Environmental management plan of the Pacaya volcano natural monument

EXECUTIVE SUMMARY

The Pacaya Volcano National Park -PNVP-, is located in the municipality of San Vicente Pacaya, located between the coordinates 14 25 ′ North Latitude and 90 35 ′ West Longitude, it is distant from the capital city by 43 kilometers, it comprises approximately 1,800 hectares, and it contains biological and geological resources unique to Guatemala and the Neotropical region.

natural-areas-management-plan

The Pacaya Volcano National Park -PNVP-, is one of the areas that meets the characteristics of serving as one of the most important natural parks in the country, and that for many years has been admired and visited, since in it manifestations of volcanic activity with a spectacular landscape that includes the Laguna de Calderas.

The coordination and management of the Pacaya Volcano Natural Monument is under the responsibility of the National Institute of Forests (INAB), which has defined as a priority of its management the delegation of the management of the different protected areas under its responsibility, to governmental and non-governmental entities for considering this form of administration more efficient and effective for the protection, conservation and management of the natural resources that they contain.

INAB has determined as a priority for 2002-2004 the update of the Management Plan and its implementation to administer and manage the Pacaya Volcano National Park

The Pacaya volcano is located within the Pacific Volcanic Slope physiographic unit, it is part of an area of recent tectonic history, whose geological activity is associated with geological faults parallel to the coastal zone, along the side slopes. south of the volcanic chain. (Dengo 1973)

The most outstanding hydrological detail is the Laguna de Calderas, formed at the bottom of a caldera, it is geologically recent. This 0.35 km2 lagoon is the only source of water in the volcano area.

The water from the lagoon is used mainly for human consumption by the inhabitants settled in the micro-basin and by 14 neighboring towns, with a total of 7,797 inhabitants. See Populations that consume water from the Calderas lagoon

As for the climate, the average temperature varies between 15 and 20 C, depending on the time of year and the altitude. The prevailing winds in the region come from the Northwest (NNE), and influence those that come from the Pacific Ocean, creating more humid areas on the southern slope of the massif. The pluvial precipitation, is greater during the months of June to September, reaches an average of 2,000 mm / year. The months that have little or no precipitation are from December to March. The annual average relative humidity is 80%. This area is considered as a Sub-Tropical climatological zone.According to the De la Cruz Life Zones classification, (1982) Based on the Leslie R. Holdridge Classification System, the "park" area is located in the life zone called«Subtropical (temperate) humid forest.

Regarding vegetation, the most widespread community in the area is the broadleaf type between Cerro Grande and Cerro Chino, which includes species of Quercus oocarpa, Chiranthrodendron sp. and Annona sp.

The other vegetative type found is the coniferous type, on the south side of the park in the old lava flows. the species are exclusively Pinus oocarpa, which are formed from a very open forest.

The land uses present in the volcano area and the vegetation cover correspond to:

A) Mixed Broadleaf Forest, Low Broadleaf with alder B) Alder, Pine forests, Shrublands, Pastures, annual crops C) Riparian aquatic vegetation, Fumarole Belt, Lava flows with primary vegetation.

A more detailed analysis of the situation of the flora in the Pacaya volcano shows that the number of threatened species is really large, which are currently subjected to over-exploitation and constant deterioration due to volcanic eruptions. These are: Cedros, Cedrela pacayana; C. impartialipinata; Pines Pinus pseudostrobus; Pinus oocarpa; Oak, Quercus spp; Pacaya oak Q. oocarpa; Pacayas, Camaedorea spp; Laurel, Nectandra membranaceae; Alder, Alnus arguta, Alnus jorullensis; Custard apple Annona diversiflora; Annona purpúrea, A. lutescens; Manzanote, Olmedieella bestecheriana; various species of the Bromeliad families, Tillandsia usneoides; Catopsios spp.; Araceas, Philodendrom spp.; Anhtricum spp. And Orchidaceae, Bothriochilus guatemalensis; Bleti purpurata; Licaste bloody; Odontoglossum laeve.

As for the mammals found in the Pacaya Volcano region, they are the coyote Canis latrans, the mount cat Urocyon cinereoargentus; thornbody Coendu mexicanus, armadillo Dasypus novenoncintus, tepezcuintle Agouti paca; tacuazín Didelphis marsupialis, mouse tacuazín Marmosa mexicana, skunk Mephitis macroura, Weasel Mustela frenata. Rodents, Peromyscus sp. and Reithrodontomys sp. Heteromys sp.,Baiomys sp. and Oryzomys; bats, Ptenorotus spp.; Myotis spp.; Phyllostomus spp.ardillas Sciurus sp. and the rabbit Sylvilagus floridanus.

It is considered that at present the individuals of the larger species do not form stable populations capable of surviving in the future, due to the accelerated destruction of their habitat, restricting them to quite reduced and isolated territories without connections with other wooded areas.

