Groundwater contributes a significant proportion of stream flow, and its contribution varies temporally throughout the year. The objective of this study was to investigate the temporal dynamics of groundwater contribution to stream flow under the effects of climate and land use changes. A study area of the Mainstem sub-watershed of the Kiskatinaw River watershed, British Columbia, Canada was used as a case study. A physically conceptual model, Gridded Surface Subsurface Hydrologic Analysis (GSSHA), was developed for the study area. One greenhouse gas (GHG) emission scenario (i.e., B1: more integrated and environmental friendly world) was used for climate change study for 2012-2016, and land use changes scenarios were generated for short-term period (2012-2016) due to limited future projected land use data. The simulation results revealed that climate change affects significantly the temporal patterns of mean groundwater contribution to stream flow. Due to precipitation variability, these contributions varied monthly, seasonally, and annually. When land use changes (i.e., increasing forest clear cut area, and decreasing forest and agricultural areas) were combined with climate change scenarios, these contributions were decreased due to changes in the flow patterns to the regime with more surface runoff and stream flow but less groundwater discharge. Compared to the reference period (2007-2011), the mean annual groundwater contribution to stream flow from 2012 to 2016 under the B1 climate change scenario and the combined effects of B1 scenario and land use changes is expected to decrease by 1.8% and 4.3%, respectively, due to increased precipitation (on average 3.6% under the B1 scenario) and temperature (on average 0.36°C under the B1 scenario), and land use changes. The results obtained from this study will provide useful information for seasonal and annual water extractions from the river and allocation to the stakeholders for future water supply, as well as ecological conditions of the stream, which will be beneficial to aquatic ecosystems. They will also provide how land use changes can impact the groundwater contribution to stream flow, which will be useful for planning of water resources management considering future climate and land use changes.
Groundwater is still an important water source for many parts of the world, especially in countries such as Sri Lanka, because, despite a huge government investment to divert some of the rivers to dry areas, there are many areas which this river water cannot reach, and hence a large number of people depend on groundwater for their basic water requirements. The effects of climate change are evident in all parts of the world which include significant weather pattern changes, effect on fauna and flora, see level changes etc. Groundwater recharge, which results mostly from rainfall in many areas of the dry zone, will therefore be different from what they are now. This study looks at the possible effects of climate change on the estimates of potential groundwater recharge in the dry zone of Sri Lanka. The study locations chosen were Angunakolapellessa, MahaIllupallama and Kalpitiya, where estimates of recharge were obtained with a soil water balance model, programmed on a spreadsheet. The model was validated with estimates of recharge obtained by different workers at different locations including Sri Lanka. Parameters of (rainfall and evapotranspiration) generated from a Regional Climate Model (PRECIS)were inputted to the model both for the 1961-89 (baseline) as well as for the 2071-99 (generated) periods, giving estimates of recharge for the periods 1961-89 and 2071-99. The results show that the current estimates of recharge are likely to be reduced by 20 – 40% in the three study locations. The possible effects of such changes in recharge estimates and possible action to mitigate these possible effects of high/low estimates of recharge are also discussed.
In this study future flooding frequencies have been estimated for the Grand River catchment located in south-western Ontario, Canada. Historical and future climatic projections made by fifteen Coupled Model Inter-comparison Project-3 climate models are bias-corrected and downscaled before they are used to obtain mid- and end of 21st century streamflow projections. By comparing the future projected and historically observed precipitation and temperature records it is found that the mean and extreme temperature events will intensify in future across the catchment. The increase is more drastic in the case of extreme events than the mean events. The sign of change in future precipitation is uncertain. Further flow extremes are expected to increase in magnitude and frequency in future across the catchment. The confidence in the projection is more for low return period (<10 years) extreme events than higher return period (10-100 years) events. It can be expected that increases in temperature will play a dominant role in increasing the magnitude of low return period flooding events while precipitation seems to play an important role in shaping the high return period events.
Cement industry accounts for the second largest emitter of anthropogenic greenhouse gas in the globe with 900 kg CO2 emitted into the atmosphere from producing one tonne of cement. Hence, the effort made to mitigate this issue seems not productive , which gives rise to the design of the carbon capture and sequestration [CCS] process which is one of the few ways obtained to greatly reduce CO2 production from the cement plant. The research work assessed the technology used for the cement plant by employing an old cement plant with post-combustion CO2 capture using physical solvent (Selexol). The Aspen Hysys simulation results show that the process can capture 97% of the CO2 and lean loading of 0.37. The Ashaka Cement Plant operates at maximum capacity of approx. 1 million tonnes cement /year with CO2 released at about 500,000 tonnes per year. The capture unit was able to reduce the CO2 released into the atmosphere from 4.86% to 0.13%. The overall result of the analysis shows that selexol has proven to be thermally and chemically stable under the operating conditions used. It is recommended that, the simulation results should be retrofitted into the Ashaka cement plant, in order to determine the best CO2 capture efficiency, performance which results to the choice of this capture technology.
In order to study the influence of the hydrothermal treatment technology (HTT) on macro/micro nutrients extraction from two types of chicken manure (broiler chicken manure (BCM) and laying hen chicken manure (LCM)), hydrothermal treatment followed by the solid/liquid separation of the HTT product was performed with a fixed feedstock to water mass ratio (1:3), 30 min reaction time and three different reaction temperatures (160ºC, 180ºC, 200ºC). More than 50% of N can be extracted from solid to liquid after HTT for both BCM and LCM. Moreover, the organic N content was more than 80% in all liquid samples and it was increasing with the increase of HTT temperature. According to all the results, 180ºC is the optimum temperature for both types of chicken manure and the pH value of the liquid extracted at the optimum temperature was close to 7 for both types of chicken manure. The heavy metal contents in the liquid obtained from BCM and LCM were not detected. It was observed that macro nutrients and micro-nutrients were dissolved in the liquid after HTT.