Climate change is a consequence of changing in climate on environment over the worldwide. The increase in developmental activities and Greenhouse Gases (GHGS) put a strain on environment, resulting in increased use of fuel resources. The consequence of such an emission to the atmosphere exacerbates climate pattern. There are numerous Climate Change Downscaling studies in coarse resolution, which have largely centred on employing the dynamic approaches, and in most of these investigations, the Regional Climate Model (RCM) has been reported to numerically predict the local climatic variables. The majority of previous investigations have failed to account for the spatial watershed scale, which could generate an average value of downscaled variables over the watershed scale. To address shortcomings of previous investigations, the work undertaken in this project has two main objectives. The study first aims to implement a spatially distributed Statistical Downscaling Model (SDSM) to downscale the predictands, and second to evaluate the impact of climate changes on the future discharge and peak flow. It is conducted based on the IPCC Scenarios A2 (Medium–High Emission scenario) and B2 (Medium–Low Emission scenario). The main objectives of the study are as follows: • To generate fine resolution climate change scenarios using Statistical Downscaling Model in the watershed scale, • To project the variability in temperature, precipitation and evaporation for the three time slices, 2020s (2010 to 2039), 2050s (2040 to 2069) and 2080s (2070 to 2099), based on A2 and B2 scenarios, • To calibrate and validate hydrological model using historical observed flow data to verify the performance of the hydrological model, • To evaluate the impact of climate changes on the future discharge and future peak flow for three timeslices: 2020s (2010 to 2039), 2050s (2040 to 2069) and 2080s (2070 to 2099). Thus, to meet the objectives of the study, projection of the future climate based on climate change scenarios from IPCC is carried out as the most important component in the research. The results of this research are presented as follows: • The study indicates that there will be an increase of mean monthly precipitation but with an intensified decrease in the number of consecutive wet-days and can be concluded as a possibility of more precipitation amount in fewer days. • The watershed is found to experience increased rainfall towards the end of the century. However, the analysis indicates that there will likely be a negative trend of mean precipitation in 2020s and with no difference in 2050s. The precipitation experiences a mean annual decrease by 7.9%, 0.6% in 2020s and 2050s and an increase by 12.4% in 2080s corresponding A2 scenario. • The maximum and minimum temperatures are likely to be increased toward the end of the century by 2.7oC and 0.8oC respectively when compared to the current observed temperature (1975-2001) at the Subang temperature station. • The average annual mean discharge is predicted to be decreasing by 9.4%, 4.9% and an increase of 3.4% for the A2 and a decrease of 17.3%, 13.6% and 5.1% for the B2 scenario, respectively in the 2020s, 2050s and 2080s. • The average annual maximum discharge is projected to decrease by 7.7% in 2020s and an increase by 4.2% and 29% in A2 scenario for 2050s and 2080s, respectively. But there will most likely be a decrease in the maximum discharge for all the future under B2 scenario. It is projected a decrease of 32.3%, 19.5% and 2.3% for 2020s, 2050s and 2080s, respectively. • The projected mean discharge indicates a decline in the months from January to April and also from July to August in all the three future periods for A2 and B2 scenarios. There is an increasing trend in the discharge of September and October in the 2020s according to the A2 and B2 scenarios. • The highest increase in precipitation frequency occurs in 2080s under A2 scenario in which the increase in the magnitude of 100 Return Year is found to be 88% greater than the one of the maximum observed. • The highest increase in flood frequency at Sulaiman streamflow station occurs in 2080s under A2 scenario. The increase in the magnitude of 100 Return Year is found to be 26.5% greater than the one of the maximum observed.

