Browsing by Author "Altunel, Arif Oguz"

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Suitability of open-access elevation models for micro-scale watershed planning.
(2018-08-10T00:00:00Z) Altunel, Arif Oguz; Altunel, AO
Watershed planning is a major issue in Turkey and other parts of the world. Surrounded by seawater on almost three-quarters of its international borders and by sheer mountains along the coastal regions and throughout the country, Turkey experiences a range of climatic changes, which constantly shape its topography. Recently, the occurrences of floods, landslides, and torrents have increased, forcing decision-makers to come up with solutions to manage and rehabilitate the upper watersheds in order to stop or limit the impact of disasters on downstream areas. Possible solutions should reduce flow coefficients, erosion, and sedimentation and increase reservoir capacities. It is expected that torrent volumes will decrease, drainage regimes on slopes will be better organized and adjusted, thawing snow will be better deposited and delayed, evapotranspiration will increase, surface runoffs will be delayed, and water regimes will be better managed, meaning that flood and torrent control will be achieved. For the reasons mentioned above, watershed parameters need to be firmly set. In the scope of this study, the elevation, slope acreage, and reservoir capacity of a small watershed, as extracted from open-access elevation models, were compared to a real-time kinematic (RTK) global positioning system (GPS)-generated point cloud and the resulting elevation model through various geospatial and analytical means. The Shuttle Radar Topography Mission (SRTM) C-band digital elevation model (DEM) (version 3) proved to be a satisfactory method in making residual, correlation, mean, and reservoir capacity comparisons. An L-band Advanced Land Observing Satellite (ALOS) phased-array-type synthetic aperture radar (PALSAR) and an X-band DLR_SRTM ASTER were slightly superior methods in terms of defining a greater number of slope categories than the other models. Finally, DLR_SRTM and SRTMv3 could match a greater number of slope façades than the other models. Seventeen years after its acquisition, SRTM and its derivatives have continued leading the topographic definition of the Earth.
Suitability of open-access elevation models for micro-scale watershed planning.
(2018-08-10T00:00:00Z) Altunel, Arif Oguz
Watershed planning is a major issue in Turkey and other parts of the world. Surrounded by seawater on almost three-quarters of its international borders and by sheer mountains along the coastal regions and throughout the country, Turkey experiences a range of climatic changes, which constantly shape its topography. Recently, the occurrences of floods, landslides, and torrents have increased, forcing decision-makers to come up with solutions to manage and rehabilitate the upper watersheds in order to stop or limit the impact of disasters on downstream areas. Possible solutions should reduce flow coefficients, erosion, and sedimentation and increase reservoir capacities. It is expected that torrent volumes will decrease, drainage regimes on slopes will be better organized and adjusted, thawing snow will be better deposited and delayed, evapotranspiration will increase, surface runoffs will be delayed, and water regimes will be better managed, meaning that flood and torrent control will be achieved. For the reasons mentioned above, watershed parameters need to be firmly set. In the scope of this study, the elevation, slope acreage, and reservoir capacity of a small watershed, as extracted from open-access elevation models, were compared to a real-time kinematic (RTK) global positioning system (GPS)-generated point cloud and the resulting elevation model through various geospatial and analytical means. The Shuttle Radar Topography Mission (SRTM) C-band digital elevation model (DEM) (version 3) proved to be a satisfactory method in making residual, correlation, mean, and reservoir capacity comparisons. An L-band Advanced Land Observing Satellite (ALOS) phased-array-type synthetic aperture radar (PALSAR) and an X-band DLR_SRTM ASTER were slightly superior methods in terms of defining a greater number of slope categories than the other models. Finally, DLR_SRTM and SRTMv3 could match a greater number of slope façades than the other models. Seventeen years after its acquisition, SRTM and its derivatives have continued leading the topographic definition of the Earth.
The effect of population shift on land cover change and illegal forest activities.
(2021-01-29T00:00:00Z) Guloglu, Yavuz; Bulut, Alper; Altunel, Arif Oguz; Bayramoglu, Mahmut Muhammet
Interaction between humans and forests has always been strong. Wood has been at the core of all humankind's endeavors since the discovery of fire and learning how to fabricate it out of trees. The exploitation of forests has not been limited to the procurement of wood, but the concepts of sheltering, hunting, and protection have also been matured near or within the forests. This win-win situation intuitively attracted more and more people to this type of resource. As the human population has grown in forest villages, the pressure caused by the human on the forests has increased. Without active management of the forests, the situation has become so dire that uncontrolled and irregular utilization has started jeopardizing the existence of this resource. The objective of this study was to examine the changes in forest road, forestland cover, and forest crimes in the Daday Forest Enterprise (DFE) located in Kastamonu Regional Directorate of Forestry, Turkey. The results indicated that the population in 51 forest villages was decreased from 1975 to 1990. This decrease was also apparent in all villages across the region during the 1990-2000 period and continued decreasing in 45 villages during the 2000-2016 period. The forestland cover was 57% in 1975, 44% in 2000, and 57% in 2016 while the density in the forest road kept increasing. A noticeable decrease in the forest-related crimes was also determined, and the results showed that effective forest management, consciousness, and conservation policies stopped the deterioration.
Visibility analysis of fire lookout towers in the Boyabat State Forest Enterprise in Turkey.
(2017-07-01T00:00:00Z) Kucuk, Omer; Topaloglu, Ozer; Altunel, Arif Oguz; Cetin, Mehmet
For a successful fire suppression, it is essential to detect and intervene forest fires as early as possible. Fire lookout towers are crucial assets in detecting forest fires, in addition to other technological advancements. In this study, we performed a visibility analysis on a network of fire lookout towers currently operating in a relatively fire-prone region in Turkey's Western Black Sea region. Some of these towers had not been functioning properly; it was proposed that these be taken out of the grid and replaced with new ones. The percentage of visible areas under the current network of fire lookout towers was 73%; it could rise to 81% with the addition of newly proposed towers. This study was the first research to conduct a visibility analysis of current and newly proposed fire lookout towers in the Western Black Sea region and focus on its forest fire problem.