Turgeon P, Brazeau S, Kotchi S O, Pelcat Y, Michel P
Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Saint-Hyacinthe, Quebec.
Can Commun Dis Rep. 2014 Sep 18;40(16):326-334. doi: 10.14745/ccdr.v40i16a02.
Fecal contamination of recreational waters may lead to gastroenteritis, respiratory infections, dermatitis and ear infections. In addition to directly testing waters for contamination, the World Health Organization (WHO) recommends the assessment of environmental factors known to influence water quality as part of monitoring efforts. Measurement of these factors using satellite imagery may be helpful in Canada where monitoring over large areas or difficult to access locations is needed.
To assess the added value of using satellite imagery as part of monitoring and managing microbial risks associated with recreational waters in Canada.
Satellite images were used to calculate five environmental indices that may affect the risk of contamination of recreational waters: agricultural land, urban areas (impervious surfaces), forest and wetlands. Statistical models including these indices were then compared with the average contamination level of beaches in southern Quebec, Canada. Various satellite sensors were compared against criteria of accuracy and performance.
Satellite imagery classification performed well for the study area. Two of the variables were significantly associated with higher coliform levels: agricultural land and urban areas. In the context of this assessment, the Landsat-5 sensor offered the best cost-benefit ratio.
Satellite imagery can be used to identify environmental factors associated with a higher risk of fecal contamination of recreational waters in Canada and may supplement current monitoring and risk assessment efforts.
休闲水域的粪便污染可能导致肠胃炎、呼吸道感染、皮炎和耳部感染。除了直接检测水域污染外，世界卫生组织（WHO）建议在监测工作中评估已知会影响水质的环境因素。在加拿大，利用卫星图像测量这些因素可能会有所帮助，因为该国需要对大面积或难以到达的地点进行监测。
评估在加拿大将卫星图像作为监测和管理与休闲水域相关的微生物风险的一部分所具有的附加价值。
利用卫星图像计算五个可能影响休闲水域污染风险的环境指数：农业用地、城市地区（不透水表面）、森林和湿地。然后将包含这些指数的统计模型与加拿大魁北克省南部海滩的平均污染水平进行比较。根据准确性和性能标准对各种卫星传感器进行了比较。
卫星图像分类在研究区域表现良好。其中两个变量与较高的大肠菌群水平显著相关：农业用地和城市地区。在此评估背景下，陆地卫星5号传感器的性价比最高。
卫星图像可用于识别与加拿大休闲水域粪便污染风险较高相关的环境因素，并可能补充当前的监测和风险评估工作。
