Estimation of regional mass anomalies from Gravity Recovery and Climate Experiment (GRACE) over Himalayan region

Time-variable gravity changes are caused by a combination of postglacial rebound, redistribution of water and snow/ice on land and as well as in the ocean. The Gravity Recovery and Climate Experiment (GRACE) satellite mission, launched in 2002, provides monthly average of the spherical harmonic co-efficient. These spherical harmonic co-efficient describe earth’s gravity field with a resolution of few hundred kilometers. Time-variability of gravity field represents the change in mass over regional level with accuracies in cm in terms of Water Equivalent Height (WEH). The WEH reflects the changes in the integrated vertically store water including snow cover, surface water, ground water and soil moisture at regional scale. GRACE data are also sensitive towards interior strain variation, surface uplift and surface subsidence cover over a large area. GRACE data was extracted over the three major Indian River basins, Indus, Ganga and Brahmaputra, in the Himalayas which are perennial source of fresh water throughout the year in Northern Indian Plain. Time series analysis of the GRACE data was carried out from 2003-2012 over the study area. Trends and amplitudes of the regional mass anomalies in the region were estimated using level 3 GRACE data product with a spatial resolution at 10 by 10 grid provided by Center for Space Research (CSR), University of Texas at Austin. Indus basin has shown a subtle decreasing trend from 2003-2012 however it was observed to be statistically insignificant at 95% confidence level. Ganga and Brahmaputra basins have shown a clear decreasing trend in WEH which was also observed to be statistically significant. The trend analysis over Ganga and Brahamputra basins have shown an average annual change of -1.28 cm and -1.06 cm in terms of WEH whereas Indus basin has shown a slight annual change of -0.07 cm. This analysis will be helpful to understand the loss of mass in terms of WEH over Indian Himalayas and will be crucial for hydrological and climate applications at regional scale.


Investigation of Sea Surface Temperature (SST) Anomalies over Cyprus Area
Georgiou, Andreas; Akcit, Nuhcan (2016-04-08)
The temperature of the sea surface has been identified as an important parameter of the natural environment, governing processes that occur in the upper ocean. This paper focuses on the analysis of the Sea Surface Temperature (SST) anomalies at the greater area of Cyprus. For that, SST data derived from MODerate-resolution Imaging Spectroradiometer (MODIS) instrument on board both Aqua and Terra sun synchronous satellites were used. A four year period was chosen as a first approach to address and describe t...
Effects of harbour shape on the induced sedimentation
Kian, Rozita; Velioglu, Deniz; Yalçıner, Ahmet Cevdet; Pelinovsky, Efim; Kurkin, Andrey; Zaytsev, Andrey; Yalciner, Bora; Pamuk, Aykut (2017-01-01)
Tsunamis in shallow water zones lead to sea water level rise and fall, strong currents, forces (drag, impact, uplift, etc.), morphological changes (erosion, deposition), dynamic water pressure, as well as resonant oscillations. As a result, ground materials under the tsunami motion move and scour/erosion/deposition patterns can be observed in the region. Ports and harbours as enclosed basins are the main examples of coastal structures that usually encounter natural hazards with small or huge damaging scales...
Analysis of one-dimensional ground-water flow in a nonuniform aquifer
Onder, H (American Society of Civil Engineers (ASCE), 1997-08-01)
A one-dimensional (1D) flow, resulting from a sudden rise or decline in the water stage of a flood channel in a composite aquifer, which consists of two different regions separated by a linear discontinuity parallel to the channel, is considered. Governing equations are solved analytically for appropriate initial and boundary conditions. The obtained solution allows the determination of water level fluctuations in both regions of the composite aquifer and the time-dependent flow rate to (or from) the aquife...
Numerical investigation of effective surge tank dimensions in hydropower plants under various hydraulic conditions
Berberoğlu, Pınar; Bozkuş, Zafer; Department of Civil Engineering (2013)
In water conveyance systems, sudden changes in the flow velocity cause a phenomenon called waterhammer associated with high pressure head changes. Unless a control device is used as a precaution, waterhammer may result in costly damages and even in some cases, loss of human lives. In light of this concept, different control devices that can protect the systems against waterhammer are introduced so that the great pressure differences are absorbed and the system is maintained undamaged. In this thesis, the ma...
Determination of geostatistically representative sampling locations in Porsuk Dam Reservoir Turkey
Aksoy, Ayşegül; Düzgün, Hafize Şebnem (2013-09-13)
Several factors such as wind action, bathymetry and shape of a lake/reservoir, inflows, outflows, point and diffuse pollution sources result in spatial and temporal variations in water quality of lakes and reservoirs. The guides by the United Nations Environment Programme and the World Health Organization to design and implement water quality monitoring programs suggest that even a single monitoring station near the center or at the deepest part of a lake will be sufficient to observe long-term trends if th...
Citation Formats
M. T. Yılmaz, “Estimation of regional mass anomalies from Gravity Recovery and Climate Experiment (GRACE) over Himalayan region ,” 2014, Accessed: 00, 2020. [Online]. Available: