Environmental economics and sustainable development

1. Introduction

Environmental impact assessment, in the design of works and activities of public or private interest, is a technical tool that has been formally incorporated into the complex process of development planning. Knowing what type of development it refers to and what are the objectives and strategies and, in general, the conceptual vision of this development, are still a matter of debate.

Social indicators show a heterogeneous face where the reflection of an impoverished rural world contrasts sharply with relatively rich metropolises. In any case, a broad layer of the average population has been strengthened, determined to consolidate a hard-to-reach socioeconomic position that has recently been threatened by recurring economic crises.

Today, the most critical environmental threat in history is confronted: deterioration of soil, water and marine resources, essential for growing food production. Air pollution with direct effects on health, loss of biodiversity and its modest, but no less important contribution to damage to the ozone layer and global climate change. Simultaneously, serious human problems such as poverty and uncontrolled population growth are faced.

The modern vision of development not only seeks to raise the levels of well-being in today's human societies, but also concerns itself with the possibility of inheriting to future generations a planet with acceptable levels of environmental and economic health. Hence, the analysis of human behavior, forces to modify attitudes and redefine the trends that point towards an ecocide; overpopulation, which will affect greater amounts of food and better spaces; and to economic growth that will put dramatic pressure on natural resources.

On this principle, the concept of sustainable development emerges, the definition of which establishes that it is a development that meets the needs of the present without compromising the ability of future ones to satisfy their own needs.

The concept of sustainable development in its most general sense has been widely accepted and supported. However, it has been more difficult to translate this concept into objectives, programs and practical policies around which nations can unite, since they face very variable circumstances.

The conceptual framework of sustainable development presents several approaches depending on the disciplinary approach that addresses it. Thus, for some the important thing is the use of renewable natural resources, so that it does not deplete or degrade them and results in a real reduction in their renewable utility for future generations, keeping the inventories of natural resources constant.

Development does not necessarily mean economic growth, the type of economic activity can change without increasing the quantity of goods and services. Economic growth is said not only to be compatible with sustainable development, but also necessary to alleviate poverty, generate resources for development and prevent environmental degradation. The question is the quality of growth and how its benefits are distributed, not just mere expansion.

Sustainable development is also often defined as development that improves health care, education, and social well-being. Currently it is recognized that human development is decisive for economic development and for the rapid stabilization of the population.

Some authors have further extended the definition of sustainable development by including a rapid transformation of the technological base of industrial civilization; For which they point out that it is necessary for the new technology to be cleaner, more efficient and save natural resources in order to reduce pollution, help stabilize the climate and adjust population growth and economic activity.

An important component implicit in all definitions of sustainable development relates to equity: equity for generations to come, whose interests are not represented in standard economic analyzes or in the forces that disregard the future, and equity for people. currently living, who do not have equal access to natural resources or social and economic assets.

There is indeed a certain conflict between both types of equity. While on the one hand it is pointed out that environmental problems in developing countries cannot be solved without alleviating poverty and demanding a redistribution of wealth or income, both within countries and between rich and poor nations. On the other hand, intergenerational equity, participation in well-being between people of today and those of the future are emphasized and focuses on the need to reduce current consumption to provide investments that form resources such as knowledge and technology for the future.

The World Conservation Union defined sustainable development in terms of improving the quality of human life without exceeding the carrying capacity of the ecosystems that support it. This assumes that sustainable development is a process that requires simultaneous progress in various economic, human, environmental and technological dimensions.

Development Characterization

The use of the term "development", rather than economic growth, implies accepting the limitations of the use of measures such as a nation's GDP or well-being. Development includes greater interests in quality of life, educational attainment, nutritional status, access to liberties and spiritual well-being. The emphasis on sustainability suggests that a targeted political effort is needed to make these development scopes end well in the future.

Since development is a value term, it implies, then, changes that are desirable, however, there is still no consensus on its meaning. What constitutes development depends on the social goals that are invoked by the Government or the analyst.

