Study on the method to estimate the subsurface flow in alluvial sandbars

冲积沙洲地下流量估算方法研究

基本信息

批准号：
11555133
负责人：
TSUJIMOTO Tetsuro
金额：
$ 4.35万
依托单位：
NAGOYA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11555133/
关键词：
Sand bar Stream-aquifer Formation of soil layer Unsaturated soil 不飽和土壤

项目摘要

The aim of the project is to establish the method to estimate the subsurface flow in riparian sandbars in order to evaluate the spatial distribution of habitat of riparian species in sandbar's material or to evaluate water exchange rate with surface flow to estimate the effect of water purification of sandbars in the future. Objects are, (1) subsurface flow in whole sandbar and local flow around small pools, (2 the water exchange rate and its temporal characteristics between subsurface water and unsaturated zone caused by rainfall or evapotranspiration.The methods have been summarized below :1.Development of a method to estimate subsurface water level, flow structure and water budgetThis method has two parts :1) Observation of subsurface water distribution by installing 50-100 wells2) 2-D numerical simulation of subsurface flowThese enable to estimate the subsurface flow structure, retention time in sandbar and water budget with surface water region.2. Development of a combined method … More to estimate subsurface flow around sandbar poolsThe following methods are developed and examined its efficiency.(1) Measurement of subsurface water level distribution around pools installing pipes(2) 2-D subsurface simulation around pools, which affect as inner boundary condition.(3) surface flow analysis to judge the continuity to main channel, and estimate flow condition in it during floods.3. Development of a combined method to estimate exchange rate between subsurface water and unsaturated zone.This method is useful to evaluate water budget of sandbar subsurface water adding to in/out flow at the surface flow boundary by combination of following method :(1) Experiment measurement of hydraulic characteristics of unsaturated soil(2) Core sampling of unsaturated zone to see layer structure(3) 1-D subsurface simulation to estimate water exchange rate at the boundary between saturated zone and unsaturated one.Applications to river Kizu showed that these methods can supply us overall of sandbar subsurface flow, its budget, water exchanging of pools. Less

该项目的目的是建立估算河岸沙洲地下流量的方法，以评估沙洲物质中河岸物种栖息地的空间分布，或评估与地表水流的水交换率，以评估河岸沙洲的水净化效果。未来沙洲的研究对象是，（1）整个沙洲的地下水流和小水池周围的局部水流，（2）降雨或降雨引起的地下水与非饱和带之间的水交换率及其时间特征。方法总结如下：1.开发一种估算地下水位、流动结构和水收支的方法该方法分为两个部分：1）通过安装50-100口井观测地下水分布2）二维数值模拟这些能够估计地下流结构、沙洲中的停留时间以及地表水区域的水预算。2. 开发一种组合方法来估计沙坝池周围的地下流以下方法是开发并检验了其效率。（1）安装管道的水池周围地下水位分布的测量（2）水池周围的二维地下模拟，其影响作为内部边界条件。（3）表面流分析以判断与主渠道的连续性，并估计洪水期间其中的水流状况。 3.开发了一种估计地下水与非饱和区之间交换率的组合方法。该方法可用于评估沙洲地下水在地表流中加入流入/流出流量的水收支情况。结合以下方法进行边界：（1）非饱和土水力特性的实验测量（2）非饱和区岩心取样以查看层结构（3）一维地下模拟以估计饱和区和非饱和区之间边界处的水交换率。在河流中的应用Kizu 表明，这些方法可以为我们提供沙洲地下水流、其预算、水池水交换的整体情况。