Dogal Afetler ve Cevre Dergisi

1-13

Authors: Emre KEBAPÇIOĞLU; Turgay PARTAL

Recent studies show that global atmospheric circulations are efficient on climate parameters. This study has been carried out to analyze the relationship between the streamflow data in Büyük Menderes/Gediz Basin and the global atmospheric oscillations such as the Southern Oscillation (SO), the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO). The average annual and seasonal flows at the current 5 stations located in Büyük Menderes basin and Gediz basin, whose measurements were made by the DSI in the 45 year period between 1970 and 2015 have been studied. Then, the relationship between NAO, AO, SO indices and streamflows was determined by correlation analysis. In addition, in order to obtain the periodic components, the original observed data were separated into their components by discrete wavelet transform. The correlations between the found wavelet components (D1, D2, D3, D4 and A) and atmospheric indices were examined. As a result, this study found that there is a strong negative correlation between the streamflow and the AO/NAO indices at the annual/winter and spring period. Moreover, the wavelet periodic components showed to the main factors for the relationship of the streamflow data with the global atmospheric patterns.

25-36

Authors: Evren TURHAN; Buse DUYAN ÇULHA; Serin DEĞERLİ

Drought has been among the priority issues for a long time because of its effects that vary depending on duration and severity. Hydrological drought can be explained as the decrease in clean water resources caused by climate change. In this paper, Arsuz Plain, one of the agricultural protected area in the Asi River Basin, was selected as the case study for the hydrological drought analysis. Firstly, discharge-time and flow duration curves (FDC) were created by using monthly average discharge data between the years of 1990 and 2015 which were obtained from three different Flow Observation Stations (FOSs) (numbered D19A021, D19A022 and D19A023), located close to each other. With the help of these data, Streamflow Drought Index (SDI) values were calculated for different time scales such as 3, 6 and 12 months. Consequently, it has been seen that all three stations have similar results in terms of the peak flow rate values excluding a few periods. As of 2000, it has been observed that Extreme Drought and Extremely Wet periods have started to occur in the basin for these stations. While the most wet period began between the years 2009 and 2010, the driest period was 2014. Considering the course of the drought event in different time scales, it can be concluded that the number of dry periods has increased in recent years.

53-65

Authors: Aslı TEKLİ; Seda ASLAN KILAVUZ; Zehra BOZKURT

Düzce province, where industry, traffic and residential areas are intertwined, is developing rapidly and therefore environmental pollution is intensely felt in the region. Air pollutants from emission sources cannot be dispersed due to the geographical location of the province and pose important health risks. In this study, dust samples were collected at different locations in order to explain the regional pollution distribution and various emission sources. Because children are more sensitive to air pollutants, indoor and outdoor environments of primary schools were selected for sampling. PCB levels were determined in dust samples collected from indoor and outdoor environments of the primary schools in Düzce. PCB analyses were performed by using the Gas chromatograph/Mass Spectrometer (GC/MS) instrument. In the obtained results, outdoor ΣPCB concentrations were between 0.737 and 22.307 ng/gr, with an average of 3,626 ng/gr. Indoor ΣPCB concentrations were between 17.17 and 294.22 ng/gr, with an average of 66.89 ng/gr. High ∑PCB concentrations in indoor samples show that the contribution of indoor sources and the effect of accumulation in indoor environments by transport from the outdoor environments is greater. In the evaluation made according to outdoor sources, the highest concentrations were obtained mostly at points close to the industrial area. The lowest concentrations were measured at rural sampling points.

76-86

Authors: Beyza YILMAZ; Mehveş DEMİREL; Filiz BALÇIK

Recently, increasing wildfires have caused severe damage to vegetation and many living creatures. Remote sensing technologies and various algorithms are used to determine and analyze the burned forest areas. Different remotely sensed images such as Sentinel-2 MSI, Landsat, MODIS, SPOT were used to determine forest fire damage and to produce maps for burned areas. In this study, the 6 July 2020 dated wildfire that occurred in the Gallipoli district of Çanakkale province has been analyzed by using Sentinel-2 MSI and Landsat-8 OLI satellite images. Burned Area Index (BAI), Normalized Moisture Index (NDMI), Normalized Burn Ratio (NBR), and Normalized Difference Vegetation Index (NDVI) were calculated with the pre and post-fire satellite images of the study area. The differences of the pre and post-fire indices were calculated to determine the burned forest area. Error matrix was produced for accuracy assessment. Overall accuracy, user accuracy, producer accuracy, and Kappa statistics were calculated, and performances were evaluated for different sensors and different indices by comparing the accuracy assessment results. The highest accuracy results were achieved with Differenced Normalized Difference Vegetation Index (dNDVI) for both Landsat-8 OLI and Sentinel-2 MSI images, and Kappa statistic results were obtained as 0.94 and 0.95, respectively.

