The water management area of the IGCS has a long experience in dealing with a high range of water issues that include fresh and seawater. IGCS seeks to understand sustainable management of coastal infrastructure and water resources in the context of climate change. The work involves climate dynamics, storm surge, inundation modelling, flood mitigation, sustainable urban drainage and integrated urban water management and effects of surface and sub-surface interaction on water. At a catchment scale, IGCS develops sustainable concepts for rural and urban river basins with an ecohydrological perspective. It includes finding the effect of multiple stressors, such as land-use change or rapid industrialization, on water quality and quantity and its effect on aquatic ecosystems.
Current research projects
Climate change impacts on coastal infrastructure and the adaptation strategies
India has a coastline of about 7.500 km including the islands facing a variety of problems even under normal conditions. Problems like erosion, flooding, breaching, closure of river mouths, islands being disconnected, breaking of land masses, discontinuity in coastal highways, submergence of structures of archeological importance, flooding of coastal villages do occur on a regular basis. These affect the livelihood of the coastal community in a significant way. The livelihood of a large percentage of population along the coast is through fishing and other activities related to the marine environment. The scenario becomes worse during extreme events like storm surges during cyclones and inundation during tsunamis. Although conservation as well as sustainable integrated coastal zone management has been a great topical interest in the recent years worldwide, any management strategy should have a clear understanding of the extreme events that could strike the coastline and disturb the strategy and demoralize the coastal community. The potential levels of inundation height and distance is fairly known along the Indian coast including that during the worst scenario of the tsunami in 2004. However, in the context of climate change that will govern the sea level rise leading to an increased inundation height and distance, the impacts of climate change are yet to be understood completely and more so, the risk involved under such scenarios. Furthermore, the importance of risk involved as well as the adaptation measures to be followed need careful understanding, planning and its conveyance to the coastal community.
The current research project focuses on the prediction of impact on the coastal community and strategically important infrastructures (ports, power plants, jetties, etc.), including water resources, by the climate-change-induced sea level rise and the change in the frequency of the extreme events. The development of a GIS tool for mapping the exposure levels of various coastal areas for extreme events like storm surges and tsunamis coupled with sea level rise due to climate change, the associated risks and finally the adaptation measures. In order to do so, following major topics will be taken up for study in the proposed project:
- the measurement and modeling of aerosol hygroscopic properties using an advanced mass based hygroscopic technique;
- the use of various global climate models to create a new situation like RCPs by perturbing the extensive properties of aerosols obtained using measurements and impact on cyclone formation and track; estimation of extreme waves and the resulting morphological changes;
- storm surge modeling to predict the extent of surge uprush into the land through estuaries;
- systematic adaptation strategies will be proposed following a risk assessment and an elaborate laboratory modeling of the adaptation measures.
- Climate change and sea level rise impact on:
- the availability of water resources
- salt water intrusion
- resilience of waste management infrastructure and its effect on the quality of water resources
- overall vulnerability on the coastal community will be evaluated to bring out the risk involved and for designing appropriate adaptation measures.
- To investigate the implications of climate change driven extreme events in the Indian coastal regions.
- To evaluate the vulnerability of coastal infrastructure (examples: ports, fishing harbor’s, power plants, etc.) and water resources due to the climate change.
- To propose suitable climate change adaptation measures for coastal infrastructure.
- To Propose effective water resource management strategies (quality, quantity and urban flooding) in coastal areas, under climate change scenarios
- Guidelines on how to develop/apply an integrated model consisting of different sub-models (forcing, storm surge, wave propagation / run-up / overtopping / coastal erosion / inundation, coupling with other models).
- Fine resolution wind-wave modeling (prediction, propagation, run‐up and overtopping)
- Integrating numerical models simulation with land use maps (GIS) to access the inundation level and damage.
- Flood potential will be estimated through the maximum water level associated to each storm including meteorological effects (storm surge) and wave induced runup from numerical simulations for 150 years (1951‐2100). The results will be given in a user‐friendly database, supplying the decision support system with all necessary input.
- The importance of the inclusion of eco-based adaptation into coastal zone management is not well dimensioned. Many countries agreed for the need to use eco-based adaptation, however it is in its infancy. The physics and design aspects of the vegetation belt will be beneficial for the designers and planners. Further, there is great opportunity for coastal planning improvements because it provides benefits beyond climate change scenarios. This would be highly beneficial for the coastal communities.
- Suggestions for adaptation measures for surface and groundwater resources management in coastal regions to face the impact of climate change
- Innovative waste treatment technology for addressing the twin challenges of poor water quality and environmental degradation in coastal areas, exacerbated by climate change
Results will be published in reputed scientific Journals and presented in national as well as international conferences. Moreover, publications through popular newspapers and media are planned for more visibility. Two Workshops in the final year will be organized to share the knowledge gained and results obtained with
- the academic and research fraternity
- the user industry consisting of private companies and government establishments such as port trusts, ONGC, IRS, SCI, EIL.
