Managing Nitrogen and Phosphorus Loads to Water Bodies: Characterisation and Solutions Towards Macro-Regional Integrated Nutrient Management

Abstract

Eutrophication is a water quality problem as a biological event that formed under the influence of many factors. Ammonia, nitrate, nitrite, phosphate, and other inorganic substances which are the main reasons of eutrophication and formed due to microbial decomposition of organic waste not only affect benthic organisms, but also lead to a change in habitat and result in the formation of sensitive areas. With the project “Determination of Sensitive Areas and Water Quality Objectives On The Basis of Watershed in Turkey” sensitive water areas in terms of water pollution, nitrate vulnerable water areas, and nitrate vulnerable zones in the surface waters, water quality objectives and measures to be taken to improve water quality will be determined in twenty five river basin in Turkey. In this context, Watershed-Based Integrated Water Management Approach that is implemented by the Member States of the European Union under the Water Framework Directive has been adopted in Turkey, and also determination and management of sensitive areas will be considered in this approach. Urban wastewaters, industrial wastewaters and runoff waters from agricultural areas change ecological status of the current system and lead to degradation of water quality and increasing production of algae due to the nutrients by affecting directly and indirectly physical, chemical and biological processes of aquatic environment. Eutrophication occurs over time as a result of death and deterioration of algeas with decrease in the amount of oxygen in the water. Water resources should be considered with integrated water management approach which include physical, social, economic and environmental factors by meeting the requirements of current and future. This issue have been raised in recent years and started to be implemented in other countries. The basis of integrated management of water is to accept water both natural resource and as a commodity which may change depending on the purpose of use as well as the quantity and quality.In Europe, water legislation has been implementing under Water Framework Directive (WFD) by adopting the integrated water management. The Water Framework Directive reveals a more coherent and integrated approach for the management of eutrophication in water by fully taking into account the requirements of the Nitrates Directive and Urban Waste Water Treatment Directive. In the context of harmonization of the WFD to national legislation in Turkey, studies are ongoing related to determination and management of sensitive areas. In this project, sensitive water areas in terms of water pollution, nitrate vulnerable water areas, and nitrate vulnerable zones in the surface waters, water quality objectives and measures to be taken to improve