns and geoid undulations extracted from the Global Geopotential Model EGM08. This analysis was performed in the Ecuadoria...