Water Quality of Seven Persons Creek

Water quality of Seven Persons Creek at two riparian restoration sites was assessed to provide baseline information, identify water quality issues, and for educational purposes. At the Saamis Archaeological Site (SAS), City of Medicine Hat, there were two water sampling locations, upstream and downstream, 1.25 km apart. A third location was adjacent to a private agricultural land 61 km upstream of the two SAS locations. The SAS is a recreational trail park and was used as an off-leash dog park at the time of the study. Upstream of the SAS are two riparian golf courses, and within SAS are two draws utilized for stormwater conveyance into the creek. Land use in the watershed is predominantly agriculture. Water samples were collected from the two SAS locations on 4 Apr, 20 Jun, and 8 Aug 2018, and field measurements were also taken on 4 Apr. The Private land location was sampled on 29 May, 16 Jul and 13 Aug 2018. Samples were sent to a laboratory for analysis. Results were compared with provincial guidelines for surface waters or literature. For all locations, key water quality issues in creek were bacteria and nutrients (nitrogen (N) and phosphorus (P)). Except for bacteria and pH, highest values of water quality variables occurred at the start of the snowmelt in Apr. At the SAS, there were differences in water quality between locations depending on the season and a number of variables. In terms of bacteria, the downstream location had better water quality than the upstream location throughout the season. The downstream location also had lower values for nitrate, total nitrogen, total Kjeldahl nitrogen, total phosphorus and total dissolved phosphorus at the start of the snowmelt. In contrast, based on total dissolved and suspended solids, dissolved oxygen, conductivity, chloride and oxidation-reduction potential, the upstream location was of better quality at the start of the snowmelt. By late summer, total N and total Kjeldahl N were lower at the upstream location.

本研究对两处河岸修复位点处的七人溪（Seven Persons Creek）水质开展评估，旨在提供基线数据、识别水质问题并服务于教学用途。在梅迪辛哈特市（City of Medicine Hat）的萨米斯考古遗址（Saamis Archaeological Site, SAS）内，设有两处水质采样点位，分别位于上下游且相距1.25公里。第三处采样点位紧邻一处私有农用地，位于上述两处SAS采样点位上游61公里处。该SAS遗址为休闲步道公园，研究开展期间被用作无牵绳犬只活动区。SAS遗址上游分布有两处滨河高尔夫球场，遗址内部设有两条汇水沟，用于将雨水输送至溪中。该流域土地利用类型以农业为主。研究人员于2018年4月4日、6月20日及8月8日对两处SAS采样点位采集水样，并于4月4日完成现场监测。私有农用地点位则于2018年5月29日、7月16日及8月13日完成采样。所有水样均送至实验室开展分析，检测结果与省级地表水水质导则或相关文献标准进行比对。所有采样点位的溪流水质核心问题均为细菌污染与营养盐（氮(N)、磷(P)）污染。除细菌与pH值外，其余水质指标的最高浓度均出现在4月融雪初期。在SAS遗址范围内，不同采样点位的水质差异随季节与多项指标而变化。就细菌污染而言，整个监测周期内下游点位的水质均优于上游点位。融雪初期，下游点位的硝酸盐、总氮、凯氏总氮、总磷及溶解态总磷浓度均更低。相较之下，融雪初期上游点位的溶解态与悬浮态固体、溶解氧、电导率、氯化物及氧化还原电位等指标表现更优。至夏末阶段，上游点位的总氮与凯氏总氮浓度更低。