Impact of excessive groundwater pumping on rejuvenation processes in the Bandung basin (Indonesia) as determined by hydrogeochemistry and modeling

Abstract

In the Bandung basin, Indonesia, excessive groundwater pumping caused by rapid increases in industrialization and population growth has caused subsurface environmental problems, such as excessive groundwater drawdown and land subsidence. In this study, multiple hydrogeochemical techniques and numerical modeling have been applied to evaluate the recharge processes and groundwater age (rejuvenation). Although all the groundwater in the Bandung basin is recharged at the same elevation at the periphery of the basin, the water type and residence time of the shallow and deep groundwater could be clearly differentiated. However, there was significant groundwater drawdown in all the depression areas and there is evidence of groundwater mixing between the shallow and deep groundwater. The groundwater mixing was traced from the high dichlorodifluoromethane (CFC-12) concentrations in some deep groundwater samples and by estimating the rejuvenation ratio (R) in some representative observation wells. The magnitude of CFC-12 concentration, as an indicator of young groundwater, showed a good correlation with R, determined using 14 C activity in samples taken between 2008 and 2012. These correlations were confirmed with the estimation of vertical downward flux from shallower to deeper aquifers using numerical modeling. Furthermore, the change in vertical flux is affected by the change in groundwater pumping. Since the 1970s, the vertical flux increased significantly and reached approximately 15% of the total pumping amount during the 2000s, as it compensated the groundwater pumping. This study clearly revealed the processes of groundwater impact caused by excessive groundwater pumping using a combination of hydrogeochemical methods and modeling.

Assessing Bandung's Governance Challenges of Water, Waste, and Climate Change: Lessons from Urban Indonesia

“…This is in line with the conclusions of Sholeh et al (2019) who conclude that Bandung fails to implement 3 instruments of policy innovation as part of the smart city policy in Bandung, that is, by regulation, economic and financial instruments and soft instruments. The findings are confirmed by other studies (Antasari 2017;Nastiti et al 2018;Taufiq 2018;Wang et al 2018;Hasbiah and Kurniasih 2019;OECD 2019a). Koop and van Leeuwen (2015b) demonstrated a high correlation between the BCI and governance effectiveness as defined by the World Bank (2020).…”

“…Despite an annual precipitation of 1700 mm (Abidin et al 2013), the city struggles with water scarcity, pollution, and groundwater depletion (Taufiq et al 2018). Based on the projections of water demand, Hasbiah and Kurniasih (2019) conclude that Bandung's water demand will exceed its supply by 2034.…”

Numerical prediction of the groundwater drawdown impact in Jakarta

“…Industrialization and urbanization also cause land subsidence in other big cities in Indonesia, e.g. Semarang ( Sarah et al, 2018) and Bandung ( Taufiq et al, 2018a) with nearly the same subsidence rate like Jakarta. Figure 9.…”

“…A significant groundwater level drawdown in large cities in Indonesia (Wirakusumah & Danaryanto, 2004;Taniguchi, Burnett, & Ness, 2008;Hosono, et al, 2011;Kagabu, et al, 2011, 2012, Taufiq, et al, 2018a, has caused many subsurface issues: land subsidence (Taufiq, 2010;Sarah, et al, 2018;Bandono, 1983;DGTL & Dinas Pertambangan DKI Jakarta, 1996;Ramdhan & Hutasoit, 2007), seawater intrusion (Hehanusa, 1979;Djijono, 2002;Setiawan, et al, 2017, groundwater pollution (Hosono, et al, 2009;Taufiq, et al, 2019), the increase of groundwater temperature (Lubis, et al, 2013), groundwater mixing (Taufiq, et al, 2018b), groundwater age rejuvenation (Kagabu, et al, 2012;Taufiq, et al, 2018a) and others.…”

Geochemistry of groundwater and saltwater intrusion in a coastal region of an island in Malacca Strait, Indonesia

“…The people in developing countries often had dependency to groundwater resource and thus it becomes an essential and valuable water resource [1], the number of societies facing water shortages is increasing as the level of the groundwater table decreases as a consequence of excessive usage and the level of pollution of surface and groundwater resources increases due to several anthropogenic activities [2]. For this reason, there have been many studies on water quality in various parts of the world.…”