18O studies on recharge of phreatic aquifers and groundwater flow-paths of mixing in the Delhi area

Datta, P. S. ; Bhattacharya, S. K. ; Tyagi, S. K. (1996) 18O studies on recharge of phreatic aquifers and groundwater flow-paths of mixing in the Delhi area Journal of Hydrology, 176 (1-4). pp. 25-36. ISSN 0022-1694

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/0...

Related URL: http://dx.doi.org/10.1016/0022-1694(95)02784-X


Widespread decline in the groundwater level and growth of salinization are the critical factors controlling future groundwater quality and availability in the Delhi area. 5180 and salinity data have been integrated for studying recharge conditions of phreatic aquifers and tracing the flowpaths of groundwater mixing. Wide range (-2.8‰ to -8.6‰) and spatial inhomogeneity of δ18O in groundwater indicate that the aquifer is characterized by a slow process of natural mixing of groundwater in its lateral extent. There is infiltration of river water to the groundwater, in addition to the recharge from rainfall. Groundwater recharge in the area also occurs through stagnant water pools in low elevation areas where water surface run-off collects. Chloride concentration in groundwater has a wide range from 15 ppm. to 5070 ppm with a log-normal frequency distribution indicating that the salt deposits in the area are not homogeneously distributed. The δ18O-Cl relationship clearly suggests mixing of multiple sources of high salinity groundwater with low salinity groundwater or river water along specific pathways. The data also indicates leaching of salts present in the soil during vertical recharge from rainfall and irrigation. Large lateral variation in chloride concentration indicates changes in evapotranspiration rate during recharge. Detailed investigations on identifying the potential recharging zones, flow-paths of mixing and recharge conditions will be useful to protect the groundwater resources from depletion and salinization.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:67059
Deposited On:28 Oct 2011 10:58
Last Modified:28 Oct 2011 10:58

Repository Staff Only: item control page