Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka

Abstract The present study describes a river channel management method for restoring riverine environments degraded by sand mining in rivers. Specifically, three conditions that must be met for a restored river channel in the lower reach of the Kelani River in Sri Lanka were proposed: (1) flood disc...

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Main Authors: Dissanayaka Mudiyanselage Pavithra Sudeshika, Yoshiyuki Imamura, Daisuke Harada, Shinji Egashira
Format: Article
Language:English
Published: Wiley-VCH 2025-05-01
Series:River
Subjects:
Online Access:https://doi.org/10.1002/rvr2.70011
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author Dissanayaka Mudiyanselage Pavithra Sudeshika
Yoshiyuki Imamura
Daisuke Harada
Shinji Egashira
author_facet Dissanayaka Mudiyanselage Pavithra Sudeshika
Yoshiyuki Imamura
Daisuke Harada
Shinji Egashira
author_sort Dissanayaka Mudiyanselage Pavithra Sudeshika
collection DOAJ
description Abstract The present study describes a river channel management method for restoring riverine environments degraded by sand mining in rivers. Specifically, three conditions that must be met for a restored river channel in the lower reach of the Kelani River in Sri Lanka were proposed: (1) flood discharge capacity of the channel for a given flood, (2) prevention of saltwater intrusion, and (3) creation of a diverse physical environment. The allowable mining volume satisfies the three conditions, while continuing to mine sand was discussed based on the sediment budget calculations in the target river reach. In this case, the amount of sediment stored in the target reach and its variation are determined by the amount of sediment supplied to the target reach, the amount of sediment discharged from the target reach to the sea, and the amount of sediment excavated. This means that the dynamic equilibrium channel of the target reach is determined by the amount of sediment supplied and the amount of sediment excavated. The amount of sand mined when the dynamic equilibrium channel meets the three conditions of the restored channel is a candidate for the allowable amount of sand mined. One of these, the most desirable one, is set as the allowable mining volume. As described above, we proposed a method to develop a restoring reach taking the sediment budget and associated hydraulic and hydro morphological conditions in the target reach into consideration.
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spelling doaj-art-a8bdc11d09b341c993c814f9f26bbdf82025-08-20T02:37:49ZengWiley-VCHRiver2750-48672025-05-014217719210.1002/rvr2.70011Method on sediment management for restoring the lower reach of the Kelani River, Sri LankaDissanayaka Mudiyanselage Pavithra Sudeshika0Yoshiyuki Imamura1Daisuke Harada2Shinji Egashira3Department of Civil and Environmental Engineering Tokyo Metropolitan University Hachioji JapanDepartment of Civil and Environmental Engineering Tokyo Metropolitan University Hachioji JapanInternational Centre for Water Hazards and Risk Management (ICHARM), Public Water Research Institute (PWRI) Tsukuba JapanInternational Centre for Water Hazards and Risk Management (ICHARM), Public Water Research Institute (PWRI) Tsukuba JapanAbstract The present study describes a river channel management method for restoring riverine environments degraded by sand mining in rivers. Specifically, three conditions that must be met for a restored river channel in the lower reach of the Kelani River in Sri Lanka were proposed: (1) flood discharge capacity of the channel for a given flood, (2) prevention of saltwater intrusion, and (3) creation of a diverse physical environment. The allowable mining volume satisfies the three conditions, while continuing to mine sand was discussed based on the sediment budget calculations in the target river reach. In this case, the amount of sediment stored in the target reach and its variation are determined by the amount of sediment supplied to the target reach, the amount of sediment discharged from the target reach to the sea, and the amount of sediment excavated. This means that the dynamic equilibrium channel of the target reach is determined by the amount of sediment supplied and the amount of sediment excavated. The amount of sand mined when the dynamic equilibrium channel meets the three conditions of the restored channel is a candidate for the allowable amount of sand mined. One of these, the most desirable one, is set as the allowable mining volume. As described above, we proposed a method to develop a restoring reach taking the sediment budget and associated hydraulic and hydro morphological conditions in the target reach into consideration.https://doi.org/10.1002/rvr2.70011flood managementphysical environmentriver channel restoringsalt wedgesand miningsediment budget
spellingShingle Dissanayaka Mudiyanselage Pavithra Sudeshika
Yoshiyuki Imamura
Daisuke Harada
Shinji Egashira
Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka
River
flood management
physical environment
river channel restoring
salt wedge
sand mining
sediment budget
title Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka
title_full Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka
title_fullStr Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka
title_full_unstemmed Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka
title_short Method on sediment management for restoring the lower reach of the Kelani River, Sri Lanka
title_sort method on sediment management for restoring the lower reach of the kelani river sri lanka
topic flood management
physical environment
river channel restoring
salt wedge
sand mining
sediment budget
url https://doi.org/10.1002/rvr2.70011
work_keys_str_mv AT dissanayakamudiyanselagepavithrasudeshika methodonsedimentmanagementforrestoringthelowerreachofthekelaniriversrilanka
AT yoshiyukiimamura methodonsedimentmanagementforrestoringthelowerreachofthekelaniriversrilanka
AT daisukeharada methodonsedimentmanagementforrestoringthelowerreachofthekelaniriversrilanka
AT shinjiegashira methodonsedimentmanagementforrestoringthelowerreachofthekelaniriversrilanka