Sonu Kumar

Mr. Sonu Kumar

National Institute of Education, Nanyang Technological University, Singapore, Central Singapore, Singapore
+1
orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 September 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Sonu KumarSonu Kumar
Sonu Kumar
GAGiriraj Amarnath
Giriraj Amarnath
SGSurajit Ghosh
Surajit Ghosh
Edward ParkEdward Park
Edward Park
TBTriambak Baghel
Triambak Baghel
DBDevesh Belbase
Devesh Belbase
Located on the south-facing slope of the Himalayas, Nepal receives intense, long-lasting precipitation during the Asian summer monsoon, making Nepal one of the most susceptible countries to flood and landslide hazards in the region. However, sparse gauging and irregular measurement constrain the vulnerability assessments of floods and landslides, which rely highly on the accuracy of precipitation. Therefore, this study evaluates the performance of Satellite-based Precipitation Products (SPPs) in the Himalayas region by comparing different datasets and identifying the best alternative of gauge-based precipitation for hydro-meteorological applications. We compared eight SPPs using statistical metrics and then used the Multi-Criteria Decision-Making (MCDM) technique to rank them. Secondly, we assessed the hydrological utility of SPPs by simulating them through the GR4J hydrological model. We found a high POD (0.60–0.80) for all SPPs except CHIRPS and PERSIANN; however, a high CC (0.20–0.40) only for CHIRPS, IMERG_Final, and CMORPH. Based on MCDM, CMORPH and IMERG_Final rank first and second. While SPPs could not simulate daily discharge (NSE < 0.28), they performed better for monthly streamflow (NSE > 0.54). Overall, this study recommends CMORPH and IMERG_Final and improves the understanding of data quality to better manage hydrological disasters in the data-sparse Himalayas. This study framework can also be used in other Himalayan regions to systematically rank and identify the most suitable datasets for hydro-meteorological applications.

21 March 2022 in International Journal of Applied Earth Observation and Geoinformation
Verified
Journal Article
Open access
CGCharles-Robin Gruel
Charles-Robin Gruel
EPEdward Park
Edward Park
ASAdam D. Switzer
Adam D. Switzer
Sonu KumarSonu Kumar
Sonu Kumar
HHHuu Loc Ho
Huu Loc Ho
LFLian Feng
Lian Feng

13 December 2023 in GIScience & Remote Sensing
Verified
Journal Article
Open access
Sonu KumarSonu Kumar
Sonu Kumar
Edward ParkEdward Park
Edward Park
DTDung Duc Tran
Dung Duc Tran
JWJingyu Wang
Jingyu Wang
HHHuu Loc Ho
Huu Loc Ho
ASAdam D. Switzer
Adam D. Switzer

20 July 2026 in Reviews of Geophysics
Verified
Journal Article
Open access
PDF file
Edward ParkEdward Park
Edward Park
CHChristopher R. Hackney
Christopher R. Hackney
Dung TranDung Tran
Dung Tran
MBMette Bendixen
Mette Bendixen
JBJim Best
Jim Best
ASAdam Switzer
Adam Switzer
River sand and gravel are mined worldwide at volumes that now rival their natural replenishment, yet quantitative knowledge of this mining activity and its consequences lags far behind many other global environmental pressures. We synthesize 411 peer‐reviewed studies published since 1974 within a new Driver‐to‐Management Pathway for Sustainable Sand and Gravel Mining framework that links socio‐economic demand, spatial‐temporal extent of extraction, hydrogeomorphic change, socio‐ecological disruption, and management response. Evidence shows a pronounced scale mismatch: regional‐to‐global drivers fuel largely unreported local extraction, while impacts propagate well beyond mining sites. In most documented cases, annual removal exceeds bed‐material supply several‐fold, producing channel incision, bank collapse, declining groundwater tables, deteriorating water quality, and inland migration of saline water in coastal areas. These physical changes cascade into habitat loss, infrastructure damage, and livelihood insecurity, especially across rapidly developing regions of Asia and Africa. Despite the proliferation of impact studies (69% of the literature), research is dominated by hydrogeomorphic perspectives, with ecological and socio‐economic impacts far more often treated as secondary or co‐occurring components rather than primary foci; meanwhile, only 27% of studies quantify extraction extent and 24% analyze demand drivers, hampering the design of effective interventions. Together, these findings highlight the need for basin‐scale monitoring, cross‐boundary governance, and demand‐side interventions that explicitly link extraction limits to sediment budgets.

10 June 2022 in Research Square
Verified
Preprint
Open access
PDF file
Sonu KumarSonu Kumar
Sonu Kumar
GAGiriraj Amarnath
Giriraj Amarnath
SGSurajit Ghosh
Surajit Ghosh
EPEdward Park
Edward Park
TBTriambak Baghel
Triambak Baghel
DBDevesh Belbase
Devesh Belbase
Located on the south-facing slope of the Himalayas, Nepal receives intense, long-lasting precipitation during the Asian summer monsoon, making Nepal one of the most susceptible countries to flood and landslide hazards in the region. However, sparse gauging and irregular measurement constrain the vulnerability assessments of floods and landslides which rely highly on the accuracy of precipitation. Therefore, this study evaluates the performance of Satellite-based Precipitation Products (SPPs) in the Himalayas region by comparing different datasets and identifying the best alternative of gauge-based precipitation for hydro-meteorological applications. We compared eight SPPs using statistical metrics and then used the Multi-Criteria Decision-Making (MCDM) technique to rank them. Secondly, we assessed the hydrological utility of SPPs by simulating through the GR4J hydrological model. We found a high POD (0.60–0.80) for all SPPs except CHIRPS and PERSIANN; however, a high CC (0.20–0.40) only for CHIRPS, IMERG_Final, and CMORPH. Based on MCDM, CMORPH and IMERG_Final rank first and second. While SPPs could not simulate daily discharge (NSE < 0.28), they performed better for monthly streamflow (NSE > 0.54). Overall, this study recommends CMORPH and IMERG_Final and improves the understanding of data quality to better manage hydrological disasters in the data-sparse Himalayas. This study framework can also be used in other Himalayan regions to systematically rank and identify the most suitable datasets for hydro-meteorological applications.

1 September 1993 in Journal of the Indian Society of Remote Sensing
Verified
Journal Article
Closed access
PDF file
ANA S K Nair
A S K Nair
GSG Sankar
G Sankar
Sonu KumarSonu Kumar
Sonu Kumar