Implications of Climate Change on Water Budgets and Reservoir Water Harvesting of Nuuanu Area Watersheds, Oahu, Hawaii

Leta, Olkeba Tolessa; El‐Kadi, Aly I.; Dulai, Henrietta

doi:10.1061/(asce)wr.1943-5452.0000839

Cited by 19 publications

(30 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In recent years, SWAT has been successfully applied in the study of hydrological elements in various watersheds. For example, the SWAT model was applied to study changes in the water budget caused by climate change [20][21][22][23]. The SWAT model was used to study hydrological elements in ice-and snow-covered mountainous area [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Application of SWAT Model with CMADS Data to Estimate Hydrological Elements and Parameter Uncertainty Based on SUFI-2 Algorithm in the Lijiang River Basin, China

Cao

Zhang

Yang

et al. 2018

Water

View full text Add to dashboard Cite

The China Meteorological Assimilation Driving Datasets for the Soil and Water AssessmentTool model (CMADS) have been widely applied in recent years because of their accuracy. An evaluation of the accuracy and efficiency of the Soil and Water Assessment Tool (SWAT) model and CMADS for simulating hydrological processes in the fan-shaped Lijiang River Basin, China, was carried out. The Sequential Uncertainty Fitting (SUFI-2) algorithm was used for parameter sensitivity and uncertainty analysis at the daily scale. The pair-wise correlation between parameters and the uncertainties associated with equifinality in model parameter estimation were investigated. The results showed that the SWAT model performed well in predicting daily streamflow for the calibration period (2009)(2010). The correlation coefficient (R 2 ) was 0.92, and the Nash-Sutcliffe model efficiency coefficient (NSE) was 0.89. For the validation period (2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018), R 2 = 0.89, NSE = 0.88, and reasonable values for the P-factor, R-factor, and percent bias (PBIAS) were obtained. In addition, the spatial and temporal variation of evapotranspiration (ET), surface runoff, and groundwater discharge were analyzed. The results clearly showed that spatial variation in surface runoff and groundwater discharge are strongly related to precipitation, while ET is largely controlled by land use types. The contributions to the water budget by surface runoff, groundwater discharge, and lateral flow were very different in flood years and dry years.

show abstract

Section: Introductionmentioning

confidence: 99%

Application of SWAT Model with CMADS Data to Estimate Hydrological Elements and Parameter Uncertainty Based on SUFI-2 Algorithm in the Lijiang River Basin, China

Cao

Zhang

Yang

et al. 2018

Water

View full text Add to dashboard Cite

show abstract

“…The Nuuanu watershed has four reservoirs, but only the Nuuanu Reservoir #4 (NR4) (Figure 2a) has significant role on the hydrology of the watershed and is thus considered in the modeling processes. Detailed description about the NR4 can be found in Leta et al [4]. scales and characteristics, and environmental problems.…”

Section: Study Areamentioning

confidence: 99%

“…The parameter values as reported by Leta et al [4] were also used. The goodness-of-fit statistics evaluating the performance of SWAT at the three stations are given in Table 2.…”

Section: Streamflow Simulationmentioning

confidence: 99%

“…On the basis of sensitive and important parameters, which were identified by Leta et al [4] for the watersheds, the SWAT model was calibrated and validated for a number of years of streamflow data at the three USGS flow gauging stations ( Table 2). The parameter values as reported by Leta et al [4] were also used.…”

Section: Streamflow Simulationmentioning

confidence: 99%

“…As a consequence, several studies have shown the impacts of future climate change on freshwater budgets [5,[33][34][35][36], streamflow [2,6,7,37,38], and hydrological extremes [6,[8][9][10]39,40] at large-scale continental watersheds. In small-scale Pacific island watersheds, such as in Hawaii, a few studies [3,4,41] have also assessed the impact of climate change on water budgets but focused at monthly and yearly mean values. However, there are no watershed-wide assessment of climate change impact on daily streamflow and its extreme values in Hawaii.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impact of Climate Change on Daily Streamflow and Its Extreme Values in Pacific Island Watersheds

