Using Time Series Analysis to Support the Water Resources Management in the Upper Basin of the Suquia River: An Observational Study

Abstract. Satellite observations of evapotranspiration (ET) have been widely used for water resources management in China. An accurate ET product with a high spatiotemporal resolution is required for research on drought stress and water resources management. However, such a product is currently lacking. Moreover, the performances of different ET estimation algorithms for China have not been clearly studied, especially under different environmental conditions. Therefore, the aims of this study were as follows: (1) to use multisource images to generate a long-time-series (2001–2018) daily ET product with a spatial resolution of 1 km × 1 km based on the Surface Energy Balance Algorithm for Land (SEBAL); (2) to comprehensively evaluate the performance of the SEBAL ET in China using flux observational data and hydrological observational data; and (3) to compare the performance of the SEBAL ET with the MOD16 ET product at the point scale and basin scale under different environmental conditions in China. At the point scale, both the models performed best in the conditions of forest cover, subtropical zones, hilly terrain, or summer, respectively, and SEBAL performed better in most conditions. In general, the accuracy of the SEBAL ET (rRMSE = 44.91 %) was slightly higher than that of the MOD16 ET (rRMSE = 48.72 %). In the basin-scale validation, both the models performed better than in the point-scale validation, with SEBAL obtaining results superior (rRMSE = 13.57 %) to MOD16 (rRMSE = 32.84 %). Additionally, both the models showed a negative bias, with the bias of the MOD16 ET being higher than that of the SEBAL ET. In the daily-scale validation, the SEBAL ET product showed a root mean square error (RMSE) of 0.92 mm d−1 and an r value of 0.79. In general, the SEBAL ET product can be used for the qualitative analysis and most quantitative analyses of regional ET. The SEBAL ET product is freely available at https://doi.org/10.5281/zenodo.4243988 and https://doi.org/10.5281/zenodo.4896147 (Cheng, 2020a, b). The results of this study can provide a reference for the application of remotely sensed ET products and the improvement of satellite ET observation algorithms.

Download Full-text

Assessment of Groundwater Resource in Climate Variability Context at Sinematiali (North of Côte d'Ivoire)

European Journal of Environment and Earth Sciences ◽

10.24018/ejgeo.2020.1.5.73 ◽

2020 ◽

Vol 1 (5) ◽

Author(s):

Omer Zephir De Lasme ◽

Avy Stephane Koffi ◽

Dodo Guy Gnali Cedric

Keyword(s):

Time Series ◽

Water Resources ◽

Climate Variability ◽

Water Resources Management ◽

Integrated Water Resources Management ◽

Statistical Test ◽

Groundwater Resource ◽

Resources Management ◽

Pettitt Test ◽

Software Models

Study of climate variability gets great importance for integrated water resources management. This work examines impact of climate variability on the evolution of water resources in the Bandama sub-watershed at Sinematiali with a view of better management. The time series of rainfall and discharge were used as a database for this purpose. Known calculation hydrologic methods of Nicholson, Maillet as well as the statistical test for breaking detection (Pettitt test) were applied. The effective rain and recharge were estimated by using the ESPERE software models over the period 1980 to 1987. Climate variability is characterized by alternative season of wet, normal, and dry periods, and a pluviometry break occurred in 1984 year. The annual effective rain was assessed from 30 to 570 mm while recharge of aquifers estimated between 2 and 333 mm. This work constitutes a fundamental base for modeling water resources management at Sinematiali.

Download Full-text

Change of access to emergency care in a repopulated village after the 2011 Fukushima nuclear disaster: a retrospective observational study

BMJ Open ◽

10.1136/bmjopen-2018-023836 ◽

2019 ◽

Vol 9 (2) ◽

pp. e023836 ◽

Cited By ~ 1

Author(s):

Yoshitaka Nishikawa ◽

Masaharu Tsubokura ◽

Yoshimitsu Takahashi ◽

Shuhei Nomura ◽

Akihiko Ozaki ◽

...

