Climate Change, Sea Level Rise, and Saltwater Intrusion

Author(s):  
Nebiyu D. Tiruneh ◽  
Louis H. Motz
2017 ◽  
Vol 1 (T4) ◽  
pp. 255-264
Author(s):  
Tuan Ngoc Le ◽  
Hoang Xuan Tran

The study aimed to assess the exposure level (E) to saltwater intrusion (SI) in the context of climate change (CC) at Dong Nai province to 2030. The results serve to assess vulnerability due to this phenomenon. The research scope included 57 wards in Bien Hoa city, Long Thanh, and Nhon Trach districts where have been facing to SI. Results showed that: (i) The high exposure area (E ≥ 75): near Long Tau, Dong Tranh, Go Gia rivers and Thi Vai river downstream; (ii) The medium – high exposure area (50 ≤ E < 75): Thi Vai river upstream, Nha Be, and Long Tau rivers; (iii) The medium – low exposure area (25 < E < 50): Dong Nai river above the confluence with Saigon river about 10 km and the area between Dong Mon and Thi Vai rivers; (iv) The low exposure area (E ≤ 25): the entire of Bien Hoa city, a part of Long Thanh district located near Buong river, part 4 of Dong Nai river, and Thi Vai river upstream.The exposure level tends to increase over time (2020, 2030) and under CC scenarios. The differences between the current E and that in 2030 are relatively small: 8.6, 1.96, and 2.71 in Bien Hoa, Long Thanh, and Nhon Trach, respectively. Thus, effects of climate change and sea level rise to the exposure level to SI are not really clear in the period 2014–2030. However, the increase in exposure index partly reflects the challenges for local governments and communities in response to SI and CC.


2016 ◽  
Vol 17 (2) ◽  
pp. 311-323 ◽  
Author(s):  
Hany F. Abd-Elhamid

Seawater intrusion is considered one of the main processes that degrade water quality by raising salinity. Over-pumping and decreasing recharge are considered the main causes of saltwater intrusion. Moreover, climate change and sea-level rise accelerate saltwater intrusion. In this paper SEAWAT code was used to study groundwater flow and seawater intrusion in the Eastern Nile Delta aquifer considering four scenarios of climate change including sea-level rise, increasing abstraction, decreasing recharge and the combination of these scenarios. The results showed that decreasing recharge has a significant effect on seawater intrusion. However, the combinations of these scenarios resulted in harmful intrusion and loss of groundwater. The soil salinity increased, which decreased agricultural production. The control of seawater intrusion and protection of groundwater resources and soil is very important. Different scenarios were implemented to protect the aquifer from seawater intrusion including decreasing abstraction, increasing recharge, abstracting brackish water and the combination of these three scenarios. The abstraction of brackish water gave a higher reduction of seawater intrusion and decreased groundwater table in the aquifer near the shore line, which protected the soil from salinity and increased agricultural production. However, the combination of these three scenarios gave the highest reduction of seawater intrusion.


2013 ◽  
Vol 17 (1) ◽  
pp. 421-443 ◽  
Author(s):  
P. Rasmussen ◽  
T. O. Sonnenborg ◽  
G. Goncear ◽  
K. Hinsby

Abstract. Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. The low-lying central area of the investigated part of the island was extensively drained and reclaimed during the second half of the 19th century by a system of artificial drainage canals that significantly affects the flow dynamics of the area. The drinking water, mainly for summer cottages, is abstracted from 11 wells drilled to a depth of around 20 m into the upper 5–10 m of a confined chalk aquifer, and the total pumping is only 5–6% of the drainage pumping. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater-sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise does not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area, below which the sea is hydraulically connected to the drainage canals, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the drainage canals all have significant impacts on saltwater intrusion and the chloride concentrations found in abstraction wells.


EDIS ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 5
Author(s):  
Bailey Emrick ◽  
Misti Sharp ◽  
Xiang Bi

Sea-level rise and climate change are important issues in science, politics, and communities. Sea-level rise is a particularly contentious topic in Florida, where expected impacts include coastal flooding, shrinking shorelines, and saltwater intrusion. It is unclear what Floridians think about sea-level rise and the ways in which the state can adapt to these impacts. This 5-page fact sheet written by Bailey Emrick, Misti Sharp, and Xiang Bi and published by the UF/IFAS Food and Resource Economics Department summarizes findings from two recent surveys examining attitudes of Miami residents and those of residents of the rest of Florida about sea-level rise and potential adaptations to it


2019 ◽  
Vol 2 (3) ◽  
pp. 102-112
Author(s):  
Tuan Ngoc Le ◽  
Kim Thi Tran ◽  
Phung Ky Nguyen

This work aimed to assess the risk of the saltwater intrusion (SI) in main rivers in Ho Chi Minh City (HCMC) in the context of climate change by 2100 under scenarios of RCP4.5 and RCP8.5. By modeling and GIS methods, results showed that SI has been increasing and moving upstream. Differences in the salinity between the RCP4.5 and RCP8.5 scenarios could be only visible from the middle to the end of the 21st century. In Saigon river, for RCP4.5, corresponding to 2025, 2030, 2050, and 2100, the salt line of 0.25‰ would be 0.25km, 1.6 km, 4.09km and 6.22km, respectively from Hoa Phu pump station as compared to that of 0.75 km; 1.6km; 4.6 km and 8.6 km, respectively for RCP8.5. In Dong Nai river, from Hoa An pump station, the corresponding figures would be 3.7km; 4.9km; 7.7km; 11.7km according to RCP4.5 and 3.7km, 4.9 km, 8.1km, 12.6km according to RCP8.5. The research results provide an important basis for planning suitable adaptation solutions, ensuring local activities and production.


2012 ◽  
Vol 9 (7) ◽  
pp. 7969-8026 ◽  
Author(s):  
P. Rasmussen ◽  
T. O. Sonnenborg ◽  
G. Goncear ◽  
K. Hinsby

Abstract. Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. Agricultural land dominates the western and central parts of the island, which geologically are developed as push moraine hills and a former lagoon (later wetland area) behind barrier islands to the east. The low-lying central area of the island was extensively drained and reclaimed during the second half of the 19th century. Summer cottages along the beach on the former barrier islands dominate the eastern part of the island. The main water abstraction is for holiday cottages during the summer period (June–August). The water is abstracted from 11 wells drilled to a depth of around 20 m in the upper 5–10 m of a confined chalk aquifer. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater–sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise do not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area below which the sea is hydraulically connected to the drainage canal, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the drainage canal all have significant impacts on saltwater intrusion and hence the chloride concentrations found in the abstraction wells.


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