Classification[3]
First classification
According to the topics discussed, and in clear relation to the classic division of Geography into physical and human, regionalizations of the physical environment (physiographic, climatic, hydrological, etc.) can be distinguished from those of social content[9] such as those that divide the countries of the world according to the prevailing religion, the official language, the gross domestic product per inhabitant or the infant mortality rate. However, it is common for regionalizations to combine physical and social themes, so combined or mixed regionalizations must be added to the two previous types of classification, such as, in the case of the Mexican Republic, those of Bassols, 2002, Bataillon, 1986, and García Martínez, 2008.
Second classification
The second classification is based on the number of variables, which allows us to distinguish unidimensional regionalizations from multidimensional ones. Unidimensional regionalizations are not frequent in those referring to both the physical environment (for example, those related to temperature) and the social environment (for example, ethnic ones), but, logically, combined regionalizations are not always multidimensional.
Third classification
A third classification refers to limits, which constitute a crucial element in all regionalization. Based on the degree of precision of their limits, compact or continuous regionalizations can be distinguished from imprecise or discontinuous ones. In the former, the spatial units are contiguous, adjoin each other, are juxtaposed, without overlapping or having intermediate extensions. This implies that the limits are precise and linear (not diffuse), and that they are shared by two spatial units: where one ends, another begins. Political and administrative divisions usually constitute clear examples of this type of regionalization. On the contrary, in discontinuous or imprecise regionalizations, the spatial units are separated by areas that do not belong to any of them (as happens with the continental extensions of Central America or South America with respect to the Caribbean islands), have imprecise limits (such as those that frequently separated the colonies of the Spanish empire in America or those that sometimes separate the regions established by García Martínez)[10] or overlap (as sometimes happens in regionalizations based on the interaction of human collectivities).
Fourth classification
This classification, which distinguishes two types of regionalization that are very different conceptually and methodologically, but that appear combined in many regionalizations.[11] Although all regionalization involves the detection of similarities (within each region) and differences (between some regions and others), which implies the establishment of criteria (and limits) that distinguish what is similar from what is different,[7] the dimensions used to detect such similarities and differences can be grouped into two clearly differentiated types, which gives rise to two types from disparate regions.[12].
The first can delimit its regions based on multiple dimensions that allow detecting homogeneous extensions differentiated from each other; In the second, the only dimension that determines the extension of the regions—the interaction of human collectivities—does not establish homogeneous spaces, but spaces delimited by virtue of interrelated human settlements.
On the one hand, there are regionalizations made from dimensions, variables or factors, which, when manifested in disparate ways, allow the establishment of homogeneous regions that differ from each other. The region is homogeneous, but the set of them, the agglutinating spatial unit, is heterogeneous. The same variable that allows establishing the homogeneity of each region serves to distinguish the regions from each other. The uniformity-disparity dichotomy plays a central role in the elaboration of this type of regionalization. Throughout each of the regions into which the agglutinating spatial unit is divided, the variable used to regionalize manifests itself with similar and specific characteristics, which distinguish it from the other regions. Each region is homogeneous because it has been delimited based on the extension covered by similar manifestations of the variable. The limits indicate both the extension of a region and the end of the homogeneity that characterizes one region and the beginning of another homogeneity that characterizes the neighboring region. Based on the characterization that has just been made of this type of regionalization, we call it regionalization elaborated through differentiating homogeneities or uniformities, while we describe the corresponding regions as homogeneous or uniform. This type of regionalization can be developed from both natural dimensions (physiography, landscape, hydrology, climate, pedology, vegetation, etc.) and social dimensions (urban-rural contrast, ethnicity, language, religion, forms of government, etc.). Regionalizations of this type can, logically, be unidimensional or multidimensional. Sometimes, the differences that allow regions to be distinguished with respect to a single dimension are manifested by opposition (such as those based on hydrology, the prevailing language or religion, forms of government, etc.), but on other occasions the manifestation is expressed through a continuum, so the differences between regions have to be established by gradation, which requires determining the ranges (of temperature, precipitation, gross domestic product per inhabitant, illiteracy, educational coverage, etc.) from which will distinguish one region from another.
For its part, the second type of regionalizations, as anticipated, is established based on a single dimension (even though this can be analyzed through numerous variables): the interaction between human collectivities. In general, this interaction occurs between collectivities with different hierarchies, where one of them plays the role of nucleus, articulating center, central place, pole of attraction or node in relation to the others. Furthermore, it is common for the cores, with their respective hinterlands, to be interconnected forming more complex networks. In accordance with such ideas, the following definition of region could be ventured: a spatial unit composed of collectivities articulated around a higher hierarchy and generally urban one that functions as the nucleus of a network, which in turn can be articulated with another network of greater hierarchy and extension. For all of the above, both this type of regionalizations and the regions that are derived from them could be described as nuclear, because the nuclei are their main elements, or reticular, because they give rise to networks formed around such nuclei.[1].
Below, a quote is reproduced verbatim that clearly describes the interrelation of the units of analysis typical of this type of regionalization, while allowing us to glimpse the language used in this regard by some economists:
Fifth classification
Due to the function they perform, four types of regionalization can be distinguished, in principle: political, administrative, non-state organizational (religious, union, etc.) and academic.[13] Political regionalization, that made up of territories, is the oldest, the most common and, in a certain sense, the most relevant, because it is the one that most clearly conditions people's daily lives. It is even normal that the territories of some of them, such as municipal ones, are related to intense feelings of belonging. In general, political regionalizations, which represent a spatial distribution of power, are predominantly nuclear, since the very fact that the authorities that characterize them usually reside in a specific locality of the territory over which they have jurisdiction gives special relevance to said locality, which, in addition, is usually associated with greater importance in other aspects such as economic and cultural aspects. This explains why the localities that serve as the headquarters of public powers are often articulating centers of surfaces similar to those of the territories concerned by the binding decisions they make.
Political regionalization is clearly opposed to academic regionalization, while administrative regionalization, although it responds to logic similar to that of political regionalization, could sometimes be considered a hybrid between the previous two.
Non-state organizational regionalization has the following similarities and differences with political regionalization: the two types of regionalization have in common the fact that they are composed of spatial units with specific authorities; The difference lies in the nature of such authorities, since in politics they are those that have executive, legislative and/or judicial powers that involve all the inhabitants of the corresponding spatial unit, in contrast to the authorities of the spatial units of non-state organizational regionalizations, which in general were created by that type of collectivities that can be called organization[14] and that only involves a portion of the inhabitants of the spatial units where they are settled (examples: religious regionalization only involves to the parishioners of the organization in question and union regionalization only includes the members of a certain union).[3].
Administrative regionalizations have a lower hierarchy than political ones because they have much more limited functions than these and are of a technical nature. Furthermore, they are usually subject to more variations than policies and, like non-state organizational regionalizations, do not involve the entire population of their regions, but rather a portion of it. Administrative regionalizations can be divided, in turn, into two. The first is prepared and implemented by agencies that are part of the Executive and Judicial branches, both at the national and subnational levels, to address specific issues corresponding to such agencies. The third is prepared by autonomous institutions of the highest national and subnational powers, such as, in the Mexican Republic, the electoral institutes.