Abstract
This research aims to estimate baseflow (BF) and baseflow index (BFI) in ungauged basins in the southern part of Thailand. Three spatial interpolation methods (namely, inverse distance weighting (IDW), kriging, and spline) were utilized and compared in regard to their performance. Two baseflow separation methods, i.e., the local minimum method (LM) and the Eckhardt filter method (EF), were investigated. Runoff data were collected from 65 runoff stations. These runoff stations were randomly selected and divided into two parts: 75% and 25% for the calibration and validation stages, respectively, with a total of 36 study cases. Four statistical indices including mean absolute error (MAE), root mean squared error (RMSE), correlation coefficient (r), and combined accuracy (CA), were applied for the performance evaluation. The findings revealed that monthly and annual BF and BFI calculated by EF were mostly lower than those calculated by LM. Furthermore, IDW gave the best performance among the three spatial interpolation techniques by providing the highest r-value and the lowest MAE, RMSE, and CA values for both the calibration and validation stages, followed by kriging and spline, respectively. We also provided monthly and annual BF and BFI maps to benefit water resource management.
Highlights
Baseflow (BF) is a complete streamflow portion that slowly flows into a stream from the saturated soil or groundwater storage [1,2] and predominantly contributes to streamflow during the dry season
From reviewing the literature for the applicability of spatial interpolation techniques in estimating BF and baseflow index (BFI) in ungauged watersheds, we found only one study that used the Inverse Distance Weighting (IDW) and kriging approaches to interpolate BFI with a grid resolution of 1000 m for the conterminous United States [31]
We found that the kriging technique gave a lower r-value and higher mean absolute error (MAE), root mean squared error (RMSE), and combined accuracy (CA) values than the values provided by the spline technique for the calibration stage
Summary
Baseflow (BF) is a complete streamflow portion that slowly flows into a stream from the saturated soil or groundwater storage [1,2] and predominantly contributes to streamflow during the dry season. It is crucial to understand the hydrological characteristics, especially the spatiotemporal variation of BF availability in the watershed, to plan and monitor water resources and ecological systems. BF helps us understand the hydrology of the watershed in terms of surface and subsurface water interactions, urbanization effects on runoff generation, and healthy aquatic habitats within a stream. Many researchers have applied and compared the performance of several different separation methods to obtain BF [3,4,5,6]. Eckhardt [3] recommended a two-parameter filter to be more reasonable than a one-parameter filter and indicated that the maximum baseflow index (BFImax ) values depended on the watershed’s hydrological and hydrogeological characteristics. To get precision during the non-precipitation season, Shao, Zhang, Guan, Sadat and
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
