One Ecosystem :
Research Article
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Corresponding author: Fernando Flores Vilchez (vilchez@hotmail.com)
Academic editor: Leena Karrasch
Received: 29 Mar 2022 | Accepted: 22 Jun 2022 | Published: 11 Jul 2022
© 2022 Armando Avalos Jiménez, Fernando Flores Vilchez, Montserrat Gómez Delgado, Francisco Aguilera Benavente, Oyolsi Nájera González
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Avalos Jiménez A, Flores Vilchez F, Gómez Delgado M, Aguilera Benavente F, Nájera González O (2022) Future urban growth scenarios and ecosystem services valuation in the Tepic-Xalisco Metropolitan area, Mexico. One Ecosystem 7: e84518. https://doi.org/10.3897/oneeco.7.e84518
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Currently, there is a need to establish new territorial planning instruments focused on sustainable development. The simulation of spatial scenarios is an essential tool to evaluate different alternatives for urban planning. The objective of this work was to explore future urban growth through the analysis of landscape patterns and the economic quantification of ecosystem services of three prospective scenarios, simulated towards the horizon year 2045. Each scenario was formulated, based on the application of different socioeconomic, political and environmental development strategies whose actions have a direct impact on land-use changes. The starting point was an urban growth simulation model, based on Cellular Automata with Markov Chains (CA-Markov), developed from previous work for the study area. Three scenarios were constructed with the intention of showing the spatial characteristics of three different alternatives of the evolution of future urban growth and through them, quantify the economic value and the consequences that would occur in the territory due to the effect of the different decisions taken. Landscape metrics were applied to detect the spatial processes and patterns of urban growth for each of the simulated scenarios and, finally, the costs of ecosystem services associated with the loss or gain of territory (that each of the different land covers and land uses would contribute) were quantified. The three simulated scenarios revealed that the Tepic-Xalisco Metropolitan Zone (MZ) will be in a process of urban coalescence in the next 30 years; and that the path designed to move towards an Industrialisation Scenario (ES2-IN) estimates economic losses of more than $31 million dollars per year for the ecosystem services associated particularly with the reduction of forest cover.
CA-Markov, spatial planning, landscape metrics, future scenarios, ecosystem services valuation
Urban areas in most developing countries in the world have been expanding at a very rapid pace (
In this sense, the simulation of spatial scenarios is an essential tool for evaluating different alternatives in urban planning. Urban planning through the use of scenarios refers to the process of creating multiple plausible futures that can be used as territorial planning tools with a focus on sustainable development (
Scenarios are not in themselves future predictions of urban growth (
The use of scenarios and the application of models to simulate those scenarios have been widely field-tested in some European countries (
Given these circumstances, it is evident that the decision-making process for territorial planning and the formulation of scenarios must move towards sustainable development. For this, it is necessary to evaluate, amongst other aspects, the ecological integrity of future scenarios; for example, by guaranteeing the ability of future generations to access ecosystem services (
The ecosystem services valuation (ESV) has become an important tool to quantify the benefits provided by natural resources (
In this same context, landscape metrics have taken great relevance in the urban environment due to their ability to analyse the structure and configuration of the landscape (
The objective of this work is to explore future urban growth through the analysis of landscape patterns and the economic quantification of ecosystem services in three prospective scenarios, simulated towards the 2045 horizon. Each scenario was formulated, based on the application of different socioeconomic, political and environmental development strategies whose actions have a direct impact on future urban land-use changes. The starting point was an urban growth simulation model, based on Cellular Automata with Markov Chains (CA-Markov). Three exploratory scenarios were built with the intention of showing three different alternatives for the evolution of future urban growth and its spatial characteristics. They were then evaluated using landscape metrics to compare the effects and consequences for each scenario and, finally, the changes occurred were economically quantified by linking the value of ecosystem services with the different land covers and land uses. The results obtained constitute a valuable source of information for decision-making when evaluating different land-use planning alternatives, as well as providing a first approximation of the economic value of the ecosystem services that subsist in the Tepic-Xalisco Metropolitan Zone (MZ). The methodology proposed in this paper is intended to be a contribution in the sense of evaluating the sustainability of prospective scenarios that can be replicated in the search for sustainable urban planning.
Fig.
