There is growing recognition of the importance of preserving Canada’s forests. Canada’s 348 million hectares of forest land cover 35% of its land area, representing 9% of the world’s forests and 24% of the world’s boreal forests. As a renewable resource, forests offer significant environmental, economic and recreational benefits and innumerable services contributing to the quality of life. Canada has recently entered an era of increased frequency and severity of natural disasters. Ecosystems and communities especially in western Canada have recently undergone a trend of increasing pressures from natural disturbances. These disturbances include wildfires associated with increased fuel load levels from past fire suppression regimes and a widely spread infestation of the mountain pine beetle in addition to changes in weather patterns. Wildfire activity has reached extreme levels in many of the recent years. This thesis profiles an area of western Canada within the Montane Cordillera covering the Nechako Lakes Electoral District in central British Columbia and assesses its vulnerability to the specific hazard of wildfires caused by natural and man-made sources. The objectives of this research are to review, simulate and assess the impact of various fuel management strategies in a sub-section of the Nechako Lakes Electoral District called the Southside. Values at risk include private property and old growth forest in respectively timber supply areas, provincial parks, woodlots and community forests. Simulation results show that firebreaks are effective in significantly reducing the area burned in different parts of the landscape. The performance of different strategies shows large variation. Although this has not been investigated further, such variation has likely been caused by topographic aspects and the positioning of firebreaks in the landscape in relation to climatic parameters. These results can therefore not be extrapolated beyond the simulated area, but do give an indication of the performance variation that may be expected when similar firebreaks are applied elsewhere. The results also show that model performance of all firebreak strategies is heavily and fairly consistently influenced by weather stream parameters. Sensitivity analyses of weather stream parameters show that although the reduction in total area burned varies, the ranking between strategies in their overall performance is consistent regardless of the weather pattern. Combined dry, warm and windy weather conditions lead to a 3.44-fold increase in total area burned as compared to the scenario with average weather conditions. In favourable weather conditions represented by wet, cold and nearly windless conditions, the model shows an 85% reduction in total burned area as compared to the average scenario. These results illustrate the significant impact of uncontrollable variables on the overall result.

The focus of this study is on potential damages to buildings resulting from expansive soils in Tanzania, particularly clay soils in Kibaha. For the fact that most of the affected structures are founded on expansive soils, a clear understanding of the behaviour of soils and their interaction with structures has been of interest to the study in order to evaluate properly the source of the problem.The geotechnical behaviour of expansive clay soils is investigated by looking into the geomorphologic, geological and climatic conditions and mineralogical composition of the soils in the study area.Two sites, representative of known problem-areas in Kibaha were selected for geotechnical tests. Geotechnical site investigation consisted of open trial pits, profile description and the collection of both disturbed and undisturbed samples. To extend and amplify the findings, supplementary samples were collected from the environs of the two sites.The collected samples were submitted to soil laboratories at KTH, ARU, SEAMIC and DIT for mineralogical composition tests, natural water content, density, Atterberg limits and swell tests. The results of this investigation indicate that soils in Kibaha contains clay (31%), have high liquid limit (59%) and plastic limit (37%) which indicate high potential swell.Since swell pressure, free swell and swell percent are key properties of expansive soils, the swell properties were measured by free swell tests and one-dimensional oedometer swell tests. The free swell ranged from 100% to 150% and the swell pressure was in the region of 45 kPa. The coefficient of linear extensibility (COLE) was determined for characterizing expansive clays. For all tested samples, COLE ranged from 0.09 to 0.14 indicating that soils fall in the region of high to very high expansion potential rating. The properties of expansive soils were confirmed by the x-ray diffraction test which showed the presence of smectite in the soil. Furthermore, total suction measurement technique using filter paper method indicated that the soils have high suction values, signifying that they have a tendency to swell upon wetting depending on plasticity of particular soil.The depth of the active zone was measured as a function of moisture variations in the profiles during two extreme weather conditions. The active zone depth was found to be between 1.0 and 2.0 m deep. Procedures to assess models to predict swell in the case study were outlined together with their validity.Vertical and horizontal spatial variability in selected soil properties was defined using geostatistical techniques through the fitting of variogram. The indicator semivariograms of both clay contents and free swell gave a range of 20 m horizontally and 1.0 m vertically, with the horizontal variograms exhibiting greater ranges than the dipping variograms.Physical conditions of the surveyed properties in the area confirmed that building damages are associated with poor building materials triggered by expansive soils. In support of the obtained data, the actual behaviour of the foundations was supplemented with prototypes of strip foundations whose performances were monitored over a period of four months. Finally, suggested are the ways forward to solve the problem of foundation on expansive soil / QC 20100824

