Yeşilırmak havzasında pestisit kirliliği kaynak belirleme çalışması ve metaller için arkaplan konsantrasyonlarının belirlenmesi

Surface waters are one of the most vulnerable environmental compartment to the pollution pressures arising from numerous point and nonpoint sources. In this thesis, pesticide pollution and metal pollution as being two major concerns of the Yeşilırmak River Basin were addressed by pursuing target-oriented analysis and comprehensive assessment approaches. The main objective of this thesis is to establish the basin-spesific normal background concentrations (NBCs) and environmental quality standards (EQSs) for the metals and to determine target-specific agricultural sources of the pesticides in the Yeşilırmak River Basin. In this context, the basin-specific NBCs and EQSs were determined for 26 metals and metalloids. As a result of these analysis and assessments, the basin-specific EQSs were derived as 47.8 µg/L, 13.2 µg/L, and 98.6 µg/L for Al, Cu, and Fe, respectively. Within the scope of the agricultural source identification of the pesticide pollution, the insecticide, herbicide, and fungicide spraying schedules of each crop type raised in the districts of the river basin were analyzed by focusing on district-specific assessments. Furthermore, the spatial distribution pathway and the temporal occurrence trend of the pesticides across the river basin were identified to establish the basin-wide profile of the pesticide pollution. Precipitation regime, district altitude, mobility, and persistence of pesticides, which are the major factors affecting pesticide occurrences in the river, were also analyzed for the well-supported source identification of the pesticide pollution. This thesis offers a goal-oriented baseline to fulfill the functional implementations of the river basin management strategies that are adjusted to site-specific conditions.