Development is a vector of desirable purposes, that is, it is a list of attributes that society seeks to achieve or maximize, the elements of this vector may include:

• Increase in real per capita income.

• Improvement in the state of health and nutrition.

• Educational advances.

• Access to resources.

• A more equitable income distribution.

• Increase in basic freedoms.

Sustainable development requires a series of conditions for it to take place. In principle, the inventory of natural capital should not decrease over time. In this context, the natural capital inventory includes all the assets of natural and environmental resources, from oil in the subsoil, the quality of the soil and groundwater, the fishing in the oceans and the ability of the globe to recycle and absorb carbon. The meaning of a constant inventory of natural capital is more problematic.

2. Economic Growth

Economic theories should be valued within the context of their broader structure (paradigm). There is a complex interaction that takes place between the evolution of scientific theory (natural, physical and social) and the social order. The way in which scientific research responds to questions of the natural and human world seeks to explain when they will be influenced by social, cultural and political factors. Hence, attitudes towards nature and preservation / conservation will change as nature and humanity evolve.

The classical economic paradigm.- The classical economists left a legacy of ideas, many of them relevant, and which have been reintroduced in contemporary environmental debates. Classical political economy stimulated market power by privileging growth and innovation, but remained essentially pessimistic about long-term growth prospects. The growth of the economy was thought to be a temporary phase between stable equilibrium positions, with positions representing the existence of an unsuccessful subsistence level: the steady state.

The Marxist Paradigm.- Karl Marx (1818-1883), adopted the theory of labor value from the classical economists (workers were the only source of net economic product) and was equally pessimistic about the future standard of living standard for the most people (the working class) in capitalist society. According to Marx, classical economists have failed in capitalist economic organization, in its historical context. He sought to formulate a generalized model of comfort production that characterized comfort production as a social relationship. History would be interpreted as a dialectical phenomenon, a process of conflict of material and economic forces from which a synthesis arises, a resolution of the conflict.

The Neoclassical and Humanistic Paradigm.- At the beginning of 1870, neoclassical economists thought to develop the analysis within the mainstream economist. The theory of the value of labor was abandoned and a comfort price was seen, not as a measure of the cost of labor but of its scarcity. Concentrating on the value of scarcity allowed both sides of the market to be analyzed simultaneously. Analysts compared the amount of comfort available (supply) with the quantity required (demand). The interaction of supply and demand determined the equilibrium of the market price for comfort.The economic activity observed in the real world was seen as a result of the interaction between productive activity (determined by technological progress) and the preferences of individual buyers contracted by the feasible range of selection and income.

The basic theorem of welfare economics seeks to legitimize rational behavior as a socially desirable good and also to justify some government intervention to provide conditions under which individuals select. The intervention would be especially justified when the so-called market failures exist. ie when it is clear that the markets are not qualifying the collective welfare. The basic neoclassical vision sees government as an essential ethical agent that only intervenes in the market in the public interest, to facilitate the inevitable tension between individual rationality and collective ethics. Ethical or moral obligations are not recognized at the level of the individual.

Paradigm of the institutional economy. The environmental management market model: Property Rights vs. Material Balance Analysis.- The conventional approach has generated two variants of an environmental information management model. These approaches are that of property rights and that of material balance.

Approximation of property rights.- Some analyzes at first argued that the problem of pollution costs were not covered and could be well covered through a process of redefining the existing structure of property rights. A particular interpretation of the Coase Theorem (Coase, 1960) was used as the theoretical basis for a non-interventionist control policy. According to Coase, given certain assumptions, it would be a process of convenience between the polluter and the affected party. If the polluter has the right, the affected party can compensate him for not polluting; if the affected party has the rights, the polluter can compensate him for tolerating it.