In addition to the forests of the Volcano area, and the Calderas lagoon, they provide a very important place on the route of several migratory species, mainly a number of birds such as Muscivora forticata flycatchers; Tyrannus tyrannus and Woodpecker Sphyraoicus varius; swallows, Hirundo rustic, Riparia riparia, grebe Podiceps dominicus, gallareta Fulica americana, and various ducks such as Anas affinis, Oxyura jamaicensis. (INAFOR, 1983)

Common are the chocoyos Arantinga holchlora, Asian Zenaida pigeons; warblers, Wilsonia pisuilla, Denroica townsendii; tile Sialia sialis; Thrush Tangavius arneus; sensontle Mimuis gilvus; Tolobojos, Asphata gularis; Guardabarranca, Myadestes obscurus; spiny Atlapetes gutturalis; clarinero Cassidix mexicanus, coronadito, Zonatricha capensis.

Regarding amphibians, the groups that are in greatest danger in the area of the Pacaya volcano are the species of frogs (Fam. Hylidae) and salamanders (Fam. Pletodontidae) that live in the sub-tropical humid forests and cloud forests of the altiplano of the country.

The Pacaya Volcano Park has already lost species and forms, which shows the serious and continuing threats to which wild mammals are especially subjected. This has happened in the Park where most of the larger mammals are no longer found.

The human populations in the area of influence and buffer of the Natural Monument have 9,147 inhabitants, 48% women 52% men. of which 855 belong to the San José Calderas village and 700 to the San Francisco de Sales village, both villages are within the limits of the Park.

Regarding land use, within the volcano area, the lands are dedicated to the production of traditional crops such as coffee (Coffea arabica), avocado (Persea sp.) Jocote (Spondias mombim), orange (Citrus sinensis). The important food crops include the production of Corn (Zea mays) and beans (Phaseolus sp, and the cultivation of vegetables for self-consumption.

Land tenure is unevenly distributed throughout the Park area, with the largest units concentrated in the northern and eastern part of the Lagoon up to Cerro Grande and Cerro Chiquito and Hoja de Queso.

Virtually only the volcanic cone of Pacaya, nobody claims it as their own, so 90% of the totality of the National Park is considered private property.

Essentially the use of the park by visitors is related to outdoor walking activities, along the existing trails to observe volcanic activity, followed by lunches or snacks in the plateau area. Much less intensively, bathing activities or fishing are practiced in the Calderas lagoon. It is notorious that there is a marked tendency to seek recreation in this area during weekdays and holidays, which is largely due to the park's proximity to the capital city and its rapid population growth.However, there are no adequate facilities for the attention of tourists who visit the Pacaya volcano and Laguana Calderas, despite the fact that they are constituted as visitor and recreation centers with great potential for the development of nature and landscape-loving tourism..

There are no exact censuses on the number of visitors to the Pacaya volcano, but it is estimated that approximately 100 people arrive daily on average. The region of influence of the Pacaya volcano is made up of the municipal seat of San Vicente Pacaya, and the villages of El Cedro, Patrocinio, El Rodeo, El Caracol, and the villages of the municipality of Amatitlán: El bejucal, El Pepinal, and Mesias. High. These communities are in a situation of marginalization and underdevelopment that translates into poverty and quite low standards of living. Some of them are characterized by disorderly growth, without having basic household water services, drainage, public lighting, transportation, etc. The Pacaya volcano has biophysical and landscape characteristics such,that justifies its inclusion within the Guatemalan System of Protected Areas (SIGAP), within the category of management of Natural Monument

The main objectives to be achieved in the management and development of the Pacaya Volcano Natural Monument are the following:

Protect and manage the geomorphological features and biodiversity of the Pacaya volcano Provide opportunities for recreation and outdoor tourism Provide environmental education and interpretation services on the resources of the monument Properly manage the area through techniques that conserve and protect soil and water Promote activities of technical assistance Encourage the regeneration of marginal areas affected by inappropriate agricultural practices Encourage study and research on the area's natural resources Contribute to the social improvement and economic well-being of the inhabitants Encourage the recovery of degraded areasContribute to developing sustainable management models

For the assigned category, the following characteristics are presented that justify its category as Pacaya Volcano Natural Monument (MNVP).

The Pacaya volcano area has natural values that justify its designation under the category of Natural Monument, due to its permanent geological activity, its ecological and hydrological features, of scientific and geomorphological interest.

The PNVP is considered as a social, cultural and ecological integrating entity.

The PNVP includes zones of natural forests that increase the biodiversity index, maintain several endemic species of flora and species of fauna in danger of extinction, especially mammals, amphibians and reptiles.

The landscape of the Volcano essentially comprises agricultural areas (100 ha); pastures and bushes (150 ha); coffee with leftovers (300 ha); and areas with intervened forest (400 ha). Sterile areas (800 ha). Its protection is vital for the conservation of water resources (35 ha) of the area corresponds to the Calderas lagoon). In the Multiple Use Zone, the productive uses of the soil and in general the sustainable use of natural resources will have higher priority than the protection of nature.

The MNVP has panoramic areas of great scenic quality in mountainous and volcanic regions with high potential for recreational and educational use.

The Pacaya Volcano appears as one of the great attractions of national and international tourism in Guatemala; about 100 tourists who arrive daily visit the volcano.

