Characterisation of the hydrology of an estuarine wetland
Characterisation of the hydrology of an estuarine wetland
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DOI：
10.1016/s0022-1694(98)00194-2
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发表时间：
1998-11
影响因子：
6.4
通讯作者：
C. Hughes;P. Binning;G. Willgoose
中科院分区：
文献类型：
--
作者：
C. Hughes;P. Binning;G. Willgoose
河口湿地潮间带的特点是随着离潮汐流距离的增加，从含盐海洋环境向淡水环境过渡。在澳大利亚亨特河河口的红树林和盐沼湿地建立了一个实验场，为潮间带水文模型提供数据。该试验场的设计是为了监测小尺度（36米）的水通量。已经安装了一个气象站和地下水监测威尔斯井，并在沿着一个涵盖潮汐和淡水系统之间过渡的短一维样带的10周期间内监测水头和潮汐水位。土壤性质已在实验室和现场测定。利用SEEP/W软件建立了场地的二维有限元模型，分析了饱和和非饱和孔隙水运动。修改的保水功能模型蟹洞大孔隙被发现有必要重现所观察到的含水层的响应。地下水对潮汐波动的反应被观察到几乎是均匀的潮间带以外，由于存在高渗透性的地下沉积物低于渗透性较低的表层沉积物。在36米的样带，潮汐强迫被发现产生的传入通量的顺序为0.22立方米/天每米宽的小溪银行在干燥期间，部分平衡的蒸发通量约0.13立方米/天每米宽。在暴雨期间，降雨通量约为0.61m3/天/米宽，占水量平衡的主导地位。蒸发蒸腾速率大于盐沼为主的潮间带比非潮间带。高盐度和盐结壳观测表明，蒸散通量是非常重要的，在非降雨期间，被认为是显着影响盐分浓度在表层土壤基质和下伏含水层。
The intertidal zone of estuarine wetlands is characterised by a transition from a saline marine environment to a freshwater environment with increasing distance from tidal streams. An experimental site has been established in an area of mangrove and salt marsh wetland in the Hunter River estuary, Australia, to characterise and provide data for a model of intertidal zone hydrology. The experimental site is designed to monitor water fluxes at a small scale (36m). A weather station and groundwater monitoring wells have been installed and hydraulic head and tidal levels are monitored over a 10-week period along a short one-dimensional transect covering the transition between the tidal and freshwater systems. Soil properties have been determined in the laboratory and the field. A two-dimensional finite element model of the site was developed using SEEP/W to analyse saturated and unsaturated pore water movement. Modification of the water retention function to model crab hole macropores was found necessary to reproduce the observed aquifer response. Groundwater response to tidal fluctuations was observed to be almost uniform beyond the intertidal zone, due to the presence of highly permeable subsurface sediments below the less permeable surface sediments. Over the 36m transect, tidal forcing was found to generate incoming fluxes in the order of 0.22m3/day per metre width of creek bank during dry periods, partially balanced by evaporative fluxes of about 0.13m3/day per metre width. During heavy rainfall periods, rainfall fluxes were about 0.61m3/day per metre width, dominating the water balance. Evapotranspiration rates were greater for the salt marsh dominated intertidal zone than the non-tidal zone. Hypersalinity and salt encrustation observed show that evapotranspiration fluxes are very important during non-rainfall periods and are believed to significantly influence salt concentration both in the surface soil matrix and the underlying aquifer.