8 research outputs found
Annual forest cover conditions across the Southwestern Amazon, 2003-2021
A Landsat-based machine learning algorithm (Reygadas et al. 2021, Environmental Research Communications) adapted from Wang et al. (2019, Remote Sensing of Environment) to the Southwestern Amazon was used to map intact forest, degradation, and deforestation in this region on a yearly basis during the 2003-2021 period. Degradation is defined as a long-term process in which forest is negatively affected but it is not converted into another land-cover. In contrast, deforestation is defined as the permanent, or long-term, conversion of forest into non-forest. The algorithm classifies forest covers by training a random forest model with sixty-six metrics derived from six time series variables (i.e., the Normalized Difference Vegetation Index, two shortwave infrared bands, two Normalized Difference Water Indices, and the Soil-Adjusted Vegetation Index) from which eleven descriptive statistics are calculated. As the algorithm uses statistical characteristics of time series to determine the forest conditions in the end of the study period, time series composed of the last 20 years prior to the target year were used in each annual run. A forest mask, composed of all areas covered by forest at least three consecutive years and never covered by water during the 2000-2018 period, was applied to all maps. A data key is included in the description of each file. Note: Although the same algorithm is used in Reygadas et al. (2021), these data differ from those of the manuscript as they are annual and cover a larger area. (2020-01-05
Cambio en la amenaza de inundación en cuatro subcuencas del sur de la Ciudad de Morelia, Michoacán, 1995-2050
Mapa de Carreteras Propuestas, Parques Nacionales, y Topografía de la Sierra del Divisor, Perú-Brasil
Cartógrafos: Yunuen Reygadas, D. S. Salisbury
Información disponible: http://www.stephaniespera.com/, https://servir.ciat.cgiar.org/ , https://blog.richmond.edu/dsalisbury/
A finales de 2020 las bases de datos geográficos oficiales de los dos países muestran a las dos carreteras propuestas que llegan a la frontera internacional en dos lugares separados que no se unen entre sí.
“En el suroeste de la Amazonía se encuentra la Sierra del Divisor, un grupo aislado de picos y crestas cubiertos de niebla que se elevan desde la húmeda selva baja de las tierras bajas. Los bosques de estas crestas y valles ferozmente diseccionados aún resuenan con el gruñido bajo del jaguar y los ruidos atronadores de cientos de manadas de pecaríes de raya blanca, mientras el dosel se balancea con las tropas del raro mono rojo Uakarí. Esta biodiversidad inspiró la creación del Parque Nacional Serra do Divisor y su reserva hermana transfronteriza, pero estos bosques también son el hogar de seres humanos: los descendientes de los guerreros Ashéninka y los extractores de caucho, un pueblo Nawa resurgente y el más esquivo, los Isconahua no contactados . Estos territorios y ecosistemas se entrecruzan con las cicatrices efímeras de los recién llegados: madereros, mineros y narcotraficantes. Sin embargo, la línea más importante de la Sierra del Divisor es la frontera en sí, el límite internacional que sigue la cordillera de la Sierra que divide la cuenca del río Ucayali en Perú de la cuenca Juruá de Brasil en el estado de Acre. Relativamente equidistantes de la línea divisoria de la cordillera se encuentran dos ciudades, Pucallpa, la capital de Ucayali, y el centro comercial occidental de Acre, Cruzeiro do Sul. Ambas ciudades son el final del camino para la red de carreteras de su país. Por ahora. Los planificadores y funcionarios gubernamentales ven cada vez más los 160 kilómetros de bosque que separan las dos ciudades como una obstrucción temporal a la integración continental” (Salisbury et al., 2013, p. 129).https://scholarship.richmond.edu/geography-maps/1018/thumbnail.jp
Mapa de Estradas Propostas, Parques Nacionales, e Topografia da Serra do Divisor, Perú-Brasil
Cartógrafos: Yunuen Reygadas, D. S. Salisbury
Informação disponível: http://www.stephaniespera.com/, https://servir.ciat.cgiar.org/ , https://blog.richmond.edu/dsalisbury/
No final de 2020, as bases de dados geográficas oficiais dos dois países mostram as duas estradas propostas alcançando a fronteira internacional em dois locais separados que não se ligam entre si.
