Title of Dataset: Land deformation estimates over Central Valley California associated with Water Resources Research Publication: Sustained Groundwater Loss in California’s Central Valley Exacerbated by Intense Drought Periods by Ojha et al. 2018
Author(s): C. Ojha, M. Shirzaei, S. Werth, D. F. Argus, and T. G. Farr 
Corresponding Author Email Address: swerth@vt.edu
Categories: Solid Earth Sciences
Group: Department of Geosciences
Item Type: Dataset
Keywords: surface deformation, InSAR, aquifer compaction, groundwater, geodesy, drought
Description: This dataset contains rate and seasonal variations in line of site (LOS) of ALOS-1 satellite as calculated from an interferrometric analysis of synthetic aperture radar aquisitions over Central Valley, California, from December 24th, 2006 to January 1st, 2010. Details of the processing are provided in the work of Ojha et al. (2018):
C. Ojha, M. Shirzaei, S. Werth, D. F. Argus, T. G. Farr, Sustained Groundwater Loss in California’s Central Valley Exacerbated by Intense Drought Periods. Water Resour. Res. 54, 4449–4460 (2018).
Land deformation in line of site can be converted to vertical land motion given incidence (~34.5°) and heading angle (~240°) of the ALOS-1 satellites (see Ojha et al., 2018).
LOS rates and seasonal variations are provided in two separate files Rate_all.csv and SeasnCoef_InSAR_CV_Anu_krig.csv respectively. Rates are given for all elite pixel from the InSAR analysis of each aquisition. Seasonal variations are provided in form of sine and cosine amplitudes (sine_amp, cosine_amp) for pixel within the Central Valley aquifer only. To retrieve seasonal amplitude and phase of VLM, the amplitudes should be combined as of the following equations:
•	seas_amplitude_VLM = sqrt(sine_amp^2 + cosine_amp^2)
•	seas_phase_VLM = atan(sine_amp / cosine_amp)
Units of the rates and seasonal amplitudes are given in mm and cm/year respectively.
Funding: National Science Foundation grants EAR-1357079 and EAR-0951430; NASA grant NNX17AD98G. THIS 3-YEAR PROJECT IS COLLABORATION BETWEEN SCIENTISTS FROM TWO UNIVERSITIES (ASU AND BGSU) AND JPL WITH THE AIM TO SIGNIFICANTLY IMPROVE RESOLUTION AND ACCURACY OF CURRENT ESTIMATES OF TOTAL WATER MASS BUDGET VARIATIONS OVER CALIFORNIA. THE SUCCESS OF T.
Resource Title: Sustained Groundwater Loss in California’s Central Valley Exacerbated by Intense Drought Periods
Resource DOI: 10.1029/2017WR022250
Other References: https://sites.google.com/vt.edu/hydrogeodesy/research/rosewater
License: CC-0 1.0 Universal (CC0 1.0) Public Domain Dedication
Publisher: University Libraries, Virginia Tech
Language: English (USA)

Files/Folders in Dataset and Description of Files
Rate_all.csv - deformation deformation in line of site of satellite MVel (column3) in units of cm/year at coordinates lon (column 1), lat (column2)
SeasnCoef_InSAR_CV_Anu_krig.csv - seasonal variation of deformation in line of site of satellite in form of sine and cosine amplitudes (sine_amp = column 3, cosine_amp = column 4) in units of mm at coordinates lon (column 1), lat (column2)