The study area was consisted of the Río Grande de Comitán watershed within an area of 80,993 hectares located in Chiapas State, Mexico (Figure 1). The watershed belongs to four municipalities: Comitán de Domínguez, La Independencia, Las Margaritas and La Trinitaria. Land use types in the watersheds are agricultural livestock, grassland, flood areas, urban zones, and rural settlements, such as private, public, and social properties legally constituted as Núcleos agrários (based in the land tenure system, classified in Ejidos and Comunidades Agrarias) (Ventura Patiño, 2008). The region’s climate is temperate, sub-humid with a maxim temperature of 24˚C - 27˚C from May to October with mean annual precipitation of 1372.8 mm (CONAGUA, 2009).

The Lagunas de Montebello National Park is an important lake system and it is inside in this lower part of the watershed. It covers because it was declared a protected natural area in 1959, in 2003 it was integrated into the RAMSAR Convention, and in 2009 it was declared how the international network of biosphere reserves (Ponce Calderón et al., 2020). This area is localized in southern Mexico of the state of Chiapas (Figure 1).

The land-use classification was carried out in Arc Map 10.5 software by the Segment Mean Shift algorithm and scale level of 50 (Ming et al., 2015). Landsat-5 and Landsat-8 imagery were obtained for 1999, 2009, and 2019 and georeferenced to the Universal Transversal Mercator (UTM) projection, World Geodetic System 1984 datum 15 N. These images have a spatial resolution of 30 m

and a spectral composition of three bands RGB (Red, Green and Blue). The categories don’t identify by the algorithm were corroborated by field visits in different years.

We performed modifications in the hemeroby scale by studies of (Rüdisser et al., 2012) and (Almeida et al., 2018), to introduce socio-historic characteristics of the study area (Table 1). Land uses and land covers are associated with level 2 (Near-natural) because the natural system of the area study area is in Núcleos Agrarios. According to Article 27 of the Agrarian Law (Congreso de la Unión, 1917), rural social property constitutes the ejidos and comunidades agrarias (i.e., land, forests, and water), which the government grants to farmers and indigenous people for their use. Since the Núcleos Agrarios, in its territorial structure, they are composed of one or several ejidos or communal areas. This is a land property type unique in the world. Level 4 (Altered) is the pasture, level 5 (Cultural) regarding the local agricultural system that is integrated into zone parceled in Núcleos Agrarios, level 6 (Artificial with elements natural) known as ejidos these properties are the rural assessment and level 7 (artificial). All descriptions, categories and division criteria are summarized in Table 1.

A principal component analysis was performed: PCA to three (0 - 0.06/0.06 - 0.35/0.35 - 1), and five categories (0 - 0.06/0.06 - 0.35/0.35 - 0.8/0.8 - 0.9/0.9 - 1) D2N to determine if it is possible to identify the subcategory of anthropic use that most influences the territorial expression of the watershed. The analysis was made with PAST 4.03 (Abdi & Williams, 2010).

In this study, we demonstrated the increase of agricultural land during the last 20 years, and consequently, the greatest loss of native vegetation. Land classification and the use of land were classified by the degree of hemeroby showing variation during the years: 1999 (45.43%), 2009 (37.32%), 2019 (31.00%). These spatial patterns have natural conditions by the agriculture expansion. The most frequent anthropogenic influences on naturalness were the altered (level 4) and the cultural degree (level 5) of hemeroby, with 46.41% (1999), 53.84% (2009), and 58.58% (2019), which include grassland and agricultural areas. The artificial with natural elements and artificial level (6 - 7) of hemeroby, represented by rural areas and road networks, increased in the period considered: 8.16% (1999), 8.84% (2009), and 10.42% (2019).

The application of the D2N methodology resulted in a map for each one of the studied years. We classified the continuous original scale (from 0 to 1) with a three-category proposed by Rüdisser (0 - 0.06/0.06 - 0.35/0.35 - 1). We identified a continuous rise of anthropogenic effects over the entire period. The category 0 - 0.06 is related to the lower values of D2N, in which 15% reduction seen in native vegetation. The remaining area remained restricted to fragments of native vegetation as well as The National Park Montebello Lakes stands out located in the extreme southeastern and another preserved area extreme northeast in the highest part of the watershed.

