TY - JOUR
T1 - Retrospective study on changes in Dondra lagoon (2006-2017) resulting from tsunami impact and post-tsunami development
AU - Madarasinghe, Sanduni Kanishka
AU - Amarasinghe, Yattowita Withanage Praveen
AU - Liyanage, Chamod Harshana
AU - Gunathilake, Hitihami Mudiyanselage Shashini Amalka Thathsarani
AU - Jayasingha, Jayasinghe Arachchige Iraj Kaushan
AU - Jayasingha, Madhuka
AU - Priyankara, Wisnaha Kadawarage Lahiru
AU - Kodikara, Kodikara Arachchilage Sunanda
AU - Koedam, Nico
AU - Dahdouh-Guebas, Farid
AU - Jayatissa, Loku Pullukuttige
N1 - Publisher Copyright:
© 2020, Springer Nature B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/9/2
Y1 - 2020/9/2
N2 - Spatio-temporal changes during the last twelve year period (2006–2017) and their impacts on ecological and socio-economic status of Dondra lagoon, southern coast of Sri Lanka were studied as many lagoons in southern Sri Lanka are being seriously affected due to anthropogenic pressure in the recent past. The changes of Dondra lagoon and its immediate surroundings were studied in conjunction with a GIS-coupled ecological survey and a questionnaire survey. The lagoon water surface area has decreased by about 0.92 ha (~8%) and the mangrove cover has increased by about 1.38 ha (~11%) over this period. The salinity of the lagoon has also reduced, forming a ‘low saline’ (3 psu) regime. About 40% of the lost water surface has scarified for a newly formed land mass (~0.4 ha) within the proximal part of the lagoon. The bridge, broken by the tsunami of 2004, has newly been constructed twice during the reporting period. The construction most likely led to impair the inflow and outflow through the lagoon mouth. Several development projects were launched in the immediate periphery of the lagoon stimulated soil erosion causing heavy siltation in the lagoon. The above changes in the morphometry of the lagoon is a cumulative effect of two factors; impaired inflow and outflow through the lagoon mouth, and the increase of the sediment input to the lagoon. If the ongoing processes are sustained, the lagoon will change into a different landscape. Therefore, early intervention to restore the lagoon hydrology is highly recommended if the lagoon ecosystem is to be protected.
AB - Spatio-temporal changes during the last twelve year period (2006–2017) and their impacts on ecological and socio-economic status of Dondra lagoon, southern coast of Sri Lanka were studied as many lagoons in southern Sri Lanka are being seriously affected due to anthropogenic pressure in the recent past. The changes of Dondra lagoon and its immediate surroundings were studied in conjunction with a GIS-coupled ecological survey and a questionnaire survey. The lagoon water surface area has decreased by about 0.92 ha (~8%) and the mangrove cover has increased by about 1.38 ha (~11%) over this period. The salinity of the lagoon has also reduced, forming a ‘low saline’ (3 psu) regime. About 40% of the lost water surface has scarified for a newly formed land mass (~0.4 ha) within the proximal part of the lagoon. The bridge, broken by the tsunami of 2004, has newly been constructed twice during the reporting period. The construction most likely led to impair the inflow and outflow through the lagoon mouth. Several development projects were launched in the immediate periphery of the lagoon stimulated soil erosion causing heavy siltation in the lagoon. The above changes in the morphometry of the lagoon is a cumulative effect of two factors; impaired inflow and outflow through the lagoon mouth, and the increase of the sediment input to the lagoon. If the ongoing processes are sustained, the lagoon will change into a different landscape. Therefore, early intervention to restore the lagoon hydrology is highly recommended if the lagoon ecosystem is to be protected.
KW - Dondra lagoon
KW - Hydrology
KW - True mangroves
KW - Tidal inflow
KW - Salinity
KW - Siltation
U2 - 10.1007/s11852-020-00777-1
DO - 10.1007/s11852-020-00777-1
M3 - Article
SN - 1400-0350
VL - 24
JO - Journal of Coastal Conservation
JF - Journal of Coastal Conservation
IS - 5
M1 - 58
ER -