Flooding is a frequent, naturally recurring phenomenon worldwide that can become disastrous if not addressed accordingly. This paper aims to evaluate the impacts of land use change and climate change on flooding in the Segamat River Basin, Johor, Malaysia, with 1D–2D hydrodynamic river modeling, using InfoWorks Integrated Catchment Modeling (ICM). The study involved the development of flood maps for four different scenarios: (1) future land use in 2030; (2) the impacts of climate change; (3) three mitigation strategies comprising detention ponds, rainwater harvesting systems (RWHSs), and permeable pavers; and (4) a combination of these three mitigation strategies. The obtained results show increases in the flood peaks under both the land use change and climate change scenarios. With the anticipated increase in development activities within the vicinity up to 2030, the overall impact of urbanization on the extent of flooding would be rather moderate, as the upper and middle parts of the basin would still be dominated by forests and agricultural activities (approximately 81.13%). In contrast, the potential flood-inundated area is expected to increase from 12.25% to 16.64% under storms of 10-, 50-, 100-, and 1000-year average recurrence intervals (ARI). Interestingly, the simulation results suggest that only the detention pond mitigation strategy has a considerable impact on reducing floods, while the other two mitigation strategies have less flood reduction advantages for this agricultural-based rural basin located in a tropical region.

Many new agricultural activities resulted in severe soil erosion across the Cameron Highlands’ land surface. Therefore, this study determines the cover (C) and land management (P) factors of the USLE for predicting soil loss risk in Cameron Highlands using a Geographic Information System (GIS). For this study, data from the Department of Agriculture Malaysia (DOAM) and the Department of Town and Country Planning Malaysia (PLANMalaysia) were used to generate several C&P factors in the Cameron Highlands. Data from both agencies have resulted in C factors with 0.01 to 1.00 and P factors with 0.30 to 0.49. Due to the cover and land management factor varies depending on the data collected by the various agencies, this study used the two data sets to come up with a C&P factor that accurately reflected both agricultural and urban growth effects. RKLS factors of USLE were obtained from the DOAM with values R (2375–2875), K (0.005), LS (2.5–25), respectively. The Cameron Highlands’ soil loss risk with these new C&P values resulted in a soil loss of 6.72 per cent (4547.22 hectares) from high to critical, with a percentage difference range of −0.77 to +3.37 under both agencies, respectively.

No abstract

The quality of Klang river water is deteriorating dramatically since it is in urban places every day and become one of the major problems.  Therefore, the Malaysian government had initiated one river cleaning project named River of Life (ROL) project. This project is for rehabilitating and restoring the Klang river. A series of river water treatment plant (RWTP)s have been operated in Klang river catchment since 2014. Six RWTPs station has been monitored up to eight stations until presents. Eight parameters consisting of physio-chemical types and biological types have been recorded. RWTP effluent discharges are targeted to achieve Malaysia Interim National Water Quality Standard (INWQS) under Class II B. Since previous RWTP performance only emphasized on local river pollutants and certain conditions, this paper will investigate the effectiveness of full-scale RWTP unit process for river condition. Water quality assessment are involved which are consist of effluent water quality monitoring and pollutant removal efficiency. Most of the major pollutants able to be reduced by more than 50% reduction. Although BOD and AN still not able to achieve standard range gazetted by INWQS Class IIB, there is an improvement of river water quality at Klang River by using IFAS technology adopted in the RWTP system.

No abstract