Mukand Babel | Asian Institute of Technology (original) (raw)
Papers by Mukand Babel
Theoretical and Applied Climatology
Theoretical and Applied Climatology
APN Science Bulletin
The objective of the project was to develop a web-based digital tool called the Water Security As... more The objective of the project was to develop a web-based digital tool called the Water Security Assessment Tool (WATSAT) to help city authorities and decision-makers make an objective evaluation of the water security situation in the city. It uses an indicator-based methodology that measures five distinct dimensions (broad elements) of water security: “Water supply and sanitation”, “Water productivity”, “Water-related disasters”, “Water environment”, and “Water governance”, which together culminate into a Water Security Index (WSI). The tool is developed based on the water security assessment framework developed by Babel, Dang, Sharma, and Shinde (2015). WATSAT results in a quantitative assessment of water security in a city, wherein the WSI provides an overall picture of the water security situation in a city, while the evaluation of the various dimensions helps identify areas of concern. WATSAT aids city authorities in having a holistic understanding of water security and interconn...
Water Security in Asia, 2021
The various negative impacts on the environment and society caused by land subsidence have been a... more The various negative impacts on the environment and society caused by land subsidence have been a problem in Bangkok, Thailand, since the 1970s. Intensive groundwater extraction for industrial and domestic purposes since the 1950s, which led to a decline of groundwater levels, has been identified by various studies as the primary cause of the phenomenon of land subsidence. This paper gives an overview of the occurrence of land subsidence in Bangkok. The history, characteristics, identified causes, and measures for mitigation of land subsidence in the area are discussed. Efforts to alleviate the problems and studies that have been conducted to understand the problem are presented and analyzed.
Urban Water Journal, 2020
Accurate model-based forecasts (discharge and water level) are considered significant for efficie... more Accurate model-based forecasts (discharge and water level) are considered significant for efficient planning and management of urban drainage systems. These model-based predictions can be improved by assimilating system measurements in physically based, distributed, 1D hydrodynamic urban drainage models. In the present research, a combined filtering and error forecast method was applied for the data assimilation to update the states of the urban drainage model. The developed data assimilation set-up in combination with the 1D hydrodynamic model was applied at the Damhusåen Catchment, Copenhagen. Discharge assimilation represented significant potential to update model forecast, and maximum volume error was reduced by 22% and 6% at two verification locations. The assimilation of water levels had a minor impact on the update of the system states. The updated forecast skill using error forecast models was enhanced up to 1–2 hours and 6–7 hours lead time at upstream assimilation and down...
Hydrology, 2021
Accurate rainfall estimates are important in many hydrologic activities. Rainfall data are retrie... more Accurate rainfall estimates are important in many hydrologic activities. Rainfall data are retrieved from rain gauges (RGs), satellites, radars, and re-analysis products. The accuracy of gauge-based gridded precipitation products (GbGPPs) relies on the distribution of RGs and the quality of rainfall data records obtained from these. The accuracy of satellite-based precipitation products (SbPPs) depends on many factors, including basin climatology, basin topography, precipitation mechanism, etc. The hydrologic utility of different precipitation products was examined in many developed regions; however, less focused on the developing world. The Huai Bang Sai (HBS) watershed in north-eastern Thailand is a less focused but an important catchment that significantly contributes to the water resources in Thailand. Therefore, this research presents the investigation results of the hydrologic utility of SbPPs and GbGPPs in the HBS watershed. The efficiency of nine SbPPs (including 3B42, 3B42-...
