Impact of Flood Mitigation Project on the River Water Salinity

Abstract

The impact of flood mitigation project in the Kemaman River Basin was assessed in this study. Salinity intrusion was simulated in the study area by 1D numerical model. A 1-D hydrodynamic model coupled with a salinity model was used to analyze the salinity intrusion within Chukai River after the implementation of the flood mitigation project. The model was calibrated and validated using the data measured in Chukai River at 3 points from January 2007 until August 2013. Water quality simulation of salinity has been carried out once an excellent hydrodynamic model was established. The simulated river flow was reasonably matched to the measured data with R2 value 0.88, 0.92 and 0.82, respectively. Results suggest that after the realignment of Chukai River, the seawater intrudes further to the upstream river, causing the increasing salinity in the river about 10 - 15 ppt. However, with the floodway development, the channel would allow more water from Kemaman River being discharged into Chukai River. Increased in the volume of water in Chukai River has led to seawater dilution. Further, it invades the unique stretch of Chukai River and takes the salinity back to the initial state. Findings from the implementation of the flood mitigation project in the Kemaman river basin has benefitted the local society, watershed, and the surrounding biota ecosystems. Importantly, a greater prevention with the risk of repetitive flood damage to the buildings and structures in Kemaman area which has significantly achievable.
 HIGHLIGHTS
 
 Salinity model is used for flood mitigation project
 High salinity in Chukai river resulted from seawater intrusion
 Hydrodynamic model is to assess the water quality simulation

Multifaceted Linkages among Eco-Climatic Factors, Plankton Abundance, and Gonadal Maturation of Hilsa Shad, Tenualosa ilisha, Populations in Bangladesh

“…The presence of dissolved substances, such as acids or bases, can also affect the pH levels in water [61]. Salinity levels in water are mainly influenced by the influx of freshwater into the system, such as from rainfall or rivers [62]. Higher levels of rainfall can result in lower salinity levels, whereas lower levels of rainfall can lead to higher salinity levels [62,63].…”

“…Salinity levels in water are mainly influenced by the influx of freshwater into the system, such as from rainfall or rivers [62]. Higher levels of rainfall can result in lower salinity levels, whereas lower levels of rainfall can lead to higher salinity levels [62,63]. High humidity indirectly impacts water quality by influencing the hydrological cycle, resulting in increased precipitation and the influx of water into water bodies [64,65].…”

Hydrological and climate impacts on river characteristics of pahang river basin, Malaysia

“…For mitigation measures, alternative management is proposed for Pahang River Maintenance, such as the service of natural flood ponds and flood mitigation projects [ [35] , [36] , [37] , [38] ]. The recommendation of an alternative integrated management system for flooding, which has discussed the proposal and management that can reduce and prevent the occurrence of flooding as a result of the weakness of the Pahang River Basin management [ [39] , [40] , [41] , [42] ]. Proposals such as adding flood mitigation to the river banks, such as flood barriers, maximizing the usage of natural water storage areas, and strengthening the management of development at Pekan and Paloh Inai, Pahang, Malaysia, are based in low-lying areas to avoid overflow of river water quickly and also reduce the impact on the surrounding areas and populated areas [ [42] , [43] , [44] ].…”

“…The recommendation of an alternative integrated management system for flooding, which has discussed the proposal and management that can reduce and prevent the occurrence of flooding as a result of the weakness of the Pahang River Basin management [ [39] , [40] , [41] , [42] ]. Proposals such as adding flood mitigation to the river banks, such as flood barriers, maximizing the usage of natural water storage areas, and strengthening the management of development at Pekan and Paloh Inai, Pahang, Malaysia, are based in low-lying areas to avoid overflow of river water quickly and also reduce the impact on the surrounding areas and populated areas [ [42] , [43] , [44] ]. In addition, maintenance of natural water reservoirs that have been identified can also help to accommodate the strong flood runoff and prevent or delay the occurrence of flooding in low-lying areas [ 11 , [44] , [45] , [46] ].…”