Yazar "Topaloglu, Fatih" seçeneğine göre listele

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    Estimating spatial distribution of soil loss over Seyhan River Basin in Turkey
    (Elsevier Science Bv, 2007) Irvem, Ahmet; Topaloglu, Fatih; Uygur, Veli
    The purpose of this study was to investigate the spatial distribution of annual soil loss; soil loss in Seyhan River Basin using USLE model. A geographic information system (GIS) was used to generate maps of the USLE factors which are rainfall erosivity (R), soil erodibitity (K), slope length and steepness (LS), cover (C) and conservation practices (P) factors. By integrating these maps in GIS, spatial distribution of soil loss over the Seyhan River Basin was obtained. Annual average soil loss for the Seyhan River Basin was 16.38 t ha(-1) y(-1). Annual soil loss more than 200 t ha(-1) y(-1) in pixel level was in the southern region, white the northern region showed the lower annual values. These results are verified by comparing sediment yield measurements in the basin. An area about 198.25 km(2) (0.96%) experiences extremely severe erosion risk, which needs suitable conservation measures to be adopted on a priority basis. The spatial distribution of erosion risk classes estimated 61.03% very low, 8.76% low, 23.52% moderate, 4.03% severe and 1.70% very severe. Thus, the USLE model was used in a GIS environment to identify regions susceptible to water erosion and needing immediate soil conservation planning and application in the Seyhan River Basin in Turkey. (c) 2006 Elsevier B.V. All rights reserved.
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    Identification of flood risk area in the Orontes river basin, Turkey, using multi-criteria decision analyses
    (Wfl Publ, 2012) Irvem, Ahmet; Topaloglu, Fatih
    The objective of this study was to evaluate flood risk area for the Orontes river basin in Turkey, using the Multi-Criteria Decision Analysis (MCDA) within the Geographic Information Systems. Flood risk areas were evaluated using rainfall, slope, elevations, size of sub-watersheds and soil types. These factors were chosen as the most influential factors for generating the flood risk map. MCDA was performed by adding the weighted flood rankings of all the causative factors, according to their relative importance to each other and to their expected importance in causing floods. ILWIS, GIS software was used for spatial analyses and MCDA. Estimated risk map for the Orontes river basin obtained by adding the weighted flood rankings of all factors classified in five categories. producing risk levels of non-flood, low, moderate, high, and very high. It was found that non-flood accounted for 1252.2 km(2) (15.7%) of the total. low for 1032.3 km(2) (13%), moderate for 1596 km(2) (20%), high for 2607.4 km(2) (32.8%) and very high flood risk area for 1471.4 km(2) (18.5%). The Ministry of Agriculture and Rural Affairs of Turkey mapped the flood area for the Orontes river basin from field measurement and their observations were compared with a generated flood risk map. The comparison showed satisfactory results because observed flood area was determined to be in very high flood risk region in the flood risk map. Thus, flood risk area identification using MCDA is possibly suitable for flood planning and management.
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    RE-EVALUATION OF TRENDS IN ANNUAL STREAMFLOWS OF TURKISH RIVERS FOR THE PERIOD 1968-2007
    (Parlar Scientific Publications (P S P), 2012) Topaloglu, Fatih; Irvem, Ahmet; Ozfidaner, Mete
    The Mann-Kendall rank correlation test was performed to detect trends in this study. The research investigated 3 annual stream-flow variables including annual instantaneous minimum, mean and instantaneous maximum streamflows for a network of 57 Turkish streamflow gauging stations in 25 basins of Turkey, during 1968-2007. The application of trend detection technique to 3 stream-flow variables has resulted in the identification of significant decreasing trends at the 0.05 level, appearing mostly in the basins in western and partly in southeastern Turkey, whereas almost no evidence of significant change was experienced with a general downward direction in the rest of the country. Of the 25 basins, however, only basins with the numbers of 12 and 22 exhibited significant increasing trend for one station each. The number of stations showing a decreasing trend is more than 9-fold that of stations with an upward trend whereas the significant downtrend exceeded the uptrends 49-fold. Besides, almost 2/3 of the decreasing trends (144 times over 159) were found to be statistically significant while approximately 13% of the increasing trends (15 times) exhibited significant trend.
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    Trends in Turkish monthly mean streamflow
    (Wfl Publ, 2012) Irvem, Ahmet; Topaloglu, Fatih; Ozfidaner, Mete
    The research explored trends in monthly mean streamflow variables for a network of 57 Turkish streamflow gauging stations in 25 basins of Turkey. The procedure employs the Mann-Kendall rank correlation test to detect trends. The application of Mann-Kendall test resulted in the identification of significant decreasing trends at the 0.05 level appearing mostly in the basins in western Turkey whereas almost no evidence of significant change was experienced with a general downward direction in the rest of the country. Of the 57 stations, however, only 406, 712, 1226, 1402, 1517 and 2233 exhibited significant increasing trend over Turkey. The number of stations showing a decreasing trend is more than sevenfolds the number of stations with an upward trend, whereas the significant downtrend exceeded the uptrends by twentyfolds. Besides, more than half of the decreasing trends were found statistically significant while approximately 21% of the increasing trends exhibited significant trend. Hydrologically, these results indicate that Turkey is generally getting drier.