International Journal of Climatology, 2021
In this study, 28 climate models from the fifth phase of the Coupled Model Intercomparison Projec... more In this study, 28 climate models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and 32 models from the sixth phase (CMIP6) have been evaluated for their ability to simulate large‐scale atmospheric circulations (using rainfall, wind fields, geopotential height, temperature, and moisture flux convergence) for the summer monsoon in Southeast Asia. Using a multi‐criteria decision making technique, models have been ranked based on 25 metrics which compare their performances with observation data. Results indicate a better representation of annual rainfall cycles as well as spatial pattern by CMIP6 models compared to CMIP5. Though majority of the models from both CMIPs show late onset and early retreat of the rainy season, CMIP6 GCMs simulate the onset, retreat, and the length of the rainy season closer to the observation. Large‐scale circulation patterns evaluated using spatial correlation and root mean square error (RMSE) show improvements in CMIP6 across all metrics, especially for the moisture flux convergence. Performances for large‐scale circulation are generally reflected in rainfall simulation; however, few models showed that better simulations of rainfall do not exclusively depend on their performance for large‐scale variables. Overall, CMIP6 models are found to be superior to CMIP5 models in simulating rainfall and large‐scale circulation, which is likely attributable to CMIP6 model's higher spatial resolutions, increased number of vertical levels, improved atmospheric and land surface parameterization, etc. Finally, subsets of optimal models from CMIP5 and CMIP6 that proved to be better at representing the summer monsoons in the study area are identified. These models are recommended to develop robust future projections that can be used for climate change impact and adaptation studies.
Revista Recursos Hídricos, 2019
Growing pressure on the available water resources requires a better understanding of the river fl... more Growing pressure on the available water resources requires a better understanding of the river flow systems in the Hari Rod River basin of Afghanistan for its effective allocation considering environmental flow requirement (EFR) by the riverine ecosystem. The present study attempts to quantify EFR for healthy ecosystem in the basin. Indicators of Hydrologic Alteration (IHA) method along with Range of Variability Analysis (RVA) technique were applied to quantify EFR. The obtained results are then compared with other well-known hydrological based approaches (e.g. Tessman or modified Tennant method, Flow Duration Curve (FDC) method and 7Q10 method) and hydraulic based approaches (e.g. Wetted Perimeter method). The results show that hydrological based approaches are appropriate to estimate EFR in the basin. Generally, there is an indirect effect of allocating EFR on other existing demands from different sectors. Keeping this assumption in mind, reservoir simulation technique was applied for the proposed multipurpose reservoir (Salma Dam), which is under construction in the Hari Rod River basin of Afghanistan. By simulating the reservoir operation using HEC-ResSim model, different alternative scenarios were generated to evaluate the possible impacts of allocating EFR on the other demands (e.g. irrigation and hydropower generation). In addition, different mitigation options were suggested to minimize those impacts. For this purpose, a new rule curve for the conservation zone was developed. It helps to minimize water shortages for irrigation activities caused by the additional demand due to EFR allocations. This study finally provides another solution for impact mitigation, by which water shortages can be reduced substantially by improving the existing irrigation efficiency in the basin.
Climate Change and Water Resources, 2014
The data of the World Meteorological Organization show that the significant climate change has al... more The data of the World Meteorological Organization show that the significant climate change has already started. The average annual temperature has increased about 0.6-0.9 °C compared to that of the end of the 19 th to the end of the 20 th centuries. The average temperature of winter and spring has increased at middle altitudes. The global sea-level has risen about 10-25 cm during the last 100 years. The increased average temperature causes changes in hydrological cycles. Lithuanian climate fluctuation also depends on the processes of atmosphere circulation. Lithuanian scientists have seen into these tendencies and have estimated that deep cyclones more often move to Lithuania in winter starting with the 30 th of the last century. Consequently, winters have become warmer, long-lasting frosts have decreased, and the contrast between seasons has almost disappeared. In the last decades of the last century the phenomena of abnormal heats and the amount of precipitation in winter have appeared in Lithuania. Among the evidence for climate change is ice phenology observations of lakes and rivers (observations of annual periodically recurring seasonal ice phenomena, recording of ice freeze-up date and duration). Ice phenology researches seasonal meteorological and hydrological phenomena. Long-term