The Discharge-Storage Relationship and the Long-Term Storage Changes of Southern Taiwan

Abstract

In this study, the water balance concept is used to understand the relationship between discharge and storage in a basin. Three low flow analysis models developed by Brutsaert, Vogel and Kroll, and Kirchner are used to select recession curves that are parameterized using lower envelope, linear regression, and binning methods to characterize basin hydrological behavior. Furthermore, the lowest annual groundwater storage, which is analyzed according to trend, slope, and a change point test, is used to assess the long-term storage properties of southern Taiwan and is also quantified. The water balance concept is used to assess the impact of discharge on groundwater storage that is affected by the different low flow analysis models. This can lead to a more clear understanding of the relationship between groundwater storage and discharge. After statistical tests of trend, it was determined that Chaozhou Station, which has a significant decreasing trend of the lowest groundwater storage, should implement precautionary measures such as an underground reservoir, an artificial recharge, and a collection gallery in the Donggang River Basin. The method is based on the water balance concept and low flow analysis, where precipitation and evapotranspiration in the natural river system are causing the base flow to be directly controlled by groundwater storage. Therefore, the observed streamflow can be used to assess the discharge-storage relationship and quantify the catchment groundwater storage. The results from this study show that the methods are valid for evaluating the discharge-storage relationship and long-term groundwater storage trends. concept method indicated different low flow analysis models will affect the of and groundwater The Kirchner is the under consideration.