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蒙德勒(Mundel)湖是斯里兰卡西海岸一个浅水潟湖系统的最内陆部分。在其最北端通过一条长而狭窄的运河系统——达奇(Dutch)运河与海洋联接。这条运河抑制了该湖中所有的潮汐运动。海潮潮位大约平均为0.5m。淡水通过一条季节河——Battulu Oya进入蒙德勒湖。直到最近,该潟湖还在其南端间断性地通过沙洲同海洋相通。这个开口使该湖可以与海洋快速地进行交换,从而有效地抵消湖中的高盐度和水平面变化。本文于1993年2月至1994年7月期间。在蒙德勒湖南端开口关闭的时候对该湖的水平面和盐度进行了测量。湖水盐度在5～46.5psu之间,与大洋相比其水平面在-0.25～+1.2m之间。水平衡和盐平衡计算表明,水平面的下降导致盐在湖底及其附近区域沉积。蒙德勒湖和大洋水平面之间的位势差驱动水体通过达奇运河进行交换。这个位势差受净淡水供应量变化和大洋水平面变化的影响。根据运河内的盐度梯度所估算出的平均水平面差为0.12m,逆海洋方向的平均驻留时间为几个月,这个驻留时间由于达奇运河中潜坝的存在而延长。为了减少盐度和水平面的变化,增加水体交换,我们建议重新开放沙坝。在此地点和达奇运河设立一个闸门,在Battulu Oya河设立一个调节坝,即使在较长的雨季和旱季也可使盐度和水平面的控制成为可能。
Mundel Lake is the most inland part of a shallow lagoon system on the west coast of Sri Lanka. At its northernmost end, it joins the ocean with a long, narrow canal system, the Dutch canal. This canal suppresses all tidal movements in the lake. The tidal range of the tide is about 0.5m on average. Fresh water enters Lake Mondsee through a seasonal river, Batulu Oya. Until recently, the lagoon was intermittently connected to the sea through sandbanks at its southern tip. This opening allows the lake to exchange swiftly with the ocean, effectively offsetting the high salinity and water level changes in the lake. This article from February 1993 to July 1994 period. The level and salinity of the lake were measured at the opening of the southern tip of Lake Mondle. The salinity of the lake is between 5 and 46.5psu, which is between -0.25 and + 1.2m above sea level. Water balance and salt balance calculations show that the descending of the water level leads to salt deposition in the lake bottom and its vicinity. The potential difference between Lake Mondsee and the oceanic level drives the exchange of water through the Datacial Canal. This situation is badly affected by changes in net freshwater supplies and ocean level changes. According to the salinity gradient in the canal, the average horizontal difference is estimated to be 0.12m, and the average dwell time in the reverse ocean direction is several months. This dwell time is prolonged by the presence of submarine dams in the Daciqu Canal. In order to reduce changes in salinity and water level and increase water exchange, we propose to re-open the sand dam. Setting up a gate at this site and on the Daci Canal and the setting up of a regulating dam on the Battulu Oya River make salinity and water level control possible even in the longer rainy and dry seasons.