澳大利亚依亚瓦拉澙湖的沉积和整治

依亚瓦拉半封闭澙湖是澳大利亚西南侧最著名的海岸澙湖,是全新世海侵以来残留的濒危脆弱地貌。湖面约35km2,流域面积达270km2,长期沉积速率不足1mm/a,短期沉积速率约5~6mm/a。近几十年来,由于受陆源泥沙淤积和工矿重金属污染,澙湖正处于快速退化阶段。当局采取以疏为主的多项整治措施,隔绝陆沙入湖、浚深湖底、加固湖岸、杜绝圈湖养殖、扩宽潮道,缩短了海、湖水交换的时间,目前已变成湖水清澈、鱼虾洄游的旅游圣地。该整治经验可为我国海岸澙湖研究提供借鉴。

DEPOSITION AND REMEDIATION OF THE ILLAWARRA LAGOON IN AUSTRALIA

The Lake Illawarra, as an almost landlocked coastal lagoon is rather famous in southwestern Australia. It is a fragile residual landscape of the Holocene transgression. The lagoon is a shallow elongated waterbody, with a water surface of 35 km2 and a catchment of 270 km2. The long-term sedimentation rate is less than lmm/a, and the short-term sedimentation rate is about 5-6 mm/a. Influenced by land-sourced sand and heavy metal contamination, the lagoon has been in speedy degenera- tion in recent decades. Recently, various measures have been taken to stop the input of land-based sediments, deepen the lake, strengthen the lakeshore, stop lake breeding, widen tidal channels, and shorten the exchange time of seawater and lakewater. The water quality of the Illawarra lake is improving and some species of fishes are moving back. The lake has become an ideal place for tourists. The experience of remediation of the lake is helpful for coastal lagoon research.