“No sudoeste da Amazônia fica a Serra do Divisor, um grupo isolado de picos e cumes cobertos de névoa que se erguem da floresta úmida de planície. As florestas desses picos e vales fortemente delineados ainda ecoam com o rosnado baixo do jaguar e os ruídos estrondosos de centenas de rebanhos de queixadas, enquanto a cobertura florestal balança com os bandos do raro macaco vermelho Uakari. Essa biodiversidade inspirou a criação do Parque Nacional da Serra do Divisor e sua reserva irmã transfronteiriça, mas essas florestas também abrigam humanos: os descendentes dos guerreiros Asheninka e seringueiros, o povo Nawa ressurgente e o mais evasivo, o povo Isconahua não contactados . Esses territorios e ecossistemas estão entrelaçados com as cicatrizes efêmeras dos recém-chegados: madeireiros, mineiros e traficantes de drogas. No entanto, a linha mais importante da Sierra do Divisor é a própria fronteira; a fronteira internacional que segue a cordilheira da Sierra que divide a bacia do rio Ucayali, no Peru, da bacia do rio Juruá no estado do Acre. Relativamente equidistantes da linha divisória da cordilheira estão duas cidades: Pucallpa, a capital de Ucayali, e o centro comercial ocidental do Acre, Cruzeiro do Sul. Ambas as cidades são o fim da malha rodoviária de seu país. Por agora. Empreendedores e funcionários do governo vêem cada vez mais os 160 quilômetros de floresta que separam as duas cidades como uma obstrução temporária à integração continental” (Salisbury et al., 2013, p. 129).https://scholarship.richmond.edu/geography-maps/1017/thumbnail.jp
Map of Road Proposals, National Parks, and Topography of the Sierra del Divisor Range, Peru-Brazil Borderlands
Cartographers: Yunuen Reygadas, D. S. Salisbury
Informação disponível: http://www.stephaniespera.com/, https://servir.ciat.cgiar.org/ , https://blog.richmond.edu/dsalisbury/
At the end of 2020 the official geodatabases of the two countries show the two road proposals reaching the international border in two separate locations not linking one to the other.
“In the southwestern Amazon lies the Sierra del Divisor, an isolated cluster of mist-covered peaks and ridges rising out of the steamy lowland rainforest. The forests of these fiercely dissected crests and valleys still ring with the low grunt of jaguar and the thunderous clacks of hundreds-strong herds of whitelipped peccaries, while the canopy sways with troops of the rare red Uakari monkey. This biodiversity inspired the Serra do Divisor National Park, and its transboundary sister reserve, but these forests are also home to humans: the descendants of Asheninka warriors and rubber tappers, a re-emergent Nawa people, and most elusive, the uncontacted Isconahua. These homelands and ecosystems are crisscrossed with the ephemeral scars made by more recent arrivals: loggers, miners, and drug traffickers. However, the most important line in the Sierra del Divisor is the border itself, the international boundary that follows the Sierra\u27s ridge dividing Peru\u27s Ucayali river basin from Brazil\u27s Jurua basin in the state of Acre. Relatively equidistant from the boundary ridgeline lie two cities, Ucayali\u27s capital of Pucallpa, and Western Acre\u27s commercial center, Cruzeiro do Sul. Both cities are the end of the road for their country\u27s network of thoroughfares. For now. Planners and government officials increasingly view the 160 kilometers of forest separating the two cities as a temporary obstruction to continental integration” (Salisbury et al., 2013, p. 129).https://scholarship.richmond.edu/geography-maps/1016/thumbnail.jp
Effects of deforestation and forest degradation on ecosystem service indicators across the Southwestern Amazon
The Southwestern Amazon (SWA) is home to one of the Earth́s remaining intact ecosystems and a key provider of continental atmospheric moisture flows. However, the integrity of this region is threatened by global changes in climate and local to regional changes in land-use and land-cover. Here, unlike most Amazonia-land-change research which has focused primarily on deforestation, we evaluated the effects of both deforestation and forest degradation on three Ecosystem Service Indicators (ESIs) – evapotranspiration (ET), land surface temperature (LST), and precipitation (P) – at the local and watershed scale across the SWA between 2003 and 2020. We computed annual and monthly ESI differences over distinct forest conditions and buffers around