Estimating flow duration curve in the humid tropics: a disaggregation approach in Hawaiian watersheds

Hydrological Research Letters

2019

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The authors proposed a methodology for estimating flow duration curves (FDC) for perennial and ephemeral catchments in islands using a disaggregated approach. The proposed method is approached statistically and uses no complex parameters in order to reduce uncertainty and retain simplicity. Firstly, the FDC was disaggregated into three parts (high, middle and low) and, for the purpose of this study, it focusses on the low flow section. Initially, the mean monthly flow was used for estimating runoff in both types of catchments. The results show the mean monthly flow provided proper estimates in the perennial catchments, but for the ephemeral catchments the estimates were substandard. Therefore, a different approach using climate indices such as aridity and a precipitation index was used in a generalized regression equation. The results show the majority of the ephemeral catchments responded properly to the climate indices indicating climate as a major controlling factor at the lower end of the FDC.

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Section: Concluding Discussionmentioning

confidence: 99%

Section: Estimating the Shape Of The Fdcmentioning

confidence: 99%

Section: Estimating the Shape Of The Fdcmentioning

confidence: 99%

Section: Estimating the Shape Of The Fdcmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Estimating flow duration curves in perennial and ephemeral catchments using a disaggregated approach

Hydrological Research Letters

2019

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A multiple hydrograph separation technique for identifying hydrological model structures and an interpretation of dominant process controls on flow duration curves

2022

Hydrological Processes

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There has been significant progress made towards understanding the process controls that govern the shapes of flow duration curves (FDC). However, the transferability of the knowledge gained to large spatial scales is still lacking, partly due to the fixed representation of the model structures representing the unobserved underground layer. In the context of improving large scale applicability/transferability of FDC studies: (1) we propose a novel approach to transform/restructure the representation of the subsurface component in hydrological models to be flexible and adaptable in any environment and (2) provide a thorough interpretation of the dominant processes that impact the shape of FDCs. The flexible structure is designed from a series of multiple connected linear reservoirs that are developed from a unique multiple hydrograph separation procedure, to estimate the number of distinct hydrological processes at play. The main results are: (1) wet catchments have more complex model structures (more reservoirs) than arid catchments; indicating that subsurface processes are potentially more present in wet catchments than in drier ones. Dry catchments have more near surface occurring processes, thus have less complex model structures. However, more complexity is potentially required within the internal reservoirs of dry catchments. (2) The strength of interference in the intermediate reservoirs in controlling the dominant processes towards the bottom determined the shape of FDCs, and this increased with aridity. The novel finding is that a model structure can be determined by the catchment's ability to generate flows as well as the strength of low flow persistence. Hence, we propose a conceptual framework for the development of flexible model structures based on the shapes of FDCs. The transformation of models to be flexible in this research, should contribute to studies that seek the transferability of models over large spatial scales.

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A step toward global-scale applicability and transferability of flow duration curve studies: A flow duration curve review (2000–2020)

2021

Journal of Hydrology