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Climate change impacts wildfire events as well as water availability. Exposure of water resources to wildfire can reduce water quality supplied to humans and resulting health problems. On the other hand, water resources such as rivers and ponds are essential in wildfire firefighting. This paper intended to assess spatially the exposure of water resources to wildfire. A case study in Johor, Malaysia is utilised to asses and determine locations of water bodies in an area which are vulnerable to wildfire. Post wildfire runoff water can contaminate water resources. Fire data collected by MODIS from 2000–2020 are used to create a hotspot map. Water resources and waterbody data originated from Department of Surveying and Mapping Malaysia used to identify the stream and dams that are exposed to wildfire. 5 class exposure level has been set to show the degree of closeness of water resources to wildfire hotspot area. Using the spatial analysis method, low to high level of potential wildfire-water exposures were able to be locate. Analysis shows, 7% of Johor's water sources is exposed to medium levels of wildfire, while just 1% is exposed to the highest levels. The majority of the streams have very low levels of exposure. In addition, the wildfire-water exposure map aids in first respondent preparedness and planning. [ABSTRACT FROM AUTHOR]

The future projections of climate change by means of global climate models of the Earth provide fundamental coarse-grid-resolution hydroclimate data for studies of the effect of climate change on water resources. This paper reports on a study that was performed during 2001-2006, in which the climate change simulations of the coupled global climate model of the Canadian Center for Climate Modeling and Analysis were downscaled by a regional hydroclimate model of Peninsular Malaysia (RegHCM-PM) to the scale of the subregions and watersheds of Peninsular Malaysia (PM), to assess the effect of future climate change on its water resources. On the basis of the simulations of hydroclimatic conditions during the historical period of 1984-1993 and future periods of 2025-2034 and 2041-2050, this report concludes that the overall mean monthly streamflow is approximately the same during both the future period, and the historical period for most of the watersheds of Peninsular Malaysia, except Kelantan and Pahang. In those two watersheds, a significant increase occurs in the overall mean monthly streamflow during the future period. In the future, high flow conditions will be magnified in the Kelantan, Terengganu, Pahang, and Perak River watersheds during the wet months, whereas low monthly flows will be significantly lower in the Selangor and Klang watersheds during the dry months. [ABSTRACT FROM AUTHOR]

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Spatial and temporal variability of streamflow due to climate change affects hydrological processes and irrigation demands at a basin scale. This study investigated the impacts of climate change on the Kurau River in Malaysia using metalearning, an ensemble machine learning technique using support vector regression (SVR) and random forest (RF) coupled with the Coupled Model Intercomparison Project CMIP6 multi-Global Climate Model (GCM). Five global climate models and three shared socioeconomic pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5) were used. The climate sequences generated by the delta change factor method were applied as input to the metalearning model to predict the streamflow changes in the Kurau River from 2021 to 2080. The model fitted reasonably well, with Kling–Gupta efficiency (KGE), Nash–Sutcliffe efficiency (NSE), percent bias (PBias), and RMS Error (RMSE) of 0.79, 0.83, 2.52, and 4.51, respectively, for the training period (1976–1995) and 0.72, 0.72, 5.85, and 6.90, respectively, for the testing period (1995–2005). Future projections of multi-GCM over the 2021–2080 period under three SSPs predicted an increase in rainfall for all months except April–June during the dry period (off-season), with a higher increase occurring during the wet period (main season). Temperature projections indicated an increase in maximum and minimum temperatures under all SSP scenarios, with a higher increase of approximately 2.0°C under SSP5-8.5 predicted during the 2051–2080 period relative to the baseline period of 1976–2005. The model predicted that the seasonal changes in streamflow of two planting periods range between −7.5% and 7.1% and between 1.2% and 5.9% during the off-season and the main season, respectively. A significant streamflow decrease was predicted in April and May for all SSP scenarios due to high temperatures during the off-season, with SSP5-8.5 being the worst. The impact assessment of climate variabilities on the availability of water resources is vital to identify appropriate adaptation strategies to deal with an expected increase in irrigation demand due to global warming in the future. The predicted future streamflow under the potential climate change impacts is crucial for the Bukit Merah Reservoir to establish suitable operational policies for irrigation release. [ABSTRACT FROM AUTHOR]

Climate change-induced spatial and temporal variability of stremflow has significant implications for hydrological processes and water supplies at basin scale. This study investigated the impacts of climate change on streamflow of the Kurau River Basin in Malaysia using a Climate-Smart Decision Support System (CSDSS) to predict future climate sequences. For this, we used 25 reliazations consisting from 10 Global Climate Models (GCMs) and three IPCC Representative Concentration Pathways (RCP4.5, RCP6.0 and RCP8.5). The generated climate sequences were used as input to Soil and Water Assessment Tool (SWAT) to simulate projected changes in hydrological processes in the basin over the period 2021–2080. The model performed fairly well for the Kurau River Basin, with coefficient of determination (R2), Nash-Sutcliffe Efficiency (NSE) and Percent Bias (PBIAS) of 0.65, 0.65 and –3.0, respectively for calibration period (1981–1998) and 0.60, 0.59 and −4.6, respectively for validation period (1996–2005). Future projections over 2021–2080 period show an increase in rainfall during August to January (relatively wet season, called the main irrigation season) but a decrease in rainfall during February to July (relatively dry season, called the off season). Temperature projections show increase in both the maximum and minimum temperatures under the three RCP scenarios, with a maximum increase of 2.5 °C by 2021–2080 relative to baseline period of 1976–2005 under RCP8.5 scenario. The model predicted reduced streamflow under all RCP scenarios compared to the baseline period. Compared to 2021–2050 period, the projected streamflow will be higher during 2051–2080 period by 1.5 m3/s except in February for RCP8.5. The highest streamflow is predicted during August to December for both future periods under RCP8.5. The seasonal changes in streamflow range between –2.8% and –4.3% during the off season, and between 0% (nil) and –3.8% during the main season. The assessment of the impacts of climatic variabilities on the available water resources is necessary to identify adaptation strategies. It is supposed that such assessment on the Kurau River Basin under changing climate would improve operation policy for the Bukit Merah reservoir located at downstream of the basin. Thus, the predicted streamflow of the basin would be of importance to quantify potential impacts of climate change on the Bukit Merah reservoir and to determine the best possible operational strategies for irrigation release. [ABSTRACT FROM AUTHOR]

The article presents author's views regarding the impact of climate change on the conflict between water resources and agricultural water use, increasing carbon dioxide emission and sustainability of regional water resources management. Topics include hydroclimatic variables, agricultural development and water resources management.