Intermediate values of D2N related to the category 0.06 - 0.35 showed a reduction in the middle region of the watershed. Category 0.35 - 1 showed the highest change due to the replacement of scheduled areas in the degree of hemeroby. Furthermore, there is a contrast between Near Natural and Alteral hemeroby categories, which means an increase of anthropization in the watershed. This showed two trending scenarios: 1) the lack of the original natural condition of the watershed and 2) the expansion of anthropic activities resulting from the agricultural activities and urbanization increase. Thus, the modification of the original landscape and ecosystem is observed, as well as the replacement of a natural component of the watershed. It is a progressive transformation into a cultural landscape, with a predominantly anthropic matrix.

Reclassification of the simplified scheme to a five-category scheme (0 - 0.06/0.06 - 0.35/0.35 - 0.8/0.8 - 0.9/0.9 - 1) allowed greater clarity in the interpretation of changes in the values of D2N of watershed, particularly, to the range 0.35 - 1. This reclassification enables a greater visibility as for the area of extension and location in the watershed, of the different types of influences of anthropic activities associated with agriculture and urbanization. The social land property (mainly called ejidos) has a long and interesting historic socio-economic background in Mexico. The way that they operate and manage the space has an impact in the decisions and managements of ecosystems. Therefore, it is a very important consideration in the whole analysis.

Furthermore, in this classification, we observe that component Ejidos can be considered as “anthropization nuclei in the watershed”.

The components of the PCA (Figure 2) based on anthropic impacts, explained 100% of the total variance to three categories (Figure 2(A)) and 99.97% of the total variance to five categories (Figure 2(B)). The first component F1, 86.34% of the three categories (Figure 2(A)) showed a positive correlation with the years 1999, 2009, and 2019. However, it does not show which component has the greatest anthropogenic impact over time. In both cases (Figure 2), the year 1999

is closer to the 0 - 0.06 variable, which shows a higher naturalness condition compared to the other years.

With the subcategorization of the anthropic component (0.35 - 0.1), according to hemeroby levels, it was possible to identify the variable that most influenced the territorial expression (Figure 2(B)). In this case, the direction of the variable 0.35 - 0.8 (agricultural anthropic) manages to characterize the nature of the anthropic spatial configurations in 2019, about the non-agricultural anthropic use variables (0.35 - 0.9; 0.9 - 1), which do not explain the total variation of components evaluate classified into categories.

The increased anthropic pressures can be explained by historic process, for example, the Agrarian Reform (1910-1920), their inclusion at the institutional level how Land Reform Law (Diario Oficial de la Federación (DOF) de 16/04/1971, Article 27), and the amendment to Article 27 (1992). These actions constitute some of the determinants factors of spatial organization in Mexico. Despite the Agrarian Reform, in the '70 s, resulted in an increase in the deforested areas in Chiapas for the production of pasture in the ejidal territories for private sector cattle, due to the extreme poverty of the farmers (García & Bórquez, 2006).

Agriculture is the main source of income in the region with the production of tomatoes grown in greenhouses and, in rainfed agriculture, corn and beans rainfed agriculture. Studies in the area have shown the influence of deforestation of native vegetation, replacing it with intensive agriculture using synthetic fertilizers. For example: the presence of high concentrations of nitrates (Olea-Olea & Escolero, 2018); anthropogenic development and the impact on the water quality of the Parque Nacional Lagunas de Montebello (Alcocer et al., 2018); eutrophication (Alcocer et al., 2021), and the increase of near-cyclic sediments, such as the case of Lake Balamtetik (Caballero et al., 2020). Additionally, starting in 2003, there was a modification in some lakes from crystalline to yellowish water, foul odors and fish mortality (Fernández et al., 2021; Alcocer et al., 2016).

On the other hand, rural and urban population growth from 1990 to 2020 was 50.28% (90,156 inhabitants - 179,304 inhabitants). The growth of rural areas was 63.58% (41,857 inhabitants - 65,825 inhabitants) (INEGI, 2020). This suggests that the increase in rural human settlements in the Núcleos Agrarios is correlated with the increase in the anthropogenic agricultural component in the region (Figure 3).

The differentiated representation of the three categories of D2N for the range 0.35 - 1 stressed the contribution and clarity that can be delegated in environmental monitoring and planning, enabling the identification of priority areas and conservation actions as well as those most committed by the expansion of anthropic activities, effectively, adding to the social inclusion of local communities.