Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers
Barrier walls are considered one of the most effective methods for facilitating the retreat of saltwater intrusion (SWI). This research plans to examine the effect of using barrier walls for controlling of SWI in sloped unconfined aquifers. The sloping unconfined aquifer is considered with three dif...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-08-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/12/9/2403 |
| _version_ | 1797555421061316608 |
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| author | Asaad M. Armanuos Nadhir Al-Ansari Zaher Mundher Yaseen |
| author_facet | Asaad M. Armanuos Nadhir Al-Ansari Zaher Mundher Yaseen |
| author_sort | Asaad M. Armanuos |
| collection | DOAJ |
| description | Barrier walls are considered one of the most effective methods for facilitating the retreat of saltwater intrusion (SWI). This research plans to examine the effect of using barrier walls for controlling of SWI in sloped unconfined aquifers. The sloping unconfined aquifer is considered with three different bed slopes. The SEAWAT model is implemented to simulate the SWI. For model validation, the numerical results of the seawater wedge at steady state were compared with the analytical solution. Increasing the ratio of flow barrier depth (d<sub>b</sub>/d) forced the saltwater interface to move seaward and increased the repulsion ratio (R). With a positive sloping bed, further embedding the barrier wall from 0.2 to 0.7 caused R to increase from 0.3% to 59%, while it increased from 1.8% to 41.7% and from 3.4% to 46.9% in the case of negative and horizontal slopes, respectively. Embedding the barrier wall to a d<sub>b</sub>/d value of more than 0.4 achieved a greater R value in the three bed-sloping cases. Installing the barrier wall near the saltwater side with greater depth contributed to the retreat of the SWI. With a negative bed slope, moving the barrier wall from X<sub>b</sub>/L<sub>o</sub> = 1.0 toward the saltwater side (X<sub>b</sub>/L<sub>o</sub> = 0.2) increased R from 7.21% to 68.75%, whereas R increased from 5.3% to 67% for the horizontal sloping bed and from 5.1% to 64% for the positive sloping bed. The numerical results for the Akrotiri coastal aquifer confirm that the embedment of the barrier wall significantly affects the controlling of SWI by increasing the repulsion ratio (R) and decreasing the SWI length ratio (L/L<sub>a</sub>). Cost-benefit analysis is recommended to determine the optimal design of barrier walls for increasing the cost-effectiveness of the application of barrier walls as a countermeasure for controlling and preventing SWI in sloped unconfined aquifers. |
| first_indexed | 2024-03-10T16:47:15Z |
| format | Article |
| id | doaj.art-dd0fa1b811b54cb2b301fa4a08210496 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T16:47:15Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-dd0fa1b811b54cb2b301fa4a082104962023-11-20T11:32:55ZengMDPI AGWater2073-44412020-08-01129240310.3390/w12092403Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal AquifersAsaad M. Armanuos0Nadhir Al-Ansari1Zaher Mundher Yaseen2Irrigation and Hydraulics Engineering Department, Civil Engineering Department, Faculty of Engineering, Tanta University, Tanta 31733, EgyptCivil, Environmental and Natural Resources Engineering, Lulea University of Technology, 97187 Lulea, SwedenSustainable Developments in Civil Engineering Research Group, Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City, VietnamBarrier walls are considered one of the most effective methods for facilitating the retreat of saltwater intrusion (SWI). This research plans to examine the effect of using barrier walls for controlling of SWI in sloped unconfined aquifers. The sloping unconfined aquifer is considered with three different bed slopes. The SEAWAT model is implemented to simulate the SWI. For model validation, the numerical results of the seawater wedge at steady state were compared with the analytical solution. Increasing the ratio of flow barrier depth (d<sub>b</sub>/d) forced the saltwater interface to move seaward and increased the repulsion ratio (R). With a positive sloping bed, further embedding the barrier wall from 0.2 to 0.7 caused R to increase from 0.3% to 59%, while it increased from 1.8% to 41.7% and from 3.4% to 46.9% in the case of negative and horizontal slopes, respectively. Embedding the barrier wall to a d<sub>b</sub>/d value of more than 0.4 achieved a greater R value in the three bed-sloping cases. Installing the barrier wall near the saltwater side with greater depth contributed to the retreat of the SWI. With a negative bed slope, moving the barrier wall from X<sub>b</sub>/L<sub>o</sub> = 1.0 toward the saltwater side (X<sub>b</sub>/L<sub>o</sub> = 0.2) increased R from 7.21% to 68.75%, whereas R increased from 5.3% to 67% for the horizontal sloping bed and from 5.1% to 64% for the positive sloping bed. The numerical results for the Akrotiri coastal aquifer confirm that the embedment of the barrier wall significantly affects the controlling of SWI by increasing the repulsion ratio (R) and decreasing the SWI length ratio (L/L<sub>a</sub>). Cost-benefit analysis is recommended to determine the optimal design of barrier walls for increasing the cost-effectiveness of the application of barrier walls as a countermeasure for controlling and preventing SWI in sloped unconfined aquifers.https://www.mdpi.com/2073-4441/12/9/2403saltwater intrusionnumerical modelingembedment depthbarrier wallcoastal aquifer sustainabilitygroundwater pollution |
| spellingShingle | Asaad M. Armanuos Nadhir Al-Ansari Zaher Mundher Yaseen Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers Water saltwater intrusion numerical modeling embedment depth barrier wall coastal aquifer sustainability groundwater pollution |
| title | Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers |
| title_full | Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers |
| title_fullStr | Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers |
| title_full_unstemmed | Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers |
| title_short | Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers |
| title_sort | underground barrier wall evaluation for controlling saltwater intrusion in sloping unconfined coastal aquifers |
| topic | saltwater intrusion numerical modeling embedment depth barrier wall coastal aquifer sustainability groundwater pollution |
| url | https://www.mdpi.com/2073-4441/12/9/2403 |
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