Kourgialas Nektarios N, Karatzas George P, Koubouris Georgios C
School of Environmental Engineering - Technical University of Crete, Polytechneioupolis, 73100, Chania, Greece; Hellenic Agricultural Organization - DIMITRA, National Agricultural Research Foundation (N.AG.RE.F.) - Institute for Olive Tree, Subtropical Crops and Viticulture, Agrokipio, 73100, Chania, Greece.
School of Environmental Engineering - Technical University of Crete, Polytechneioupolis, 73100, Chania, Greece.
J Environ Manage. 2017 Mar 15;189:150-159. doi: 10.1016/j.jenvman.2016.12.038. Epub 2016 Dec 23.
Fertilizers have undoubtedly contributed to the significant increase in yields worldwide and therefore to the considerable improvement of quality of life of man and animals. Today, attention is focussed on the risks imposed by agricultural fertilizers. These effects include the dissolution and transport of excess quantities of fertilizer major- and trace-elements to the groundwater that deteriorate the quality of drinking and irrigation water. In this study, a map for the Fertilizer Water Pollution Index (FWPI) was generated for assessing the impact of agricultural fertilizers on drinking and irrigation water quality. The proposed methodology was applied to one of the most intensively cultivated with tree crops area in Crete (Greece) where potential pollutant loads are derived exclusively from agricultural activities and groundwater is the main water source. In this region of 215 km, groundwater sampling data from 235 wells were collected over a 15-year time period and analyzed for the presence of anionic (ΝΟ, PO) and cationic (K, Fe, Mn, Zn, Cu, B) fertilizer trace elements. These chemicals are the components of the primary fertilizers used in local tree crop production. Eight factors/maps were considered in order to estimate the spatial distribution of groundwater contamination for each fertilizer element. The eight factors combined were used to generate the Fertilizer Water Pollution Index (FWPI) map indicating the areas with drinking/irrigation water pollution due to the high groundwater contamination caused by excessive fertilizer use. Moreover, by taking into consideration the groundwater flow direction and seepage velocity, the pathway through which groundwater supply become polluted can be predicted. The groundwater quality results show that a small part of the study area, about 8 km (3.72%), is polluted or moderately polluted by the excessive use of fertilizers. Considering that in this area drinking water sources (wells) are located, this study highlights an analytic method for delineation wellhead protection zones. All these approaches were incorporated in a useful GIS decision support system that aids decision makers in the difficult task of protection groundwater resources.
化肥无疑促成了全球粮食产量的显著增长，进而极大地提升了人类和动物的生活质量。如今，人们的注意力集中在农用化肥带来的风险上。这些影响包括过量的化肥主要元素和微量元素溶解并输送到地下水中，从而降低饮用水和灌溉用水的质量。在本研究中，绘制了化肥水污染指数（FWPI）图，以评估农用化肥对饮用水和灌溉用水质量的影响。所提出的方法应用于希腊克里特岛树木作物种植最为密集的地区之一，该地区潜在污染物负荷完全来自农业活动，且地下水是主要水源。在这片215平方公里的区域内，在15年的时间里收集了来自235口水井的地下水采样数据，并分析了阴离子（NO、PO）和阳离子（K、Fe、Mn、Zn、Cu、B）化肥微量元素的存在情况。这些化学物质是当地树木作物生产中使用的主要化肥成分。为了估算每种化肥元素的地下水污染空间分布，考虑了八个因素/地图。将这八个因素综合起来，生成了化肥水污染指数（FWPI）图，该图表明了由于过量使用化肥导致地下水污染严重而造成饮用水/灌溉水污染的区域。此外，通过考虑地下水流向和渗流速度，可以预测地下水供应被污染的途径。地下水质量结果表明，研究区域的一小部分，约8平方公里（3.72%），因过量使用化肥而受到污染或中度污染。鉴于该地区有饮用水源（水井），本研究突出了一种划定井口保护区的分析方法。所有这些方法都被纳入一个有用的地理信息系统决策支持系统，该系统有助于决策者完成保护地下水资源这一艰巨任务。