Keyword(s):

Time Series ◽

Observational Study ◽

Time Series Analysis ◽

Emergency Care ◽

Credible Interval ◽

Retrospective Observational Study ◽

Series Analysis ◽

Major Disaster ◽

Bayesian Time Series ◽

Fukushima Disaster

ObjectivesSustaining emergency care access is of great concern. The aim of this study is to evaluate access to emergency care in a repopulated village following the 2011 Fukushima disaster.DesignThis research was a retrospective observational study. The primary outcome measure was total emergency medical services (EMS) time. A Bayesian time series analysis was performed to consider local time series trend and seasonality.SettingThe residents in Kawauchi Village, Fukushima, Japan were forced to evacuate after the 2011 Fukushima disaster. As the radiation dose was an acceptable level, the residents began the process of repopulation in April 2012.ParticipantsThis study included patients transported by EMS from January 2009 to October 2015. Patients transported during the evacuation period (from March 2011 to March 2012) were excluded.ResultsA total of 781 patients were transferred by EMS (281 patients before the disaster, 416 after repopulation and 84 during the evacuation period). A Bayesian time series analysis revealed an increase in total EMS time, from the first request call to arrival at a hospital of 21.85 min (95% credible interval 14.2–29.0, Bayesian one-sided tail-area probability p=0.001). After the disaster, 42.3% of patients were transported to a partner hospital.ConclusionsTotal EMS time increased after repopulation of the area affected because of a massive number of hospital closures. Proactive partnerships would be a possible countermeasure in the affected areas after a major disaster.

Download Full-text

Long time series of daily evapotranspiration in China based on the SEBAL model and multisource images and validation

10.5194/essd-2020-345 ◽

2020 ◽

Author(s):

Minghan Cheng ◽

Xiyun Jiao ◽

Binbin Li ◽

Xun Yu ◽

Mingchao Shao ◽

...

Keyword(s):

Time Series ◽

Water Resources ◽

Observational Data ◽

Water Resources Management ◽

Environmental Conditions ◽

Scale Validation ◽

Point Scale ◽

Resources Management ◽

Basin Scale ◽

Long Time

Abstract. Satellite observations of evapotranspiration (ET) have been widely used for water resources management in China. An accurate ET product with a high spatiotemporal resolution is required for research on drought stress and water resources management. However, such a product is currently lacking. Moreover, the performances of different ET estimation algorithms for China have not been clearly studied, especially under different environmental conditions. Therefore, the aims of this study were as follows: (1) to use multisource images to generate a long time series (2001–2018) daily ET product with a spatial resolution of 1 km × 1 km based on the Surface Energy Balance Algorithm for Land (SEBAL); (2) to comprehensively evaluate the performance of the SEBAL ET in China using flux observational data and hydrological observational data; (3) to compare the performance of the SEBAL ET with the MOD16 ET product at the point-scale and basin-scale under different environmental conditions in China. At the point-scale, both the models performed best in the conditions of forest cover, subtropical zones, hilly terrain, or summer, respectively, and SEBAL performed better in most conditions. In general, the accuracy of the SEBAL ET (rRMSE = 44.91 %) was slightly higher than that of the MOD16 ET (rRMSE = 48.72 %). In the basin-scale validation, both the models performed better than in the point-scale validation, with SEBAL obtaining superior results (rRMSE = 19.15 %) to MOD16 (rRMSE = 33.62 %). Additionally, both the models showed a negative bias, with the bias of the MOD16 ET being higher than that of the SEBAL ET. In the daily-scale validation, the SEBAL ET product showed an RMSE of 0.92 mm/d and an r-value of 0.79. In general, the SEBAL ET product can be used for the qualitative analysis and most quantitative analysis of regional ET. SEBAL ET product is freely available at https://doi.org/10.5281/zenodo.4218413 (Cheng, 2020). The results of this study can provide a reference for the application of remotely sensed ET products and the improvement of satellite ET observation algorithms.

Download Full-text