Batman University, Civil Engineering Department, Turkey.
Sci Total Environ. 2020 Nov 10;742:140553. doi: 10.1016/j.scitotenv.2020.140553. Epub 2020 Jun 27.
Agricultural activities are responsible for three quarter of global nitrate (NO) pollution. Many surface and ground water resources have been detrimentally affected from high rate of nitrogen (N) deposition due to excessive fertilizer and manure application. Grey water footprint (GWF) is one of the internationally accepted indicators quantifying the environmental effects of contaminants on water bodies. The main scope of this study is to assess GWF of agricultural nitrogen utilization in Turkey using Tier-1 approach, which is proposed by Water Footprint Network considering detailed spatially continuous soil, climate and agricultural data in order to provide quantifications at both provincial and basin level. Leaching runoff fractions of diffuse N loads are very important for GWF accounts. However, the previous studies are mainly relied on assigning constant leaching runoff fractions and superficial N applications rates. Nevertheless, many studies reported remarkable variations in leaching fractions due to heterogeneities in soil and water resources. To the author's knowledge, this is the first GWF assessment of the study area employing high resolution leaching runoff fractions which is estimated using soil texture, natural drainage and climate data maps. Nitrogen emissions and GWF accounts of 81 administrative provinces and 25 hydrological basins were quantified using provincial N application and surplus amounts. Accordingly, GWF of anthropogenic N accumulation is estimated to be 24.7 Gm/y corresponding to an average water height of 114 mm per agricultural land area and 340 m per capita for the time period of five years (2007-2011). The water pollution level (WPL) is found to be critical (>0.75) at several river basins while the national average WPL is around 0.13. This study is expected to contribute to the national and international water and agricultural management and planning studies in order to decrease the water pollution levels by providing suitable information to policy-makers.
农业活动是导致全球硝酸盐（NO）污染的四分之三的原因。由于过度施肥和粪肥的应用，许多地表水和地下水都受到了高氮（N）沉积的不利影响。灰色水足迹（GWF）是国际上用于量化污染物对水体环境影响的指标之一。本研究的主要目的是使用 Tier-1 方法评估土耳其农业氮利用的 GWF，该方法由水资源足迹网络提出，考虑了详细的、空间连续的土壤、气候和农业数据，以便在省级和流域级提供量化数据。漫散 N 负荷的淋溶径流分数对 GWF 核算非常重要。然而，以前的研究主要依赖于分配恒定的淋溶径流分数和表面 N 应用率。尽管如此，许多研究报告称由于土壤和水资源的异质性，淋溶分数有很大的变化。据作者所知，这是首次在研究区域内使用高分辨率的淋溶径流分数进行 GWF 评估，该分数是使用土壤质地、自然排水和气候数据图来估计的。使用省级氮应用量和盈余量，对 81 个行政省和 25 个流域的氮排放和 GWF 核算进行了量化。据此，人为 N 积累的 GWF 估计为 24.7 Gm/y，对应于农业土地面积平均水深 114 毫米，人均 340 米，时间跨度为五年（2007-2011 年）。在几个流域发现水污染水平（WPL）为临界值（>0.75），而全国平均 WPL 约为 0.13。本研究有望为国家和国际水资源和农业管理和规划研究做出贡献，通过为决策者提供合适的信息来降低水污染水平。
