Necla Türkoğlu

Space-time kriging of precipitation variability in Turkey for the period 1976–2010

The purpose of this study is to revaluate the changing spatial and temporal trends of precipitation in Turkey. Turkey is located in one of the regions at greatest risk from the potential effects of climate change. Since the 1970s, a decreasing trend in annual precipitation has been observed, in addition to an increasing number of precipitation-related natural hazards such as floods, extreme precipitation, and droughts. An understanding of the temporal and spatial characteristics of precipitation is therefore crucial to hazard management as well as planning and managing water resources, which depend heavily on precipitation. The ordinary kriging method was employed to interpolate precipitation estimates using precipitation records from 228 meteorological stations across the country for the period 1976–2010. A decreasing trend was observed across the Central Anatolian region, except for 1996–2000 which saw an increase in precipitation. However, this same period is identified as the driest year in Eastern and South Eastern Anatolia. The Eastern Black Sea region has the highest precipitation in the country; after 1996, an increase in annual precipitation in this region is observed. An overall reduction is also seen in southwest Turkey, with less variation in precipitation.

The effects of elevation on thermal bioclimatic conditions in Uludag (Turkey)

This study compares the thermal bioclimatic conditions recorded at Bursa (100 m) and Uludag (1878 m) meteorological stations at 7:00, 14:00 and 21:00 LST (local standard time) between 1975 and 2006, by using the physiologically equivalent temperature (PET), which is calculated from meteorological parameters. The effects of elevation-dependent environmental and atmospheric conditions on thermal perception (i.e., PET) values were analyzed and assessed. The analysis showed that the mean annual difference between PET values in Bursa and Uludag was 12 oC. The difference was lower in winter (9 oC PET) and higher in summer (15 oC PET). The highest difference between PET values occurred in the afternoon (16 oC PET) and the lowest difference occurred in the morning (8.4 oC PET). The differences occur as a result of high altitude and higher surface albedo due to snowfall, which leads to lower PET values and thus to less comfortable thermal conditions. The mean PET values of Bursa and Uludag decrease 0.67 oC every 100 m.

Characterising the Seasonal Variations and Spatial Distribution of Ambient PM10 in Urban Ankara, Turkey

The urban airshed of Turkey is under the influence of both traffic and heating emissions. Periodic monitoring and management of air pollution is a must for an up-to-date exposure assessment for effective health and environmental management. The main objective of this paper is to assess the spatial and temporal variability of particulate matter (PM10) in urban areas of Turkey using the metropolitan area of Ankara as a case study, exploring the seasonal variation of PM10 concentrations resulting from indoor heating and transport. This study employed spatiotemporal kriging with external drift to examine the space-time variability and distribution of PM10 concentrations in Ankara for year 2015. The measurements of PM10 in and around metropolitan Ankara were carried out at nine stations. Measurements for the period December 2014 – November 2015 were used and averaged using a 6-h interval for each season: Winter (Dec, Jan, Feb), Spring (Mar, Apr, May), Summer (Jun, Jul, Aug) and Autumn (Sep, Oct, Nov). Population distribution, used as a proxy for indoor heating, and proximity to roads were used as auxiliary variables for kriging analysis. PM10 concentration levels were observed to be highest during autumn and winter. Summer was identified as the “cleanest” period although, in some regions of the city, pollution levels remained high. The southeast region of metropolitan Ankara was identified to be the most polluted region of the city after the city centre.

Correction to: Landslide susceptibility mapping of the Sera River Basin using logistic regression model

The article “Landslide susceptibility mapping of the Sera River Basin using logistic regression model,” written by Nussaïbah B. Raja, Ihsan Çiçek, Necla Türkoğlu, Olgu Aydin, and Akiyuki Kawasaki, was originally published Online First without open access.

Effects of climate changes on phenological periods of apple, cherry and wheat in Turkey Türkiye’de iklim değişikliğinin elma, kiraz ve buğdayın fenolojik dönemlerine etkileri

It is known that the increase in air temperature from 1980 to present has dramatically changed the phenological periods of the plants in a large part of the world. In this study, the relationships between phenological periods of wheat plant, apple and cherry trees planted large areas in Turkey and climate change were investigated. In this study, the climate and phenological data for 1971-2012 period belonging to the General Directorate of Meteorology were used. The correlation coefficients between temperature and phenological data were calculated, and their trends were examined using Mann-Kendall trend analysis. In Turkey, positive temperature anomalies have been observed since 1994 until present days. Negative relationships were found between phenological periods of apple, cherry and wheat and the average temperatures of February-May period when the plants grow faster. This situation shows that the plants shift their phenological periods to the earlier times in response to the increasing temperatures. The trend calculated for harvest times of apple, cherry, and wheat are -25, -22, -40 days/100 years respectively. It was calculated that an increase of 1.0oC in the temperatures of the February-May period will shift the harvest times of apple, cheery and wheat by 5, 4 and 8 days earlier respectively.