Location and delimitation of the study area. Source: Our own elaboration using data from National Institute of Statistics and Geography of Mexico (“Instituto Nacional de Estadística y Geografía”, INEGI). Base map: LandSat Image 8 (OLI) 2015 of the United States Geological Survey (USGS), natural composition (Bands 432).
The settlements in the MZ date back to the 16th century, particularly Tepic (26), which was officially founded in 1532, with a concentric urban layout, based on a main square. In Mexico's colonial period (1960), the Guadalajara-Tepic-Mazatlán highway was built, producing new functions for the urban layout, as an obligatory communication route to the northern (Sinaloa) and southern (Jalisco) zones of the country. Therefore, Tepic City became the centre of attraction of its State, due to its housing and permanent employment services and also became a centre of supply and distribution of products, mainly agricultural and livestock products (
We started from the data obtained in previous works by
The urban growth simulation model was developed in previous works by
The core of the CA-Markov model was to obtain the Markov chains used to generate the Transition Probability Matrix (TPM), the Conditional Probability Image (CPI) and the Transition Area Matrix (TAM) for the land-use classes, all of which are necessary to design and configure the different scenarios to be simulated. The model used was built from the 1985-2000 land use mapping, to simulate urban growth towards 2015 and was subsequently validated by comparing it with the actual urban mapping of 2015 (30-year analysis period that was established as the time horizon).
The methodology followed for the simulation of scenarios, analysis of spatial processes and quantification of ecosystem services were established for the two stages described in Fig.
Three alternatives were formulated as the minimum options necessary for proper exploration and comparison of the different decisions implemented (
Ecological Conservation Scenario (SC1-EC). The environmental situation is considered to be of great importance through strict enforcement of environmental laws. In this scenario, Mexico’s economic situation is expected to strengthen, enabling greater federal support for programmes and actions aimed at environmental care and protection. Local strategies and public policies focus on the conservation of sites of scenic and ecological value, including forests and bodies of water (such as the Mololoa River), promoting the creation of biological corridors for wildlife activities, greater conservation of watercourses and bodies of water by protecting the rivers and run-offs that are part of the natural drainage system. Ecological restoration through the reforestation of areas of scenic value and the integration of the urban aspect into the natural landscape is promoted. Sustainable agricultural use is considered, maintaining the trend of change of the current stable agricultural surface, the real protection of protected natural areas is promoted, with a tendency towards the sustainable use of natural resources, limiting urban growth.
Industrialisation Scenario (SC2-IN). Strategies and public policies promote productive activities in areas of high industrial and agricultural production, with greater provision of equipment and urban infrastructure. The generation of industrial corridors is promoted and the territorial reserve is increased to intensify mining extractive activities. Environmental protection restrictions are eliminated, allowing uncontrolled exploitation of natural resources with imminent overexploitation of aquifers and bodies of water to supply industrial and agricultural activities. This scenario considers the intensive use of forests with considerable loss of surface area and, on the other hand, the increase in urban and industrial areas that are reflected in the replacement of secondary vegetation and agricultural areas by industrial and service activities.
Northern Bypass Scenario (SC3-NB). This scenario involves the expansion and improvement of the road structure through the construction of new communication routes, such as the Libramiento Norte Highway. In this scenario, the urban growth trend of recent years is maintained, giving continuity to environmental regulation without further investment in local environmental programmes. Urban growth continues with the trend registered in the last 30 years, displacing agricultural land and eliminating forest vegetation (
Each of the different policies and strategies considered above were assessed by the same panel of experts to form the Transition Area Allocation Matrix (TAAM) in Table
Transition Area Allocation Matrix (TAAM) for the design of the three future scenarios. Sign (+) Indicates increase; and, (-) Reflects reduction of surface area. Source. Own elaboration.
