Using Baseflow Ensembles for Hydrologic Hysteresis Characterization in Humid Basins of Southeastern China
21
Citation
87
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract Baseflow plays a vital role in protecting the environment and ensuring a stable water supply for farming. There are still gaps in the current understanding of baseflow convergence rates in the humid region due to the abundance of rainfall and the high‐water table. Therefore, this study focused on the evolution and hysteresis characteristics of baseflow in humid basins of southeastern China. The baseflow ensemble simulation (BES) method was established to improve the reliability and applicability of baseflow simulation. We suggest a way of differentiating the wet and dry seasons based on the multi‐year average monthly baseflow index (BFI) to determine the intra‐annual distribution of water effectively and simply. The hydrological hysteresis effect of baseflow on precipitation is revealed by characterizing baseflow response to precipitation under precipitation events during wet and dry seasons. A methodology for assessing the performance of baseflow simulation was proposed from observations of streamflow and precipitation. We found that the BES method performed better in baseflow simulation than other single separation methods. Using the BES method, the lag time of baseflow to precipitation during the wet and dry seasons was found to be 3.09 and 4.04 days after utilizing the BFI to divide the hydrological situation into wet and dry seasons. Additionally, precipitation had nearly twice as much intensity influence on baseflow during the dry season compared to the wet season. These findings have significant ramifications for the use, management, and planning of water resources in humid areas of China.Keywords:
Base flow
Dry season
ABSTRACT The quantification of baseflow is key for water resources management. However, there are few reports on the precision and accuracy in low streamflow measurements. In this paper, we systematically analyze the precision and accuracy of dilution streamflow measurements in headwater channels during baseflow. Precision refers to the variability of the values for repeated measurements and accuracy is how much the measured value approximates the reference one. We measured streamflow in 31 different cross-sections with contributing areas ranging from 0.02 to 5.33 km2. Streamflow measurements with the current meter were adopted as reference for accuracy estimation. A precision error of ±5.0% was found for the measurements. The percent errors compared to reference streamflow ranged from 0.7 to 45.6%, with a median of 6.1%. Precision and accuracy are in the same order of magnitude found in the literature for larger streams. These results can be used for constraining the uncertainty of streamflow measurements and rainfall-runoff modeling of headwater streams.
Base flow
Accuracy and precision
Cite
Citations (11)
Abstract Paleoclimatic perspectives on hydrological variability can offer valuable information on the frequency and magnitude of extreme events. Tree‐ring records are a common proxy used to reconstruct past streamflow due to their interannual resolution and often strong correlation with hydroclimate variability. The separation of streamflow into theoretical baseflow and stormflow constituents is regularly utilized to differentiate between flow‐generating processes; however, it has yet to see use in paleoclimate reconstructions. We compare three approaches which use log‐linear, gamma‐distributed, and baseflow‐separated regression, respectively, to reconstructing flow at a well‐studied gage—the Potomac River at Point of Rock, Maryland. Preinstrumental baseflow and streamflow for summer were estimated for the past 350 years using a regional network of tree‐ring chronologies. Additionally, estimates of winter flow were produced for the same period using a nonoverlapping set of tree‐ring data. Tree growth appears to have a stronger relationship with baseflow than with streamflow for both seasons, supporting the use of baseflow as predictand. The number of chronologies subsequently chosen as predictors for streamflow was also lower than for baseflow and represents an additional source of reconstruction bias/uncertainty when total streamflow is the predictand. Historical records support the validity of both summer and winter reconstructions. The winter reconstruction indicates that several years of consecutive below‐mean flows, on par with the 1960s drought, occurred with higher frequency prior to the instrumental era. Our results suggest that baseflow separation can improve reconstruction skill and provide additional information to water resource management on the long‐term variability of hydrological extremes.
Base flow
Proxy (statistics)
Water year
Cite
Citations (14)
Distinct seasonal characteristics of monsoon climate significantly affect river streamflow in South Korea. The roles of direct runoff and baseflow on streamflow have become more important to ecosystems and human communities in various watersheds of South Korea. Understanding river characteristics, including direct runoff and baseflow, is the first step of river management and can make a significant contribution to maintaining a sustainable and effective river environment. In this regard, this study involves twin objectives: (1) developing the web-based BFlow system to gain advantages in the time and effort required relative to the DOS (Disk Operation System)-based BFlow program; and (2) assessing the contributions of baseflow and direct runoff to streamflow for river management at the national level. For this, we investigated all streamflow gauge stations in South Korea and, then, used the BFlow program to separate baseflow from the available streamflow data. The results showed that baseflow index for 254 streamflow gauge stations ranged from 0.28 to 0.89. Gauge stations with a baseflow index greater than 0.5 accounted for 64% of total stations. The web-based system developed in this study is a more MS (Microsoft) user-friendly version of BFlow. Furthermore, this study illustrated that high baseflow indexes were generally found at gauge stations with a low coefficient of variation of streamflow. The web-based BFlow system will provide understanding to strategically control rivers and improve the efficiency and safety of river management at the national level.
Base flow
Cite
Citations (12)
The streamflow into Miyun Reservoir, the only surface drinking water source for Beijing City, has declined dramatically over the past five decades. Thus, the impacts of climate variability and human activities (direct and indirect human activities) on streamflow and its components (baseflow and quickflow) needs to be quantitatively estimated for the sustainability of regional water resources management. Based on a heuristic segmentation algorithm, the chosen study period (1969–2012) was segmented into three subseries: a baseline period (1969–1979) and two impact periods I (1980–1998) and II (1999–2012). The Soil and Water Assessment Tool (SWAT) was adopted to investigate the attributions for streamflow change. Our results indicated that the baseflow accounted for almost 63.5% of the annual streamflow based on baseflow separation. The contributions of climate variability and human activities to streamflow decrease varied with different stages. During impact period I, human activities was accountable for 54.3% of the streamflow decrease. In impact period II, climate variability was responsible for 64.9%, and about 8.3 mm of baseflow was extracted from the stream on average based on the comparison of the observed streamflow and simulated baseflow. The results in this study could provide necessary information for water resources management in the watershed.
Base flow
SWAT model
Cite
Citations (44)
Base flow
Hydrometeorology
Midstream
Water cycle
Cite
Citations (17)
Accurate long-term streamflow forecast is essential to alleviate and solve the water security problems related to flood and drought disaster warnings. In this study, a new strategy for forecasting monthly streamflow is proposed and four scenarios are designed for the evaluation of different roles of baseflow and surface runoff on performances of long-term streamflow forecasting. The developed models are evaluated at multiple streamflow sites located in the Zhejiang Province of China. The results show that artificial intelligence (AI)-based models with two predictor variables (i.e. baseflow and surface runoff) performed better than that with a single predictor (streamflow) for all the months in a year, and the prediction accuracy of annual peak and monthly streamflow values is improved. Based on the comprehensive evaluations of all the models, the baseflow and surface runoff values are recommended as inputs to AI-based models for an improved prediction accuracy of streamflows.
Base flow
Flood forecasting
Cite
Citations (15)