Traditional irrigation practices sustain groundwater quality in a semiarid piedmont
Traditional irrigation practices sustain groundwater quality in a semiarid piedmont
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DOI：
10.1016/j.catena.2021.105923
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发表时间：
2022-03-01
期刊：
影响因子：
6.2
通讯作者：
Chehbouni, A.
中科院分区：
文献类型：
--
作者：
Bouimouass, H.;Fakir, Y.;Chehbouni, A.
在半干旱地区，农业实践已被发现会显着改变地下水质量。尽管人们对集约化灌溉农业的影响进行了大量研究，但与传统农业实践对地下水质量影响有关的许多关键问题仍未得到解答。在这项研究中，对在摩洛哥中部高阿特拉斯山脉半干旱山麓采集的 91 个水样的主要离子分析结果用于评估传统灌溉做法对地下水质量的影响。尽管灌区使用了有机肥，但地下水中 NO3 浓度仍然较低（中位数 = 9 mg/L），并且在灌溉季节平均仅增加 3.6 mg/L。根据化学指标，灌溉区采样的所有地下水都具有优良的品质，可用于饮用和灌溉。总体而言，地下水化学是由地质过程控制的。地下水中主要离子之间的关系反映了溪流通过灌溉从山区流向冲积平原过程中的矿物质溶解和离子交换过程。相比之下，在非灌溉地区，石盐溶解和/或蒸腾过程导致电导率值增加，是灌溉地区电导率值的两倍以上。灌溉区域下方地下水电导率值的季节性下降（平均从 841 至 692 mu S/cm）是灌溉补给的结果，这抵消了盐化机制的影响，而盐化机制通常是灌溉干旱地区的特征。这些结果凸显了这种古老的水力农业系统对地下水质量的影响很小。这种传统的灌溉系统将粮食生产、低能源成本（通过重力灌溉渠道进行水流改道）和低环境影响联系起来。在快速扩张的现代灌溉措施导致全球变化影响加速的背景下，应尽可能强调和保护这种传统的水农业系统。
In semi-arid areas, agricultural practices have been found to significantly alter groundwater quality. Although significant research has been conducted on the impacts of the intensification of irrigated agriculture, many pivotal questions relating to the impact of traditional agricultural practices on groundwater quality remain unanswered. In this study, the results of major ions analysis of 91 water samples collected in the semi-arid piedmont of the High Atlas Mountains, central Morocco, are used to assess the impact of traditional irrigation practices on groundwater quality. Despite the use of organic fertilizer in the irrigated area, the NO3 groundwater concentrations remain low (median = 9 mg/L) and only increase on average by 3.6 mg/L during the irrigation season. All groundwater sampled in the irrigation area has an excellent quality for both drinking and irrigation purposes based on the chemical indices. Overall, groundwater chemistry is controlled by geogenic processes. Relationships between major ion in groundwater reflects the mineral dissolution and ion exchange processes during the trajectory of the streamwaters from the mountain to the alluvial plain via irrigation practices. In comparison, in the non-irrigated area, halite dissolution and/or transpiration processes results in increases in electrical conductivity values that were over twice the values in the irrigated area. The seasonal decrease of electrical conductivity values in groundwater beneath the irrigated area (on average from 841 to 692 mu S/cm) is a result of irrigation recharge, which counterbalances effects of salinization mechanisms that can often characterize irrigated arid zones. These results highlight the low impacts of this ancestral hydro-agro system on groundwater quality. Such a traditional irrigation system provides a nexus between food production, low energy costs (streamflow diversions by gravity-fed channels), and low environmental impacts. In the context of accelerations in global change impacts via the rapidly expanding modern irrigation practices, such traditional hydroagro systems, where possible, should be highlighted and preserved.