Land cover and land use classes |
Land use surface transition |
||||||||||||||
SC1-CE |
SC2-IN |
SC3-NB |
|||||||||||||
Cls-Urb |
Cls-Agri |
Cls-Water |
Cls-SecVeg |
Cls-For |
Cls-Urb |
Cls-Agri |
Cls-Water |
Cls-SecVeg |
Cls-For |
Cls-Urb |
Cls-Agri |
Cls-Water |
Cls-SecVeg |
Cls-For |
|
Cls-Urb |
0 |
0 |
0 |
0 |
0 |
+25% |
0 |
0 |
0 |
0 |
+10% |
0 |
0 |
0 |
0 |
Cls-Agri |
0 |
0 |
0 |
0 |
0 |
0 |
+10% |
0 |
0 |
0 |
0 |
+5% |
0 |
0 |
0 |
Cls-Water |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Cls-SecVeg |
0 |
0 |
0 |
-20% |
0 |
0 |
0 |
0 |
-15% |
0 |
0 |
0 |
0 |
-15% |
0 |
Cls-For |
0 |
0 |
0 |
0 |
+20% |
0 |
0 |
0 |
0 |
-20% |
0 |
0 |
0 |
0 |
0 |
The simulation for each of the three scenarios designed was developed through the execution of the Markov CA model using the starting data (TPM, CPI and TAM) and the Configured Matrix of Transition Areas (CMTA), which was obtained by combining two matrices: the Transition Area Matrix (TAM) containing the trend values of transition areas and the Transition Area Allocation Matrix (TAAM) elaborated from the values agreed upon by the panel of experts for each scenario designed.
In particular, the CMTA was constructed by converting the values of percent area change contained in the TAM into area quantity (number of pixels) with respect to the total area of the landscape and these values were then added to the TAAM of the trend model. The allocation of the number of areas established in the CMTA will indicate an increase or decrease in the surface area of each land cover and land use in the landscape, directly impacting the process of allocating the number of areas during the execution and allocation of pixels in the CA-Markov model, while, on the other hand, the CPI will determine the location of the change, leading to the generation of each of the scenarios proposed.
Landscape metrics were applied to evaluate and quantify the spatial characteristics of each simulated scenario through the analysis of patches or tessellations in the landscape mosaic (
A review of the literature identified the phases of: Diffusion (
The ESV was developed according to the proposal of
The estimation value was obtained through the ecosystem service value estimation function according to equation 1.
\(ESV = \displaystyle\sum_{i=1}^{n} CA_i UV\)
Where, ESV is the ecosystem service value, "CAi" is the class area in patch "i" expressed in ha, "n" the number of patches per class area and "UV" the unit value of the ecosystem service expressed in USD.
The process to estimate the value was developed through the direct association of the biome or global ecosystem with the type of land cover or land use present in the MZ. This estimate was obtained for the three simulated scenarios and for 2015; this year was used as a starting point for the comparison and evaluation of the changes in value between the different periods.
Table
Linkage of ecosystem services with land-cover and land-use classes present in the MZ. Source: *List of ecosystem services adapted from
Classification |
Ecosystem service |
Land cover and use of the ZM |
||||
Cls-Urb |
Cls-Agri |
Cls-Water |
Cls-SecVeg |
Cls-For |
||
Services of regulation |
Air quality regulation (1)* |
X |
||||
Climate regulation (2) |
X |
X |
||||
Regulation of disturbances (protection of natural hazards) (3) |
X |
|||||
Regulation of the water cycle (4) |
X |
X |
||||
Sewage and waste treatment (9) |
X |
X |
||||
Soil formation (7) |
||||||
Pollination (10) |
X |
|||||
Biological control (11) |
X |
|||||
Provisioning services |
Food production (13) |
X |
X |
|||
Water supply (5) |
X |
|||||
Raw Materials (14) |
X |
X |
||||
Genetic resources (15) |
X |
|||||
Medicinal resources (15) |
X |
X |
||||
Habitat services |
Refuge (12) |
X |
X |
X |
||
Nutrient cycle (8) |
X |
X |
||||
Erosion control and sediment retention (6) |
X |
X |
||||
Cultural services |
Recreation and ecotourism (16) |
X |
X |
X |
||
Cultural diversity (17) |
X |
Fig.
Future urban growth scenarios (year 2045) with respect to land cover and land use; a) Ecological Conservation Scenario (ES1-CE); b) Industrialisation Scenario (ES2-IN); c) Northern Bypass Scenario (ES3-LN). Note: Land-cover and land-use classes: Urban (Cls-Urb), Agricultural (Cls-Agri), Water bodies (Cls-Water), Secondary vegetation (Cls-SecVeg) and Forest (Cls-For). Source. Own elaboration.