Dust from mining activities is produced from several unit operations and is often a serious problem to the industry, due to the influence it can have on human health and the safety record and productivity of a mine. So far, legislative parties and the industry have approached dust as an issue that needs to be controlled, only when a mining operation or process generates undesirable particulates. Nevertheless, new legislation and standards, such as the EU IPPC directive (Integrated Pollution Prevention and Control) and air quality strategies aim to drive mining companies to incorporate dust assessment planning that will be implemented through the whole life cycle of the mine. Mitigation and monitoring practices as well as health surveillance programs will need to be clearly defined. This project’s purpose is to understand how mining processes and in particular how the mechanisms inherent within common unit operations (i.e transfer processes using haulage roads or conveyor belts, the tipping, loading and stockpiling process, the screening process etc) result in the generation of dust. If the operation of unit operations could by optimized to produce less dust, then a “fit-for-purpose” strategy for dust minimisation could be developed to follow exploitation, processing and production demand. The literature on dust from mining operations identified that generation of fines/dust occurs due to the presence of the mechanisms of abrasion and impact. Based on this logic, an experimental methodology was developed, which aimed to assess how dust was generated for each different mechanism and for a variety of ores of different mineralogy. Five different ores were tested, a limestone, talc, an iron ore, a lamproite and a copper ore and the same experimental methodology was followed for each. Experimentation using the HSE-WSL tumbling mill test determined that under the effect of abrasion, ores yielded higher dustiness values during longer tumbling times, whilst parameters such as the sample mass and the particle size distribution of the feed sample could also influence the dust generation patterns. The findings of the computational modelling (discreet element modelling) and experimentation (high speed video recording) suggested that control and optimisation of operational parameters (e.g mill velocity, or tumbling time) within processes that involve abrasion, such as the use of conveyor belts, mills, and screens could minimise the potential of dust generation by this mechanism. The use of a novel impact test determined a positive relationship between the energy input and the particle size distributions of the broken particles, as well as the accumulation of fine particulates in the range of dust (<75μm). Also an increase in the bulk volume of ores resulted in larger quantities of fine particulates. These observations suggest that it is possible to reduce dust in processes that involve drop from heights and impaction (i.e transfer points in conveyor belts, tipping, loading) by adjusting the energy input and the bulk volume of ore at impact to as low a level possible. Particle size analysis of the produced dust fractions were found to be material dependent and varied considerably for the different ores. Almost all materials produced significant amounts of ultra fine particles below 10μm and 2.5μm, both under impact and abrasion, which reveals the potential adverse impacts to the environment and human health. Quantitative mineralogical analysis using the mineral liberation analyser determined that the dust fraction presents a different composition to that of the ore. Comparison of the results collected for the five different ores using the HSE-WSL mill and the impact test identified that certain materials yielded high dust levels under abrasion and low under impact. Therefore it would be expected that dust control approaches for such materials would differ according to the mechanisms of the involved process and the mineralogy of the sample. According to the findings of this study a reduction in dust produced from mining unit operations could be possible by optimising the involved processes either by altering their operating parameters (drop height during tipping, velocity of conveyor belt) or by optimising the design of processes so as to reduce abrasion or impact. New legislation such as the EU IPPC directive has already started considering such an approach as important, and newly developed Best Available Techniques documents refer to this as the primary step companies should follow to minimise dust. Additional advantages of this approach are that it can reduce cost for dust control by making use of less conventional mitigation practices, and in the long term it could also minimise the utilization of energy and water going to suppression, extraction and dust collection systems. In certain cases the proposed route could also optimise the production chain, especially where the generation of fines is undesirable (e.g iron ore processing or aggregates production).

Results are presented from sets of field and laboratory experiments conducted to measure and quantify the Hydraulic Residence Time Distribution in treatment ponds containing vegetation. The field measurements were taken in the Lyby field pond (Sweden) with complementary experiments on a distorted, laboratory scale model pond designed and built in the University of Warwick’s engineering laboratory. Rhodamine WT Dye tracer experiments were used in both the Lyby field pond and the distorted physical scale model to investigate vegetation and discharge affects on HRTD characteristics and the technique of PIV (Particle Image Velocimetry) was used in the distorted physical scale model to investigate how surface flow profiles were affected by different vegetation and discharge configurations. The results show that the distorted physical scale pond did not reflect the HRTD characteristics of the field site, with the actual residence time, (tm), for the distorted physical scale pond ranging from 85 % to 125% of its nominal residence time. For the distorted scale model, pond vegetation and discharge did not affect the relative HRTD centroid, em, or the actual residence time, tm. This finding is attributed to the unique pond geography and associated aspect ratios However, flow rates did have a significant effect on the HRTD e0 (time of first dye arrival at the outlet) and ep (time of peak dye concentration). Changes in vegetation were found to have little effect on e0 and ep. For the laboratory pond, vegetation had a significant control on the surface flow field whereas, flow rates did not – the latter suggests that surface flow fields are not representative of the internal flow field in different layers of the pond. The experiments demonstrate that the specific shape of the distorted physical scale pond in this study enables optimal actual resident times to be achieved over a wide range of vegetation and flow rate configurations. If full scale field ponds based upon this design give the same stable centroid results, then this would be a substantial breakthrough in pond design, which would aid the design and management of pond treatment and allow more robust optimisation of treatment efficiency.

