With approximately 32,809,370 ha (25.5% of the country’s area) covered by hyper-arid, arid, semi-arid, and dry sub-humid areas, Peru is one of the South American countries with the largest extension of drylands [1]. As part of the UNCCD Land Degradation Neutrality Target setting process, in 2020, the Ministry of the Environment (MINAM) estimated the national baseline of degraded lands [2]. A total of 22,248,100 ha (17.47% of the country’s total area) of degraded land was identified in 2015. Several types of land degradation occur in Peru.
According to Peru’s National Strategy to Combat Desertification and Drought (2016–2030) [1], severe erosion affects about eight million hectares, mostly in the Sierra region (5.8 million ha), followed by the Costa (1.9 million ha), and the Selva (0.3 million ha) regions. About 31 million hectares of the country shows moderate erosion, 33.9 million hectares are slightly eroded, and 55.6 million ha are very slightly eroded.
Areas in which municipal waste has been continuously dumped without proper environmental protection measures have been degraded and have been permanently closed to be restored or reconverted. A 2018 countrywide inventory of the areas degraded by accumulation of municipal waste identified a total of 1,585 degraded sites, covering 1977.6 ha, mainly in the Lambayeque, Ica, Piura, and Lima departments [3].
Widespread small-scale, artisanal mining causes severe environmental impacts such as destruction of vegetation and soils, and release of mercury and other hazardous substances into water, soils, and the environment. A 2014 inventory carried out by the Ministry of the Environment estimated annual emissions and release of mercury as of 69–343 tonnes. The main sources included mercury amalgamation-based processes for gold and silver extraction, copper and zinc mining, and other industrial processes. In addition, numerous mines that were shut down long ago, with no decommissioning treatment nor environmental cleanup, exist across the country. Small-scale, artisanal mining has also left numerous sites that, after having been depleted, were simply abandoned with no decommissioning treatment. Parts of those heavily contaminated sites are, or can be, exposed to weather and their contents lixiviated and infiltrated into the ground, or eroded and carried away by rainwater, thus passively polluting the soil, ground and surface waters in their vicinity. The Ministry of the Environment has been inventorying legacy contaminated sites from mining activities; the latest (2020) iteration [4] identified a total of 7,956 contaminated sites across the country, most of them in the departments of Ancash, Cajamarca, Puno, and Huancavelica.
Legacy contaminated sites from the hydrocarbon sector include abandoned oil wells and facilities, contaminated soils, waste, and waste deposits that were improperly decommissioned after cessation of operations [5]. By being exposed to weather, chemicals contained in these heavily contaminated sites can passively contaminate soils, ground and surface waters in the vicinity. The Ministry of Mines and Energy has been inventorying legacy contaminated sites from the hydrocarbon sector; the latest (2017) iteration [6] identified a total of 3,457 contaminated sites, most of them in the in the department of Piura in the Pacific hydrographic region, and only 26 in the Amazonian region.
Agriculture is the economic activity most severely affected by soil degradation, especially in the departments of Cajamarca, Áncash, Cerro de Pasco, Huancavelica, Ayacucho, Puno, and Huánuco. Most of Peru's desertified areas are home to populations with medium to low human development indices; as they are highly dependent on agriculture productivity for their livelihoods, poor communities are most severely affected by desertification [7], [8].
Desertification in Peru is caused by both anthropic and natural causes. Natural causes include extreme weather events such as protracted droughts that contribute to the expansion of arid areas. Anthropic causes mainly include inadequate management practices such as the removal of vegetation cover on slopes, land use change, use of inadequate irrigation schemes, inadequate farming practices (e.g., cultivation of annual crops on slopes, extensive cattle ranching in tropical rainforest areas), unsustainable forestry and mining activities, and others [1], [7].
Soil salinization, water erosion, wind erosion, and soil contamination by mining tailings are the main drivers of desertification in the Costa region. At least 40% of the cultivated area in the Costa is estimated to present salinization problems, caused by inadequate irrigation techniques that have favored salt deposition. Water and wind erosion, soil compaction by overgrazing, and contamination are the main drivers in the Sierra region; and water erosion in the Selva region.
Key policies and governance approach
Peru is party to the United Nations Convention to Combat Desertification since 1995. In compliance to its obligations to the convention, Peru produced its first National Programme of Action to Combat Desertification in 1996 [9] and is currently formulating an updated version.
Peru’s National Strategy to Combat Desertification and Drought 2016-2030 [1] was approved in 2016. The strategy pursues the general objective of preventing and reducing desertification, land degradation, and the impact of drought on the national territory over the 2016–2030 period. The strategy’s targets include: restore 7.5% of desertified, degraded, and drought-affected land, recovering at least 0.5% of affected land annually; implement actions to prevent desertification, land degradation, and the impact of drought in 35% of the affected areas; increase carbon stocks (soil and plant biomass) in the affected areas by at least 2% annually; increase net primary productivity in affected areas by at least 2%; among others. MINAM is formulating an updated National Programme of Action to Combat Desertification to support implementation of the Strategy 2016–2030.
Peru submitted its Land Degradation Neutrality Target pledge [10] to the UNCCD in 2020, including the estimation and definition of the voluntary target, as well as the identification of measures to attain land degradation neutrality in the country. Peru pledged to contain or reduce the extent of degraded land estimated for 2015 (baseline year), 22,248,100 ha (approximately 17.47% of the country territory), up to 2030.
Measures taken to address soil degradation caused by gold mining operations include ratification of the Minamata Convention in 2015. In compliance to its obligations to the convention, Peru formulated its National Plan of Implementation of the Minamata Convention on Mercury and, to implement the National Plan, MINAM is carrying out the project 'Capacity Building for the Control of Mercury Emissions and Releases in Peru'. This project will allow regularly updating the national inventory of mercury emissions and release, as well as formulating a plan to reduce mercury emissions and releases.
A contingency fund for financing the environmental remediation of sites contaminated by hydrocarbon activities was created [11] in 2015. The Act that created the Contingency Fund for Environmental Remediation also sets the guidelines for environmental remediation of impacted sites.
Specific regulations and technical standards have also been issued. For instance, regulations to address soil degradation by solid waste include the 2017 Integrated Solid Waste Management Act [12], the National Plan for Integrated Solid Waste Management 2016-2024 [13], and others.
SUCCESSES AND REMAINING CHALLENGES
Updated data on the evolution of land degradation in Peru are not available. However, despite the recent attention and efforts devoted to address these issues, it is believed [7], [8] that much remains to be done on this regard.
Peru's ratification of the Minamata Convention on Mercury is an important step towards reducing the emission and release of mercury, particularly in small-scale artisanal mining. It is essential, however, to tighten the environmental regulation and control of such activities. Remediation measures have been applied to only 10% of the sites contaminated by mining activities identified by the national inventory [8].
Regularly updated, comprehensive data on the evolution of land degradation in Peru are not available. This deficiency makes identifying hot-spots and direct corrective actions difficult and uncertain.
However, addressing the anthropic causes of land degradation involves long-term, large-scale, costly interventions including:
- preventing or reducing the environmental impact of mining operations,
- the remediation and reclamation of contaminated sites,
- adoption of sustainable farming practices and irrigation schemes, etc. [10]
[5] Ley Nº 29134 Ley que regula los pasivos ambientales del subsector hidrocarburos.
[7] Ministerio del Ambiente 2021. Informe Nacional sobre el Estado del Ambiente 2019.
[9] MINAGRI. 1996. Programa de acción nacional de lucha contra la desertificación
[11] Ley No. 30321. Ley que crea el fondo de contingencia para remediación ambiental.