The irrigated agriculture in the Lower Chenab Canal (LCC) of Pakistan is characterized by huge water utilization both from surface and groundwater resources. Need of utilization of water from five rivers in Punjab province along with accelerated population growth has forced the construction of world’s largest irrigation network. Nevertheless, huge irrigation infrastructure, together with inappropriate drainage infrastructure, led to a build-up of shal-low groundwater levels, followed by waterlogging and secondary salinization in the soil profile. Following this era, decreased efficiency of irrigation supply system along with higher food demands had increased burdens on groundwater use, which led to a drop in groundwater levels in major parts of LCC. Previous studies in the study region revealed lacking management and maintenance of irrigation system, inflexible irrigation strategies, poor linkages between field level water supply and demands. No future strategy is present or under consideration to deal with this long time emerged groundwater situation particularly under unchanged irrigation water supply and climate change. Therefore, there is an utmost importance to assess the current profile of water use in the irrigation scheme and to device some workable strategies under future situations of land use and climate change. This study aims to investigate the spatio-temporal status of water utilization and performance of irrigation system using remote sensing data and techniques (SEBAL) in combination with other point data. Different irrigation performance indicators including equity, adequacy and reliability using evaporation fraction as main input parameter are utilized. Current profiles of land use/land cover (LULC) areas are assessed and their change detections are worked out to establish realistic future scenarios. Spatially distributed seasonal net recharge, a very important input parameter for groundwater modeling, is estimated by employing water balance approaches using spatial data from remote sensing and local norms. Such recharge results are also compared with a water table fluctuation approach. Following recharge estimation, a regional 3-D groundwater flow model using FEFLOW was set up. This model was calibrated by different approaches ranging from manual to automated pilot point (PP) approach. Sensitivity analysis was performed to see the model response against different model input parameters and to identify model regions which demand further improvements. Future climate parameters were downscaled to establish scenarios by using statistical downscaling under IPCC future emission scenarios. Modified recharge raster maps were prepared under both LULC and climate change scenarios and were fed to the groundwater model to investigate groundwater dynamics. Seasonal consumptive water use analysis revealed almost double use for kharif as compared to rabi cropping seasons with decrease from upper LCC to lower regions. Intra irrigation subdivision analysis of equity, an important irrigation performance indicator, shows less differences in water consumption in LCC. However, the other indicators (adequacy and reliability) indicate that the irrigation system is neither adequate nor reliable. Adequacy is found more pronounced during kharif as compared to rabi seasons with aver-age evaporation fraction of 0.60 and 0.67, respectively. Similarly, reliability is relatively higher in upper LCC regions as compared to lower regions. LULC classification shows that wheat and rice are major crops with least volatility in cultivation from season to season. The results of change detection show that cotton exhibited maximum positive change while kharif fodder showed maximum negative change during 2005-2012. Transformation of cotton area to rice cultivation is less conspicuous. The water consumption in upper LCC regions with similar crops is relatively higher as compared to lower regions. Groundwater recharge results revealed that, during the kharif cropping seasons, rainfall is the main source of recharge followed by field percolation losses, while for rabi cropping seasons, canal seepage remains the major source. Seasonal net groundwater recharge is mainly positive during all kharif seasons with a gradual increase in groundwater level in major parts of LCC. Model optimization indicates that PP is more flexible and robust as compared to manual and zone based approaches. Different statistical indicators show that this method yields reliable calibration and validation as values of Nash Sutcliffe Efficiency are 0.976 and 0.969, % BIAS are 0.026 and -0.205 and root mean square errors are 1.23 m and 1.31 m, respectively. Results of model output sensitivity suggest that hydraulic conductivity is a more influential parameter in the study area than drain/fillable porosity. Model simulation results under different scenarios show that rice cultivation has the highest impact on groundwater levels in upper LCC regions whereas major negative changes are observed for lower parts under decreased kharif fodder area in place of rice, cotton and sugarcane. Fluctuations in groundwater level among different proposed LULC scenarios are within ±1 m, thus showing a limited potential for groundwater management. For future climate scenarios, a rise in groundwater level is observed for 2011 to 2025 under H3A2 emission regime. Nevertheless, a drop in groundwater level is expected due to increased crop consumptive water use and decreased precipitations under H3A2 scenario for the periods 2026-2035 and 2036-2045. Although no imminent threat of groundwater shortage is anticipated, there is an opportunity for developing groundwater resources in the lower model regions through water re-allocation that would be helpful in dealing water shortages. The groundwater situation under H3B2 emission regime is relatively complex due to very low expectation of rise in groundwater level through precipitation during 2011-2025. Any positive change in groundwater under such scenarios is mainly associated with changes in crop consumptive water uses. Consequently, water management under such situation requires revisiting of current cropping patterns as well as augmenting water supply through additional surface water resources.