The performance and sustainability of ground source heat systems is dependent on the thermal behaviour of neighbouring ground. This thesis describes a comprehensive experimental and numerical investigation into the ground behaviour in response to horizontal ground source heat systems. Experimental investigations comprised of a field-scale monitoring scheme, designed and implemented in a horizontal ground source heat system providing space heating to a domestic property located in Mid-Wales, UK. A high resolution ground temperature data-set has been compiled over a 13 month period via 112 thermistors buried in the ground. Further data-sets representing the climatic variables and heat pump behaviour were also compiled over the same period, facilitating a thorough investigation of the ground behaviour in response to heat extraction at the site. Soil properties were also measured at the site as part of a larger site investigation undertaken. The numerical model applied is a coupled thermal-hydraulic (TH) model previously developed at the Geoenvironmental Research Centre (GRC). The GRC’s current model was extended to include developed boundary conditions for the TH simulation of horizontal ground source heat systems, describing the soil’s interaction with the ground-loop and atmosphere. Developments were subject to rigorous validation including comparisons with ground-data collected at the experimental site. The validated model was applied to investigate the long-term ground behaviour at the monitoring site and the effects of different surface materials on the ground behaviour including the recharge process. Finally, the model was applied to investigate the validity of an existing design code for ground source heat system design. The resolution and duration of the collated data-set facilitated extensive analysis, including a thorough investigation of the ground thermal distributions resulting from heat extraction and recharge. Findings indicated unsymmetrical distributions, highlighting potential avenues for system optimisation. Further to this it can be said that the data-set, in its own right, is a significant contribution to the scientific community and is able to provide a means of validation for future models. Results from the numerical investigation indicated that the ground thermal behaviour exhibits an annual cyclic pattern after approximately 3 years. From a holistic perspective, the results demonstrate that horizontal ground source heat systems can provide a sustainable means of providing space heating. Further long-term studies investigating the effects of surface materials show that more thermal energy can be sustainably extracted from systems with urban surface types (i.e. asphalt and brick). Investigations into an existing design code revealed that a ground-loop designed to meet the loads of the monitoring site resulted in unsustainable heat extraction, in doing so demonstrating the simplification of ground-loop burial depth within the current design process. Knowledge regarding the ground response to horizontal ground source heat systems has been furthered through the collection and analysis of field-scale data within this study. Further to this, the boundary developments and validation undertaken have allowed for a more thorough investigation of the long-term ground behaviour than previous studies.

Several methods of river water quality assessment techniques have been introduced. Among the most commonly used are the water quality index system and classification scheme. These two systems are designed to simplify the huge amount of water quality data down to its simplest form, while retaining the essential meaning of the information. They offer the means for measuring the effectiveness of pollution abatement strategies by comparing the status of water quality both temporally and spatially. In this way, it is useful for management purposes, especially in determining priorities for resource allocation and planning of new development areas. The water quality index system and the classification schemes currently available, however have some limitations in their structural design. They often exhibit inherent loss of information, are complex and may involve subjective judgement in their interpretation. However, because of the critical issues on water pollution and the scarcity of water resources, these systems are being applied despite of these limitations. The current situation is that, different countries are applying different models of water quality assessment system. Based on the limitations of the existing assessment systems, it is appropriate to explore other approaches that can be more flexible, robust to noisy data, and adaptable to new form of environmental data, in order to provide direct and prompt results for classifying of river water quality. One avenue for research is that based on Artificial Neural Network (ANN). Artificial Neural Network comprises of several techniques. One of this technique that is widely being used is the Back-Error Propagation (BEP). BEP of ANN was used in this research in conjunction with the Interim National Water Quality Standard (INWQS) data for Malaysia. The findings of the study shows that the classification results based on the evaluation of the water quality variables were good when compared with the results obtained from other water quality classification models, which include: the Department of Environment Water Quality Index (DOE-WQI), the Harkins'-WQI, Mahalanobis Distance Classifier, Maximum Likelihood Distance Classifier and the Decision Tree Classifier. The accuracy for BEP of ANN was found to be 86.9% and correlated well with all of these five models. The highest correlation was, with the Mahalanobis Distance Classifier and the DOE-WQI. The analysis on sensitivity shows that the BEP of ANN was sensitive to Dissolved Oxygen, a condition similar to the