This area, under proper management, can provide elements for the sustainable performance of a series of products and services. In later sections, the following are mentioned as more relevant:

Maintaining essential ecological processes is a tangible benefit if the volcanic macerate is protected. This will allow the maintenance of the production of quality water, in a complementary way it will avoid erosion and deterioration of the water quality of the Calderas lagoon.

Maintaining the forest cover reduces the risks of wind erosion, in the same way it helps to preserve the quality of the water and reduce silting of the Calderas lagoon. With this, collaterally the flow regime and the quality of the water that the downstream populations require for their supply will be maintained.

By protecting this area, tourism will be favored, so local economies can benefit considerably. Tourism currently provides the country with foreign exchange and local income. The local economy will be stimulated with hotels, restaurants, transportation systems, handicrafts and guide services.

Local communities as well as national or foreign visitors will benefit from the recreational and educational facilities that are intended to be developed.

Its management can help to develop the infrastructure and services necessary to facilitate education, training and studies that allow to form the bases to understand the natural and geological history of the area, disseminate the knowledge obtained and thereby support the improvement of education. environmental, and the valuation of natural heritage.

Taking the area of the Pacaya Volcano as a base for educational and community outreach operations, the administration of the reserve will be able to promote in its interior and in its areas of influence, demonstrative and explanatory actions about the benefits of the sustainable use of the natural resources and regional sustainable development based on the analysis and execution of socioeconomic options.

The inhabitants can benefit in many ways from the sustainable management of this protected area, including from the use of its resources, the preservation of their traditional rights or cultural practices, to the employment opportunities or social services with which they would be favored.

Much germplasm of the natural patrimony that this area possesses represents a treasure; the short and long term value of these genetic resources is enormous. As a fundamental principle of the conservation of protected areas, the in situ protection of germplasm constitutes an important criterion.

The implementation of mechanisms aimed at the production of firewood and construction wood with continuous yield, reforesting with energy forests, may lead to meeting the demand for such products without detriment to the ecological quality of the remnants of the area. The Pacaya Volcano Area must maintain open multiple-use options, to substantially improve the regional economy. Under this aspect, agriculture can be made compatible with management through zoning and the coupling of other management programs.

The limits always include areas that constitute the geological and ecological values, as well as the most relevant natural features of the Pacaya Volcano, to guarantee that its management results in direct benefits in the conservation of the country's natural heritage, and that it maintains the scenic quality and the natural landscapes of the natural monument. To achieve the proposed management objectives, the Pacaya Volcano National Park was zoned based on the characteristics of its natural elements, the potential and current uses of the soil, the need to maintain both the qualitative and quantitative capacity of water production. and the capacity to provide recreation, tourism, education, research, recovery and sustainable use services. Under such conditions, FOUR management zones were identified.

Protection Zone, Multiple Use Zone, Extensive Use Zone, Recovery Zone.

In this Management Plan, the management programs to be executed in the Pacaya Volcano area are precisely defined, the following programs are suggested: Resource management, social development, technical assistance, research, forest resource management, education environmental, tourism, protection, administration, public relations and extension.

Regarding the development areas, the following are proposed: San Francisco de Sales, La Meseta, Cerro Chino and Laguna Calderas.

INTRODUCTION:

In Guatemala, the recent recognition in government circles of the great importance of natural parks, is having as a consequence the creation of the National System of Protected Areas, (SIGAP) in which the Pacaya Volcano is included. However, this area has not been protected or managed to date, although it is one of the sites that meets the characteristics of being very close to the capital city and for many years it has been admired and visited, to observe the manifestations of volcanic activity and the spectacular landscape that includes the Calderas lagoon. Currently the National Institute of Forests (INAB) within its institutional policies has considered the "National Park" Pacaya Volcano and the Calderas Lagoon, as an area of quite significant tourist potential,which is proposed to develop, so that later, this area is managed with the participation of the residents of the communities surrounding the park.

The decentralization processes of the Government and the interest of non-governmental organizations, the private productive sector and the local communities inserted or adjacent to the Pacaya Volcano area, will facilitate the constitution of an alliance of interested and affected parties, where it is assumed that each one will assume the role that corresponds to him, under clearly established and accepted governmental policies and norms.

The central aspect of this Master Plan is the specification of objectives and goals that guide the management of the area, updated, and prepared through a participatory, dynamic and flexible process, taking into account the need to make human presence and protection compatible. of the biological diversity of the area, making special reference to the rights and interests of the communities that interact with the protected area. The Master Plan may be used to document deficiencies and to list the needs of the area; in this way it becomes a valuable tool for obtaining funds. This plan is intended to serve as a communication tool to gain understanding and support from both the public and state officials.

The Estro Plan is framed within the global operational planning framework of the government of the Republic through the execution of specific actions for the conservation, protection and development of natural resources, as indicated in the Government's Social Policy Matrix 2000-2004. (See Annex No. 5)

OBJECTIVES OF THE MASTER PLAN:

Provide INAB as the administrator of the area, CONAP as rector of the Guatemalan System of Protected Areas -SIGAP-, the municipality of San Vicente Pacaya and civil society, the technical guiding and regulatory instrument necessary for the management and administration of the Park Pacaya Volcano National Operate actions that allow the appropriate management of the Park with the participation of civil society Provide general guidelines to guide the current use and future development of promotion and development actions of the Park Establish general regulations for comprehensive management with the social base of the Park. Serve as an instrument of promotion and guideline to stimulate the conservation and sustainable development of the Park through the active participation of civil society groups and local power.

