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PROJECTS & OUTPUTS

FOREST & WATER

Synergise with nature
Enhancing soil and water

Natural forests. Plantation forests. Timber harvesting.

Forests are the best land-use for water resource conservation and flood protection. Today, however, most forested areas comprise secondary forests or plantation forests due to timber exploitation in the early days. With continuous timber production, how can we aid forests (existing and new) in maintaining water-conservation and flood protection services? What management techniques should be applied? Which species should be prioritised?

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Key findings:

  1. In tropical rainforests, natural regeneration (8-22 years) after logging have shown buffered stormwater runoff and erosion although still not as good as that in virgin forests.

  2. Riparian buffers are important in controlling damages caused by forestry.

  3. Understorey vegetation in older regenerated and primary forests can provide erosion protection.

  4. Restoring forests reduces streamflow but increases baseflow on dry days.

  5. Thinning of Japanese Cypress plantation reduces peak runoff but increases baseflow.

  6. Conifer species has lower annual water use compared to deciduous species.

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Sabah August 2011 038-01.jpeg

AGRICULTURE & WATER

Optimising irrigation and discharge
Erosion control

Agriculture is the key to meet the growing global population. While crop production experts are focussing on intensifying yields, knowledge in agricultural water management must gain equal pace. Challenges differ according to region - dry areas (mediterranean, arid, temperate) focus on managing and optimising limited water resources. The humid tropics and temperate need to manage stormwater, erosion and fertiliser runoff. 

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Key findings:

  1. Sediment yields from oil palm agriculture are 3-6 times higher than logged forests.

  2. Increased erosion from oil palm agriculture negatively impacts aquatic life.

  3. Converting forests into oil palm agriculture reduces baseflow but greatly increases storm runoff responses.

  4. Adverse impacts from oil palm can be minimised by improved management practices such as retaining riparian buffers,maintaining ground cover, and proper channeling of rainwater.

ENERGY & URBAN

Preserving the original function of water resources

Urban development and energy generation (solar farm, hydropower) modifies the landscape and ground properties resulting in altered runoff ratio, water temperature and quality. This may cause adverse impacts downstream water users especially in agriculture and animal husbandry. How do water properties change with such development and how can we mitigate the effects?

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In progress.​

Sustainable Energy
Projects & outputs: Services

Selected publication

  1. Nainar, A., Tanaka, N., Sato, T., Kishimoto, K. and Kuraji, K. 2021. A comparison of the baseflow recession constant (K) between a Japanese cypress and mixed-broadleaf forest via six estimation methods. Sustainable Water Resources Management. 7(1): 1-13

  2. Nainar, A., Tanaka, N., Sato, T., Mizuuchi, Y. and Kuraji, K. 2020. A comparison of hydrological characteristics between a cypress and mixed-broadleaf forest: implication on water resource and floods. Journal of Hydrology, 125679

  3. Sato, T., Tanaka, N., Nainar, A., Kuraji, K., Gomyo, M. and Suzuki, H. 2020. Soil erosion and overland flow in Japanese cypress plantations: spatio-temporal variations and a sampling strategy. Hydrological Sciences Journal. 65(13): 2322-2335

  4. Kuraji, K., Gomyo, M. and Nainar, A. 2019. Thinning of cypress forest increases subsurface runoff but reduces peak storm-runoff: a lysimeter observation. Hydrological Research Letters. 13(3):49-54

  5. Sato, T., Tanaka, N., Nainar, A., Kuraji, K., Gomyo, M., Kitaoka, A., Suzuki, H., and Nakashima, R., 2019. The effect of fine root cover on soil erosion and overland flow in Japanese cypress plantation. Chubu Forestry Research. 67:91-91

  6. Nainar, A., Tanaka, N., Bidin, K., K. V. Annammala, Ewers, R. M., Reynolds, G. and Walsh, R. P. D. 2018. Hydrological dynamics of tropical streams on a gradient of land-use disturbance and recovery: A multi-catchment experiment. Journal of Hydrology. 566:581-594

  7. Nainar, A., Bidin, K., Walsh, R. P. D., Ewers, R. M. and Reynolds, G. 2017. The effects of different land use on suspended sediment dynamics in Sabah (North Borneo). Hydrological Research Letters. 11(1):79-84

  8. Luke, S. H., Barclay, H., Bidin, K., Chey, V. K., Ewers, R. M., Foster, W. A., Nainar, A., Pfeiffer, M., Reynolds, G., Turner, E. C., Walsh, R. P. D., and Aldridge, D. C. 2017. The effects of catchment and riparian forest quality on stream environmental conditions across a tropical rainforest and oil palm landscape in Sabah, Malaysian Borneo. Ecohydrology. e1827

  9. Barclay, H., Gray, C. L., Luke, S. H., Nainar, A., Snaddon, J. L. and Turner, E. C. 2017. RSPO Manual on Best Management Practices (BMPs) for the Management and Rehabilitation of Riparian Reserves. RSPO document: RSPO-GUI-T03-003 V1.0 ENG. DOI:10.13140/RG.2.2.17011.22561

Projects & outputs: Text
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