Flood Effect on Groundwater Recharge on a Typical Silt Loam Soil

Guohua Zhang,Xiaoyu Pi,Xinhu Li,Congbao Xie,Gary Feng

doi:10.3390/w9070523

Abstract

Floods are of great concern as the global climate changes, and investigations of flood water infiltration and groundwater recharge are important for water resource management worldwide, especially under conditions of global climate changes. However, information on the relationship between the flood water and groundwater recharge is limited. The objective of this study was to determine the relationship between the flood water depth and the height of groundwater rise using lysimeters and numerical modeling in the floodplain of the Tarim River in northwestern China. The experimental results suggested that the rise in height of the groundwater table was closely related to the flood water ponding depth, and the groundwater depth decreased quickly after flooding due to the high infiltration rate of water originating at the Tarim River. The water table falling velocity was significantly less than the water table rising velocity. If the initial groundwater table was deeper, the variation in the water table rise depth was smaller and the water table falling velocity was slower. The numerical simulation results showed good agreement with the observed data, with a determination coefficient (R2) of 0.87 and a root mean square error (RMSE) of 63.91 cm. A good relationship (R2 = 0.789) between the initial groundwater table depth (H0), initial soil water content (W0), flood water depth (h), and height of the water table rise (H) was established. Considering that natural and artificial flood frequencies are related to flood time interval (dt), a relationship (R2 = 0.892) was developed between them. These results can enhance the understanding of flood recharge characteristics in the floodplains of inland rivers.

Highlights

Floods are important sources of groundwater recharge in most of the world’s arid lands [1]
The experimental results showed that the flood water depth significantly contributed to
The experimental results showed that the flood water depth significantly contributed to groundwater recharge and that various flood water depths had different effects under different groundwater recharge and that various flood water depths had different effects under different initial initial groundwater tables

Summary

Introduction

Floods are important sources of groundwater recharge in most of the world’s arid lands [1]. Flood spreading (due to river overflows) is one of the methods used for flood management and water harvesting that increases the groundwater recharge [3]. Recharge is the portion of infiltration that reaches the water table after passing through the soil profile [4]. Stream beds of ephemeral rivers are largely composed of permeable, coarse alluvial sediments that promote relatively rapid infiltration of flood water, which recharges the local alluvial aquifers [5]. Several methods including direct observation [5,6], mathematical modeling [7], and stable isotope studies [8,9] have been used to estimate flood water infiltration and groundwater recharge

Objectives

Results

Conclusion