Partner Institutions (planned and ongoing)
- RWTH Aachen (Prof. Holger Schuettrumpf; Chair and Institute for Hydraulic Engineering and Water Management)
- Technical University of Hamburg (Prof. Dr.-Ing. Peter Fröhle, Head, Institute of Hydraulic Engg.)
- Kiel University (Prof. Dr. Nicola Fohrer; Dr. Paul Wagner)
- Technical University of Stuttgart (Prof. Dr. Martin Kranert)
- Institute for Tropospheric Research, Leipzig (Prof. Dr. Ali Wiedensohler)
- Max Planck Institute for Chemistry, Mainz (Prof. Dr. Ulrich Poschl)
- Helmholtz-Zentrum Geesthacht
- Khan, A.S., Mandal, S.K and Rajan, S.C. Devdyuti, B. (2019). BASIEC: A coastal climate service awareness framework for community-based adaptation to rising sea-levels. Springer’s Handbook of Climate Services, Berlin, Germany.
- Khan, A.S., Mandal, S.K and Rajan, S.C., Devdyuti, B. (2019). Chennai city and coastal hazards: Addressing community-based adaptation through the lens of climate change and sea-level rise. Springer’s Book on Climate Change and Natural Hazards, Berlin, Germany.
- Devi, N. N., Sridharan, B., & Kuiry, S. N. (2019). Impact of urban sprawl on future flooding in Chennai city, India. Journal of Hydrology, 574, 486-496. (IF: 4.405)
- Thomas, A. R., Arulraj, P. R., Kranert, M., & Philip, L. (2019). Investigation on greenhouse gas emissions and compost dynamics during in-vessel co-composting of septage and mixed organic wastes. International Journal of Environmental Science and Technology, 1-16. (IF: 2.031)
- Prabu, P., Bhallamudi, S. M., Chaudhuri, A., & Sannasiraj, S. A. (2019). Numerical investigations for mitigation of tsunami wave impact on onshore buildings using sea dikes. Ocean Engineering, 187, 106159. (IF: 2.73)
- Varghese, V. A., & Saha, N. (2019). Investigation of stochastic nonlinear dynamics of ocean engineering systems through path integration. Physica D: Nonlinear Phenomena, 132227. (IF: 1.81)
- Anu Rachel Thomas, Martin Kranert and Ligy Philip “Application of mixed organic waste for effective septage treatment through In-vessel co-composting” The Thirty-Fourth International Conference on Solid Waste Technology and Management, Annapolis (Washington, D.C.) U.S.A. March 31 – April 3, 2019.
- Anu Rachel Thomas and Ligy Philip “Transfer of pharmaceutical and personal care product during in-vessel co-composting of septage and mixed organic wastes” The 12th CESE Conference, 3 – 7 Nov. 2019, Kaohsiung, Taiwan.
- B Santosh kumar, K Murali, S A Sannasiraj, R Sundaravadivelu, V Sundar; Adaptation measures for coastal infrastructure; National seminar of climate change and coastal ocean processes (CCCOP-2019), IIT Delhi, 4-5 July 2019.
- B Santosh kumar, K Murali, S A Sannasiraj, R Sundaravadivelu; Sea environment induced climate change impacts on coastal infrastructure; Coastal Structures conference, Hannover, Germany, 30 Sept – 2 Oct. 2019.
- Christi Jose, R. Ravikrishna, Pengfei Liu, C. Balaji, and Sachin S. Gunthe; Hygroscopicity of atmospheric aerosols in sub-saturated region: A novel mass-based approach over size-based technique for improved characterization. presented in Water Future Conference 2019 at IISc
- Khan, A.S., Mandal, S.K and Rajan, S.C. Devdyuti, B. (2019). “BASIEC: A coastal climate service awareness framework for community-based adaptation to rising sea-levels”. International Symposium on Disaster Resilience and Sustainable Development, Asian Institute of Technology, Thailand, Bangkok, 7th -8th March, 2019.
- Khan, A.S., Mandal, S.K and Rajan, S.C, Devdyuti, B. (2019). “Chennai city and coastal hazards: Addressing community-based adaptation through the lens of climate change and sea-level rise”. International Symposium on Climate change and natural hazards: Coping with and managing hazards in the context of climate change. University of Padova, Padova, Italy, 25th -26th February, 2019.
- Mikkilineni Dhananjayan, Sannasiraj S A, Murali K; Shoreline change due to an extreme weather event; National seminar of climate change and coastal ocean processes (CCCOP-2019), IIT Delhi, 4-5 July 2019
- Sridharan, B., Chaitanya, R. K., Sudheer, K. P. and Kuiry, S. N. (2019). Probablistic storm surge analysis along the Tamil Nadu coast: A case study on Kalpakkam. In: National Conference of Flood Early Warning for Disaster Risk Reduction, 30-31 may 2019, Hyderabad.
