Dr Mehdi Khaki

Dr Mehdi Khaki

Lecturer

School of Engineering

Career Summary

Biography

After finishing my study on the application of satellite remote sensing in hydrology and geodesy during my MSc in 2014, I started my PhD in 2015 in Curtin University and finished it in 2018, focusing on the integrating satellite data products with hydrological models using advanced statistical methods. My research is centred about the application of geodetic and remote sensing techniques and their integration with available models to improve the hydrological knowledge in various spatial scales, e.g., from medium- to large-scale river basins to a global scale. During my researches, I have used a variety of satellite data products to study Earth and proposed new satellite data filtering, e.g., to account for satellite radar altimetry and the Gravity Recovery And Climate Experiment (GRACE) errors and to improve the quality of their data. The enhanced satellite products have been used for different objectives such as studying inland surface water variations, coastal water level changes, deriving gravity anomalies over areas without reliable ground measurements, and last but not least improving land hydrological models estimates.

During and after my PhD I have mainly worked in the field of satellite data assimilation. I have developed data assimilation techniques for integrating multiple satellite-derived measurements, e.g., from terrestrial water storage (TWS) from GRACE and satellite soil moisture with hydrological models using nonlinear static analysis. The proposed methods include parametric and non-parametric (data-driven) approaches, which led to a more accurate estimation of changes in water storage compartments (including surface and subsurface storage compartments), as well as internal interactions between storage changes and fluxes (precipitation, evapotranspiration, and runoff) or external-interactions due to large-scale ocean-atmosphere phenomena. My experience with statistical analyses in model-data integration and implementing various satellite remote sensing data in hydrology and geodesy have helped me to study global water cycles, as well as to acquire unprecedented information about water storage changes over different regions such as Australia, Bangladesh, South America, and Africa. I have also merged various datasets from different satellite platforms and ground-based measurements to analyse the anthropogenic and climatic impacts on different water compartments, e.g., over Iran, Nile, and Lake Victoria, as well as to study global hydrological drought. 


Qualifications

  • PhD, Curtin University of Technology
  • Bachelor of Civil Engineering, University of Tehran - Iran
  • Master of Civil Engineering, University of Tehran - Iran

Keywords

  • Data assimilation
  • Geodesy
  • Satellite remote sensing

Fields of Research

Code Description Percentage
049999 Earth Sciences not elsewhere classified 30
090902 Geodesy 40
080205 Numerical Computation 30

Professional Experience

UON Appointment

Title Organisation / Department
Lecturer University of Newcastle
School of Engineering
Australia

Awards

Recipient

Year Award
2019 Western Australia Asia-Pacific Spatial Excellence Awards (APSEA-WA)
The Surveying & Spatial Sciences Institute (SSSI)

Scholarship

Year Award
2015 Curtin International Postgraduate Research Scholarships (CIPRS)
Curtin University
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Publications

For publications that are currently unpublished or in-press, details are shown in italics.


Journal article (19 outputs)

