Evaluation of the best management practices to control agricultural diffuse pollution in lake mogan watershed with swat model


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2016

Öğrenci: ZEYNEP ÖZCAN

Eş Danışman: EMRE ALP, ELÇİN KENTEL ERDOĞAN

Özet:

Lake Mogan which is located in Gölbaşı County, Ankara, Turkey is one of the most important wetlands of Turkey and it was declared as Special Environmental Protection Region in 1990. Total area of semi-arid Lake Mogan watershed is 970 km2 and dry farming is practiced approximately in 40% of the basin. Therefore, agricultural diffuse source pollution is a serious concern in the watershed. In the context of this thesis, the effects of implementation of different agricultural best management practices on sediment, total nitrogen and total phosphorus loads were evaluated by using Soil and Water Assessment Tool (SWAT). Meteorological data, digital elevation model (DEM), land use/land cover (LULC) map, soil properties and the information on agricultural practices are required to build SWAT model. The model was calibrated with SWAT-CUP for streamflow, sediment, nitrogen and phosphorus by using monthly data (2007 – 2010) from Yavrucak monitoring station. The model validation was carried out in Sukesen monitoring station for the same time period with calibration. With the calibrated and validated model, 11 different agricultural best management practice (BMP) scenarios were developed. The most efficient scenario in terms of pollutant load reduction was the one in which 30% reduction in fertilizer, no tillage and terracing were combined. This study aimed to help decision-makers to decide on the most efficient BMPs and thus to develop sustainable watershed management plans in Lake Mogan watershed and in watersheds showing similar characteristics with Lake Mogan.