Today, within the scope of planning, development and management of water resources affected adversely by climate change, the issue of minimization of the adverse effects of drought has become very important. In this study, drought risk analyses were performed using meteorological, hydrogeological and hydrological data of the Asi basin and as a result of the determination of different indices and indicators available in the literature. First, the missing data was completed by regional analyses. The DI (Deciles Index), SPI (Standardized Precipitation Index), SPEI (Standardized Precipitation Evapotranspiration Index) and SRI (Standardized Runoff Index) indices were described. Drought severity and magnitude were found according to these indices. Based on 1, 3, 6, 9, 12, 48-month recurrence intervals, analyses were made. Classification of droughts and their threshold values were determined. For some places, drought incidence rates were presented according to each index. The indices were compared, the correlation between them was examined and a common conclusion was reached. The drought severities, which has a precipitation area of 7800 m², were evaluated for certain recurrence intervals. For this purpose, based on meteorological, hydrological and hydrogeological data for the years between 1970 and 2016, DI, SPI, SPEI, and SRI indices were analyzed and compared.

Various drought indices have been developed to monitor drought, which is a result of climate change, and mitigate its adverse effects on water resources, especially in agriculture. Vegetation indices determined by remote sensing were examined by many recent studies and shed light on drought risk management. In the current study, one of the 25 drainage basins in Turkey—the Seyhan Basin, located in the south of the country—was investigated. The Normalized Difference Vegetation Index (NDVI) and the Vegetation Condition Index (VCI) are the most widely used vegetation indices and are very useful because they give results only based on satellite images. This study examined the Seyhan Basin using satellite data in which the vegetation transformation occurring due to the decline of agricultural and forest areas was seen. An increase in drought frequency was detected in the Seyhan Basin using the NDVI and VCI indices and compared with different indices. The results obtained revealed that climate change and drought is increasing with a linear uptrend. It is recommended that decision-makers take the necessary measures by considering the drought risk maps. Long-term drought management plans should also be prepared and implemented.

İklim değişikliği, günümüz bilim dünyasının gelecek için en tedirgin olduğu araştırma konularının başında gelir. Bu sebeple oluşan, kuraklık ve taşkın risklerinin giderek artması, devamında yapılan detaylı araştırmalar, son yıllarda su yönetimi konusunda bütüncül bir anlayışın benimsenmesini sağlamıştır. Artan kuraklık riskinin yönetilmesi ve sürdürülebilir bir planlamanın yapılması için öncelikle kuraklığın eğilimi bilinmelidir. Kuraklık yavaş başlayan ve ilerleyen hidrolojik bir olay olması dolayısıyla, izlenmesi ve analizi büyük bir önem taşımaktadır. Birçok testin yanında Mann-Kendall testi en yaygın ve muteber trend analizi testlerinden biridir. Bu çalışmada, yaklaşık 7800 km2 alana sahip, Asi havzası için bir kuraklık eğilimi olup olmadığı incelenmiştir. Bu amaçla 1970-2016 yılları arası meteorolojik, hidrolojik ve hidrojeolojik veriler ele alınmıştır. Yağış, akış, buharlaşma, sıcaklık ve yeraltı suyu verilerinin yıllara göre nasıl bir eğilim gösterdiği detaylı olarak incelenmiş, kuraklık riski Asi havzası için araştırılmıştır. Öncelikle havzada bulunan meteoroloji ve akım gözlem istasyonlarından uygun olanları belirlenmiş ve eksik veriler literatüre uygun yöntemler ile tamamlanmıştır. Bu analizlerin sonucunda Asi havzası genelinde yıllık toplam yağışlarda %95 güven düzeyinde istatistiksel olarak anlamlı olmasa da bir artış eğilimi olduğu görülmüştür. Yıllık ortalama sıcaklıklarda ise, hem alt havza hem havza bazlı bariz bir artış eğilimi görülmüştür.

En tr Climate change and global warming are among the issues that humanity is most concerned about the future. The growing drought and flood risks that increase despite the taken measures have led to the adoption of an integrated understanding on the topic of water management in recent years. To manage the increased risk of drought and to make sustainable planning, the dimensions of drought should be known first. For this purpose, many drought indices have been developed. The Normalized Difference Vegetation Index (NDVI) and Vegetation Condition Index (VCI), which determined by remote sensing, are two of these. In this study, in which the agricultural drought was analyzed with vegetation indices by taking into consideration the historical drought archive, the Asi Basin was addressed. The data of the Asi Basin, which covers an area of 7800 km² and was obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Very High-Resolution Radiometer (AVHRR) satellites, was used in this study. With the satellites benefited in remote sensing and with the Coordination of Information on the Environment (CORINE), where the layers of vegetation were determined, agricultural and forest areas were evaluated separately. The vegetation indices, which change with the increase in temperature, have revealed the necessity of a long-term drought management for the Asi Basin. Result of the work pointed that NDVI index is more appropriated to the Asi Basin than the VCI index to monitor drought. Climate change and global warming are among the issues that humanity is most concerned about the future. The growing drought and flood risks that increase despite the taken measures have led to the adoption of an integrated understanding on the topic of water management in recent years. To manage the increased risk of drought and to make sustainable planning, the dimensions of drought should be known first. For this purpose, many drought indices have been developed. The Normalized Difference Vegetation Index (NDVI) and Vegetation Condition Index (VCI), which determined by remote sensing, are two of these. In this study, in which the agricultural drought was analyzed with vegetation indices by taking into consideration the historical drought archive, the Asi Basin was addressed. The data of the Asi Basin, which covers an area of 7800 km² and was obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Very High-Resolution Radiometer (AVHRR) satellites, was used in this study. With the satellites benefited in remote sensing and with the Coordination of Information on the Environment (CORINE), where the layers of vegetation were determined, agricultural and forest areas were evaluated separately. The vegetation indices, which change with the increase in temperature, have revealed the necessity of a long-term drought management for the Asi Basin. Result of the work pointed that NDVI index is more appropriated to the Asi Basin than the VCI index to monitor drought.

Taşkın, son yıllarda iklim değişikliği ve şehirleşmenin de etkisiyle sayısız zararlara yol açan bir afet durumuna gelmiştir. Taşkının zamanını, büyüklüğünü ve şiddetini bilmek; etkilerini azaltmak için son derece önemlidir. Taşkının hidrolik modellemesinin yapılarak etki alanı tahmin edilebilir. Bunun için de maksimum taşkın debisini bilmek gerekir. İstatistik, sentetik ve hidrolojik model yöntemleri ile hesaplanan taşkın debisinin oluşturduğu taşkın hidrografı, hidrolik modele altlık olur ve taşkın risk haritaları belirlenebilir. Bu çalışmada Mockus, Snyder, Rasyonel ve DSİ sentetik yöntemleri ile taşkın frekans analizi ve ayrıca MIKE hidrolojik model programı yardımıyla taşkın pik debileri, 21682,8 km2 alana sahip Doğu Akdeniz Havzası için bulunmuştur. Sonuç olarak geniş bir havzada çok sayıda gözlem istasyonu yardımıyla da yapılan değerlendirmede, havza büyüklüğüne göre en uygun taşkın debisi tahmin yöntemleri belirlenmiştir.