Similarly, Fig.
Land-cover and land-use change to urban use 2015-2045. a) Ecological Conservation Scenario (ES1-CE); b) Industrialisation Scenario (ES2-IN); c) Northern Bypass Scenario (ES3-LN). Land-cover and land-use class: Urban (Cls-Urb), Agricultural (Cls-Agri), Water bodies (Cls-Water), Secondary vegetation (Cls-SecVeg) and Forest (Cls-For). Source. Own elaboration.
The evaluation of the simulated scenarios through the exploration of the processes and spatial patterns of urban growth was obtained with the application of the landscape metrics whose results were analysed with the standard index (standard z) estimated from the mean and standard deviation; a method used to bring the absolute values of the metrics obtained to the same unit of measurement and to enable them to be comparable for the purpose of analysing the composition of the different land-cover and land-use classes of the landscape with respect to each type of land cover and land use in 2015. Fig.
Standard value of metrics applied for land-cover and land-use class for each simulated scenario. Land-cover and land-use class: Urban (Cls-Urb), Agricultural (Cls-Agri), Water bodies (Cls-Water), Secondary vegetation (Cls-SecVeg) and Forest (Cls-For).
Source. Own elaboration with standardised values of landscape metrics.
The analysis of the applied landscape metrics suggests that the three simulated alternatives assume similar processes and spatial patterns of urban growth in the future, with only some variations in the amount of surface change. The values obtained indicate that the amount of "NP" for the urban land use class is reduced, with respect to 2015, revealing that the patches for urban land use will be in a process of Coalescence, where, specifically for urban use, the tesserae dispersed will become a conurbation with nearby localities, thus forming larger urban patches. This characteristic is similar for the other land-use classes and, when compared with respect to "AREA_MN", it is observed that "NP" decreases, while "AREA _MN" increases; due to this behaviour, it is inferred that there is a reduction in the degree of fragmentation of the landscape.
Together, the landscape metrics show that the "NP" decreases in comparison with the "ENN_MN" of the same land-use class where the latter increases at the same rate as the "AREA_MN". This corroborates that there is a pattern of aggregation for the urban use classes, particularly in the three simulated scenarios. In the case of the "SHAPE_MN" index, there is a decrease for urban and agricultural use in the three scenarios, which implies that, since there is an aggregation between patches, there is also a greater homogeneity in the shapes of the patches.
On the other hand, Table
Cost of ecosystem services as a function of the link to the global ecosystem. Source. Own elaboration.
Global ecosystem |
Equivalent ecosystem in the ZM |
Estimated value (USD / ha / year) |
Base value for 2015 (Millions of USD) |
Value of Scenarios to the year 2045 (Millions of USD) |
Net change 2015-2045 (Millions of USD) |
||||
SC1-EC |
SC2-IN |
SC3-BN |
SC1-EC |
SC2-IN |
SC3-BN |
||||
Urban systems |
Cls-Urb |
6.661 |
45.69 |
72.57 |
86.33 |
76.99 |
26.88 |
40.64 |
31.29 |
Farmland |
Cls-Agri |
5.567 |
121.66 |
147.82 |
106.65 |
113.18 |
26.16 |
-15.00 |
-847 |
Lakes / rivers |
Cls-Water |
12.512 |
1.81 |
1.61 |
1.60 |
1.61 |
-0.20 |
-0.21 |
-0.20 |
Grass / pasture |
Cls-Sec_Veg |
4.166 |
167.35 |
131.69 |
177.74 |
173.29 |
-35.66 |
10.39 |
5.94 |
Tropical forest |
Cls-For |
5.382 |
112.87 |
112.01 |
81.20 |
88.19 |
-0.86 |
-31.67 |
-24.67 |
Total |
35.689 |
449.38 |
465.71 |
453.53 |
453.27 |
16.33 |
4.15 |
3.89 |
The ESV is particularly affected by the loss of forest area, the base value of which is the highest and by 2045 a reduction of up to 60 km2 is quantified, which implies economic losses of almost $32 million dollars.
The joint application of the different tools used in this study to explore future scenarios and their evaluation through the application of metrics revealed that the MZ will be in a process of urban coalescence in the next 30 years, associated with a pattern of aggregates between urban land-use patches through the conurbation of the closest contiguous localities to the MZ, such as Pantanal (20) and San Cayetano (23) in a south-southeast direction (see Fig.
