Wetland restoration policies and the sustainability of agricultural productions, lessons learnt from Zrebar Lake, Iran

Abstract

Algal bloom and Eutrophication are well-known problems in surface waters, particularly lakes, wetlands, and estuaries. These problems are the consequences of unsustainable farming, urban development, and rural activities like grazing livestock or recreation. Any uncontrolled pollution discharge from these point or nonpoint emission sources introduces nitrogen and phosphorous compounds into water bodies. High concentrations of total nitrogen (TN) and total phosphorous (TP) accelerate Eutrophication and consequently endangers aquatic ecosystem with human inhabitants. This chapter introduces some integrated sustainable management strategies for the restoration of wetland and lakes from Eutrophication. Based on this purpose, the basin of Zrebar Lake located in western Iran was chosen as the studied area. According to the recent studies, this natural wetland encounters Eutrophication. Here, water quality, sediments, emission sources, and ecological specifications of Zrebar Lake are initially reviewed. It is concluded that agricultural activities, such as irrigation and land-uses changes upstream, are mainly responsible for TN and TP pollution loads. Therefore, with a local point of view, integrated farm and basin management (IBFM) strategies are recommended as a solution. However, their sustainability depends on the effectiveness of management practices, impacts on production yields, and the willingness of locals and farmers. The geographical, social, and economic conditions of this area limit implementing some management practices. Therefore, the application of basin simulation tools, like the SWAT model, is recommended as it is inevitable for accounting the effectiveness of management practices. This method can include land-use changes and provide a framework for evaluating the amount of pollution loads removal, changing production yields, and estimating regionally oriented water footprint (WF) of productions in different management practices. For example, 50% reduction of chemical fertilizers, animal manures, and water for irrigation in a decade may approximately reduce 85% of TN pollution loads and 25% of TP pollution loads discharged per one ton of product to the lake. However, this strategy can also reduce the net income of farmers cultivating apple, tobacco and tomato between 25% and 65%. It is also not clear whether these applications can improve ecosystem in this period. Therefore, this chapter implies that the modeling framework requires supplementary quantitative methods for detailed sustainability assessment. WF sustainability (WS) and life cycle impact assessment (LCIA) are two quantitative approaches introduced as auxiliary tools. Accordingly, the WFs of agricultural productions can be compared with annual available water in the study area. LCIA can also accumulate the impacts and show how environmental indicators would be improved by different policies in IBFM. © 2023 Scrivener Publishing LLC.