observation data collected by the Nemunas at Smalininkai water measurement station show that in the 20 th century the ice cover formed on an average 13 days later than in the 19 th century and remained unbroken on average 30 days less. Changes in the climate terms (temperature and precipitation) influence directly the conditions of river runoff formation. In the second half of the 20 th century, the tendencies of river runoff variation were observed in many countries of the world. Depending upon the region the river runoff changes differed greatly. Nowadays the contrast between the seasons in the runoff of Lithuanian rivers is disappearing, i.e. spring floods are decreasing and a runoff of winter season is increasing Knowledge of possible changes in water resources in the 21 th century is of great importance to planning the activities of hydropower stations. There is a long tradition of cooperation between Nordic hydrologists in the field of hydrological modelling for the hydropower sector and of studies of global warming impact on water resources. The Nordic Climate and Energy Project addresses the impact of global warming on renewable energy production in the Nordic area including the Baltic countries. The use of renewable energy sources in Lithuania as well as in the EU countries would make it possible to reduce negative effects (for instance, the greenhouse effect) of the climate change. One of the most usable sources of renewable energy is the river hydropower resources which directly depend on the river runoff parameters. Following the global warming, changing river water resources may directly affect the hydropower production under extreme nature conditions. Statistical analysis of the climate and Lithuanian river runoff in the 20 th century and the forecast of the change parameters in the 21 th century indicate that their change tendencies are the same Redistribution of river runoff in different seasons occurs due to the temperature increase and the precipitation amount change. The analysis of temperature, precipitation and river runoff shows that the strongest relation between them is in the winter season. The runoff decrease will have a great impact on Kaunas Hydro Power Plant energy production in our century. The analysis of seasonal runoff distribution indicates that energy amounts remain increased in winter; but they decrease in spring, summer and autumn. Decrease in the average energy production is forecast from 7 to 26 % in 2001-2100 in comparison with the baseline period.
Fluids
In the present study, the streamflow simulation capacities between the Soil and Water Assessment ... more In the present study, the streamflow simulation capacities between the Soil and Water Assessment Tool (SWAT) and the Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS) were compared for the Huai Bang Sai (HBS) watershed in northeastern Thailand. During calibration (2007–2010) and validation (2011–2014), the SWAT model demonstrated a Coefficient of Determination (R2) and a Nash Sutcliffe Efficiency (NSE) of 0.83 and 0.82, and 0.78 and 0.77, respectively. During the same periods, the HEC-HMS model demonstrated values of 0.80 and 0.79, and 0.84 and 0.82. The exceedance probabilities at 10%, 40%, and 90% were 144.5, 14.5, and 0.9 mm in the flow duration curves (FDCs) obtained for observed flow. From the HEC-HMS and SWAT models, these indices yielded 109.0, 15.0, and 0.02 mm, and 123.5, 16.95, and 0.02 mm. These results inferred those high flows were captured well by the SWAT model, while medium flows were captured well by the HEC-HMS model. It is noteworthy that the low...
Hydrogeology Journal
Groundwater exploitation for different sectors in Cambodia is expanding. Groundwater levels have ... more Groundwater exploitation for different sectors in Cambodia is expanding. Groundwater levels have already begun to decline in some parts of the country. Monitoring and assessing groundwater storage (GWS) change, aquifer stress and aquifer resilience will support the proper planning and management of the country's groundwater resources; however, information regarding groundwater in Cambodia is currently scarce. Thus, GWS change in Cambodia over the 15 years from April 2002 to March 2017 was assessed using remote-sensing-based Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) datasets, with a comprehensive validation of the GRACE-derived groundwater storage anomaly (GWSA) with respect to in-situ field-based observations. The current study also investigated the impact of surface water storage (SWS) change in Tonle Sap Lake, SouthEast Asia's largest freshwater lake, on deriving the GWS change in Cambodia. The groundwater aquifer stresses (GAS), and aquifer resilience (AR) were also evaluated. The validation results were promising, with the correlation coefficient between satellite-based estimations and ground-based measurements ranging from 0.82 to 0.88 over four subbasins. The overall decreasing rate of GWS was found to be-0.63 mm/month, with two basins having the highest declining rate of more than 1.4 mm/month. Meanwhile, the aquifer experiencing stress during the dry season had a very low ability to quickly recover from these stresses. These findings emphasise that appropriate management is urgently needed to ensure the sustainability of the groundwater resource system in this country.
