GIS integration for spatial analysis of urban expansion in Tisaleo canton (Ecuador).

Spatial analysis

Spatial analysis, emerging since the 1950s and 1970s, addresses the need to examine temporal and spatial data, overcoming limitations in data sourcing and representation (Goodchild, 2005). This field, also known as cartographic modelling, involves interactive operations and commands that use maps for spatial decisions, focusing on processes. It reveals geographical structures and analyses formative processes, using concepts such as distance and spatial interaction (Pumain, 2004). Geographic space, according to Pulgarín (2007), is the living framework of an organism, while Castañeda (1997) defines it as the interaction between nature and society, differentiating into urban and rural contexts.

Scale

Spatial measurement scales are a long-standing problem in spatial analysis; more details are available in the modifiable area unit (MAUP) topic. Landscape ecologists have developed a number of scale-invariant metrics for ecological aspects of fractal properties. More generally, scale-independent approaches to spatial statistical analysis are not widely accepted.

Spatial sampling

Spatial sampling allows the identification of a limited number of localities in geographic space to faithfully measure phenomena affected by dependencies and heterogeneity. Dependencies show that, given a location, the value of different locations can be predicted, which does not require observations at both locations. Heterogeneity suggests that the relationship may vary spatially, making it impossible to rely on any degree of dependence outside what may be a small area. Basic spatial sampling schemes include the following modes: random, cluster, and system.

Depending on a given spatial hierarchy (e.g., urban area, city, neighborhood), these basic schemes can be applied at multiple levels. Secondary data, such as the use of property values as a guide in spatial sampling schemes, can also be leveraged to measure educational attainment and income. Spatial models, such as autocorrelation statistics, regression, and interpolation, can also determine sample designs.

Geographic information systems (GIS)

The perspectives of the definition of GIS, depends on its functionality, for the purposes of this study, we take the ability of these systems to create digital models of reality with the use of tools as discipline provides for these purposes.

According to the National Center for Geographic Information and Analysis (NCGIA) of USA, 1990, taken by Del Bosque et al. in 2012, GIS is a System composed of hardware, software and procedures for the capture, management, manipulation, analysis, modeling and representation of georeferenced data, with the objective of solving complex planning and management problems (Del Bosque González, Fernández Freire, Martín-Forero & Pérez, 2012).

GIS can be confused depending on essentially different issues, since the same acronym is used for discipline, project or software. The term GIS software corresponds to the program or set of programs that make it possible to develop the discipline and implement GIS projects, thus we speak of proprietary GIS Software, Free GIS of one or another commercial house (Del Bosque González, Fernández Freire, Martín-Forero & Pérez, 2012).

Situation analysis of the canton Tisaleo

The canton of Tisaleo, according to its current Development and Land Use Plan, referred to the period 2019-2023, is a settlement that dates back more than 4 centuries with the name of San Miguel de Tisaleo, characterized until today by its fertile soil and agricultural vocation, in 1858 it was recognized as a civil parish and was elevated to canton on November 17, 1987. Tisaleo is located on the slopes of the Carihuairazo volcano, and at its eastern end is dissected by the crossing of the Pan-American Highway and the Camino Real, recognized as the old Inca Trail. It has an area of 59.64 km². Its boundaries are: to the north with the canton of Ambato, to the south with the canton of Mocha, to the east with the cantons of Ambato, Cevallos and Quero and to the west with the canton of Ambato (Figure 1).

Figure 1. Tisaleo canton limits (based on data from IGM, 2022; MAE, 2020).

Tisaleo as a canton is divided into 2 parishes: Tisaleo and Quinchicoto; which in turn contains 15 hamlets: Alobamba, Chilco la Esperanza, El Calvario, La Unión, Quinchicoto Alto, San Diego, San Francisco, San Juan, San Luis, San Vicente, Santa Lucía Arriba, Santa Lucia Centro, Santa Lucia la Libertad, Santa Marianita and a large area designated as the Chimborazo Fauna Production Reserve (Figure 2).

Figure 2. Division of the canton Tisaleo (based on data from IGM, 2022; MAE, 2020).

