Spatio-temporal vegetation changes in the Pacific-Chocó region of Colombia during the conflict and post-conflict periods

Abstract (Spanish)

En 2016, tras décadas de conflicto armado, el gobierno colombiano firmó un acuerdo de paz con las Fuerzas Armadas Revolucionarias de Colombia - Ejército del Pueblo (FARC-EP). Sin embargo, las esperanzas de paz no se han materializado, ya que persisten la violencia, los asesinatos de líderes sociales, el desplazamiento de comunidades locales y la degradación ambiental.
Nuevos grupos se están apoderando de las zonas anteriormente controladas por las FARC-EP, lo que provoca deforestación y desencadena nuevos conflictos. Empresas nacionales e internacionales y grandes terratenientes locales se están apropiando de tierras y talando la selva tropical para expandir sus cultivos o utilizar tierras recién despejadas para la ganadería y el pastoreo. Además, la minería legal e ilegal está en aumento y nuevos grupos narcotraficantes están expandiendo sus cultivos de coca, todo lo cual provoca deforestación. La Amazonía colombiana es la más afectada, pero otras zonas enfrentan los mismos problemas. En este caso, la atención se centra en la región del Pacífico-Chocó, poco estudiada y desatendida, donde habita la mayor población indígena y afrocolombiana del país.
Dado que los vínculos entre el entorno natural y las prácticas de consolidación de la paz están escasamente documentados, este estudio pretende llenar los vacíos de conocimiento. El objetivo es comparar la distribución de la vegetación en la región Pacífico-Chocó de Colombia durante los períodos de conflicto (2005-2015) y posconflicto (2016-2023); analizar los cambios observados en la vegetación y sus posibles causas, y finalmente, discutir las posibles aplicaciones de la teledetección y Sistemas de Información Geográfica (SIG) durante los períodos de conflicto y posconflicto.
La tesis utiliza datos del Índice de Vegetación Mejorado (EVI) provenientes de teledetección y los SIG para analizar los cambios espaciotemporales en la vegetación. Se estudió la fenología de la vegetación y se correlacionó con la precipitación, mientras que se calculó la tendencia del EVI mediante regresión lineal. Los resultados de la tendencia del EVI se analizaron para diferentes tipos de uso del suelo, así como para los departamentos administrativos.
En general, la tendencia del EVI fue ligeramente positiva durante el conflicto y visiblemente negativa en el posconflicto, lo que indica una disminución de la actividad de la vegetación en el posconflicto, especialmente en los departamentos del norte de la región. El área con tendencia negativa del EVI aumentó un 17%, y el área con tendencia positiva disminuyó un 2% en el posconflicto, principalmente en áreas forestales y tierras de cultivo. Se han identificado puntos críticos con una tendencia negativa del EVI, pero también algunas áreas más pequeñas con una tendencia positiva alta del EVI en cada departamento. Chocó es el departamento que experimenta la tendencia más negativa del EVI en el posconflicto. Valle del Cauca es el único departamento donde se observa un mayor reverdecimiento y una disminución de la tendencia negativa del EVI en el posconflicto.
La disminución de la actividad de la vegetación se relacionó principalmente con el cambio de uso del suelo y la deforestación para la expansión de las tierras agrícolas, la minería y los cultivos ilícitos. La disminución de la vegetación en las zonas de cultivo podría implicar abandono debido al desplazamiento de personas, mientras que el reverdecimiento puede indicar la restauración de bosques o la expansión de cultivos en áreas previamente abandonadas. Los resultados de esta tesis concluyen que el medio ambiente y los recursos naturales deben incluirse en las negociaciones de paz, ya que, sin ciertas regulaciones, aumentan las posibilidades de mal uso y devastación, lo que dificulta la construcción de una paz sostenible. Además, la teledetección y los SIG pueden proporcionar datos para facilitar la toma de decisiones durante las negociaciones de paz, así como para monitorear el uso del suelo y los cambios ambientales como medida preventiva.

