Alberta has over 70% of total irrigated land in Canada and 13 irrigation districts are mainly located along the rivers in southern Alberta. The runoff and irrigation return flow can carry excess nutrients, pesticides, and sediments, which adversely affect the river water quality. In the present study, the comprehensive spatiotemporal analysis of land use pattern and stream water quality in southern Alberta was conducted. The water quality monitoring on the South Saskatchewan River watershed within Alberta showed that most water quality indicators did not significantly change between 2003 and 2017. Land use maps demonstrated significant urban expansion and cropland decline in the study area from 2005 to 2015, while the irrigation area increased. Correlation analysis and redundancy analysis revealed that cropland, built-up land, and native grassland were three land use types that were positively correlated with water quality indicators. Stronger correlations between nitrogen concentration and built-up land were found in dry seasons compared with wet seasons. According to the results of cluster analysis, higher water quality indicator concentrations could be observed in groups with a higher proportion of cropland and built-up land. Significant relationships between land use patterns and water quality were found in this study, which demonstrated that further investigation is needed to identify the sources of water pollutants at a smaller scale.

艾伯塔省拥有加拿大总灌溉土地的 70% 以上，13 个灌区主要位于艾伯塔省南部的河流沿岸。径流和灌溉回流会携带过多的养分、农药和沉积物，对河流水质产生不利影响。在本研究中，对阿尔伯塔省南部的土地利用格局和河流水质进行了综合时空分析。阿尔伯塔省内的南萨斯喀彻温河流域的水质监测表明，大多数水质指标2003 年至 2017 年间没有显着变化。土地利用图显示，2005 年至 2015 年研究区城市扩张显着，耕地减少，而灌溉面积增加。相关分析和冗余分析表明，耕地、建设用地和原生草地是与水质指标呈正相关的三种土地利用类型。与雨季相比，旱季氮浓度与建成区的相关性更强。聚类分析结果表明，耕地和建设用地比例较高的组群水质指标浓度较高。本研究发现土地利用模式与水质之间存在显着关系，