According to Article 241 of the Constitution of the Republic of Ecuador (2008), decentralized autonomous governments are obliged to plan their land use and management, while Articles 41 and 48 of the Organic Code of Planning and Public Finance explain that development and land use plans are instruments for strategic development decisions in the territory and their development and land use plans must be updated at the beginning of each administration.

Another tool that regulates territorial planning in Ecuador is the Land Use and Management Plan, according to Article 27 of the Ley Orgánica de Uso y Gestión del Suelo (2016): “In addition to the Organic Code of Planning and Public Finance, municipal and metropolitan decentralized autonomous governments will have a land use and management plan, which will incorporate structural and urban components”.

Thus, the municipal and metropolitan Decentralized Autonomous Governments have provisions and guidelines on the control and use of both urban and rural territory; in this way the Municipal Decentralized Autonomous Government of Tisaleo in 2019 and 2020 carried out the administrative processes for the update of its Development and Land Management Plan and its Land Use and Management Plan.

In this sense, the Autonomous Decentralized Municipal Government of Tisaleo has defined its land in 2 main categories in compliance with the current legal and technical regulations issued by the Superintendence of Land Use and Land Management, as shown in Figure 3.

Figure 3. Current urban boundary (based on data from GAD Municipal de Tisaleo, 2020).

The urban boundary defined in the Development and Land Management Plan for the period 2014-2019 and in the Land Use and Management Plan for the period 2020-2032, contains an area of 132.32 Hectares, which represents 2.22% of the total cantonal area. A priori in map 3 above, one can observe the presence of agricultural land that is still within the urban area defined since 2014.

However, according to the studies that preceded this research, not all the urban area has all the services of the public system such as water, sewage or electricity, it is still worth noting that the percentage of occupation barely reaches the average of 20.74% covering the category of occupation in “formation” (Figure 4).

Figure 4. Current urban boundary Quinchicoto (based on data from GAD Municipal de Tisaleo, 2020).

Similarly, the urban area of the parish of Quinchicoto was defined in the Development and Land Use and Management Plan for the period 2014-2019 and in the Land Use and Management Plan for the period 2020-2032, and covers an area of 25.95 hectares, which represents 0.44% of the total area of the canton. According to the Land Use and Management Plan for the period 2020-2032, the current occupation of Quinchicoto is 12.97%, i.e. the urban settlement is still in its infancy (GAD Municipal de Tisaleo, 2020).

Analysis of urban growth in Tisaleo Canton

According to the Land Use and Management Plan in force for the canton of Tisaleo, two specific areas are defined as urban; Tisaleo as a city and the head of the parish Quinchicoto, which, according to the analysis of the Plan, the two do not exceed 25% of occupation, that is to say that they are still in formation.

For the same reason, the question arises as to how this urban growth has been developing. For the purposes of this research, we used current and existing tools such as satellite images of the years 2005, 2012 and 2020 (Figure 5, Google Earth, 2024).

Figure 5. Urban growth in the canton of Tisaleo (as from Google Earth, 2024).

If we analyze the percentage of growth based on the current urban limit, we obtain the following results: Table 1

The current urban boundary in relation to the urban area digitized in 2020, is oversized by 487% more than what reality indicates (Table 1), defined in relation to the concentration of housing that has been established since the base year which is 2005, this analysis is made in relation to the ordinance that defines the urban boundary does not match reality (Figure 6).

Figure 6. Current urban boundary Tisaleo (based on data from GAD Municipal de Tisaleo, 2020).

In the case of Quinchicoto, something similar happens, but due to the resolution of the satellite images and cloud coverage, it is not possible to homologate the process, in this sense, within the PUGS in force in the Gad Municipal de Tisaleo (2021).

Human settlements

The Organic Law of Land Management, Land Use and Management in its fourth article issues the definition on a populated settlement and other territorial organizations; in this sense if the city and a populated settlement are related, this differs in that a city contains the necessary and ordered goods and services to generate the economic, political, social and cultural development of its citizens, and a settlement itself is a conglomerate of settlers who settle in a concentrated or dispersed way on a space or territory (LOOTUGS, 2018).