Year Citation Altmetrics Link
2019 Khaki M, Awange J, 'The application of multi-mission satellite data assimilation for studying water storage changes over South America', Science of the Total Environment, 647 1557-1572 (2019) [C1]
DOI 10.1016/j.scitotenv.2018.08.079
Citations Scopus - 4
2019 Khaki M, Hoteit I, Kuhn M, Forootan E, Awange J, 'Assessing data assimilation frameworks for using multi-mission satellite products in a hydrological context', Science of the Total Environment, 647 1031-1043 (2019) [C1]
DOI 10.1016/j.scitotenv.2018.08.032
Citations Scopus - 2Web of Science - 2
2019 Khaki M, Zerihun A, Awange J, Dewan A, 'Integrating satellite soil-moisture estimates and hydrological model products over Australia', AUSTRALIAN JOURNAL OF EARTH SCIENCES, (2019)
DOI 10.1080/08120099.2019.1620855
2019 Awange JL, Hu KX, Khaki M, 'The newly merged satellite remotely sensed, gauge and reanalysis-based Multi-Source Weighted-Ensemble Precipitation: Evaluation over Australia and Africa (1981 2016)', Science of the Total Environment, 670 448-465 (2019) [C1]
DOI 10.1016/j.scitotenv.2019.03.148
Citations Scopus - 3
2019 Forootan E, Khaki M, Schumacher M, Wulfmeyer V, Mehrnegar N, van Dijk AIJM, et al., 'Understanding the global hydrological droughts of 2003 2016 and their relationships with teleconnections', Science of the Total Environment, 650 2587-2604 (2019) [C1]
DOI 10.1016/j.scitotenv.2018.09.231
Citations Scopus - 8
2019 Khaki M, Awange J, 'Improved remotely sensed satellite products for studying Lake Victoria's water storage changes', Science of the Total Environment, 652 915-926 (2019) [C1]
DOI 10.1016/j.scitotenv.2018.10.279
Citations Scopus - 2
2018 Khaki M, Awange J, Forootan E, Kuhn M, 'Understanding the association between climate variability and the Nile's water level fluctuations and water storage changes during 1992 2016', Science of the Total Environment, 645 1509-1521 (2018) [C1]
DOI 10.1016/j.scitotenv.2018.07.212
Citations Scopus - 3Web of Science - 2
2018 Khaki M, Forootan E, Kuhn M, Awange J, Longuevergne L, Wada Y, 'Efficient basin scale filtering of GRACE satellite products', REMOTE SENSING OF ENVIRONMENT, 204 76-93 (2018)
DOI 10.1016/j.rse.2017.10.040
Citations Scopus - 14Web of Science - 13
2018 Khaki M, Hamilton F, Forootan E, Hoteit I, Awange J, Kuhn M, 'Nonparametric Data Assimilation Scheme for Land Hydrological Applications', WATER RESOURCES RESEARCH, 54 4946-4964 (2018) [C1]
DOI 10.1029/2018WR022854
Citations Scopus - 4Web of Science - 4
2018 Khaki M, Forootan E, Kuhn M, Awange J, Papa F, Shum CK, 'A study of Bangladesh's sub-surface water storages using satellite products and data assimilation scheme', SCIENCE OF THE TOTAL ENVIRONMENT, 625 963-977 (2018)
DOI 10.1016/j.scitotenv.2017.12.289
Citations Scopus - 10Web of Science - 11
2018 Anyah RO, Forootan E, Awange JL, Khaki M, 'Understanding linkages between global climate indices and terrestrial water storage changes over Africa using GRACE products', SCIENCE OF THE TOTAL ENVIRONMENT, 635 1405-1416 (2018)
DOI 10.1016/j.scitotenv.2018.04.159
Citations Scopus - 9Web of Science - 5
2018 Khaki M, Forootan E, Kuhn M, Awange J, van Dijk AIJM, Schumacher M, Sharifie MA, 'Determining water storage depletion within Iran by assimilating GRACE data into the W3RA hydrological model', ADVANCES IN WATER RESOURCES, 114 1-18 (2018)
DOI 10.1016/j.advwatres.2018.02.008
Citations Scopus - 18Web of Science - 20
2018 Khaki M, Ait-El-Fquih B, Hoteit I, Forootan E, Awange J, Kuhn M, 'Unsupervised ensemble Kalman filtering with an uncertain constraint for land hydrological data assimilation', Journal of Hydrology, 564 175-190 (2018) [C1]
DOI 10.1016/j.jhydrol.2018.06.080
Citations Scopus - 6Web of Science - 6
2017 Khaki M, Ait-El-Fquih B, Hoteit I, Forootan E, Awange J, Kuhn M, 'A two-update ensemble Kalman filter for land hydrological data assimilation with an uncertain constraint', JOURNAL OF HYDROLOGY, 555 447-462 (2017)
DOI 10.1016/j.jhydrol.2017.10.032
Citations Scopus - 17Web of Science - 15
2017 Khaki M, Hoteit I, Kuhn M, Awange J, Forootan E, van Dijk AIJM, et al., 'Assessing sequential data assimilation techniques for integrating GRACE data into a hydrological model', ADVANCES IN WATER RESOURCES, 107 301-316 (2017)
DOI 10.1016/j.advwatres.2017.07.001
Citations Scopus - 24Web of Science - 22
2017 Khaki M, Schumacher M, Forootan E, Kuhn M, Awange JL, van Dijk AIJM, 'Accounting for spatial correlation errors in the assimilation of GRACE into hydrological models through localization', ADVANCES IN WATER RESOURCES, 108 99-112 (2017)
DOI 10.1016/j.advwatres.2017.07.024
Citations Scopus - 20Web of Science - 17
2015 Khaki M, Forootan E, Sharifi MA, Awange J, Kuhn M, 'Improved gravity anomaly fields from retracked multimission satellite radar altimetry observations over the Persian Gulf and the Caspian Sea', GEOPHYSICAL JOURNAL INTERNATIONAL, 202 1522-1534 (2015)
DOI 10.1093/gji/ggv240
Citations Scopus - 5Web of Science - 5
2015 Khaki M, Forootan E, Sharifi MA, Safari A, 'Retracking satellite radar altimetry using a new approach 'ExtR method'; Case study: Persian Gulf', Journal of the Earth and Space Physics, 41 107-123 (2015)