It is argued that in an economy with well-defined transferable property rights, individuals and businesses would have increasing incentives to use natural resources as efficiently as possible. According to the property rights approach, increasing government intervention should be resisted because public ownership of many natural resources is at the root of resource control conflicts: there are government failures. It is assumed that public sector theory should be based on the same motivational assumptions (self-interest) used in the analysis of individual private behavior. Hence, the decision maker sees maximize his own utility, not that of any institution or State.

The material balance approach.- The revisionists have sought to incorporate material balance models and, to a certain extent, entropic limits in economic analysis. As long as pollution is seen as a symptom of market failure, while it is a pervasive and inevitable phenomenon (due to thermodynamic laws), it will require government intervention through a package of incentives and regulatory instruments..

Policy analysis: Fixed standards vs. cost-benefit structures.- Facing the complex ecological interdependence and uncertainty surrounding the management of resources, two alternative approaches have emerged. Some analysts argue for adopting a cost-benefit structure, using monetary valuations, but also incorporating explicit acknowledgments of uncertainty and irreversibility. Others urge the adoption of the fixed standards approach, one or the other in selected cases or as a way of implementing a general macro-environmental policy. Macroenvironmental standards encompass zoning policies for land use, environmental quality standards for air, water, etc., although perhaps flexible in time (as knowledge increases),they would limit the landscape of cost-benefit analysis to cost-effectiveness analysis.

Economic and environmental values.- There are various interpretations of the term "value", but economists have focused on monetary value as expressed through the preferences of individual consumers. On this basis, value only occurs due to the interaction between a matter and an object and, in terms of this explanation, it is not an intrinsic quality of something. A given object may then have an assigned value number, because of differences in perception of retained values, by human assessors in different valuation contexts. The assigned economic values are expressed in terms of "individual goodwill to pay" (BVP) and "goodwill to accept compensation" (BVA)

3. Biodiversity and Germplasm.

Biodiversity is the composition in number and proportion of living forms in nature; it involves any type of variability in the living world: species richness, abundance, ecological functions that living beings perform within ecosystems, genetic variability and differential geographic distribution of species among others.

Species diversity is usually measured at three different levels: local diversity, also referred to as alpha diversity, which describes the number of species and their relative density to a relatively small extent; Beta diversity, which indicates the rate of change in species composition when we move from one locality to another; and regional diversity or gamma diversity.

Conservation of biodiversity is the foundation of ecologically sustainable development. Firstly, biodiversity is essential to maintain the viability of ecological systems that support current production. Then future needs are unpredictable and potentially valuable species would be lost. Finally, our understanding of ecosystems is still insufficient to be certain of the role they play in the global context, and even less to determine the impact that the removal of any of their components would entail. In particular, the loss of a critical ecosystem or subsystem can have irreversible and catastrophic effects. The variety of biological forms is also attractive and interesting in itself.Both human health and agricultural production depend on the preservation of biodiversity.

There are two practical problems with assigning values to biological diversity. The first is a problem of economists: it is not possible to assign the figure of real economic value of any piece contained in biodiversity, let us only leave its value in the aggregate. We do not know enough about genes, species or ecosystems to be able to calculate their ecological or economic value in the grand scheme of things.

4. Use of Natural Resources.

Resource is a term of economic origin that includes all the agents or factors of production used in an economy to produce and supply all kinds of goods and services. Conventionally three categories of resources are accepted: land, labor, capital. The first category includes not only the land area itself but also all elements that are productively valuable and naturally found in the physical environment, such as minerals, water, sun, air, soil, and wildlife.

The geographical and historical variation of cultural norms carry different meanings in different parts of the world. In this way, western culture and commerce have led the communities that own these resources to grasp the potential value of numerous minerals that were of no use to them. However, before any cultural group defines a physical substance as a resource, two conditions must be satisfied: the first is that the substance has a use or value for man and the second is that man is willing to pay the costs. involved in its acquisition, elaboration and use of the substance in question.