2018

Self Cite

View full text Add to dashboard Cite

Abstract:The integration of hydrology and climate is important for understanding the present and future impact of climate on streamflow, which may cause frequent flooding, droughts, and shortage of water supply. In view of this, we assessed the impact of climate change on daily streamflow duration curves as well as extreme peak and low flow values. The objectives were to assess how climate change impacts watershed-wide streamflow and its extreme values and to provide an overview of the impacts of different climate change scenarios (Representative Concentration Pathways (RCP) 4.5 and 8.5) on streamflow and hydrological extremes when compared with the baseline values. We used the Soil and Water Assessment Tool (SWAT) model for daily streamflow and its extreme value modeling of two watersheds located on the Island of Oahu (Hawaii). Following successful calibration and validation of SWAT at three USGS flow gauging stations, we simulated the impact of climate change by the 2050s (2041-2070) and the 2080s (2071-2100). We used climate change perturbation factors and applied the factors to the historical time series data of 1980-2014. SWAT adequately reproduced observed daily streamflow with Nash-Sutcliffe Efficiency (NSE) values of greater than 0.5 and bracketed >80% of observed streamflow data at 95% model prediction uncertainty at all flow gauging stations, indicating the applicability of the model for future daily streamflow prediction. We found that while the considered climate change scenarios generally show considerable negative impacts on daily streamflow and its extreme values, the extreme peak flows are expected to increase by as much as 22% especially under the RCP 8.5 scenario. However, a consistent decrease in extreme low flows by as much as 60% compared to the baseline values is projected. Larger negative changes of low flows are expected in the upstream part of the watersheds where higher groundwater contributions are expected. Consequently, severe problems, such as frequent hydrological droughts (groundwater scarcity), reduction in agricultural crop productivity, and increase in drinking water demand, are significantly expected on Oahu. Furthermore, the extreme values are more sensitive to rainfall change in comparison to temperature and solar radiation changes. Overall, findings generally indicated that climate change impacts will be amplified by the end of this century and may cause earlier occurrence of hydrological droughts when compared to the current hydrological regime, suggesting water resources managers, ecosystem conservationists, and ecologists to implement mitigation measures to climate change in Hawaii and similar Islands.

show abstract

Long‐term streamflow trends in Hawai'i and implications for native stream fauna

Clilverd

Tsang

Infante

et al. 2019

Hydrological Processes

View full text Add to dashboard Cite

Climate change has fundamentally altered the water cycle in tropical islands, which is a critical driver of freshwater ecosystems. To examine how changes in streamflow regime have impacted habitat quality for native migratory aquatic species, we present a 50‐year (1967–2016) analysis of hydrologic records in 23 unregulated streams across the five largest Hawaiian Islands. For each stream, flow was separated into direct run‐off and baseflow and high‐ and low‐flow statistics (i.e., Q10 and Q90) with ecologically important hydrologic indices (e.g., frequency of flooding and low flow duration) derived. Using Mann–Kendall tests with a running trend analysis, we determined the persistence of streamflow trends through time. We analysed native stream fauna from ~400 sites, sampled from 1992 to 2007, to assess species richness among islands and streams. Declines in streamflow metrics indicated a general drying across the islands. In particular, significant declines in low flow conditions (baseflows), were experienced in 57% of streams, compared with a significant decline in storm flow conditions for 22% of streams. The running trend analysis indicated that many of the significant downward trends were not persistent through time but were only significant if recent decades (1987–2016) were included, with an average decline in baseflow and run‐off of 10.90% and 8.28% per decade, respectively. Streams that supported higher native species diversity were associated with moderate discharge and baseflow index, short duration of low flows, and negligible downward trends in flow. A significant decline in dry season flows (May–October) has led to an increase in the number of no‐flow days in drier areas, indicating that more streams may become intermittent, which has important implications for mauka to makai (mountain to ocean) hydrological connectivity and management of Hawai'i's native migratory freshwater fauna.

show abstract

Implications of Climate Change on Water Budgets and Reservoir Water Harvesting of Nuuanu Area Watersheds, Oahu, Hawaii

Cited by 19 publications

References 46 publications

Application of SWAT Model with CMADS Data to Estimate Hydrological Elements and Parameter Uncertainty Based on SUFI-2 Algorithm in the Lijiang River Basin, China

Application of SWAT Model with CMADS Data to Estimate Hydrological Elements and Parameter Uncertainty Based on SUFI-2 Algorithm in the Lijiang River Basin, China

Impact of Climate Change on Daily Streamflow and Its Extreme Values in Pacific Island Watersheds

Long‐term streamflow trends in Hawai'i and implications for native stream fauna

Contact Info

Product

Resources

About