The organization of the populated settlements in the canton of Tisaleo, the subject of this study, are not differentiated, that is, according to the Development and Land Management Plan and the Land Use and Management Plan, there are currently 69 population centers, which according to data collected for this research are known as: “hamlets, sectors, communes or other names” (GAD Municipal de Tisaleo, 2020). With this background, it is concluded that the differentiation, delimitation or conceptualization of what can be considered as a city (urban) or populated settlement (urban or rural) cannot be defined by a law or manual, but rather with the individualized treatment of each territory of each canton, due to the exclusivity of the municipalities in defining the classification between urban and rural.

Erroneously, as reviewed in previous sections, the urban limits of Tisaleo and its rural parish of Quinchicoto are oversized, including agricultural and livestock areas without any housing use, and other sectors such as Alobamba, are still defined as rural, having a greater use and concentration of housing, goods, services and equipment than the parish of Quinchicoto (Figure 13).

Figure 13. Urban - rural settlement comparison (as from GAD Municipal de Tisaleo, 2020).

Public support system

The delimitation between urban and rural, under current regulations to generate a Land Use and Management Plan, are mainly the following variables: road network and transportation, water for human consumption, sewage, electric service, parks and squares, health facilities, education, social welfare, recreation and sports, security, and public administration. In this sense, for the purposes of this research, each of these factors was analyzed separately, as these are the ones that would delimit the urban expansion zones in the short, medium and long term.

Regarding the road and transportation network, it converges in the characterization of the cantonal road network that can be differentiated by some indicators such as: annual average daily traffic, roughness, roadway, condition, width, works of art, among others; however, for the purposes of this study, the hierarchy, coverage of the road network, transportation routes and their equipment are analyzed; these characteristics are a vital part as a component of the urban development of a town, canton or country. The cantonal road network has a total length of 302.53 km and is composed of five types of roads: cobblestone, asphalt, concrete, stone and dirt. Dirt roads predominate with 165.78 km, representing 54.80%, followed by asphalt roads with a length of 91.01 km, representing 30.08%, and only 2% are cobblestone roads. Figure 15 shows where asphalt and cobblestone roads are concentrated, areas that are new for building new housing or plans (GAD Municipal de Tisaleo, 2020). Traffic and transportation management in the province of Tungurahua for the cantons of Baños, Cevallos, Mocha, Patate, Pelileo, Pillaro, Quero and Tisaleo, generate their own traffic and transportation plan, where they define a hierarchy of their roads as follows (Figures 14 & 15):

Figure 14. Road network of Tungurahua province (as from Gad Municipal de Tisaleo, 2020).

Figure 15. Density of asphalt and paved roads (based on data from Gad Municipal de Tisaleo, 2020).

Tisaleo is connected by the Panamerican Highway E35 and articulated by secondary roads that connect with the cantons of Ambato, Cevallos and Mocha, and a countless number of third order roads that are paved and/or dirt roads. In terms of mobility, the Panamerican Highway and the secondary roads are currently being used as nodal roads, where all the traffic of the third order roads converge and are progressively becoming overcrowded with vehicles due to the increase in the number of vehicles. Regarding public transportation routes, the presence of the Pan-American Highway and secondary roads, this service and the infrastructure of bus stops are concentrated in these 2 types of roads; and mixed cabs complement the transportation coverage at the level of the entire canton (Empresa Pública de Mancomunidad de Tránsito de Tungurahua, 2017).

A basic element that contributes to the growth of cities is the drinking water and sewerage service, in the case of Tisaleo, for these two elements of review, the existing information of the existing multifinalitarian cadastre in the Municipal GAD, having the following results:

At the cantonal level, the concentration of water and sewerage services coincides with the presence of asphalt and paved roads, i.e., when roads are increased, they go hand in hand with water and sewerage services. As can be seen in the following map (Figure 16).

Figure 16. Water and sewerage service coverage (based on data from Gad Municipal de Tisaleo, 2020).

