eISSN: 2672-7226 © Penerbit UMT Journal of Sustainability Science and Management Volume 16 Number 6, August 2021: 15-30 IMPACT OF SALTWATER INTRUSION ON PADDY GROWTH IN KUALA KEDAH, MALAYSIA SAMERA SAMSUDDIN SAH 1,2 *, KHAIRUL NIZAM ABDUL MAULUD 2,3 , SURAYA SHARIL 2 , OTHMAN A. KARIM 2 AND NUR FADZLINA ABDUL NAHAR 1 1 Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Kejuruteraan, 02600, Arau, Perlis. 2 Department of Civil Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor. 3 Earth Observation Centre, Institute of Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor. *Corresponding author: knam@ukm.edu.my Submitted fnal draft: 31 August 2020 Accepted: 3 September 2020 Introduction In the 2010s, agriculture remained an important sector in terms of contribution to the nation’s economy. Coastal zones are major contributors to the nation’s economy, particularly through agricultural activities, such as paddy cultivation (Nordin, 2006; Nisaa et al., 2018)with a land area of some 330,000 km square and a coastline of some 4,800km, sits on the geologically stable Sunda Shelf. Half the coastline consists of beaches and slightly less than half is mangrove fringed; there is little rocky coast. It has been estimated that some 30% of the coastline is subject to varying degrees of erosion. The population of 25 million is small for a country in the region but its population growth rate of some 2.4% is amongst the highest. Over 60% of the population lives along or close to the coasts. Growing populations not only put a greater strain on already depleting resources, but are also responsible for the degradation of marine habitats for those resources. Since the oceans have limited resources, there is a need to minimize the impact that the growing size and number of coastal communities have on marine environments. Development along the coasts and hinterland has been extensive. Erosion is signifcant and may contribute to coastal sedimentations rates (in protected areas. Kedah and Perlis, located at the north of Peninsular Malaysia, where most of the nation’s rice is cultivated, are thus known as Jelapang Padi. These states have been major producers of rice for many decades. Considering that rice is the staple food of the majority of Malaysians, it has been one of the government’s main policy since 1955 to be self-suffcient in rice production. Many initiatives and strategies have been implemented by the government to improve the paddy sector. A local authority, known as the Muda Agricultural Development Authority (MADA), was established in 1970 to provide assistance to farmers in Kedah. Kamaruddin et al. Abstract: Agricultural activities along the coastal line are facing problems of seawater intrusion due to the rise in sea level, especially in Kuala Kedah, Kedah. Approximately more than 30 hectares have been affected by the increased salinity concentration in paddy felds and farmers have had to bear losses of more than 75 percent since this problem frst began in 2016. Hence, this research was conducted to assess the infuence of salinity concentration on paddy growth due to tidal variations in the paddy plot and the related irrigation canal. By considering tide events, in-situ measurement sof salinity concentrations were carried out using a salinity portable meter at ten points along the irrigation canal, as well as at outfow and infow regions in the paddy plot at two-week intervals. Assessment of paddy growth was made by regularly measuring plant height from the third to thirteenth week and grain weight on the thirteenth week of plant growth. The results show that there are reductions of 19% and 5% in paddy yields in outfow and infow regions, respectively, as well as reductions in paddy height by 50% compared with the normal paddyheight in both regions. Keywords: Low-lying zone, salt-water, sustainability. http://doi.org/10.46754/jssm.2021.08.004