- Dommetti Sriram, M.Tech Thesis, 2019: Impact of climate change on mesoscale weather systems in Bay of Bengal
- Hanumanthu Tulasi Rao, M.Tech Thesis, 2019: Experimental study on wave interaction with vegetation for reflection coefficients
- Mounika Bhukya, M.A. Thesis, 2019: An Assessment of Coastal Climate Risk and Resilience in Chennai: Ennore A Study on Community Based Adaptation of The Fisher Folk
- N.Somasundaram, M.Tech Thesis, 2019: Effect and removal of Heavy Metals during industrial and sewage sludge composting.
- Sanjeev Chhetri, , M.Tech Thesis, 2019: Sustainable Treatment and Reuse of Low Strength Household Greywater.
New techniques / models
- IMLPG_R method is developed to analyse wave-vegetation interaction
- A framework called BASIEC (Building capacities for Adaptation to climate change and sea-level rise through Information, Education and Communication for coastal communities) has been developed for community-based adaptation to Sea Level Rise.
The research project is funded from 2018 – 2022 by the Department of Science and Technology, Government of India, as a part of National Mission on Strategic Knowledge for Climate Change (NMSKCC).
Contact: Professor Dr. Sannasiraj
Assessment of water quality of the lakes of the Pallikaranai catchment, Chennai, India
Water quality has been one of the most widespread research topics for decades, along with water scarcity as one of the problems humans are facing. The United Nations has expressed their concerns about this issue in several occasions, remarkably in 2016 with the Sustainable Development Goals, that included the Sustainable Development Goal number 6: “Ensure availability and sustainable management of water and sanitation for all”. In India, the main sources of fresh-water supply are surface and ground water and their easy access to anthropogenic activities have affected them much. Due to the over exploitation of water resources and increased pollution, the whole country is facing the scarcity of fresh-water resources.
In the present study, in cooperation with Professor Indumathi Nambi’s group at the department of Civil Engineering, IIT Madras, we chose the Pallikaranai catchment in Chennai as our study area, which includes a set of lakes in a cascading system facing a few problems. The main current problems are 1) there are numbers of encroachments from which sewage is directly let into the lake, 2) waste water from the Pallavaram Municipality is discharged into the lake, 3) the lakes are suffering from heavy eutrophication, 4) there is currently no regulation for waste water disposal and no assessment indices and 5) the reduction of biodiversity in the study area. In these regards, we aim 1) to display the long-term water quality before and after monsoon season, 2) to show how cascading system affects the lake water quality, 3) thus to implement and complete the lake restoration protocol in the future water quality assessment and monitoring work.
Fig. 1 shows a map of the Pallikaranai catchment. The upper stream lakes, Chitlapakkam, Selaiyur and Rajakilpakkam, flow into Sembakkam Lake. Afterwards, the excess of it flows into Nanmangalam Lake. Other downstream lakes are Keelkatalai, Narayanapuram and the catchment outlet Okkiyam Maduvu.
Our results showed that the lakes are suffering from heavy pollution. COD levels were especially high during August and September and reached values over two-thirds of the average of wastewater in developing countries (Fig. 2). In the case of the levels of chlorophyll A, they were extremely high in Chitlapakkam Lake and suggested a severe eutrophication that might affect the biodiversity (Fig. 2).
The effect of the monsoon on the water quality of the lakes was also evident. It performed better after the monsoon season than in the dry season. It was an extremely dry year in Chennai in 2019, the lakes stayed disconnected and stagnated for most of the year. As a consequence of that, the Keelkattalai Lake (Fig. 4 and 5) was dry between July and September. The first rainfalls increased the flow, connected the lake cascading system and probably diluted all the contamination and concentrations got lower. This could be the reason why all the lakes reached the best condition in December. Sembakkam Lake is the only one currently being restored with the help of international NGO The Nature Conservancy. More similar work should be implemented in other water bodies.
There is the urgency to improve the water quality, since the water bodies are close to human’s living area. Measures could be taken, like building more waste water treatment plants (WWTPs) that prevents sewage to be discharge to the lakes without any previous treatment. Within the studied catchment, there is currently only one WWTP, which is not enough. Additionally, thresholds should be set to restrict the concentration of discharged nutrients into water. Also, to move the dump sites present in the area that contribute to the spread of disease vectors and pollution. We also suggest a science-based, careful selection of reintroduction species of local submerged macrophytes for self-purification of the lakes.
- Kiel University (Department of Hydrology and Water Resources Management: Dr. Daniel Rosado, Xiuming Sun, Lukas Paul Loose, Yueming Qu, Prof. Nicola Fohrer)
- Indian Institute of Technology Madras (Department of Civil Engineering: Prof. Indumathi Nambi)
The project is funded from December 2018 until February 2020 by The Care Earth Trust, The Nature Conservancy, Indo German Centre for Sustainability and Deutsche Hydrologische Gesellschaft.