Monitoring of the water levels within the seas and oceans has been enhanced by application of satellite radar altimetry missions, compared to the traditional in-situ tide gauge me... [more]

Monitoring of the water levels within the seas and oceans has been enhanced by application of satellite radar altimetry missions, compared to the traditional in-situ tide gauge measurements, due to their vast coverage and better spatial resolution. Satellite radar altimetry, which is originally designed to measure global ocean surface height, has been applied to inland surface water hydrological studies. Satellite radar altimetry, well known as TOPEX/POSEIDON, JASON, ENVISAT, which have been originally designed to measure global ocean surface height, nowadays, also demonstrated a great potential for the applications of inland water body studies. Altimetry was designed to determine the sea surface height based on spatial technology, electronic technology and microwave technology and basically work with sending and receiving electromagnetic pulse. Waveform is actually a curve, which shows the power of mentioned pulse reflected back to the altimeter. Altimeter on board of the satellite measures the range by sending and receiving a short pulse and calculating its travel time. The most important output of this procedure is the altimeter range. Due to the effect of topography and heterogeneity of reflecting surface and atmospheric effects, the expected waveform for altimeter returns over land differs from that over the ocean surfaces and subsequently the range is not as accurate. As a result, sea surface height values derived from altimetry over ice sheets and inland water bodies (particularly close to the coast lines) represent more errors in compared to the waveforms returned from other part of the ocean surface and may include missing data. We have developed a water-detection algorithm based on statistical analysis of decadal TOPEX/POSEIDON and JASON-1 height measurement time series and also their ground passes of the sea surface height in Persian Gulf. The Persian Gulf is certainly one of the most vital bodies of water on the planet; as gas and oil from Middle Eastern countries flow through it, supplying much of the world's energy needs.This algorithm contains a noise elimination process that includes Outlier Detection and Elimination of Unwanted Waveforms (ODEUW), an unsupervised classification of the satellite waveforms, and finally a retracking procedure. An unsupervised classification algorithm is implemented to classify the waveforms into consistent groups for which the appropriate retracking algorithms are performed. On the other hand the waveforms belong to the same group which refer to almost the land with common properties. The waveform retracking method is mainly used to calculate the offset between the practical middle point of waveform leading edge and the designed gate, based on which the retracked distance correction can be computed. Four different methods are implemented for retracking the waveforms. This includes the three previously introduced algorithms, including off center of gravity, threshold retracking and optimized iterative least squares fitting, after some improvements. We also introduce a new method based on edge detection and extracting extremum point, which is called 'ExtR retracking method'. At the end two different methods for validation of our results are examined, first consider the SSH time series before and after retracking then compare those with in situ data, the second, retrack the ground pass track lines data from two satellites and compare them with the geoid data.

2014 Khaki M, Forootan E, Sharifi MA, 'Satellite radar altimetry waveform retracking over the Caspian Sea', INTERNATIONAL JOURNAL OF REMOTE SENSING, 35 6329-6356 (2014)
DOI 10.1080/01431161.2014.951741
Citations Scopus - 14Web of Science - 13
Show 16 more journal articles
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Dr Mehdi Khaki

Position

Lecturer
School of Engineering
Faculty of Engineering and Built Environment

Contact Details

Email mehdi.khaki@newcastle.edu.au
Phone (02) 4921 6626
Mobile 0410620379

Office

Room EA128
Building Engineering Administration Building
Location Callaghan
University Drive
Callaghan, NSW 2308
Australia
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