BACKGROUND:

On July 20, 1963, the Pacaya Volcano and the Calderas lagoon were declared a National Park, located in the municipal jurisdiction of San Vicente Pacaya, Escuintla department, by agreement of the Head of Government, regarding the declaration of closed areas and National Parks. In 1974 the Food and Agriculture Organization of the United Nations (FAO) and the United Nations Development Program, in conjunction with the National Forest Institute, INAFOR, presented the Management Plan for the Pacaya Volcano Natural Monument, prepared by a multidisciplinary team.

In 1975, detailed studies of the area's natural resources were carried out by a Peace Corps team.

In 1988 a thesis on Planning and Architecture was formulated for the Pacaya Volcano Natural Monument

In 1990 a Preliminary Plan for the management of the Laguna de Calderas micro-basin was formulated.

In 1997, the Environmental Management Strengthening Project was formulated by CONAMA / BID. Elaborating a diagnosis and a Land Use Plan for the Municipality of San Vicente Pacaya.

Legal framework:

The Law of Protected Areas and its Regulations (Decree Number 4-89 of the Congress of the Republic of Guatemala), decrees in its following articles, issues related to the Pacaya Volcano National Park and the participation of social actors for this, the following:

«ARTICLE 1: National interest. Biological diversity is an integral part of the natural heritage of Guatemalans and therefore, its conservation is declared of national interest through duly declared and managed protected areas.

«ARTICLE 2: Creation of the Guatemalan System of Protected Areas. The System of Protected Areas (SIGAP) is created, made up of all the protected areas and entities that administer it, whose organization and characteristics established by this law, in order to achieve its objectives in favor of the conservation, rehabilitation, improvement and protection of the natural resources of the country and biological diversity ”.

«ARTICLE 4: Coordination: To achieve the objectives of this law, the closest link and coordination will be maintained with the provisions of the entities established by other laws that pursue similar objectives for the benefit of the conservation and protection of the country's natural and cultural resources. »

« ARTICLE 7: Protected Areas. Protected Areas, including their buffer zones, are those whose objective is the conservation, rational management and restoration of wild flora and fauna, related resources and their natural and cultural integrations, which are highly significant due to their function or their values. genetic, historical, scenic, recreational, archaeological and protective, in such a way as to preserve the natural state of biotic communities, unique geomorphological phenomena, water sources and supplies, critical river basins in protective zones of agricultural soils, in order to maintain sustainable development options.

« ARTICLE 15: Recovery of current protected areas. The recovery of the existing protected areas already declared legally is declared of urgency and national necessity.

« ARTICLE 16: Buffer zone. A buffer zone is established around all existing protected areas or those that will be created in the future, consisting of the territorial surface that protects the proper functioning of the protected area.

OF THE MANAGEMENT OF PROTECTED AREAS

ARTICLE 20 Activities within Protected Areas. The public or private companies that they currently have. or that in the future develop commercial, industrial, tourist, forestry, agricultural, experimental or transport facilities or activities within the perimeter of the protected areas, they will enter into a contract by mutual agreement with CONAP, which will establish the conditions and operating standards determined by an environmental impact study, submitted by the interested party.

«ARTICLE 22 Settlements: Individual or legal persons that are settled within the protected areas or in which in the future they obtain their legal declaration, must adapt their stay in them to the conditions and standards of operation, use and zoning of the unit in question, ensuring its full incorporation into its programmed management ”.

«ARTICLE 88: Legally declared areas. All those protected areas that on the date of issuance of this law, were legally established by legislative decree, decree-law or governmental agreement and are in force, have the full recognition of this law and constitute fundamental bases in the creation and composition of SIGAP, who will proceed to register them in the respective registry, according to article 75 of this law "

DIAGNOSIS OF THE PACAYA VOLCANO NATIONAL PARK

The Pacaya Volcano National Park is located in the municipality of San Vicente Pacaya, Escuintla department, located between the coordinates 14 25 ′ North Latitude and 90 35 ′ West Longitude, it is distant from the capital city by 43 kilometers, it comprises approximately 1,800 hectares, and it contains biological and geological resources unique to Guatemala and the neotropical region.

The Pacaya Volcano National Park is within the municipal jurisdiction of San Vicente Pacaya, administratively it corresponds to the department of Escuintla, it has an area of 236 square kilometers. located between the coordinates 14 20 ′ and 14 26 ′ North Latitude and 90 34 ′ and 90 38 ′ West Longitude. At an elevation that varies from 300 to 2,400 meters above sea level. According to the municipal code, San Vicente Pacaya has the responsibility and the right to monitor all matters related to the soil and the environment within its jurisdiction. It is also the role of the Municipality to assist those institutions dedicated to the conservation of the environment, for the benefit of the inhabitants of the municipality.

On the other hand, the Municipality of San Vicente Pacaya has shown interest in being in charge of protecting municipal territories within the Pacaya Volcano National Park.