Early warning is a key element for disaster risk reduction. However, the advances in generating h... more Early warning is a key element for disaster risk reduction. However, the advances in generating hazard risk information have not yet been incorporated into operational forecast systems and consequently, operational forecasts have not been integrated into decision making processes in order to reduce disaster risks. This article aims to design location-specific user-need based flood forecast products on different time scales for reducing flood risks. Using 1-10 days multiple weather ensemble (EPS) forecasts of the European Center for Medium Range Forecasts (ECMWF), integrating hydrological models, and combining these with GIS and local user needs, the decision support system (DSS) is designed to interpret, translate, and communicate science-based risk information into user-friendly early warning information products to assist emergency managers and decision makers. The DSS interface allows users to interactively specify the objectives and criteria that are relevant to a particular sit...
SSRN Electronic Journal, 2021
Water, 2021
This study aims to project future sea-level rise (SLR) at the Phrachula Chomklao Fort (PCF) tide ... more This study aims to project future sea-level rise (SLR) at the Phrachula Chomklao Fort (PCF) tide gauge station in the Upper Gulf of Thailand (UGoT) using the outputs of 35 climate models under two greenhouse gas concentration scenarios: representative concentration pathway 4.5 (RCP4.5) and RCP8.5. The Linear Scaling method was found to be better than Variance Scaling and Quantile Mapping methods for removing biases in raw Global Circulation Models (GCMs) sea level data. Land subsidence, induced by excessive groundwater abstraction, was found to contribute significantly to SLR during the observed period the PCF gauging station; hence, the effects of land subsidence had to be removed from relative sea level before bias correction. The overall increase in SLR is projected to be 0.94–1.05 mm/year under RCP4.5 and 1.07–1.18 mm/year under RCP8.5 for the twenty-first century in the UGoT. The results suggest that future SLR due to climate change will not be as severe in the study region com...
Water Security in Asia, 2021
Theoretical and Applied Climatology
Theoretical and Applied Climatology
APN Science Bulletin
The objective of the project was to develop a web-based digital tool called the Water Security As... more The objective of the project was to develop a web-based digital tool called the Water Security Assessment Tool (WATSAT) to help city authorities and decision-makers make an objective evaluation of the water security situation in the city. It uses an indicator-based methodology that measures five distinct dimensions (broad elements) of water security: “Water supply and sanitation”, “Water productivity”, “Water-related disasters”, “Water environment”, and “Water governance”, which together culminate into a Water Security Index (WSI). The tool is developed based on the water security assessment framework developed by Babel, Dang, Sharma, and Shinde (2015). WATSAT results in a quantitative assessment of water security in a city, wherein the WSI provides an overall picture of the water security situation in a city, while the evaluation of the various dimensions helps identify areas of concern. WATSAT aids city authorities in having a holistic understanding of water security and interconn...
Water Security in Asia, 2021
The various negative impacts on the environment and society caused by land subsidence have been a... more The various negative impacts on the environment and society caused by land subsidence have been a problem in Bangkok, Thailand, since the 1970s. Intensive groundwater extraction for industrial and domestic purposes since the 1950s, which led to a decline of groundwater levels, has been identified by various studies as the primary cause of the phenomenon of land subsidence. This paper gives an overview of the occurrence of land subsidence in Bangkok. The history, characteristics, identified causes, and measures for mitigation of land subsidence in the area are discussed. Efforts to alleviate the problems and studies that have been conducted to understand the problem are presented and analyzed.