DOE-WQI model. Comparisons were made with two types of BEP of ANN architecture, a simple network with less number of hidden nodes and a relatively complex network with more hidden nodes. It can be concluded from the analysis that a small and simple network performed well with large samples and with test data that are widely distributed than the complex network with more hidden nodes. Using the same model, different approaches were used in evaluating the classification of water quality were applied, such as the used of the land use variables and hydrological features (LUVHF) to replace the water quality data. Using these variables, the performance of the BEP of ANN in classification of water quality was low (24% and 31%). However, its performance can be improved, if more samples with wider range of LUVHF were used. Throughout this study, the BEP of ANN model has shown some remarkable achievements. In view of these, several knowledge contributions have been made. The first contribution is the flexibility of the system approach and operationally simple to perform. Secondly, it provides a practical approach in classification of river water quality, such that through a single network computation of a sample, the results are presented promptly as the probability value and the class grade value. The third contribution is that the water quality can also be classified based on the land use variables and hydrological features, without dependence on water quality data. This approach is suitable for remote areas, where accessibility is relatively difficult.

The feasibility of using CFD to model the dispersion of pollutant in the near wake of a model vehicle was investigated through a series of experimental and computational studies. The near wake structure of the MIRA 33% scale reference vehicle (fastback) was measured using Particle Image Velocimetry (PIV), and hotwire anemometry and the dispersion of a tracer measured using Flame Ionisation Detectors (FIDs). The experimental data not only provided insight into the dispersion character of the model vehicles's near wake but more importantly produced data for the validation of the numerical simulations of the measured near wake and dispersion fields. The numerical simulations of the near wake flow field were conducted using the CFD code STAR-CD with the standard, RNG, Chen and nonlinear (quadratic) k- e models in combination with Upwind (UD), Linear Upwind (LUD) and the Monotone Advection and Reconstruction (MARS) differencing schemes. Validation showed the predicted flow field to be in good agreement with the measured flow field. Using the numerical flow field predictions as a foundation the dispersion of a passive gaseous pollutant was simulated by modelling the dispersion of scalar quantity released into the computational domain using a fluid injection technique. The numerical predictions of both mean velocity and concentration fields were validated against the experimental data using various statistical validation techniques. Several short investigations into the influence of vehicle speed and exhaust mass flow rate were also conducted to further assess the applicability and use of the technique in investigating dispersion in the near wake of a vehicle. Relative successes in both the velocity field and dispersion simulations were demonstrated in making predictions of the mean velocity and concentration fields. However there is clearly the need for more development and in particular the application of time-dependent techniques for the underlying velocity solutions in order that peaks in mean concentration resulting from build-up due to unsteadiness in the flow field are fully captured. Nevertheless the study demonstrated the potential for the use of STAR-CD to investigate and understand in more detail the dispersion of pollution close behind a road vehicle and possibly assess the concentration levels, at the road side of different pollutants released.

Traffic-related air pollution is now a major concern. The Rio Earth Summit and the Government's commitment to Agenda 21 has led to Local Authorities taking responsibility to manage the growing number of vehicles and to reduce the impact of traffic on the environment. There is an urgent need to effectively monitor urban air quality at reasonable cost and to develop long and short term air pollution prediction models. The aim of the research described was to investigate relationships between traffic characteristics and kerbside air pollution concentrations. Initially, the only pollution monitoring equipment available was basic and required constant supervision. The traffic data was made available from the demand-responsive traffic signal control systems in Leicestershire and Nottinghamshire. However, it was found that the surveys were too short to produce statistically significant results, and no useful conclusions could be drawn. Subsequently, an automatic, remote kerbside monitoring system was developed specifically for this research. The data collected was analysed using multiple regression techniques in an attempt to obtain an empirical relationship which could be used to predict roadside pollution concentrations from traffic and meteorological data. However, the residual series were found to be autocorrelated, which meant that the statistical tests were invalid. It was then found to be possible to fit an accurate model to the data using time series analysis, but that it could not predict levels even in the short-term. Finally, a semi-empirical model was developed by estimating the proportion of vehicles passing a point in each operating mode (cruising, accelerating, decelerating and idling) and using real data to derive the coefficients. Unfortunately, it was again not possible to define a reliable predictive relationship. However, suggestions have been made about how this research could be progressed to achieve its aim.

