7 research outputs found

    The typology, frequency and magnitude of some behaviour events in case of torrential hydrographical management works in the upper Tarlung watershed

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    During the 20-25 years from their startup, the torrential hydrographicalmanagement works carried out in the upper Tărlung Watershed(55 dams, 22 sills, 25 traverses and 4 outlet canals) have exposed a number of 24 behaviour event types: 13 out of them reduce the safety of exploitation and the sustainability of the works (hereinafter called damages), while the other 11 reduce the functionality of the works (hereinafter called disfunctionalities). The following behaviour events have the highest frequency:(i) damages caused by water and alluvia erosion (erosive damages),followed by breakages, in the category of damages, and (ii) unsupervised installation of forest vegetation on the managed torrential hydrographical network and apron siltation, in the category of disfunctionalities. For methodological reasons, only the erosive damage of works was successively analysed, according to two criteria: the average depth (cm) in the eroded area and the percentage of the erosive area out of the total surface. Further on, by combining the two criteria for analysis, five representation areas with the same damage intensity were defined (very low, low, medium, high and very high intensity). With the aid of the event frequency values recorded in these areas and of the coefficients attributed to each intensity class (from 1 for very low intensity to 5 for very high intensity), the author reached the conclusion that the level of the recorded intensity of the damage caused by water and alluvia erosion ranged from very low to low.</p

    Planning Forest Accessibility with a Low Ecological Impact

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    This paper examines a new approach to forest accessibility planning based on a GIS road development algorithm and some topographically derived indices. The aim of the paper is to propose and validate a method of assessing forest accessibility introducing an ecological approach, based on morphological impact. For the case study, both cartographic material (DEM) and measured items (existing road network) were used in applying the method. The case study offered the data and possibility to analyze, compare and take into consideration the ecological impact on planning forest accessibility

    Planning Forest Accessibility with a Low Ecological Impact

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    This paper examines a new approach to forest accessibility planning based on a GIS road development algorithm and some topographically derived indices. The aim of the paper is to propose and validate a method of assessing forest accessibility introducing an ecological approach, based on morphological impact. For the case study, both cartographic material (DEM) and measured items (existing road network) were used in applying the method. The case study offered the data and possibility to analyze, compare and take into consideration the ecological impact on planning forest accessibility

    Assessing the Fragmentation, Canopy Loss and Spatial Distribution of Forest Cover in Kakamega National Forest Reserve, Western Kenya

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    Kakamega National Forest Reserve is a tropical forest ecosystem at high risk of irreplaceable biodiversity loss due to persistent human-induced pressures. The aim of this paper is to assess the effect of fragmentation and forest cover loss on forest ecosystems in Kakamega National Forest Reserve, with the objectives: (1) to quantify the forest cover loss and analyse fragmentation in the Kakamega forest ecosystem and (2) to analyse the effect of forest cover loss on the spatial distribution of the Kakamega forest ecosystem at different timescales. Hansen global forest change data was used as an input training dataset on the Google Earth Engine platform (GEE) to estimate the area of forest cover loss by aggregating the sum of pixel values, and to provide a time series visualization of forest change by the extent of cover loss using Sentinel-2 and Landsat 7 false colour composites (RBG) in QGIS software. Fragmentation analysis was performed using reclassified forest loss and distribution data from the Hansen product as binary raster input in Guidos software. Total forest cover loss over 20 years was estimated at 826.60 ha. The first decade (2000–2010) accounted for 146.31 ha of forest cover loss, and the second decade (2010–2020) accounted for 680.29 ha of forest cover loss. Forest area density (FAD) analysis depicted an increase in the dominant layer by 8.5% and a 2.5% decrease in the interior layer. Morphological spatial pattern analysis (MSPA) illustrated a change in the core layer of 96% and a 14% increase in the openings class layer. Therefore, this study demonstrates that forest cover loss and landscape pattern alteration changed the dynamics of species interaction within ecological communities. Fragmented habitats adversely affected the ecosystem’s ability to recover the loss of endemic species, which are at risk of extinction in the backdrop of climate change. Anthropogenic drivers i.e., the clearing of natural forest and conversion of forest land for non-forest use, have contributed significantly to the loss of forest cover in the study area

    Assessing the Fragmentation, Canopy Loss and Spatial Distribution of Forest Cover in Kakamega National Forest Reserve, Western Kenya

    No full text
    Kakamega National Forest Reserve is a tropical forest ecosystem at high risk of irreplaceable biodiversity loss due to persistent human-induced pressures. The aim of this paper is to assess the effect of fragmentation and forest cover loss on forest ecosystems in Kakamega National Forest Reserve, with the objectives: (1) to quantify the forest cover loss and analyse fragmentation in the Kakamega forest ecosystem and (2) to analyse the effect of forest cover loss on the spatial distribution of the Kakamega forest ecosystem at different timescales. Hansen global forest change data was used as an input training dataset on the Google Earth Engine platform (GEE) to estimate the area of forest cover loss by aggregating the sum of pixel values, and to provide a time series visualization of forest change by the extent of cover loss using Sentinel-2 and Landsat 7 false colour composites (RBG) in QGIS software. Fragmentation analysis was performed using reclassified forest loss and distribution data from the Hansen product as binary raster input in Guidos software. Total forest cover loss over 20 years was estimated at 826.60 ha. The first decade (2000&ndash;2010) accounted for 146.31 ha of forest cover loss, and the second decade (2010&ndash;2020) accounted for 680.29 ha of forest cover loss. Forest area density (FAD) analysis depicted an increase in the dominant layer by 8.5% and a 2.5% decrease in the interior layer. Morphological spatial pattern analysis (MSPA) illustrated a change in the core layer of 96% and a 14% increase in the openings class layer. Therefore, this study demonstrates that forest cover loss and landscape pattern alteration changed the dynamics of species interaction within ecological communities. Fragmented habitats adversely affected the ecosystem&rsquo;s ability to recover the loss of endemic species, which are at risk of extinction in the backdrop of climate change. Anthropogenic drivers i.e., the clearing of natural forest and conversion of forest land for non-forest use, have contributed significantly to the loss of forest cover in the study area

    Impact of Iran’s Forest Nationalization Law on Forest Cover Changes over Six Decades: A Case Study of a Zagros Sparse Coppice Oak Forest

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    Forest nationalization policies in developing countries have often led to a reduction in local forest ownership rights and short- or long-term exploitative behaviors of stakeholders. The purpose of this research is to quantify the effect of Iran’s Forest Nationalization Law (FNL) in a part of Zagros Forest over a 68-year time period (1955–2022) using 1955 historical aerial photos, 1968 Corona spy satellite photography, and classification of multi-temporal Landsat satellite images. A past classification change detection technique was used to identify the extent and the pattern of land use changes in time. For this purpose, six periods were defined, to cover the time before and after the implementation of FNL. A 0.27% deforestation trend was identified over the period after the FNL. Dense and open forested area has decreased from 7175.62 ha and 68,927.46 ha in 1955 to 5664.26 ha and 59,223.38 ha in 2022. The FNL brought decisive changes in the legal and forest management systems at the state level, mainly by giving their ownership to the state. Accordingly, the FNL and the related conservation plans have not fully succeeded in protecting, rehabilitating, recovering, and developing the sparse Zagros Forest ecosystems, as their most important goals
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