Abstract

In 2016, after decades of armed conflict, the Colombian government signed a peace agreement with the Revolutionary Armed Forces of Colombia – People's Army (FARC - EP). Nevertheless, the hopes for peace have not been realised, since violence, assassinations of social leaders, displacement of local communities and environmental degradation still occur. New groups are taking over the areas formerly controlled by FARC – EP, which is causing deforestation, as well as triggering new conflicts. National and international companies and large-scale local landlords are taking land and cutting down rainforests to expand their crops or to use newly cleared land for cattle ranching and pastures. Furthermore, legal and illegal mining is increasing and new narcotrafficking groups are expanding their coca crops, all of which leads to deforestation. The Colombian Amazon is the most affected, but other areas face the same issues. Here, the focus is on the Pacific-Chocó region, understudied and neglected, and home to the country’s largest indigenous and Afro-Colombian population. Since the links between the natural environment and peacebuilding practices are scarcely documented, this study aims to fill gaps in knowledge. The objective is to compare vegetation distribution in the Pacific-Chocó region in Colombia, during periods in the conflict (2005-2015) and post-conflict (2016-2023); analyse observed vegetation changes and possible causes and finally, discuss possible applications of Remote sensing and GIS during conflict and post-conflict periods. The thesis uses Enhanced Vegetation Index (EVI) data from remote sensing (RS), and Geographical Information Systems (GIS) to analyse spatio-temporal vegetation changes. Vegetation phenology was studied and correlated to precipitation while the EVI trend was calculated, using linear regression. The results of EVI trend were analysed for different land use types as well as administrative departments.
Overall, the EVI trend was slightly positive during the conflict, and it is visibly negative post-conflict, indicating a decline in vegetation activity in the post-conflict period, especially in the northern departments of the region. The size of the area with negative EVI trend has increased by 17%, and the size of the area with the positive trend has declined by 2% post-conflict, mostly in forest areas and croplands. Hotspots with a negative EVI trend have been identified, but also a few smaller areas with a high positive EVI trend in each department. Chocó is the department experiencing the most negative EVI trend post-conflict. Valle de Cauca is the only department where more greening and a decline in the negative EVI trend in the post-conflict period is observed. A decline in vegetation activity was mostly related to land use change and deforestation in order to extend agricultural land, mining and the cultivation of illicit crops. Vegetation decline in cropland areas could imply abandonment due to the displacement of people, while greening can indicate restoration of forests or larger crop cultivation of previously abandoned areas. The results from this thesis lead to the conclusion, that the environment and natural resources should be included in peace negotiations, because without certain regulations, the possibilities of misuse and devastation increase, making it harder to create a sustainable peace. Furthermore, remote sensing and GIS can provide data to help with decision-making during peace negotiations, as well as monitor land use and environmental changes as a preventive measure.

Popular Abstract

In 2016, Colombia signed a historic peace deal with the Revolutionary Armed Forces of Colombia – People's Army (FARC – EP), ending decades of armed conflict. But the hope that peace would bring harmony has faced a tough reality: violence continues, social leaders are targeted, and the environment—especially Colombia’s lush rainforests—is suffering.
This is particularly evident in the Pacific-Chocó region, a rich, biodiverse area home to many Indigenous and Afro-Colombian communities. This region, often overlooked in research and policymaking, is now caught in a new wave of land grabs and environmental destruction. After FARC’s retreat, new armed groups, big landowners, national and international companies rushed in and began exploiting land once controlled by guerrilla forces. They're clearing forests to expand their crops and cattle pastures or for legal and illegal mining activities and coca plantations.
To track vegetation change over time, the study used the Enhanced Vegetation Index (EVI) – a measure derived from satellite imagery – along with Geographical Information Systems (GIS). Data from the period in the conflict (2005 – 2015) was compared to post-conflict years (2016 -2023), and trends across different land use types and administrative departments were observed.
The study found that the areas with vegetation loss have increased by 17% since the peace deal was signed and areas showing recovery or greening have decreased by 2%. The Chocó department is experiencing the steepest decline, with only the Valle de Cauca department seeing some environmental improvement. Loss of vegetation is often tied to land use change, deforestation, mining, and illegal crops. But it can also mean people are being displaced, leaving their farmland and croplands behind. On the flip side, some green “hotspots” might mean forest recovery or returning farmers and plant cultivation.
Instead of recovering, many forests are still being cleared. This challenges the idea that peace automatically benefits the environment. The natural world is left out of peace talks, even though it plays a critical role in local livelihoods, biodiversity, and long-term stability. This research shows that peace and environmental protection must go hand in hand. It matters to policy makers, who shape post-conflict land policies; environmental organizations, who need data to guide restoration; local communities, who rely on forests for food, water, and cultural identity; and peacebuilders, who need to factor in environmental risks when planning sustainable recovery. Remote Sensing and GIS offer powerful ways to track environmental change and so highlight problem areas, thus helping policymakers protect both people and the environment. Peace isn’t just about stopping bullets—it’s about protecting forests, land, and communities. If Colombia wants true, lasting peace, its natural environment must be part of the conversation.

• author: Pretkovic, Vedrana
• supervisor: Micael Runnström
• organization: Dept of Physical Geography and Ecosystem Science
• course: GISM01 20232
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Earth and Environmental Sciences
• keywords: Geography, Geographical Information Systems, Remote sensing, EVI, Pacific-Chocó region, Colombia, post-conflict, peacebuilding, vegetation change
• publication/series: Master Thesis in Geographical Information Science
• report number: 190
• language: English
• id: 9206324
• date added to LUP: 2025-08-07 08:41:44
• date last changed: 2025-08-07 08:41:44