While many different watershed management strategies have been implemented to improve water quality, relatively few studies empirically tested the combined effects of different strategies on water quality in relation to land cover changes using long-term empirical data at the sub-basin scale. Using 10 years of total suspended solids (TSS) data, we examined how the conversion of wetland, wetland fragmentation, beaver dams, and Best Management Practices (BMPs) affect wet season TSS concentrations for the 25 monitoring stations in the Tualatin River basin, USA. Geographic information systems, Fragstat, and correlation analysis were used to identify the direction of land cover change, degree of wetland fragmentation, and the strength of the relationship between TSS change and explanatory variables. Improvement in TSS concentrations was tightly coupled with the aggregation of wetlands, presence of beaver dams, particularly during the mid-wet season when flows were highest. Other BMPs effectively reduced TSS concentrations for the early and late-wet seasons when flows were not as high as in the middle wet-season. Aggregated wetlands were more effective for improving water quality than smaller disaggregated wetlands of similar total area when combined with the presence of beaver dams and BMPs. These findings offer important scientific and practical implications for management of urbanizing watersheds that seek to achieve the dual goals of improving environmental quality and land development.

尽管已经实施了许多不同的流域管理策略来改善水质，但是相对较少的研究使用子流域规模的长期经验数据，以土地覆盖率变化为依据，测试了不同策略对水质的综合影响。我们使用10年的总悬浮固体（TSS）数据，检查了美国图拉丁河流域的25个监测站的湿地转化，湿地破碎，河狸坝和最佳管理实践（BMP）如何影响湿季TSS浓度。 。地理信息系统，Fragstat和相关分析用于确定土地覆被变化的方向，湿地破碎化程度以及TSS变化与解释变量之间关系的强度。TSS浓度的提高与湿地的聚集，河狸坝的存在紧密相关，特别是在流量最高的湿季中。当流量不如中期湿季高时，其他BMP可以有效地降低湿季早期和后期的TSS浓度。当结合有海狸水坝和BMP时，聚集湿地比总面积相似的较小分散湿地更有效地改善水质。这些发现为试图实现改善环境质量和土地开发的双重目标的城市化流域的管理提供了重要的科学和实践意义。当流量不如中期湿季高时，其他BMP可以有效地降低湿季早期和后期的TSS浓度。当结合有海狸水坝和BMP时，聚集湿地比总面积相似的较小分散湿地更有效地改善水质。这些发现为试图实现改善环境质量和土地开发的双重目标的城市化流域的管理提供了重要的科学和实践意义。当流量不如中期湿季高时，其他BMP可以有效地降低湿季早期和后期的TSS浓度。当结合有海狸水坝和BMP时，聚集湿地比总面积相似的较小分散湿地更有效地改善水质。这些发现为试图实现改善环境质量和土地开发的双重目标的城市化流域的管理提供了重要的科学和实践意义。