Nonrenewable resources

An externality is defined as any external effect caused by an individual or a user company, not accounted for, but which does affect other users of the same resource. Externalities are generally negative and occur when there is free access to the exploitation of a certain resource, without any voluntary cooperation agreement. Three types of externalities can be identified: inventory, agglomeration, and technology. There are other externalities derived from ecological interdependence that, unlike the previous ones, have positive characteristics, that is, the exploitation of a resource can bring benefits to sympatric users who interact with the former in space and time. The occurrence of externalities is due to structural market failures,they cannot automatically absorb those additional costs.

• Application of the polluter pays principle.- It is about protecting nature and avoiding using it as a garbage dump. Another closely linked mechanism is the price system, which considers the environmental cost of economic activity to be covered in relation to the scarcity of resources.

• Tradable permits. - They are permits to pollute that can be granted to a person, upon payment of rights. The system seeks to control the emission of pollutants by imposing limits on them.

• Reciprocal reductions of pollutants.- It is the establishment of reciprocal commitments to reduce pollutants that affect a common good.

• External controls.- These are taxes that one country imposes on the products of another, since the latter does not comply with the environmental protection requirements of the importing country.

• Payment and reimbursement of containers.- It involves taxing the containers, so that the consumer is forced to return them to recover their costs.

• Property rights.- They are exclusive, transferable, secure and conferred rights for a sufficiently long period. Its owners would have a particular interest and incentives to take care of an assigned asset, such as a body of water, a forest, etc.

• Voluntary schemes.- They are programs developed by industrial lines and that work by peer pressure, in such a way that one company puts pressure on others to act by investing and taking care of the environment.

• International cooperation instruments.- Includes debt swap or the use of a resource, technical and financial assistance for environmental purposes, etc.

• Packaging and labeling. It consists of the rationalization of the use of packaging, with measures that include the minimization and use of biodegradable inputs (fibers). Eco-labeling involves the inclusion of environmental advantages in the development of a product.

• Bond System.- It is an amount of money paid to the government to undertake an ecologically incompatible activity. If the damages exceed the regulations, it is applied in the restoration of the affected ecosystem, if this is not the case, then the deposit will be returned.

• Information and education system for the population. - Consists of disseminating environmental information to the entire population, so that, being informed, they participate and help solve problems.

Productive infrastructure.

The economic and social development of a given region finds one of its most objective expressions in the construction of infrastructure works. These can be of a social nature, such as buildings for health, education, culture, government and sports, and those of a productive nature such as roads, bridges, drains, industrial parks, tourist developments, agricultural, forestry and livestock developments, dams, generation and electrical conduction, mining, fishing and aquacultural developments, among others.

Obviously, the fight against poverty, territorial and cultural integration and the development of a productive plant that seeks the gradual reduction of external dependence, both technological and economic, have been central purposes that have governed the pace and location of national infrastructure.

5. Environmental Reference Framework

Criteria and typification

We will designate as an environmental reference framework, the diagnostic description of the area that will be affected by the development of a new work. The levels of environmental quality, measured in each one of the elements of the environment, will form the background environmental pattern on which the effects of the new development will be added. This diagnosis will allow, among other things, to define the existing background contamination, attributable to natural or anthropogenic causes, the fragility of ecosystems and their degree of alteration, the quality and quantity of natural assets that serve as input to development, raw materials, water, land, etc.

In carrying out environmental impact studies, the current legislation establishes a typification that depends on the nature and magnitude of the project to be evaluated, as well as the ecological characteristics of the site. In this way, preliminary reports and environmental impact manifestations are discriminated in their general, intermediate and specific modalities.

In any case, the description of the environmental scenario requires the compilation of the necessary information and only when it is insufficient and the work area lacks a background, then the original studies will take place.

Environmental frame of reference

The description of the environment is an integral part of the environmental impact studies and its extension must be exhaustive and comprehensive enough to understand the effects that the project or work would have on it. Far from being an extensive collection of sectorized studies, it basically consists of the review and interpretation of existing information and its subsequent validation, when appropriate. It is preferably generated in institutions, academic and research, government, social and / or private initiative, both national and international.