Urban Water Journal, 2020
Accurate model-based forecasts (discharge and water level) are considered significant for efficie... more Accurate model-based forecasts (discharge and water level) are considered significant for efficient planning and management of urban drainage systems. These model-based predictions can be improved by assimilating system measurements in physically based, distributed, 1D hydrodynamic urban drainage models. In the present research, a combined filtering and error forecast method was applied for the data assimilation to update the states of the urban drainage model. The developed data assimilation set-up in combination with the 1D hydrodynamic model was applied at the Damhusåen Catchment, Copenhagen. Discharge assimilation represented significant potential to update model forecast, and maximum volume error was reduced by 22% and 6% at two verification locations. The assimilation of water levels had a minor impact on the update of the system states. The updated forecast skill using error forecast models was enhanced up to 1–2 hours and 6–7 hours lead time at upstream assimilation and down...
Hydrology, 2021
Accurate rainfall estimates are important in many hydrologic activities. Rainfall data are retrie... more Accurate rainfall estimates are important in many hydrologic activities. Rainfall data are retrieved from rain gauges (RGs), satellites, radars, and re-analysis products. The accuracy of gauge-based gridded precipitation products (GbGPPs) relies on the distribution of RGs and the quality of rainfall data records obtained from these. The accuracy of satellite-based precipitation products (SbPPs) depends on many factors, including basin climatology, basin topography, precipitation mechanism, etc. The hydrologic utility of different precipitation products was examined in many developed regions; however, less focused on the developing world. The Huai Bang Sai (HBS) watershed in north-eastern Thailand is a less focused but an important catchment that significantly contributes to the water resources in Thailand. Therefore, this research presents the investigation results of the hydrologic utility of SbPPs and GbGPPs in the HBS watershed. The efficiency of nine SbPPs (including 3B42, 3B42-...
International Journal of Climatology, 2021
In this study, 28 climate models from the fifth phase of the Coupled Model Intercomparison Projec... more In this study, 28 climate models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and 32 models from the sixth phase (CMIP6) have been evaluated for their ability to simulate large‐scale atmospheric circulations (using rainfall, wind fields, geopotential height, temperature, and moisture flux convergence) for the summer monsoon in Southeast Asia. Using a multi‐criteria decision making technique, models have been ranked based on 25 metrics which compare their performances with observation data. Results indicate a better representation of annual rainfall cycles as well as spatial pattern by CMIP6 models compared to CMIP5. Though majority of the models from both CMIPs show late onset and early retreat of the rainy season, CMIP6 GCMs simulate the onset, retreat, and the length of the rainy season closer to the observation. Large‐scale circulation patterns evaluated using spatial correlation and root mean square error (RMSE) show improvements in CMIP6 across all metrics, especially for the moisture flux convergence. Performances for large‐scale circulation are generally reflected in rainfall simulation; however, few models showed that better simulations of rainfall do not exclusively depend on their performance for large‐scale variables. Overall, CMIP6 models are found to be superior to CMIP5 models in simulating rainfall and large‐scale circulation, which is likely attributable to CMIP6 model's higher spatial resolutions, increased number of vertical levels, improved atmospheric and land surface parameterization, etc. Finally, subsets of optimal models from CMIP5 and CMIP6 that proved to be better at representing the summer monsoons in the study area are identified. These models are recommended to develop robust future projections that can be used for climate change impact and adaptation studies.
Revista Recursos Hídricos, 2019
Growing pressure on the available water resources requires a better understanding of the river fl... more Growing pressure on the available water resources requires a better understanding of the river flow systems in the Hari Rod River basin of Afghanistan for its effective allocation considering environmental flow requirement (EFR) by the riverine ecosystem. The present study attempts to quantify EFR for healthy ecosystem in the basin. Indicators of Hydrologic Alteration (IHA) method along with Range of Variability Analysis (RVA) technique were applied to quantify EFR. The obtained results are then compared with other well-known hydrological based approaches (e.g. Tessman or modified Tennant method, Flow Duration Curve (FDC) method and 7Q10 method) and hydraulic based approaches (e.g. Wetted Perimeter method). The results show that hydrological based approaches are appropriate to estimate EFR in the basin. Generally, there is an indirect effect of allocating EFR on other existing demands from different sectors. Keeping this assumption in mind, reservoir simulation technique was applied for the proposed multipurpose reservoir (Salma Dam), which is under construction in the Hari Rod River basin of Afghanistan. By simulating the reservoir operation using HEC-ResSim model, different alternative scenarios were generated to evaluate the possible impacts of allocating EFR on the other demands (e.g. irrigation and hydropower generation). In addition, different mitigation options were suggested to minimize those impacts. For this purpose, a new rule curve for the conservation zone was developed. It helps to minimize water shortages for irrigation activities caused by the additional demand due to EFR allocations. This study finally provides another solution for impact mitigation, by which water shortages can be reduced substantially by improving the existing irrigation efficiency in the basin.
