Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate chang...Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate change is a natural phenomenon,many research scientists are widely in agreement that the increase in temperature in the 20 th century is anthropologically related.The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally.In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness.This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia.The comparison of decadal variation of precipitation and temperature anomalies before the 1970 s found general increases which were mostly varying.But beyond the 1970 s,global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period.There are frequent changes and a shift westward of the Indian summer monsoon.Although precipitation is observed to be 70%below normal levels,in some areas the topography affects the intensity of rainfall.These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future.The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human,financial,infrastructure and food security of the region.展开更多
Climate change and its impacts have become topical issues of global news,scientific research and conferences.Environmental Geosciences incorporate the various disciplines of geosciences and their multifaceted interact...Climate change and its impacts have become topical issues of global news,scientific research and conferences.Environmental Geosciences incorporate the various disciplines of geosciences and their multifaceted interactions with life.Research discussions on the interaction of climate change,geosciences and environment may often be blur,and Schmidt-Thoméet al.(2010)stated that“Often past climate changes that can be deduced from geological records may help in understanding the speed of potential climate change effects,i.e.how quickly have sea levels changed,how drastic has nature reacted to ups and downs in temperature,etc.These analyses of past events help in giving outlooks on potential changes in our living environment.It is also of important to understand the magnitude and potential effects of extreme events,such as droughts and floods”.展开更多
Background:This study analysed the multi-temporal trend in land cover,and modelled a future scenario of land cover for the year 2030 in the highly urbanized state of Selangor,Malaysia.The study used a Decision Forest-...Background:This study analysed the multi-temporal trend in land cover,and modelled a future scenario of land cover for the year 2030 in the highly urbanized state of Selangor,Malaysia.The study used a Decision Forest-Markov chain model in the land change modeller(LCM)tool of TerrSet software.Land cover maps of 1999,2006 and 2017 were classified into 5 classes,namely water,natural vegetation,agriculture,built-up land and cleared land.A simulated land cover map of 2017 was validated against the actual land cover map 2017.The Area Under the Curve(AUC)value of 0.84 of Total Operating Characteristics(TOC)and higher percentage of components of agreement(Hits+Correct rejection)compared to components of disagreement(Misses+False alarm+Wrong hits)indicated successful validation of the model.Results:The results showed between the years 1999 to 2017 there was an increase in built-up land cover of 608.8 km^(2)(7.5%),and agricultural land 285.5 km^(2)(3.5%),whereas natural vegetation decreased by 831.8 km^(2)(10.2%).The simulated land cover map of 2030 showed a continuation of this trend,where built-up area is estimated to increase by 723 km^(2)(8.9%),and agricultural land is estimated to increase by 57.2 km^(2)(0.7%),leading to a decrease of natural vegetation by 663.9 km^(2)(8.1%)for the period 2017 to 2030.The spatial trend of land cover change shows built-up areas mostly located in central Selangor where the highly urbanized and populated cities of Kuala Lumpur and Putrajaya and the Klang valley are located.Conclusion:The future land cover modelling indicates that built-up expansion mostly takes place at edges of existing urban boundaries.The results of this study can be used by policy makers,urban planners and other stakeholders for future decision making and city planning.展开更多
文摘Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate change is a natural phenomenon,many research scientists are widely in agreement that the increase in temperature in the 20 th century is anthropologically related.The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally.In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness.This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia.The comparison of decadal variation of precipitation and temperature anomalies before the 1970 s found general increases which were mostly varying.But beyond the 1970 s,global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period.There are frequent changes and a shift westward of the Indian summer monsoon.Although precipitation is observed to be 70%below normal levels,in some areas the topography affects the intensity of rainfall.These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future.The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human,financial,infrastructure and food security of the region.
文摘Climate change and its impacts have become topical issues of global news,scientific research and conferences.Environmental Geosciences incorporate the various disciplines of geosciences and their multifaceted interactions with life.Research discussions on the interaction of climate change,geosciences and environment may often be blur,and Schmidt-Thoméet al.(2010)stated that“Often past climate changes that can be deduced from geological records may help in understanding the speed of potential climate change effects,i.e.how quickly have sea levels changed,how drastic has nature reacted to ups and downs in temperature,etc.These analyses of past events help in giving outlooks on potential changes in our living environment.It is also of important to understand the magnitude and potential effects of extreme events,such as droughts and floods”.
文摘Background:This study analysed the multi-temporal trend in land cover,and modelled a future scenario of land cover for the year 2030 in the highly urbanized state of Selangor,Malaysia.The study used a Decision Forest-Markov chain model in the land change modeller(LCM)tool of TerrSet software.Land cover maps of 1999,2006 and 2017 were classified into 5 classes,namely water,natural vegetation,agriculture,built-up land and cleared land.A simulated land cover map of 2017 was validated against the actual land cover map 2017.The Area Under the Curve(AUC)value of 0.84 of Total Operating Characteristics(TOC)and higher percentage of components of agreement(Hits+Correct rejection)compared to components of disagreement(Misses+False alarm+Wrong hits)indicated successful validation of the model.Results:The results showed between the years 1999 to 2017 there was an increase in built-up land cover of 608.8 km^(2)(7.5%),and agricultural land 285.5 km^(2)(3.5%),whereas natural vegetation decreased by 831.8 km^(2)(10.2%).The simulated land cover map of 2030 showed a continuation of this trend,where built-up area is estimated to increase by 723 km^(2)(8.9%),and agricultural land is estimated to increase by 57.2 km^(2)(0.7%),leading to a decrease of natural vegetation by 663.9 km^(2)(8.1%)for the period 2017 to 2030.The spatial trend of land cover change shows built-up areas mostly located in central Selangor where the highly urbanized and populated cities of Kuala Lumpur and Putrajaya and the Klang valley are located.Conclusion:The future land cover modelling indicates that built-up expansion mostly takes place at edges of existing urban boundaries.The results of this study can be used by policy makers,urban planners and other stakeholders for future decision making and city planning.