Impacts on environmental elements

Delimitation of the area.- It consists of carrying out a topographic survey and describing in a plane the work area where the work or activity will be implemented. In principle, the area should indicate the polygonal areas of the property, the surface and its neighborhood limits. Likewise, the area directly occupied by the work and the areas of reserve, expansion or identifiable green areas are indicated. This plan is the same one that supports the executive project of the work or activity.

Area of influence. It happens that the activity will have a geographic space beyond its property borders, which can encompass a variable extension, as wide as a hydrological basin, when it is the case of, say, a dam or even larger extensions such as the construction of a highway. Then the cartographic location is imposed on a scale that allows visualizing the entire scenario likely to affect. In preparing this plan, it is recommended to use the cartography of the state government or the most recent DDF, from the Secretaries of Social Development, Communications and Transportation or INEGI.

Physical factors. It basically includes the elements of climate, soil, geology, hydrology and biodiversity (flora, fauna and ecosystems) that affect the area where the project will be located.

Weather

It is the set of atmospheric characters that distinguish a region. It is considered a limiting factor of various economic activities. Some elements of the climate can be modified by the displacement and substitution of plant formations, become active factors that accelerate erosion, or influence the atmospheric gas mixture related to thermal inversions. For the description of the climate, the Köeppen classification modified by Enriqueta García is commonly used.

Temperature.- Based on the climatological reports issued by the climatological stations of the National Water Commission, the National Meteorological Service, the Federal Electricity Commission or the International Commission on Limits and Waters Mexico-United States of America, the average values are used. daily, monthly and yearly, including the monthly minimum and maximum extremes.

Relative humidity.- From the same sources, a table is constructed that includes all the months of the year and estimates the monthly mean and the maximum and minimum extremes.

Precipitation.- An annual table is constructed with the same sources and the distribution and frequencies of rainfall are illustrated in a graph; dry periods are noted. Annual precipitation, monthly average and maximum rainfall in 24 hours are estimated. The construction of the annual tables requires, whenever possible, to consider a record of the greatest number of possible years.

Atmospheric pressure.- The air pressure or weight of the air column resting on a given surface, with a height equal to the thickness of the atmosphere, is measured by means of barometers. The isobars or lines connecting points of equal barometric value are compiled and constructed by seasonal periods. The records of the meteorological stations installed in the nearest airports are consulted and the monthly and annual average values are estimated.

Cloudiness and insolation.- The records of the meteorological stations installed in the closest airports are consulted and the annual averages and the months of the year with maximum and minimum values are estimated. Heat stroke or light hours is recorded on the heliographs and the average number of light hours recorded in the month is tabulated for the whole year.

Wind speed and direction.- Seasonal and annual wind roses are constructed with data from the meteorological stations indicating the speed. The frequency of calms is estimated and, when possible, the height of the air mixing layer is consulted. In the case of closed atmospheric basins, a field measurement will have to be made.

geology

Geological information is essential in all newly created projects, not only as indicative of economically important natural resource sources, but as a possibility of both natural and anthropogenic risks. The incidence of seismicity, volcanism, subsidence, floods, earth movements, cracks, active faults and erosion of natural origin, is enhanced by contamination, fires, erosion, deforestation and instability of slopes of artificial origin.

Geological formations.- Establish a stratigraphic profile that allows identifying the different stratigraphic formations.

Predominant erosive activity.- When it is the case of a deforested area, indicate if the erosion process is caused by wind, water, thawing, etc.

Porosity, permeability and resistance to geological layers.- When there is the possibility of leaks of contaminating leaks, measurements will have to be made in the field. When it is the case of municipal or hazardous waste confinement facilities, these measurements must be made.

Orogenic activity.- Specify if the area is susceptible to seismic phenomena, volcanism, landslides and landslides. This information can be consulted in studies carried out or in archives and publications related to the subject.