Climate Change and Water Resources, 2014
The data of the World Meteorological Organization show that the significant climate change has al... more The data of the World Meteorological Organization show that the significant climate change has already started. The average annual temperature has increased about 0.6-0.9 °C compared to that of the end of the 19 th to the end of the 20 th centuries. The average temperature of winter and spring has increased at middle altitudes. The global sea-level has risen about 10-25 cm during the last 100 years. The increased average temperature causes changes in hydrological cycles. Lithuanian climate fluctuation also depends on the processes of atmosphere circulation. Lithuanian scientists have seen into these tendencies and have estimated that deep cyclones more often move to Lithuania in winter starting with the 30 th of the last century. Consequently, winters have become warmer, long-lasting frosts have decreased, and the contrast between seasons has almost disappeared. In the last decades of the last century the phenomena of abnormal heats and the amount of precipitation in winter have appeared in Lithuania. Among the evidence for climate change is ice phenology observations of lakes and rivers (observations of annual periodically recurring seasonal ice phenomena, recording of ice freeze-up date and duration). Ice phenology researches seasonal meteorological and hydrological phenomena. Long-term observation data collected by the Nemunas at Smalininkai water measurement station show that in the 20 th century the ice cover formed on an average 13 days later than in the 19 th century and remained unbroken on average 30 days less. Changes in the climate terms (temperature and precipitation) influence directly the conditions of river runoff formation. In the second half of the 20 th century, the tendencies of river runoff variation were observed in many countries of the world. Depending upon the region the river runoff changes differed greatly. Nowadays the contrast between the seasons in the runoff of Lithuanian rivers is disappearing, i.e. spring floods are decreasing and a runoff of winter season is increasing Knowledge of possible changes in water resources in the 21 th century is of great importance to planning the activities of hydropower stations. There is a long tradition of cooperation between Nordic hydrologists in the field of hydrological modelling for the hydropower sector and of studies of global warming impact on water resources. The Nordic Climate and Energy Project addresses the impact of global warming on renewable energy production in the Nordic area including the Baltic countries. The use of renewable energy sources in Lithuania as well as in the EU countries would make it possible to reduce negative effects (for instance, the greenhouse effect) of the climate change. One of the most usable sources of renewable energy is the river hydropower resources which directly depend on the river runoff parameters. Following the global warming, changing river water resources may directly affect the hydropower production under extreme nature conditions. Statistical analysis of the climate and Lithuanian river runoff in the 20 th century and the forecast of the change parameters in the 21 th century indicate that their change tendencies are the same Redistribution of river runoff in different seasons occurs due to the temperature increase and the precipitation amount change. The analysis of temperature, precipitation and river runoff shows that the strongest relation between them is in the winter season. The runoff decrease will have a great impact on Kaunas Hydro Power Plant energy production in our century. The analysis of seasonal runoff distribution indicates that energy amounts remain increased in winter; but they decrease in spring, summer and autumn. Decrease in the average energy production is forecast from 7 to 26 % in 2001-2100 in comparison with the baseline period.
