Kurtköy Deresi taşkın yayılım-tehlike-risk haritalarının belirlenmesi

Abstract

Taşkınlar, bir akarsuyun farklı sebeplerle yatağın taşması veya farklı nedenler sonucunda yükselen suların yerleşim yerlerine, verimli tarımsal alanlara, altyapı ve üst yapı tesislerine ve o bölgede yaşamını sürdüren canlılara zarar veren nedeni ile doğal afet olarak adlandırılır. Dünya nüfusunun hızla artması neticesi ile meydana gelen, iklim değişikliği ve plansız kentleşme gibi etkiler son yıllarda taşkın olaylarının artmasına sebep olmuştur. Bu trendin etkisi ile Sapanca İlçesinde bulunan derelerde de sık sık taşkınlar meydana gelmektedir. Bu derelerden ikisi Kurtköy ve Mahmudiye dereleridir. Bu çalışmada, elde edilen meteorolojik veriler kullanılarak, istatistiki yöntemlerle ekstrem yağış hesabı yapılmıştır. Bu doğrultuda her iki dere için taşkın tekerrür debileri Mockus yöntemiyle hesaplanmıştır. Hesaplanan bu debiler ışığında Kurtköy ve Mahmudiye derelerine ait taşkın yayılım haritaları üretilmiş ve olası bir taşkında meydana gelebilecek tarımsal ve yapısal hasarlar öngörülmeye çalışılmıştır. Taşkın yayılım haritaları üretilirken 1/1000 ölçekli harita NetCAD ortamında üçgenleme modeline hazır hale getirilip ArcMAP'e aktarılmıştır. Üçgenleme modelinin elde edilmesinden sonra veriler analiz edilmek üzere HEC-RAS programına aktarılmıştır. Hidrolojik datalar kullanılarak 2, 5, 10, 25, 50, 100, 200, 500 ve 1000 yıllık tekerrürlü taşkın debileri hesaplandıktan sonra hidrolik modelleme yapılmıştır. Tüm bu debiler için taşkın risk analizleri, taşkın yayılım haritaları elde edilmiş, bu bağlamda çözüm önerileri sunulmuştur.

Floods are called natural disasters due to damages of the bed due to different reasons of a stream or the settlements of the rising waters due to different reasons, fertile agricultural areas, infrastructure and superstructure facilities and living creatures that live in that region. The effects of climate change and unplanned urbanization, which are caused by the rapid increase in the world population, have led to an increase in flood events in recent years. With the effect of this trend, floods occur frequently in the rivers in Sapanca District. Two of these streams are Kurtköy and Mahmudiye creeks. In this study, extreme rainfall was calculated by using statistical methods. In this direction, flood recurrence flows for both streams were calculated by Mockus method. In the light of these calculated flows, flood propagation maps belonging to the Kurtköy and Mahmudiye streams were produced and agricultural and structural damages that might occur in a possible flood were predicted. Flood propagation maps were produced and 1/1000 scale map was prepared for triangulation model in NetCAD environment and transferred to ArcMAP. After obtaining the triangulation model, the data was transferred to the HEC-RAS program for analysis. By using hydrological data, hydraulic modeling was performed after calculating 2, 5, 10, 25, 50, 100, 200, 500 and 1000-year repetitive flood flows. Flood risk analyzes and flood propagation maps were obtained for all of these flow rates. Floods are called natural disasters due to damages of the bed due to different reasons of a stream or the settlements of the rising waters due to different reasons, fertile agricultural areas, infrastructure and superstructure facilities and living creatures that live in that region. The effects of climate change and unplanned urbanization, which are caused by the rapid increase in the world population, have led to an increase in flood events in recent years. With the effect of this trend, floods occur frequently in the rivers in Sapanca District. Two of these streams are Kurtköy and Mahmudiye creeks. In this study, extreme rainfall was calculated by using statistical methods. In this direction, flood recurrence flows for both streams were calculated by Mockus method. In the light of these calculated flows, flood propagation maps belonging to the Kurtköy and Mahmudiye streams were produced and agricultural and structural damages that might occur in a possible flood were predicted. Flood propagation maps were produced and 1/1000 scale map was prepared for triangulation model in NetCAD environment and transferred to ArcMAP. After obtaining the triangulation model, the data was transferred to the HEC-RAS program for analysis. By using hydrological data, hydraulic modeling was performed after calculating 2, 5, 10, 25, 50, 100, 200, 500 and 1000-year repetitive flood flows. Flood risk analyzes and flood propagation maps were obtained for all of these flow rates.