Solar thermal is one of the most cost-effective renewable energy technologies, and solar water heating is one of the most popular solar thermal systems. Based on the considerations on the existing barriers of the solar water heating, this research will propose a novel façade-based solar water heating system employing a unique loop heat pipe (LHP) structure with top-level liquid feeder, which will lead to a façade-integrated, low cost, aesthetically appealing and highly efficient solar system and has considerable potential to provide energy savings and reduce carbon emissions to the environment. The research initially involved the conceptual design of the proposed system. The prefabricated external module could convert the solar energy to heat in the form of low-temperature vapour. The vapour will be transported to indoors through the transport line and condensed within the heat exchanger by releasing the heat to the service water. The heated water will then be stored in the tank for use. An analytical model was developed to investigate six limits to the loop heat pipe’s operation, i.e., capillary, entrainment, viscous, boiling, sonic and filled liquid mass. It was found that mesh-screen wick was able to obtain a higher capillary (governing) limit than sintered-powder. Higher fluid temperature, larger pipe diameter and larger exchanger-to-pipes height difference would lead to a higher capillary limit. Adequate system configuration and operating conditions were suggested as: pipe inner diameter of 16 mm, mesh-screen wick, heat transfer fluid temperature of 60oC and height difference of 1.5 m. This research further developed a computer model to investigate the dynamic performance of the system, taking into account heat balances occurring in different parts of the system, e.g., solar absorber, heat pipes loop, heat exchanger, and tank. Data extracted from two previously published papers were used to compare with the established model of the same setups, and an agreement could be achieved under a reasonable error limit. This research further constructed a prototype system and its associated testing rig at the SRB (Sustainable Research Building) Laboratory, University of Nottingham and conducted testing through measurement of various operational parameters, i.e., heat transfer fluid temperature, tank water temperature, solar efficiency and system COP (Coefficient of Performance). Two types of glass covers, i.e., evacuated tubes and single glazing, were applied to the prototype, and each type was tested on two different days of 8 hours from 09:00:00 to 17:00:00. By comparison of the measurement data with the modelling results, reasonable model accuracy could be achieved in predicting the LHP system performance. The water temperature remained a steady growth trend throughout the day with an increase of 13.5oC for the evacuated tube system and 10.0oC for the single glazing system. The average testing efficiencies of the evacuated tube system were 48.8% and 46.7% for the two cases with the testing COPs of 14.0 and 13.4, respectively. For the single glazing system, the average testing efficiencies were 36.0% and 30.9% for the two cases with the COPs of 10.5 and 8.9, respectively. Experimental results also indicated that the evacuated tube based system was the preferred system compared to the single glazing system. This research finally analysed the annual operational performance, economic and environmental impacts of the optimised evacuated tube system under real weather conditions in Beijing, China by running an approved computer model. It was concluded that the novel system had the potential to be highly-efficient, cost-effective and environmentally-friendly through comparison with a conventional flat-plate solar water heating system.

Despite water being apparently abundant, up to half of the world’s population is faced with water crises which is growing at an alarming rate most especially in developing countries such as African countries where both physical and economic water scarcities prevail. Thus with the abundant salty water and solar intensity in the regions or seasons when water is mostly scarce, solar powered desalination presents an attractive and promising solution towards availability of clean water. A unique and simple solar desalination system has been developed. The system which based on humidification/dehumidification process is a low cost solution and very competitive with conventional desalination systems. It can be used to provide clean water to the over one billion population who have no access or have water shortages which threaten their health and economies. The developed solar desalination system consists of a purposely designed concentrating solar collector and the desalination core which consist of the humidification and dehumidification chambers. The novel concentrating v-trough solar collector which has its focal point at the bottom of the concentrator provides enough thermal energy required to heat up seawater which is then pumped and sprayed to humidify the incoming air in the humidification chamber. The humidified air enters the dehumidification chamber and is cooled by the incoming cold seawater. The moisture is condensed out and the pure water is accumulated at the base of the chamber, and the dehumidified air is discharged to the outside. The key point is the psychrometric energy re-use, most of the energy is from the condensing of the moisture in the carrier gas. Both theoretical analysis and experimental tests were carried out and good water output up to 20kg/h and COP around 3 was obtained. This would require 8m2 of the newly designed v-trough collector operating at 100°C at 1000W/m2 solar intensity. And economic and environmental analysis showed that the solar powered desalination system can achieve a 6 year payback period when compared with when driven by electricity and also a saving of up to 4730 kgCO2 per year. The system can be manufactured from inexpensive plastics rather than exotic and expensive metals. It can easily be sized and scaled to location’s needs, can be operated in diverse geographies unattended on a continuous basis and require minimal maintenance.