103-110

Authors: Emel ZERAY ÖZTÜRK

The climate changes observed in recent years require the efficient use of water resources. In this respect, policies followed for sustainable water management necessitate continuous monitoring of water mobility. In recent years, it is possible to produce maps for the monitoring of water resources, trend estimations and visualization of changes in water areas, with remote sensing technology. Especially with the integration of satellite gravimetry and global hydrological models, these studies can be carried out relatively quickly and at low cost. In this study, water storage changes (TWSA: Total Water Storage Anomaly) in the region of Konya basin were evaluated using the GRACE (Gravity Recovery and Climate Experiment) satellite mission and GLDAS (Global Land Data Assimilation System) data. In addition, the short and long term effects of climate changes on the results have been investigated. The results show that between 2002 and 2020, groundwater and, accordingly, the total water storage changes have a negative trend in the long term, in the study area. Additionally, it can be deduced that TWSA and climatological variables including precipitation and temperature have a high correlation at 2- and 3-month lags.

122-133

Authors: İlhami DOĞAN; Murat KARABULUT

The effects of global warming are not the same in every region of the world. Turkey in the Eastern Mediterranean Basin is one of the areas affected by this warming. Summer drought significantly felt in Turkey, where climatic conditions are constantly changing due to global warming. Therefore, it is necessary to continuously observed phenological events in the climate control. Various methods such as remote sensing systems, meteorological observations and species-based local evaluations are used in the investigation of phenological events. Growing degree-days (GDD) is one of the phenological prediction models based on meteorological variability. In this study, daily maximum and daily minimum temperature records of 147 meteorological observation stations were used to determine annual and seasonal trends of GDD in Turkey. GDD trends in various periods were determined by Mann-Kendall sequential statistics method. According to the survey, seasonal and annual trends in from 1970 to 2018 GDD are positive characters. In this process in the control of climate change, important phenological shifts have occurred in Turkey. BDG increases observed in summer; In agriculture and forestry, it may have increased drought-based heat stress even more. The positive trends in the study are thought to be effective on natural ecosystems through industry, agriculture, settlement, and natural resources. For this reason, basic climatic parameters such as temperature and precipitation need to be collected at more local scales.

142-155

Authors: Alperen CİHAN; Kübra CERİT; Arzu ERENER

Fighting fires is an extremely important issue to prevent the loss of forests. With the developing technology, satellite images have become one of the basic tools for fighting fire over time. By using various indexes, it is possible to detect the burning area from satellite images with image processing analysis and surface temperature analysis. Unlike the methods made by ground measurements, it is very fast and relatively less costly. In this study, the Deliömerli forest fire that took place in Menderes district of Izmir province on July 1, 2017, and lasted about 67 hours was analyzed using Landsat-8 satellite images. The surface temperature maps were created from the images obtained before and during the fire, and surface temperature differences were examined for different land uses. Accordingly, it has been observed that the surface temperature of the area burning during the fire increased compared to other land use areas. In determining the fire area, three different methods were used and the spatial size of the fire area was compared. In this context, 1,235 hectares with Normalized Difference Vegetation Index (NDVI), 1,221 hectares with Normalized Burn Ratio (NBR) indices, and 1,296 hectares with the classification study were determined to be burned. It has been observed that the results are consistent with the damage assessment results announced by the General Directorate of Forestry. The burning areas were overlapped with the CORINE land use map and the extent of the impact of the fire on each land use class was examined. As a result of the overlap analysis, it was determined that 75.7% of the burning area was coniferous forests, 19.3% plant areas, 4.2% mixed forests and 0.7% agricultural areas.

165-177

Authors: Ayşe Handan DÖKMECİ; Öznur AKDUMAN

Due to its geostrategic location and global climate change, natural events have been experienced more frequently and severely in the last 10 years in our country. The probability of large-scale Chemical, Biological, Radiological, Nuclear and Explosive (CBRN-p) disasters that may occur with sequential effects, triggered by natural events, is generally low. However, the potential impacts on people, the environment, infrastructure, the economy of certain areas or the entire region/country are high. There are maps for natural events such as earthquakes, floods, landslides and avalanches in our country. However, there are no maps prepared for CBRN-p hazards. Considering that climate change increases the frequency and intensity of natural hazards related to weather, it is thought that knowing the inventory of hazards that may arise from existing CBRN-p substances can play a key role in reducing risks and preventing possible disasters. In our study, the concept of sequential disaster and CBRN-p hazards and risks that may arise from sequential disasters are discussed. In addition, maps containing industries and energy facilities in provinces where CBRN-p events are likely to occur, T.C. The earthquake, flood/flood, landslide and avalanche hazard maps created by the Ministry of Interior Disaster and Emergency Management Presidency (AFAD) were prepared by overlapping, and the risks that may arise as a result of sequential effects were evaluated based on the literature review. As a result of this evaluation, the interdependence of natural events and CBRN-p events; It has been revealed that critical steps such as reducing vulnerabilities, increasing resilience, assessing secondary disasters and risk reduction practices in critical infrastructures should be addressed, and the risks posed by mutually interacting, combined, interconnected and sequential hazards should not be ignored when making risk assessments. It is expected that our study will contribute to the literature in preventing CBRN-p events, which may be triggered by natural events in our country, from turning into sequential disasters, and will guide the preparation of CBRN-p hazard and risk maps.