The analysis was carried out with a universe of 16048 properties registered at the Head Office of Appraisals and Cadastre of the Municipal Government of Tisaleo, of which were selected based on the attributes of sewerage and water for human consumption; 52% of them have access to drinking water and 37% have sewerage; therefore, 37% have both water and sewerage.

Another important factor in determining the growth of urban areas is the provision of electricity service; since, in addition to water and sewage coverage and accessibility by roads and transportation, these are the basic services to encourage new construction of housing or commerce, in addition to biophysical and socioeconomic factors.

Electric power coverage covers 51.66% of the existing properties in the canton, and there is an electric substation with the same name (Tisaleo) located in the north of the canton, in the Chilco La Esperanza hamlet; this station is part of the 500 kV transmission system and connects the new Coca Codo Sinclair and Sopladora projects (Figure 17).

Figure 17. Electricity service coverage (based on data from Gad Municipal de Tisaleo, 2020).

Therefore, it is the detail of the above elements that can determine the territory’s capacity to provide for the construction of housing or urban facilities in the short, medium or long term, but it is also convenient to analyze the coverage of public or private urban services such as education, health, social welfare, recreation and sports, and security.

To analyze the coverage of social and public services and facilities (Table 3), coverage is measured using radii of influence, with neighborhood, sector, zone, city or regional scope, and for each of the services and facilities there is a corresponding radius described in the following Table 3:

The relationship between public and social service facilities and their coverage depends on the existing demand of the population, i.e., in Ecuador and Latin America the causality for the construction of social service facilities does not depend on medium or long term planning but rather on the needs of the population; i.e., the construction of streets, housing and basic services increases faster than the construction of public and social service facilities.

Socio-economic characterization:

In the last census of 2010 conducted by the Institute of Statistics and Census, it dates a number of 12,137 inhabitants, but for the year 2020 according to the same population growth data (1.80%) indicates a total of 14,317 settlers. Fifty-one percent of the population is female and 49% is male, and a quarter of the population is mostly young.

Tisaleo is an eminently agricultural canton, with agricultural activities distributed from the highest part with pastures for livestock, in the middle part with the production of short-cycle crops and in the lower part with fruit crops, taking advantage of its young economically active population, which represents 26.4% of the total EAP. According to data from its current cantonal development plan, 74.13% of its land has irrigation for its crops; as a result, agriculture and construction are the main sources of income for its inhabitants (GAD Municipal de Tisaleo, 2020).

Land fragmentation is recognized as a cause of decreased production capacity and yields, according to population data within their current plans as of the date of this research; on the other hand, an important problem is that 40% of the arable layer is worn and degraded. In terms of agroindustrial initiatives, there have been few initiatives to improve the added value of their products and to technify the areas that are still purely productive (GAD Municipal de Tisaleo, 2020).

Process of interrelation between structuring elements of urban expansion in the canton of Tisaleo.

Having described the elements that structure and determine urban growth in a generalized way, territories and their endogenous and exogenous characteristics differ greatly within each province, each country and continent; it is impossible to compare one canton with another. In this sense, for this research we define which are the most common structuring elements with easily accessible information, and the relationship that these elements have in order to later analyze these variables and better define urban limits and their expansions.

Knowing the information collected, its sources and scales are of vital importance to categorize it, weight it and evaluate whether or not it is feasible to use it within a spatial analysis with GIS software (Figure 18).

Figure 18. Interrelationship between structuring elements.

These three major groups contribute to the orderly urban growth of the canton of Tisaleo, but the degree of importance of these are very different, i.e. the causality between these parts from having a suitable biophysical area and out of natural risks in order to implement roads, services and equipment; for this reason these two major groups will be taken quantitatively, which are the biophysical structure and the public support system. In order to prioritize which of these factors has the greatest degree of intervention in urban expansion, a double-entry matrix was used, with the following evaluation criteria (Tables 4 & 5):

Once evaluated the importance between each variable, it coincides that, natural risk zones are considered as the most important factor that would determine urban growth, followed by hydrography and relief, in this way once a spatial analysis is performed will be the most suitable way the weighting of the variables and so that its value is the one that has the most interference in terms of planning an urban boundary and its growth.