The irrigated agriculture in the Lower Chenab Canal (LCC) of Pakistan is characterized by huge water utilization both from surface and groundwater resources. Need of utilization of water from five rivers in Punjab province along with accelerated population growth has forced the construction of world’s largest irrigation network. Nevertheless, huge irrigation infrastructure, together with inappropriate drainage infrastructure, led to a build-up of shal-low groundwater levels, followed by waterlogging and secondary salinization in the soil profile. Following this era, decreased efficiency of irrigation supply system along with higher food demands had increased burdens on groundwater use, which led to a drop in groundwater levels in major parts of LCC. Previous studies in the study region revealed lacking management and maintenance of irrigation system, inflexible irrigation strategies, poor linkages between field level water supply and demands. No future strategy is present or under consideration to deal with this long time emerged groundwater situation particularly under unchanged irrigation water supply and climate change. Therefore, there is an utmost importance to assess the current profile of water use in the irrigation scheme and to device some workable strategies under future situations of land use and climate change. This study aims to investigate the spatio-temporal status of water utilization and performance of irrigation system using remote sensing data and techniques (SEBAL) in combination with other point data. Different irrigation performance indicators including equity, adequacy and reliability using evaporation fraction as main input parameter are utilized. Current profiles of land use/land cover (LULC) areas are assessed and their change detections are worked out to establish realistic future scenarios. Spatially distributed seasonal net recharge, a very important input parameter for groundwater modeling, is estimated by employing water balance approaches using spatial data from remote sensing and local norms. Such recharge results are also compared with a water table fluctuation approach. Following recharge estimation, a regional 3-D groundwater flow model using FEFLOW was set up. This model was calibrated by different approaches ranging from manual to automated pilot point (PP) approach. Sensitivity analysis was performed to see the model response against different model input parameters and to identify model regions which demand further improvements. Future climate parameters were downscaled to establish scenarios by using statistical downscaling under IPCC future emission scenarios. Modified recharge raster maps were prepared under both LULC and climate change scenarios and were fed to the groundwater model to investigate groundwater dynamics. Seasonal consumptive water use analysis revealed almost double use for kharif as compared to rabi cropping seasons with decrease from upper LCC to lower regions. Intra irrigation subdivision analysis of equity, an important irrigation performance indicator, shows less differences in water consumption in LCC. However, the other indicators (adequacy and reliability) indicate that the irrigation system is neither adequate nor reliable. Adequacy is found more pronounced during kharif as compared to rabi seasons with aver-age evaporation fraction of 0.60 and 0.67, respectively. Similarly, reliability is relatively higher in upper LCC regions as compared to lower regions. LULC classification shows that wheat and rice are major crops with least volatility in cultivation from season to season. The results of change detection show that cotton exhibited maximum positive change while kharif fodder showed maximum negative change during 2005-2012. Transformation of cotton area to rice cultivation is less conspicuous. The water consumption in upper LCC regions with similar crops is relatively higher as compared to lower regions. Groundwater recharge results revealed that, during the kharif cropping seasons, rainfall is the main source of recharge followed by field percolation losses, while for rabi cropping seasons, canal seepage remains the major source. Seasonal net groundwater recharge is mainly positive during all kharif seasons with a gradual increase in groundwater level in major parts of LCC. Model optimization indicates that PP is more flexible and robust as compared to manual and zone based approaches. Different statistical indicators show that this method yields reliable calibration and validation as values of Nash Sutcliffe Efficiency are 0.976 and 0.969, % BIAS are 0.026 and -0.205 and root mean square errors are 1.23 m and 1.31 m, respectively. Results of model output sensitivity suggest that hydraulic conductivity is a more influential parameter in the study area than drain/fillable porosity. Model simulation results under different scenarios show that rice cultivation has the highest impact on groundwater levels in upper LCC regions whereas major negative changes are observed for lower parts under decreased kharif fodder area in place of rice, cotton and sugarcane. Fluctuations in groundwater level among different proposed LULC scenarios are within ±1 m, thus showing a limited potential for groundwater management. For future climate scenarios, a rise in groundwater level is observed for 2011 to 2025 under H3A2 emission regime. Nevertheless, a drop in groundwater level is expected due to increased crop consumptive water use and decreased precipitations under H3A2 scenario for the periods 2026-2035 and 2036-2045. Although no imminent threat of groundwater shortage is anticipated, there is an opportunity for developing groundwater resources in the lower model regions through water re-allocation that would be helpful in dealing water shortages. The groundwater situation under H3B2 emission regime is relatively complex due to very low expectation of rise in groundwater level through precipitation during 2011-2025. Any positive change in groundwater under such scenarios is mainly associated with changes in crop consumptive water uses. Consequently, water management under such situation requires revisiting of current cropping patterns as well as augmenting water supply through additional surface water resources.:ABSTRACT VIII ZUSAMMENFASSUNG X ACRONYMS 1 Chapter 1 3 GENERAL INTRODUCTION 3 1 Groundwater for irrigated agriculture 3 2 Groundwater development in Pakistan 4 3 Study area 6 4 History of groundwater use in the study area 7 5 Research agenda 8 5.1 Problem statement 8 5.2 Objectives and scope of the study 9 Chapter 2 12 OVERVIEW OF PUBLICATIONS 12 Chapter 3 16 GENERAL CONCLUSIONS AND POLICY RECOMMENDATIONS 16 REFERENCES 20 ANNEXES 23 ACKNOWLEDGEMENTS 123