|
Long-term analysis of the correlation between the changes in the water level of the wells and the changes in the estimated groundwater storage using Grace satellite observations in Tehran
|
Hany Mahbuby *   , Yahya DJAMOUR |
| Shahid Beheshti University |
|
|
Abstract: (1145 Views) |
Groundwater storage (GWS) of the aquifers is one of the most important sources of the drinking water supply and the required water for agriculture in Iran. The population of Tehran province is more than 9 million and the southern half of Tehran has a semi-arid climate with little rainfall. Besides, in the semi-humid northern part of Tehran and the foothills, the average rainfall is not very significant, so it is very difficult to compensate for the discharged groundwater. Therefore, it is important to closely monitor the changes in GWS of the province. Today, GRACE twin satellites are suitable tools that can help us to estimate and evaluate the monthly changes of GWS with the help of hydrological models. In addition, observations of piezometric wells are also very necessary for such studies. GRACE satellites immediately sense the changes in the gravity of a region due to the changes in the terrestrial water storage (TWS), but in the observations of the wells such changes are received with a delay. In this research, in order to investigate the long_term changes of GWS in Tehran, three types of data with a monthly rate have been used from January 2004 to December 2016. First, TWS changes were obtained using Grace-Mascon data, which were published in the form of grid points with a spatial resolution of 0.25 degrees, and then global land data assimilation system (GLDAS), with similar spatial resolution, was used to estimate the other parameters which were not relevant to groundwater. Finally, GWS changes were calculated by subtracting these two sets of data. Furthermore, monthly well water level observations were used to evaluate the correlation. In order to evaluate the correlation, the time delay between the time series of well water changes and those of GWS ones was obtained by cross-correlation. The highest correlation coefficient of the time series of wells is 0.72 and the average correlation coefficient is 0.21.
|
|
| Keywords: Groundwater storage, terrestrial water storage, GRACE, GLDAS, cross-correlation |
|
|
Full-Text [PDF 1796 kb]
(292 Downloads)
|
Type of Study: Research |
Subject:
Geodesy
Received: 2024/07/31 | Accepted: 2024/10/7 | ePublished ahead of print: 2024/10/29 | Published: 2024/10/29
|
|
|
|
|
|
|
| Send email to the article author |
|
|