This work examined the impact of soil organic matter (SOM) on the sorption, phase distribution and transport of ethanol and butanol blended gasoline vapours after release. Microcosm and mini-lysimeter experiments were conducted using sand with varying SOM and moisture contents. Synthetic gasoline alone and blended with 10 - 20% ethanol and 10 - 20% butanol by volume, referred to as UG, E10 - E20 and B10 - B20, respectively, were used. Results from the UG were used as the benchmark to assess the impact of ethanol and butanol on gasoline compounds. The findings of this work illustrate the likely behaviour of gasoline compounds at the beginning times of a gasoline spill or leak. The addition of alcohol to gasoline altered the behaviour of the gasoline compounds in the vadose zone in several ways. Firstly, it reduced the sorption of the gasoline compounds by soils. This effect was greatest on the first day of a spill and affected the gasoline compounds in decreasing order of hydrophobicity. Secondly, it altered the mass distribution of the gasoline compounds between the vadose zone phases to higher mass compounds in the mobile phases (soil air and soil water) and lower mass compounds in the immobile soil solid phase, suggesting higher risk of groundwater contamination with an increasing content of alcohol in the gasoline. Thirdly, it increased the vapour phase transport of the gasoline compounds from the source zone to the groundwater zone. These three impacts were generally greater for ethanol than butanol. The sorption coefficients (Kd) of E20 gasoline compounds were reduced by 54% for alkanes, 54% for cycloalkanes and 63% for the aromatics, while the Kd of B20 gasoline compounds decreased by 39% for alkanes, 38% for cycloalkanes and 49% for aromatics. This implies that the use of ethanol as gasoline oxygenate could result in greater risk of groundwater contamination with gasoline compounds than the use of butanol after spills. The SOM enhanced the sorption of alcohol-blended gasoline compounds in soils. This impact was similar for ethanol and butanol blended gasoline as the Kd of B20 and E20 were equally increased by 7 times for aromatics, 4 times for cycloalkanes and 2 times for alkanes, for 0 to 5% increase in the SOM fraction of sand. Although SOM enhanced the sorption of alcohol-blended gasoline, its sorptive capability was not fully realised compared with the sorption of the UG compounds. Also, it did not alter the order of groundwater contamination risk for the ethanol and butanol blended gasoline. Thus, the Kd values for all gasoline compounds for all the SOM fractions tested, including 0%fom, 1%fom, 3%fom and 5%fom, were in the order of UG>B20>E20, indicating greater risk of groundwater contamination for the ethanol-blended gasoline after a spill or leak regardless of the SOM content of the soil. The increase in the water content of soil reduced the sorptive capability of SOM and affected the overall mass distribution of gasoline compounds between the soil solid, soil air and soil water phases estimated with values of Henry’s law constant from the literature. This indicates that the degree of gasoline retention in the vadose zone by SOM could differ during the dry summer and wet winter seasons. This effect was greater for ethanol than butanol. Thus, in all seasons, the amount of gasoline compounds retained by SOM in the vadose zone is likely to be higher for butanol-blended gasoline than ethanol-blended gasoline. Overall, this study indicates that the use of high ethanol volume in gasoline to combat climate change may put the groundwater at greater risk of contamination after spills or leakages from storage. Therefore, to successfully reduce greenhouse gases emissions via high alcohol volume in gasoline and still protect the world’s groundwater resource, this study suggests the use of butanol is more benign than ethanol.