disturbed areas (degraded or deforested). We also determined the influence of forest disturbance trends on ESI trends at the pixel and watershed level through a Partial Mann-Kendall approach. The results show that ESI differences among different forest conditions are statistically-significant and more pronounced during the dry season. In comparison with intact forest, monthly P rates were up to 25 % lower over any type of disturbance; whereas ET rates were up to 15 % and 48 % lower, and LST rates up to 1.6 °C and 4.4 °C higher, over degraded and deforested areas, respectively. ET and LST edge effects were only significant within buffers around some of the most heavily disturbed areas. At the pixel scale, negative trends in ET and positive trends in both LST and P were more frequently explained by forest disturbances as these trends themselves become more pronounced. ET and LST trends determined by disturbances were generally located near roads, rivers, and human settlements; and surprisingly, we found that degradation more often influences these trends than deforestation, which we attribute to the practice of converting deforested areas into crops whose growing season ET and LST rates are similar to those in natural vegetation. At the watershed scale, the analysis suggested that the climate implications of degradation and deforestation have not scaled up to this level yet; however, literature has shown that even the local impacts we report here can have important implications for areas outside of the SWA, which emphasizes the importance of continuing to conserve this remote region
Mapping Forest Disturbances across the Southwestern Amazon: Tradeoffs between Open-Source, Landsat-Based Algorithms.
Local and cross-continental road building, increased economic teleconnections, growing agricultural demands, logging and mining practices, and general development processes are putting pressure on even the least densely populated regions of the Amazon, where local, regional, and global demand for food, fuel and fiber are resulting in observable biophysical effects. It is essential, then, that stakeholders can both map and understand the effects of these forest disturbances on ecosystem services. Multiple remote sensing algorithms focused on detecting vegetation changes have been developed: the challenge now lies in understanding which algorithm best suits the user´s study area and research objective. Using Google Earth Engine, we compared the performance of three algorithms –Continuous Degradation Detection (CODED), Landsat-based detection of trends in disturbance and recovery (LandTrendr), and Multi-variate Time-series Disturbance Detection (MTDD)– to detect and characterize forest disturbances in the Southwestern Amazon (Ucayali, Peru and Acre, Brazil) during the 2000–2020 period. In general, the results of all of the algorithms agreed with the reference data: overall accuracies were 94% (± 0.6% LandTrendr), 95% (±0.6% MTDD), and 96% (± 0.6% CODED). Although the map products exhibit similar spatial patterns, they often differ on the specific disturbance extent. CODED works well in capturing disturbances associated with roads, MTDD excels best at capturing entire disturbance patches, and LandTrendr excels both in terms of user friendliness and range of output options. Through three case study regions, we highlight land-cover change dynamics that have occurred in this remote, transboundary region over the last two decades. We also describe the strengths and weaknesses of each algorithm and demonstrate that it would be incorrect to assume that any one algorithm is the most accurate. Our work, then, improves the capacity of the community to understand how well each algorithm is suited best to map various forest disturbances to promote sustainable decision making
El Atlas de las Carreteras Propuestas en la Zona Transfronteriza Ucayali, Perú-Acre, Brasil
El Atlas de las Carreteras Propuestas en la Zona Transfronteriza Ucayali, Perú-Acre, Brasil incluye una serie de 15 mapas de dos carreteras propuestas: 1) Pucallpa, Perú-Cruzeiro do Sul, Brasil; 2) Nuevo Italia-Puerto Breu, Perú. El objetivo del atlas es presentar los mapas, posters, e información geográfica para dar una perspectiva geográfica de las propuestas de carreteras y entender mejor los posibles impactos socio-ambientales en estas áreas fronterizas con altos índices en diversidad ambiental y cultural. Los mapas y posters son de acceso público