Floor

Soil constitutes one of the elements of the environment since it is the fundamental support of all forms of terrestrial life. Each type of soil is associated with a strictly interrelated microclimate, plant formation and unique ecological structure, such that the modification of any of its parts can mean the transformation not only of the local landscape, but also of neighboring ecosystems.

Depending on the type of project in question, the possibilities of soil deterioration and destruction may include contamination, erosion, and productive and ecological uselessness.

Structure and Porosity.- It is the geometric arrangement of the primary (clay, silt and sand) and secondary particles (colloidal aggregates, organic matter and Iron and Aluminum hydroxides). This physical characteristic influences other properties such as aeration, water infiltration and heat transfer.

Color.- The color pattern of the soil is a characteristic that is studied in the profiles. It enables other measurements to be correlated and the precision of analytical determinations to be checked.

Hydrology

Water is an element of the environment that also acts as an input in human activities through the various uses that are printed on it or as a support for a wide range of ecosystems and biological forms, in such a way that changes in quality and amount can translate into serious ecological and economic imbalances.

Hydrological Basin

Watersheds or drainage basins constitute the entire area from which a stream and its tributaries receive water.

Basin definition.- Based on the cartography related to hydrological basins established by the National Water Commission, the project under study is located and, if it is the case, all the basins that concur in the same point are considered.

Catchment area.- Refers to the slopes and wooded areas that serve as recharge areas for the basin. His state of disturbance.

Maximum and extraordinary avenues.- Based on the information generated by the hydrometric stations located in the main currents, estimate the return periods of the maximum and extraordinary avenues and their flow.

Precipitation and Periods, duration and annual volume.- Construct an annual table with monthly averages, indicating the months of greatest concentration and their volumes.

Oceanography

Type of coast.- The coastline is formed by the coastline and the tidal zone. The types of coasts distinguish those of deposit, those of erosion and that of reefs.

Beaches.- They are deposit coasts covered by unconsolidated ateiral such as sand, gravel or other terrigenous material. Excludes muddy expanses of deltas. They are usually very unstable, so the waves and wind permanently shape the physiography.

Cliffs, cliffs and caves.- are cuts caused by the combined erosion of wind and water.

Reefs.- Sometimes developments of individual coral populations occur with calcareous skeletons and other animals and plants that secrete calcium, directly on the land mass (ring reefs) or separated by water deposits (barrier reefs).

Coastal marine environments.- Describes the general characteristics of the physiography, bathymetry and main features of the environments linked to the coastline.

Ecological Zones

Arid	It occupies most of the center and north of the country. It is determined by latitude. Mountain systems act as a barrier to humid winds, which accentuates aridity. This causes low precipitation volumes. The vegetation is xerophytic and scrub, so the availability of water is limited. Average annual precipitation is less than 600 mm and temperatures are extreme. Includes the states of Baja California, Baja California Sur, Coahuila, Zacatecas and Aguascalientes. Most of Sonora, Sinaloa, Chihuahua, Durango, Nuevo León and Tamaulipas and important areas of Guanajuato, Querétaro. San Luis Potosí and Hidalgo.
Temperate	It has temperatures higher than 18ºC in the hottest month and drops in the winter season to an average higher than 0ºC. Rainfall is greater than 600 mm annually concentrated in summer. The area is determined by mountainous systems and develops a forest-type vegetation of pine, oak or associations of both and grasslands. It includes the entities of Tlaxcala and the Federal District, most of the states of Mexico, Hidalgo and Jalisco, as well as areas of Oaxaca, Morelos, Querétaro, Zacatecas, Tamaulipas, Nuevo León, Michoacán Guanajuato, Nayarit, Durango, Sinaloa and Chihuahua.
Dry Tropic	It is characterized by an average annual temperature of over 18ºC and rainfall between 800 and 1200 mm per year, which occur in most of the year. The vegetation is very diverse and includes medium and low forests, savannas, palm groves and even xerophytic associations. It includes the state of Guerrero and important areas of Oaxaca, Michoacán, Colima, Jalisco, Nayarit, Sinaloa, Sonora and Morelos.
Wet Tropic	It presents annual average temperatures greater than 18ºC and precipitations greater than 1200 mm. It develops an exuberant vegetation that includes high, medium and low forests. It includes the entities of Quintana Roo, Yucatán, Campeche, Chiapas, Tabasco and Veracruz, as well as portions of Oaxaca, Tamaulipas and San Luis Potosí.

