1、2022/9/16Zhejiang UniversityThe Total Water Content of Sandy BeachesZhejiang UniversityPort、Coastal and Offshore EngineeringXiaohu Deng114340222022/9/16Zhejiang Universitycontents INTRODUCTION GROUNDWATER CONCEPTS METHODOLOGY RESULTS AND ANALYSIS DISCUSSION CONCLUSIONS2022/9/16Zhejiang UniversityINT

2、RODUCTION1: a lag between watertable elevation and changing tidal elevation2: tide induced watertable changes3: swash driven oscillations4: effects on beach aggredation and degradation2022/9/16Zhejiang University GROUNDWATER CONCEPTS1: watertable2: vandose zone3: capillary zone4: intermediate zone5:

3、 transient behaviour(Wieringermeer effect)2022/9/16Zhejiang UniversityMETHODOLOGY1: field sites2: neutron thermalisation3: neutron probe calibration2022/9/16Zhejiang UniversityMETHODOLOGYfield sites Pearl Beach Ocean Beach grain size 1.07 1.97 steepness tan=0.15 tan=0.076properties reflective dissip

4、ative2022/9/16Zhejiang UniversityMETHODOLOGYneutron thermalisation1: instrumentHydroprobe Neutron Depth Moisture Gauge containing a 50 mCi Americium-241/Be neutron source2: principlecollision3: advantagesrapid, nondestructive4: disadvantagesmeasuring a volume of sand rather than a pointb=shieldingc=

5、counterd=detectore=neutron emitter2022/9/16Zhejiang UniversityRESULTS AND ANALYSIS1: field sites2: neutron thermalisation3: neutron probe calibration2022/9/16Zhejiang UniversityDISCUSSION1: water zonation2: equipment limitations2022/9/16Zhejiang UniversityCONCLUSIONS1: capillary fringe2: runup infiltration3: Wieri