The Pacaya Volcano National Park is one of the areas that has the characteristics of serving as one of the most important natural parks in the country, and that for many years has been admired and visited, since in it manifestations of volcanic activity are combined with a spectacular landscape that includes the Laguna de Calderas. It comprises an area of 1,800 hectares, which are home to ecosystems, natural and geomorphological features, scenic beauties and species of flora and fauna of scientific value of national and international interest. Currently the entire site is in an alarming state of ecological degradation, which makes immediate action imperative for its conservation.

The coordination and management of the Pacaya Volcano National Park is under the responsibility of the National Forest Institute (INAB), which has defined as a priority of its management the delegation of the management of the different protected areas under its responsibility, to governmental and non-governmental entities. for considering this form of administration more efficient and effective for the protection, conservation and management of the natural resources that they contain.

INAB has determined as a priority for 1998-2000 the updating of the Management Plan and its implementation to administer and manage the Pacaya Volcano National Park. For this, the INAB requires the support of all the OG'S, NGO's, interest groups and, at the same time, maintain the role of supervisor for the management of the Park. In this way, INAB would have the freedom to coordinate and supervise activities with collaborating institutions, according to its legal mandate.

Physical environmental characteristics

5.1 Location

The park area is located in the Río María Linda basin, it covers an area of approximately 1,800 ha. The northern part of the area is formed by the Calderas lagoon basin, while the southern part is formed mainly by the Pacaya Volcano and the lava flows, which are part of the main drainage of the María Linda River.

5.2 Geology and Geomorphology

It is located at a height of 2,552 meters above sea level, it is part of the southern ring of the Amatitlán caldera, having produced more than 80 kms. cubes of dense rock from pyroclastic deposits caused by 12 large eruptions that occurred between 300,000 and 23,000 years ago (Wunderman 1982). The elevation of its base is around 1,500 meters, the youngest part of the Pacaya consists mainly of 3 eruptive points: MacKenney, Cerro Chino and an inactive cone.

The geology in the park area is exclusively volcanic from the Quaternary period. In the Laguna Calderas basin (geologically the oldest and most developed part of the park), it consists of domes of andesite and dacite (Qa-d) in the southern part of the basin. The remaining part of the park is made up mainly of the Pacaya Volcano and recent lava flows. (Fitzpatrick 1975).

The Pacaya Volcano, is a formation of quaternary origin, it is constituted by a series of superimposed reliefs, such as craters, cones, domes (of which there are 14), volcanic spines, calderas, lava flows, etc., whose formation occurred in different times. It was configured through the stacking of pyroclastic materials, interspersed with lava flows (4) Seen as a whole, the massif, which reaches a height of 2,552 msm, is composed of the following outstanding features:

The Volcanic Cone is made up of two peaks: one that maintained vigorous activity until the last century, and another, active since 1961, called McKenney. The old cone continues to emit a little gas and steam, however it can be scaled to observe the activity of the new cone from there, which apart from emitting smoke and gas, almost constantly launches fragments of basaltic lava, periodically occurring larger eruptions, such as 1987 and 1989. (CONRED 1997)

There are other inactive formations, such as the Cerro Grande, Cerro Chiquito and Cerro Chino, which in turn are mounted on an older volcanic relief. To this belongs the hills of Malpaso, La Mariposa, Limón, and among them are several ancient craters such as Durazno, in which the towns of San Vicente Pacaya and Laguna de Calderas are located. The entire complex rises on a very anitquisite explosion caldera, Amatitlán, which was filled, except to the northeast where Lake Amatitlán is currently located.

There are also fumaroles and solfatarras, rich in clayey materials, and which appear in the cone itself and in the strip along the Cerro Leaf de Queso fault. There are also hot springs in the region, although there are not directly in the park area.

The Laguna de Calderas, formed at the bottom of a caldera, is geologically recent, since the lava flow that closed the water outlet of the caldera belongs to modern activity, possibly from the time of the Cerro Chino cone. This 0.35 km2 lagoon constitutes the only source of water in the volcano area (Fitzpatrick 1975).

A very important volcanic feature of the area that is worth mentioning is the deposition of volcanic ash. This contributes to the permeability of the soils in the more developed areas, the deposition in the recent basalt flows aided the vegetative development. (Pereira 1990)

5.3 Geological events of the Pacaya volcano

The Pacaya volcano is located in the quaternary volcanic chain of Central America. Which extends parallel to the coast of the Pacific Ocean of Mexico and Central America. In Guatemala, the volcanic chain is associated with an outgrowth zone that runs parallel to the Pacific coast in a southeasterly direction from the Tacaná volcano on the western border to the Chingo volcano between Guatemala and El Salvador (Fitzpatrick 1975).

5.3.1 Ancestral cone

The remnant of the ancestral cone of the Pacaya volcano is located in what today corresponds to Cerro Hoja de Queso. The lava flows associated with the ancestral volcano are located in the cliff outcrop east of El Durazno (village located north of Cerro Hoja de Queso). Volcanic Products scattered on the cliffs above the Calderas lagoon and pumice deposits in the North slope of Cerro Hoja de Queso, show that this was the location of a larger chimney. The ancestral activity culminated in eruptions of dacitic pumice causing the collapse of the greater portion of the cone, exposing the caldera of the volcano.

