The use of the evapotranspiration cover for landfill is increasing because of its long-term enhan... more The use of the evapotranspiration cover for landfill is increasing because of its long-term enhanced performance. However, the performance of evapotranspiration cover primarily depends on the onsite geo-climatic conditions. Therefore, field verification of cover performance through constructed test plots is required before actual implementation. Additionally, numerical modeling and comparison with field results are necessary for future performance prediction. The objective of this study was to simulate the water balance hydrology of evapotranspiration cover using the code SEEP/W. Drainage lysimeter was constructed with fine-grained soil and native vegetation. Field water balance data from the lysimeter were obtained through instrumentation. Onsite climatological data, laboratory and field investigated soil parameters and actual field studied plant parameters were used as model input. Based on one year’s simulation, it was observed that the code nearly captured the seasonal variation...
Water balance covers for landfill closure are used as a barrier which act with the natural proces... more Water balance covers for landfill closure are used as a barrier which act with the natural processes to reduce percolation. The ideal performance of water balance cover is characterized by the minimal quantity of percolation. The rate of percolation of water balance cover largely depends on unsaturated soil behavior. In this study, percolation was evaluated through unsaturated soil parameters of six instrumented lysimeters. The field instrumentation included moisture sensors, tensiometers, rain gauge, dosing siphon, and pressure transducer. Soil water storage (SWS) capacity (SA) was quantified from the soil water characteristic curves (SWCC) which were developed based on laboratory experiments and field instrumentation data. Required SWS (SR) was also measured from the field monitoring results. Based on analysis, the relative storage ratio (SR/SA) was observed to be greater than unity (1) in most of the cases, indicating potential percolation. The SR/SA was also found competent to i...
As Dhaka city is at risk of earthquake and fire hazard, ward 29, an old part of Dhaka city has be... more As Dhaka city is at risk of earthquake and fire hazard, ward 29, an old part of Dhaka city has been selected for vulnerability assessment of both hazards in this study and social vulnerability has been included in the assessment as it has become an important issue in the recent years. The methodology of three different vulnerability assessments and the way of combining the results of the assessments to develop composite vulnerability score of the study area has been described. A sample of 350 buildings has been analyzed by a visual screening method FEMA-RVS for earthquake, a methodology developed by ADPC [1] for fire hazard and a methodology developed by World Bank [24] for social vulnerability. The composite vulnerability score has been developed by incorporating earthquake and fire hazard as well as social vulnerability condition of the study area and represented in form of map produced using ArcGIS 10 showing buildings of different vulnerable categories. The study area is relatively more vulnerable to fire hazard than earthquake. As it is one of the most densely populated wards in Dhaka city, social factors have compounded the overall vulnerability to higher scale. Most of the buildings are vulnerable to both earthquake and fire hazard considering social impacts. Thus ideal mitigation planning to reduce risk is almost impossible here without involvement of community people. By warning them of their own risk and making them resilient through awareness programs and training, disaster risk in the study area can be reduced effectively.
The use of the evapotranspiration cover for landfill is increasing because of its long-term enhan... more The use of the evapotranspiration cover for landfill is increasing because of its long-term enhanced performance. However, the performance of evapotranspiration cover primarily depends on the onsite geo-climatic conditions. Therefore, field verification of cover performance through constructed test plots is required before actual implementation. Additionally, numerical modeling and comparison with field results are necessary for future performance prediction. The objective of this study was to simulate the water balance hydrology of evapotranspiration cover using the code SEEP/W. Drainage lysimeter was constructed with fine-grained soil and native vegetation. Field water balance data from the lysimeter were obtained through instrumentation. Onsite climatological data, laboratory and field investigated soil parameters and actual field studied plant parameters were used as model input. Based on one year’s simulation, it was observed that the code nearly captured the seasonal variation...
Water balance covers for landfill closure are used as a barrier which act with the natural proces... more Water balance covers for landfill closure are used as a barrier which act with the natural processes to reduce percolation. The ideal performance of water balance cover is characterized by the minimal quantity of percolation. The rate of percolation of water balance cover largely depends on unsaturated soil behavior. In this study, percolation was evaluated through unsaturated soil parameters of six instrumented lysimeters. The field instrumentation included moisture sensors, tensiometers, rain gauge, dosing siphon, and pressure transducer. Soil water storage (SWS) capacity (SA) was quantified from the soil water characteristic curves (SWCC) which were developed based on laboratory experiments and field instrumentation data. Required SWS (SR) was also measured from the field monitoring results. Based on analysis, the relative storage ratio (SR/SA) was observed to be greater than unity (1) in most of the cases, indicating potential percolation. The SR/SA was also found competent to i...
As Dhaka city is at risk of earthquake and fire hazard, ward 29, an old part of Dhaka city has be... more As Dhaka city is at risk of earthquake and fire hazard, ward 29, an old part of Dhaka city has been selected for vulnerability assessment of both hazards in this study and social vulnerability has been included in the assessment as it has become an important issue in the recent years. The methodology of three different vulnerability assessments and the way of combining the results of the assessments to develop composite vulnerability score of the study area has been described. A sample of 350 buildings has been analyzed by a visual screening method FEMA-RVS for earthquake, a methodology developed by ADPC [1] for fire hazard and a methodology developed by World Bank [24] for social vulnerability. The composite vulnerability score has been developed by incorporating earthquake and fire hazard as well as social vulnerability condition of the study area and represented in form of map produced using ArcGIS 10 showing buildings of different vulnerable categories. The study area is relatively more vulnerable to fire hazard than earthquake. As it is one of the most densely populated wards in Dhaka city, social factors have compounded the overall vulnerability to higher scale. Most of the buildings are vulnerable to both earthquake and fire hazard considering social impacts. Thus ideal mitigation planning to reduce risk is almost impossible here without involvement of community people. By warning them of their own risk and making them resilient through awareness programs and training, disaster risk in the study area can be reduced effectively.
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