Small, semi-enclosed basins have often been the location of human settlements; however, this has subjected them to extensive anthropogenic use, negatively impacting the water quality and increasing their susceptibility to eutrophication. A coupled depth-averaged hydrodynamic-biogeochemical model has been configured of the shallow, microtidal Christchurch Harbour estuary, Dorset UK, to investigate processes driving declines in ecosystem health with particular emphasis on understanding the impact of changing river flows, river nutrient inputs and solar radiation. Instances of summer oxygen undersaturation and increased levels of chlorophyll were found to coincide with regions within the estuary yielding long residence times, even under low nutrient conditions. Inverse relationships between time undersaturated and both river flow and river nutrient concentration were observed but with no significant correlation between time undersaturated and solar irradiance which we attribute to the estuary's shallow nature. Our results showed that although river flow controls estuarine renewal, river nutrient concentration plays the greatest role in driving eutrophication development in small, shallow semi-enclosed basins.

小型半封闭盆地通常是人类住区的所在地；然而，这使它们受到广泛的人为使用，对水质产生负面影响，并增加了它们对富营养化的敏感性。一个耦合的深度平均水动力-生物地球化学模型已经配置在英国多塞特郡基督城港口浅潮汐河口，以研究导致生态系统健康下降的过程，特别强调了解变化的河流流量、河流养分输入和太阳辐射的影响. 发现夏季氧气不饱和和叶绿素水平增加的实例与河口内产生较长停留时间的区域一致，即使在低营养条件下也是如此。观察到不饱和时间与河流流量和河流养分浓度之间的反比关系，但不饱和时间与太阳辐照度之间没有显着相关性，我们将其归因于河口的浅水性质。我们的研究结果表明，虽然河流流量控制河口更新，但河流养分浓度在小型、浅半封闭盆地的富营养化发展中起着最大的作用。