5.3.2 Intermediate volcanism

The most significant activity in this stage was constituted by the presence of basal flow and eruptions of dacitic pumice. In addition, there were eruptions of viscous siliceous lava that produced volcanic domes and lateral flows in the region. There is a minimum of 14 domes in the area of the Pacaya complex. The largest dome in the complex corresponds to Cerro Grande, which is the highest part of the Laguna basin. Its formation is considered by the gradual extrusion of viscous lava. The thorns (the two peaks of Cerro Chiquito) represent the effusion of lava towers through cracks in the dome. The lack of leaks and the thorns indicate that Cerro Grande is the youngest dome in the area. (Fitzpatrick 1975)

5.3.3 Recent activity

The most recent eruptive stage began with the eruption of basalt lava and pyroclasts shortly before the completion of Cerro Grande. the eruptions originated chimneys in the Calderas somma. The oldest lava flow is south of Pacaya, the configuration indicates a chimney now covered by Cerro Grande. It is presumed that the chimney gradually moved west into the Calderas "somma", ending near the top of the Pacaya.

Two small streams spread north from other chimneys in Cerro Chiquito near the Meseta area, one formed a dam preventing the exit of water from the existing caldera, thus causing the formation of the lagoon (Fitzpatrick 1975).

5.3.4 Modern volcanism

From 1880 to June 1961, the Pacaya volcano was a simple asymmetrically composed cone. In 1961 the Pacaya volcano erupted after a quiet period of fumarole emissions for more than 80 years.

In 1962 a portion of the western slope of the cone began to collapse, thus forming the crater or 'mouth. Volcanic activity until July 1965 comprised only massive degradation of the crater walls and their enlargement, as well as emissions of smoke and gases from the fumaroles in the crater and on the summit of Pacaya. But from that date the appearance of incandescent lava began in the crater; since that time the activity has continued almost constantly. Volcanism generally alternates with explosive activity of the 'Strombolean' type to long periods of light activity of the Vulcanian type '(Fitzpatrick 1975)

To date, the Pacaya volcano has maintained constant activity for 25 years. There are historical records of the activity of this volcano since 1,565 and suggest that eruptions occur every 100 years. (CONRED 1997)

The last two explosive-type eruptions. The first was on January 21, 1987, and the second on January 25 of the same year. To date, it has had less intense activity, which according to INSIVUMEH reports have been recorded as follows:

November 21, 1996: Swarm of tecto-volcanic earthquakes, the source of which initially appeared on the surface at depths between 0.3 and 1.0 km. under the volcanic building:

November 28, 1996: Continuous fear has been registered, alternating with techno-volcanic earthquakes that occur with a frequency of one event every 2 to 3 minutes.

June 28, 1997: Weak to moderate explosions and some strong, launching pyroclastic material at heights of 25 to 50 meters.

July 7, 1997. Eruptions every two hours spewing lava at a height of approximately 5 meters from the crater level, towards the south side. In the northern part of the volcano cone, a new crater formed.

July 12, 1997: New craters were formed that expelled pyroclastic material of different sizes, which has given rise to the formation of small rivers of lava on their slopes.

July 21, 1997: Small explosions heard every 10, 15 and 20 seconds.

August 13, 1997: At 23:00 hours the activity increased (strombolian type). In the visual count of 15 minutes every hour, there is a minimum of 299 explosions and a maximum of 309; said explosions, small, moderate for the most part. Some forts lift incandescent material to 25, 50 to 300 meters or so. Emission of blue and white gases accompanies the explosive activity.

August 16, 1997: It was possible to visualize the lava that was emanating from the volcano towards the town of Patrocinio and El Rodeo, calculating the river of lava with an approximate distance of 200 meters from the central cone.

August 26, 1997: It dawned with 4 rivers of lava, two descending on the southwest flank oriented towards the Caserío El Rodeo, both emerging through the same hole about 100 meters below the craic edge, the longest is approximately 400 meters and the another parallel continuous one, reaches approximately 200 meters. This wash is approximately 850 meters long in the direction of Las Granadillas mountain, where I burn and drag some trees. (CONRED 1997)

5.4 Hydrology:

5.4.1 Drainage network:

The area of the Volcano is located within the basin of the María Linda or Michatoya river, it does not have any permanent current, only ephemeral currents, formed during the occurrence of rainfall, which decrease or increase its flow, based on the intensity of the same. As a product of the existing relief, the drainage of the ephemeral streams) in intense precipitation events are rapid due to the short concentration time. (Pereira 1990)

5.4.2 Surface waters:

The only source of surface water in the park is the Calderas lagoon, with a surface area of 32.40 hectares. The water from the lagoon is used mainly for human consumption by the residents settled in the micro-basin and by 14 neighboring towns, with a total of 7,797 inhabitants. See Towns that consume water from the Calderas lagoon For this consumption there are 4 pumps of different capacities installed that carry water to the aforementioned villages. Additionally, residents of villages and farms near the lagoon, move towards it in search of water. Despite the existence of drinking water distribution systems, the San José Calderas village always uses the water at the level of the lagoon for personal hygiene, washing clothes and collection in containers,as a result of your pumping system not working regularly. The other villages increase their consumption after pumping systems during the dry season (Pereira 1990).