Ecological Provinces

Arid zone	Temperate zone
01 Sierras de Baja. 02 California. 03 San Sebastián Vizcaíno desert. 04 Plains of the Magdalena. 05 The Cape. 06 Altar Desert. 07 Sierra del Pinacate. 08 Soreras and Sonoran Plains. 09 Sierras y Valles de Norte. 10 Sierras y Cañadas del Norte. 11 Sierras and Plains Tarahumaras. 14 Sierras and Plains of Durango 17 Sierras y Valles Zacatecanos 18 Plains and North Dunes. 19 Folded Mountains of the North 20 Mapimí Bag 21 Plains and Volcanic Sierras. 22 Mayran Lagoons. 23 Coauilenses Sierras and Plains. 24 Serranía del Burro. 25 Sierra de la Paila. 26 Folds of Saltillo-Parras 27 Transverse Saws. 29 Western Sierras and Plains. 31 Plains of Coahuila and Nuevo León. 32 Coastal Plain and Deltas of Sonora and Sinaloa. 33 Coastal Plains of Mazatlán. 36 Plains and Lomeríos. 37 Tamaulipecas Coastal Plains. 38 Sierra de San Carlos. 39 Sierra de Tamaulipas. 40 Sierras and Lomeríos of Aldama and Río Grande. 41 North Sierras and Plains. 42 Plains and Sierras Potosinas-Zacatecanas. 43 Plains of Ojuelos-Aguascalientes. 44 Sierras and Plains of the North of Guanajuato. 52 Plains and Sierras of Querétaro and Hidalgo.	13 Great Plateau and Chihuahuan Canyons 15 Great Plateau and Cannons Duranguenses. 16 Tablelands and Glens of the South. 28 Great Folded Sierra. 30 Karst Huasteco. 45 Sierra Cuatralba. 46 Sierra de Guanajuato. 48 Altos de Jalisco. 49 Sierra de Jalisco 50 Guadalajara 51 Bajío Guanajuatense 53 Chapala 54 Sierras y Bajíos Michoacanos. 55 thousand summits. 57 Lakes and Volcanoes of Anáhuac 58 Neovolcánica Tarasca 59 Colima Volcanoes 70 Eastern Sierras 87 Revillagigedo Islands
Dry Tropic Zone	Humid Tropic Zone
12 Foot of the Sierra. 34 Delta of the Rio Grande de Santiago. 47 Sierra Neovolcánica Nayarita. 60 Southern Border Escarpment. 61 South of Puebla. 65 Mountain ranges of the Coast of Jalisco and Colima. 66 Southern Coastal Mountain Range. 67 Depression of the Balsas. 68 Tepalcatepec Depression. 69 Sierras and Valles Guerrerenses. 71 Central Sierras of Oaxaca. 72 Mixteca Alta. 73 Coasts of the South. 74 Sierras and Valleys of Oaxaca. 84 Plains of the Itsmo.	36 Plains and hills. 56 Chiconquiaco. 62 Yucatecan Karts. 63 Karts and Lomeríos de Campeche. 64 Baja Costa de Quintana Roo. 75 Veracruz Coastal Plain. 76 Plains and Tabasco swamps. 77 Sierra de los Tuxtlas. 78 Sierras del Norte de Chiapas. 79 Sierra Lacandona. 80 Low Sierras of Petén 81 Altos de Chiapas. 82 Central Depression of Chiapas. 83 Sierra of the South of Chiapas. 85 Coastal Plains of Chiapas and Guatemala. 86 Volcanoes of Central America.