Fluids
In the present study, the streamflow simulation capacities between the Soil and Water Assessment ... more In the present study, the streamflow simulation capacities between the Soil and Water Assessment Tool (SWAT) and the Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS) were compared for the Huai Bang Sai (HBS) watershed in northeastern Thailand. During calibration (2007–2010) and validation (2011–2014), the SWAT model demonstrated a Coefficient of Determination (R2) and a Nash Sutcliffe Efficiency (NSE) of 0.83 and 0.82, and 0.78 and 0.77, respectively. During the same periods, the HEC-HMS model demonstrated values of 0.80 and 0.79, and 0.84 and 0.82. The exceedance probabilities at 10%, 40%, and 90% were 144.5, 14.5, and 0.9 mm in the flow duration curves (FDCs) obtained for observed flow. From the HEC-HMS and SWAT models, these indices yielded 109.0, 15.0, and 0.02 mm, and 123.5, 16.95, and 0.02 mm. These results inferred those high flows were captured well by the SWAT model, while medium flows were captured well by the HEC-HMS model. It is noteworthy that the low...
Hydrogeology Journal
Groundwater exploitation for different sectors in Cambodia is expanding. Groundwater levels have ... more Groundwater exploitation for different sectors in Cambodia is expanding. Groundwater levels have already begun to decline in some parts of the country. Monitoring and assessing groundwater storage (GWS) change, aquifer stress and aquifer resilience will support the proper planning and management of the country's groundwater resources; however, information regarding groundwater in Cambodia is currently scarce. Thus, GWS change in Cambodia over the 15 years from April 2002 to March 2017 was assessed using remote-sensing-based Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) datasets, with a comprehensive validation of the GRACE-derived groundwater storage anomaly (GWSA) with respect to in-situ field-based observations. The current study also investigated the impact of surface water storage (SWS) change in Tonle Sap Lake, SouthEast Asia's largest freshwater lake, on deriving the GWS change in Cambodia. The groundwater aquifer stresses (GAS), and aquifer resilience (AR) were also evaluated. The validation results were promising, with the correlation coefficient between satellite-based estimations and ground-based measurements ranging from 0.82 to 0.88 over four subbasins. The overall decreasing rate of GWS was found to be-0.63 mm/month, with two basins having the highest declining rate of more than 1.4 mm/month. Meanwhile, the aquifer experiencing stress during the dry season had a very low ability to quickly recover from these stresses. These findings emphasise that appropriate management is urgently needed to ensure the sustainability of the groundwater resource system in this country.
Early warning is a key element for disaster risk reduction. However, the advances in generating h... more Early warning is a key element for disaster risk reduction. However, the advances in generating hazard risk information have not yet been incorporated into operational forecast systems and consequently, operational forecasts have not been integrated into decision making processes in order to reduce disaster risks. This article aims to design location-specific user-need based flood forecast products on different time scales for reducing flood risks. Using 1-10 days multiple weather ensemble (EPS) forecasts of the European Center for Medium Range Forecasts (ECMWF), integrating hydrological models, and combining these with GIS and local user needs, the decision support system (DSS) is designed to interpret, translate, and communicate science-based risk information into user-friendly early warning information products to assist emergency managers and decision makers. The DSS interface allows users to interactively specify the objectives and criteria that are relevant to a particular sit...
SSRN Electronic Journal, 2021
Water, 2021
This study aims to project future sea-level rise (SLR) at the Phrachula Chomklao Fort (PCF) tide ... more This study aims to project future sea-level rise (SLR) at the Phrachula Chomklao Fort (PCF) tide gauge station in the Upper Gulf of Thailand (UGoT) using the outputs of 35 climate models under two greenhouse gas concentration scenarios: representative concentration pathway 4.5 (RCP4.5) and RCP8.5. The Linear Scaling method was found to be better than Variance Scaling and Quantile Mapping methods for removing biases in raw Global Circulation Models (GCMs) sea level data. Land subsidence, induced by excessive groundwater abstraction, was found to contribute significantly to SLR during the observed period the PCF gauging station; hence, the effects of land subsidence had to be removed from relative sea level before bias correction. The overall increase in SLR is projected to be 0.94–1.05 mm/year under RCP4.5 and 1.07–1.18 mm/year under RCP8.5 for the twenty-first century in the UGoT. The results suggest that future SLR due to climate change will not be as severe in the study region com...
Water Security in Asia, 2021