5.4.3 Groundwater

At present, no analysis has been carried out on this resource. Notwithstanding the above, in drilling activities for geothermal purposes carried out in the area, underground flows have been found that must be studied at a greater intensity.

5.4.4 Potential use of water

According to the current trend, the potential use of water is constituted by human consumption; however, some recreational uses can be promoted, as long as they are carried out under a resource management program. (Pereira 1990)

5.5 Climatology

According to the Thornthwaite classification system, the character of the climate is temperate, without a well-defined cold season, humid with dry winter and natural vegetation characteristic of forest. The average temperature varies between 15 and 20 C, depending on the time of year and the altitude. The prevailing winds in the region come from the Northwest (NNE), and influence those that come from the Pacific Ocean, creating more humid areas on the southern slope of the massif. The pluvial precipitation, is greater during the months of June to September, reaches an average of 2,000 mm / year. The months that have little or no precipitation are from December to March. The annual average relative humidity is 80%. This area is considered a Sub-Tropical climatological zone (FAO-INAFOR)

In the San José Calderas Village there is a key type «B» meteorological station 06-02-2h called Calderas. The mean values obtained from 1975 of the parameters temperature, precipitation and evaporation are the following: (INSIVUMEH 1997)

5.5.1. Life zones

According to the classification of Life Zones by De la Cruz, (1982) Based on the Leslie R. Holdridge Classification System, the area of the «park» is located in the life zone called «Subtropical humid forest (temperate), which presents as main characteristics: Periods of rain frequently in the months of May to November; biotemperatures between 18-24 degrees centigrade; potential evapotanspiration ratio of about 1.0. The land corresponding to this area is of undulating to rugged relief. The natural vegetation is made up of Pinus oocarpa Schide and Quercus spp. which are the indicator species. The proper use of these lands is clearly forestry (Fitzpatrick 1975).

5.6 Soils

The soils present in the volcano area correspond to the soils of the Pacific Decline, differentiated into volcanic, metamorphic and sedimentary, from moderate to highly susceptible to erosion, due to the steep slopes (URL 1987). They belong to the series of soils Palín, Metapa, Escuintla and Pacaya (Simmons et. Al, 1959). The soils in the park area are a reflection of its volcanic origin. The soils are generally permeable with high content of sand and gravel in horizons A and B. Textures in horizons A range from sandy loam soil to other sandy clay soil, with depths between 8 to 20 cm. The horizon B, is formed especially of a clayey sand and / or gravel with depth between 40 to 60 cm. The material mainly from the C horizon is also quite permeable.Due to the high permeability of the soils in the Calderas lagoon basin and on the eastern side of Cerro Grande, laminar erosion is generally not a serious problem. However, gully and furrow erosion presents a high risk of advanced erosion on steep slopes, due to the lack of cohesion of these openings. The nutritional value of cultivated lands also seems to be a consequence of its volcanic nature. The soils are generally rich in potassium, low in phosphorus and variable in nitrogen content. The Ph is slightly acidic, varied between 6.1 and 6.95. (Pereira 1990)the erosion of the gullies and furrows presents a high risk of advanced erosion on the steep slopes, due to the lack of cohesion of these openings. The nutritional value of cultivated land also appears to be a consequence of its volcanic nature. Soils are generally rich in potassium, low in phosphorus, and variable in nitrogen content. The Ph is slightly acidic, varied between 6.1 and 6.95. (Pereira 1990)the erosion of the gullies and furrows presents a high risk of advanced erosion on the steep slopes, due to the lack of cohesion of these openings. The nutritional value of cultivated lands also seems to be a consequence of its volcanic nature. The soils are generally rich in potassium, low in phosphorus and variable in nitrogen content. The Ph is slightly acidic, varied between 6.1 and 6.95. (Pereira 1990)

5.6.1 Erosion and sedimentation process:

The biggest problem of erosion and runoff in the area is the drainage of the Calderas lagoon. The main sources of sedimentation are: The gullies and the erosion of cultivated areas, trails and roads. The use of lands with forest vocation for agricultural purposes and the lack of knowledge in the implementation of soil conservation practices, are causing a high rate of erosion in channels or small furrows, which consequently could cause problems of gully formation, in addition of the existing ones.

The most serious threat to the quality of the water in the area with regard to sedimentation, is the formation of gullies. All the causes of erosion and its consequent sedimentation must be corrected to avoid irreversible damage. (Pereira 1992)

5.7 Current use and land cover

In general terms, it is indicated that there has been a decrease in permanent natural coverage, with an increase in areas dedicated to agriculture, which, given the fragility of ecosystems and the failure to adopt technical measures for the use of land, have had a negative impact in the environmental environment.

5.7.1 Current coverage

Due to the variability of land use, development, geological activity, etc., a variety of vegetative types occur in the area. Approximately 20% of the park is cultivated mainly for coffee and corn. The most widespread community in the area is the broadleaf type between Cerro Grande and Cerro Chino, which includes species of Quercus oocarpa, Chiranthrodendron sp. and Annona sp. The other vegetative type found is the coniferous type, on the south side of the park in the old lava flows. the species are exclusively Pinus oocarpa, which are formed from a very open forest.

