2021 Fiscal Year Research-status Report
Global inundation area estimation by assimilating multi-sensor satellite observations into a hydrodynamic model
Project/Area Number |
20K22428
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Research Institution | The University of Tokyo |
Principal Investigator |
ZHOU XUDONG 東京大学, 生産技術研究所, 特任助教 (20876239)
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Project Period (FY) |
2020-09-11 – 2023-03-31
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Keywords | bias correction / assessment system / levee scheme |
Outline of Annual Research Achievements |
In the previous year, the characteristics of the CaMa-Flood and Landsat were calculated were compared. It is found that CaMa-Flood has a systematic error in certain regions because of various reasons. This year, the first task is to improve the CaMa-Flood to reduce those systematic errors. A bias correction method based on rating-curve (water level and river discharge) was developed to correct the river channel parameter - river bathymetry. The method got rid of the largest bias source to the hydrodynamic model as the correction result is independent from various runoff inputs. With the corrected river bathymetry, the simulation performance of water surface area is improved to some degree. The second achievement is that an assessment system of model against global river discharge and water surface area has been built. This system evaluates the model performance at each single sites and gives an overall evaluation of model improvement with a different model setting. With which the evaluation of data assimilation can be easily achieved. The third task is integrating human water management to the model as we find ignoring of the flood control infrastructures (e.g., dams, levees, dikes) is the direct cause of large overestimation in modeling the water surface area, especially in the river deltas. However, this requires large efforts and therefore the progress was delayed also because of the covid pandemic. The project has been extended for one more year, thus the planned works is expected to finish within one year.
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Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
The plan for the second year is partially accomplished. The characteristics of the water surface area by model simulation and satellite observation are well analyzed. A bias correction method for the river bathymetry was developed and a paper was published on an international top journal. However the research plan is slightly delayed. First, it is because the accuracy of satellite-based water surface area is worse than expected. Second, the limitation of model structure (e.g., ignoring levees) is vital to the bias. Therefore, a new levee scheme is under developing. Levee data should be achieved by collaborating with other researchers, but collaboration is seriously affected by the pandemic during last year. Besides this, some sample areas with limited effects from human activities have been selected, which will help to proceed with the research plan.
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Strategy for Future Research Activity |
A new levee scheme is under developing but achieving global levee data requires collaborations. A data assimilation code package is developed using the water surface area. Some sample river regions with limited human impact were selected and will be used to test the prototype data assimilation codes.
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Causes of Carryover |
1. Article coast: remaining 396,874 (Desktop PC (Lenovo Thinkpad Station): 200,000; Network Storage: PROMISE Pegas us32 R4 16TB RAID System : 180,000) 2. Travel Expenses: 435,225 (American Geophysical Union Fall meeting (2022/12, 5days): 300,000; 土木学会水工学講演会(3days): 70,000; Kobe University workshop (3days): 70,000) 3. Miscellaneous:270,870 (Publication fee: 220,000; Registration fee: 50,000)
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Research Products
(1 results)