In the context of ESV determination, various methods have been applied in the scientific literature to value ecosystem services;
In this sense,
Each geographic region in the world is different and heterogeneous, with topography, climate and vegetation features that configure unique and varied ecosystems, in which determining the economic value can be subjective and depend on the geographic region in which they are found. The lack of information regarding the specific economic value for each ecosystem present in the study area implies a variation in the real economic quantification; however, it is necessary to have a first approach on the economic estimation of the ecosystem services of the MZ. In this sense, the recommendation for future research would be directed in two directions: the first one aimed at establishing an adaptation of the global ecosystem value equivalence coefficients for the study area, just as
The limitations of this study involve the considerations of the starting data, since the results will be biased depending on the degree of agreement between the classification of the different land-cover and land-use classes obtained, with the existing land uses (actual uses) impacting on the degree of fit (kappa index) of the simulation model and, therefore, on the level of certainty of the projected scenarios; moreover, the geographic scale and particularly the spatial resolution of analysis will impact the generation of landscape patterns and might modify the characteristics of the patches and the value of the landscape metrics.
In this sense, it is recognised that, for the study area, there are some small areas that still have the characteristics of wetland ecosystems and that were not analysed or valued in this study due to the level of scale developed and the type and number of land-cover and land-use classes classified and used as starting data. Further studies can improve and expand the characterisation of the different types of land cover and land use and perform a detailed scale level analysis (reducing the Minimum Mappable Unit) that allows the study of reduced surfaces that can include areas of wetlands, run-off and urban ecological parks, considered to have the greatest economic value according to the global estimate of the value of ecosystem services and, therefore, the richest ecosystems available in the MZ.
This article explores three alternative simulated future scenarios for the ZM, based on the application of a set of different socioeconomic, political and environmental development strategies; on the analysis and identification of processes and spatial patterns of future urban growth through landscape metrics; and on the ESV linked to changes in land cover and land use, the application of this methodological proposal could contribute to generate awareness in decision-makers about the consequences and impacts on the territory due to the application of some or other decisions and, based on this knowledge, to rethink alternative scenarios for planning and management the territory that allow us to proceed to sustainable urban development in the future.
The simulation model implemented manages to be an efficient tool for evaluating alternative urban growth scenarios (different scenarios to those developed in this work), with the possibility of configuring the different factors that condition urban growth according to the different decisions and public policies established by those in charge of planning. The model also could contribute to a better urban planning, enhancing the creation of new municipal or state programmes for urban development (“Programas de Desarrollo Urbano”, PDU). Urban growth scenarios, presented in this article, are also a valuable source of information for the knowledge of the consequences on the territory in the event that the areas could be occupied by urban land use in the future.
From the ESV results, it is concluded that there is an increase in the economic value for the three simulated scenarios due to the variation in growth for urban land use; this increase implies the reduction of other land covers, such as forest and agricultural use with the imminent loss of ecosystem services. ES2-IN represents the scenario with the highest economic value by associating land cover and land use with ecosystem services; however, it is also the one that suffers the greatest impact in the reduction of forest area; if this condition were to occur in the future, ecosystem services would have serious effects on the vitality of the population of the MZ due to the imminent lack of provision of basic services. The ESV was able to quantify economic losses for the ES2-IN scenario of almost $32 million dollars with the loss of the ecosystem services of climate regulation, water cycle regulation, reduction in the provision of raw materials, refuge for fauna species and nutrient cycling, amongst others, with a reduction of almost 60 km2 of forest cover. In the same way, losses of $15 million were determined, linked to the reduction in agricultural production capacity.
The authors are grateful for the support of the anonymous reviewers of this article, to the Universidad Autónoma de Nayarit; as well as to the Consejo Nacional de Ciencia y Tecnología de México (CONACYT), for funding the basic science research project (2015)”, No. 258991: “Simulation models of urban growth through cellular automata in the city of Tepic, Nayarit”.
AAJ Designed, developed and wrote the present article; FFV, FAB, MGD and ONG reviewed, analysed the data and approved the article.
The authors declare that they have no conflicts of interest.