The land uses present in the volcano area and the vegetation cover correspond to:

Broadleaf Mixed Forest, Broadleaf lowland with alderAliso, Pine forests, Shrublands, Pastures, annual cropsRiparian aquatic vegetation, Fumarole Belt, Lava flows with primary vegetation.

5.7.1.1 Mixed broadleaf forest.

This type of vegetation is the most complex of the existing ones, as a result of the diversity of species it harbors. Under natural conditions, the forest is formed by high, dense and mixed forest of broadleaf trees, an intermediate floor of shrubs and a low floor of well-developed guamiles. Within the forest there are areas of natural and man-made disturbances, in such areas the state of the forest varies considerably in relation to its natural composition. In this forest, epiphytes and lianas are common. Almost all trees are hosts of orchids, bromeliads, araceae, cataceas, ferns, lianas of various genera. In areas of natural disturbances caused by landslides, plants of a species of bamboo of the Chusquea genus developspp. The forest is exploited by loggers who selectively cut down trees for firewood, mainly oaks. Although to a lesser extent the destruction of the natural forest is observed for the incorporation of areas in agricultural and livestock activities. This use is producing the erosion of the forest resource, ecological destruction and the decrease of the scenic quality of the area. The inhabitants of the area graze cattle and horses in the forest. Free animals open rustic trails and disturb the guamil especially on steep slopes. Although cattle grazing started in the areas exploited for firewood, the cattle have already reached more remote areas, including the summit of Cerro Grande. The volcano is affecting the vigor of the vegetation in several areas, especially in the summits of Cerro Grande,Cerro Chino and Cerro Chiquito. The volcanic ash is forming deposits on the branches of large trees. The deposits are favorable habitats for epiphytic plants. The weight of the ash masses and the epiphytic plants cause the branches of old trees to break.

In areas of degenerated vegetation, it is observed that the regeneration of trees is very poor. It is also noted that several of the large trees are not producing fruit, especially the Quercus. sp.. It is certain that the effects of the eruptions are interfering with pollination and seed production. Another possibility is that most trees are very old, and therefore do not reproduce effectively. (Fitzpatrick 1975)

5.7.1.2 Low mount broadleaf with Alder

This type shares species with the mixed broadleaf forest and also has alder. The upper floor is much more open and the trees are short, the understory is more developed and is continuously exposed to the effects of the eruptions, that is, it is in a state of constant natural disturbance.

5.7.1.3 Alders, Alnus sp.

The area looks very arid due to the lack of vegetation cover, the open nature of the vegetation. The vegetation cover is partial, the density of the canopies is very scarce, the guamil cover is not very dense and there are areas where vegetation is completely lacking. The eruptions affect the vegetation cover as soon as there are volcanic ash deposits causing a permanent disturbance. The area looks very arid due to the lack of vegetation.

5.7.1.4 Pine forests

Within the Park there are areas to the east and south of the volcano where the predominant vegetation is pine trees, Pinus pseudostrobus and Pinus oocarpa, which have grown on old volcanic cones or old lava flows. The conditions of the pines are poor, since the forest has suffered a high mortality and the rest of the living trees are weak. Forest conditions are a result of frequent volcanic eruptions, the expulsion of ash and gases, which destroy the foliage and limit the ability of the trees to reproduce.

5.7.1.5 Shrubs and Thickets:

The origin of these vegetation is inferred as a derivative of the mixed forest due to its degeneration due to natural disturbances. The volcano is the agent of the disturbance. In the area there are isolated trees that are considered relics of the previous forest. Their physical condition is weak and they are laden with masses of volcanic ash. The largest number of vegetation present is herbaceous, grasses and shrubs.

5.7.1.6 Grasslands.

This area is made up of pastures with few shrubs, mainly Gaultheria cummingii and Myrica cerífera, it is located mainly in the basalt flow of the old Pacaya volcano and in areas of abandoned crops; in areas that have suffered from overgrazing it is common to find the Mimmosa albidia shrub considered an invasive plant after overgrazing.

5.7.1.7 Riparian aquatic vegetation.

The vegetation of this type is located on the banks of the lagoon and the hydrophytic plants. The upper vegetation corresponds to willow (Salix spp) and a guamil made up of cyperaceae, grasses, asteridaceae, among others. The plants that make up the hydrophyte community correspond to: Hidrocotyle umbellata, which prefers shallow depth, Potamogeton illioensis, with preference greater depth; tulle, Scirpus californicus at medium depth, Chara spp., which is submerged.

5.7.1.8 Fumarole Strip

The title comes from the characteristics of the site where this vegetation develops, which results from a relationship between it and the volcanism present there, this area presents special characteristics of soil with a high concentration of clays and of subsoil with high temperatures (80 at 90 degrees Celsius) circumstance that has its effects on the vegetation present. In general, the existing vegetation in the area is a combination of grasses and herbs, whose roots have limited penetration, in addition to not achieving uniformity in their existence in the area. (Fitzpatrick 1975)

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