This translation of "Guide technique des bassins de retenue d'eaux pluviales," Paris 1994, provides information about planning, construction, maintenance and management, and costs of stormwater retention basins.

The aim of this Ph.D. was to develop a technology for the remediation of seleniferous soils/sediments and to explore microbial reduction of selenium oxyanions under different respiration conditions and bioreactor configurations. Seleniferous soil collected from the wheat-grown agricultural land in Punjab (India) was characterized and its soil washing was optimized by varying parameters, where addition of oxidizing agents showed a maximum selenium removal efficiency. Aquatic plants, Lemna minor and Egeria densa were used to study phytoremediation of the selenium-rich soil leachate containing oxidizing agents. Additionally, migration of the soluble selenium fraction from the upper to the lower layers and its subsequent reduction and accumulation in the lower layers of the soil column was observed during soil flushing. Furthermore, the soil leachate containing selenium oxyanions obtained from soil washing was treated in a UASB reactor by varying the organic feed. Ex situ bioremediation of selenium oxyanions was studied under variable conditions. An aerobic bacterium (Delftia lacustris) capable of transforming selenate and selenite to elemental selenium was isolated and characterized. Anaerobic bioreduction of selenate coupled to methane oxidation was investigated in serum bottles and a biotrickling filter using marine sediment as inoculum. Finally, the effect of contamination of other chalcogen oxyanions (tellurium) on selenium bioreduction was studied in a continuous system (UASB reactor).

Increases in populations have created an increasing demand for food crops while increases in demand for biofuels have created an increase in demand for fuel crops. What has not increased is the amount of croplands and their productivity. These and many other factors such as decreasing water resources in a changing climate have created a crisis like situation in global food security. Decision makers in these situations need accurate information based on science. Remote Sensing of Global Croplands for Food Security provides a comprehensive knowledge base in use of satellite sensor-based maps and statistics that can be used to develop strategies for croplands (irrigated and rainfed) and their water use for food security. Over 50 Multi-disciplinary Global Experts Give Insight and Provide Practical Approaches Emphasizing practical mapping technologies based on advanced remote sensing data and methods, this book provides approaches for estimating irrigated and rainfed cropland areas and their water use on a national, continental, or global basis. Written by 50+ leading experts working at the forefront of this critical area, it offers case studies from a variety of continents highlighting the subtle requirements of each. In a very practical way it demonstrates the experience, utility, and models for determining water resources used and resulting yields of irrigated and rainfed croplands. The authors discuss: (a) innovative methods used for mapping croplands, (b) approaches adopted to collect cropland data in different countries by traditional and non-traditional means, (c) accuracies, uncertainties, and errors involved in producing cropland products, (d) surface energy balance models used to assess crop water use, and (e) extensive results and outcomes pertaining to global croplands and their water use. Develop Strategies for an Enhanced Green Revolution and an Accelerated Blue Revolution Linking croplands to water use and food security, the book provides a global perspective on this sensitive issue. It gives insight into the extent of cropland usage, their spatial distribution, their cropping intensities, and their water use patterns. The editors collect the experience, methods, models, and results that show the way forward and help in decision-making on water resources and food security. All of this is required for developing strategies for an enhanced green revolution and for an accelerated blue revolution.

The enhanced biological removal of phosphorus (EBPR) is a popular process due to high removal efficiency, low operational costs, and the possibility of phosphorus recovery. Nevertheless, the stability of the EBPR depends on different factors such as: temperature, pH, and the presence of toxic compounds. While extensive studies have researched the effects of temperature and pH on EBPR systems, little is known about the effects of different toxic compounds on EBPR. For example, sulphide has shown to inhibit different microbial activities in the WWTP, but the knowledge about its effects on EBPR is limited. Whereas the sulphide generated in the sewage can cause a shock effect on EBPR, the continuously exposure to sulphide potentially generated in WWTP can cause the acclimatization and adaptation of the biomass. This research suggests that sulphate reducing bacteria can proliferate in WWTP, as they are reversibly inhibited by the recirculation of sludge through anaerobic-anoxic-oxic conditions. The research enhances the understanding of the effect of sulphide on the anaerobic-oxic metabolism of PAO. It suggests that the filamentous bacteria Thiothrix caldifontis could play an important role in the biological removal of phosphorus. It questions the ability of PAO to generate energy from nitrate respiration and its use for the anoxic phosphorus uptake. Thus, the results obtained in this research can be used to understand the stability of the EBPR process under anaerobic-anoxic-oxic conditions, especially when exposed to the presence of sulphide.

Quantitative research with respect to the combination of engineering and socialcultural- religious aspects based on the Tri Hita Karana philosophy in Subak irrigation schemes is original in the field of land and water development. A scenario analysis needs a good and careful system approach. Based on a Generic Algorithm the RIBASIM model was applied using the dependable 80% of discharge and shifting the start of land preparation. The results provide evidence that the cropping pattern of the fifth scenario results in an overall optimal agriculture production of the Subak schemes. The recoverable flow considered in the river basin scheme model plays an important role in the optimisation. Nevertheless, if a normal hydro-climate occurs, the other scenarios, especially the first scenario, can be applied as well. When the indigenous knowledge of farmers is compromised with present day knowledge of agricultural and technological developments, capability of these farmers increases, thus reflects the applicability of the Tri Hita Karana philosophy on harmony among people and harmony among people and nature.

This book provides an overview of recent advances in technologies for water treatment processes, such as green technology, nano-adsorbents, photocatalysts, advanced oxidation, membranes separation and sustainable technologies. Advances in membrane technology and fabrication process is presented in detail. Latest approaches like microbial treatment, electro chemical and solar energy-based treatment techniques were presented. Also, the use of sustainable and energy efficient approaches were discussed.* The book presents the negative impact of inorganic and organic pollutants on the natural environment and human health. It describes and discussing the advanced membrane technologies, novel green adsorbents, microbial treatment techniques, electro chemical and solar based removal techniques It also compares the most effective methods of removing toxic contaminants from water solutions with the use of sustainable and energy efficient approaches It also presents the life cycle assessment of emerging technologies in industrial wastewater treatment and desalination as well as presents the benchmarking of energy efficiency during treatment process

The main objective of this research was to optimize the electron donor supply in sulphate reducing bioreactors treating sulphate rich wastewater. Two types of electron donor were tested: lactate and slow release electron donors such as carbohydrate based polymers and lignocellulosic biowastes. Biological sulphate reduction was evaluated in different bioreactor configurations: the inverse fluidized bed, sequencing batch and batch reactors. The reactors were tested under steady-state, high-rate and transient-state feeding conditions of electron donor and acceptor, respectively. The results showed that the inverse fluidized bed reactor configuration is robust and resilient to transient and high-rate feeding conditions at a hydraulic retention time as low as 0.125 d. The biological sulphate reduction was limited by the COD:sulphate ratio (< 1.7). The results from artificial neural network modelling showed that the influent sulphate concentrations synergistically affected the COD removal efficiency and the sulphide production. Concerning the role of electron donors, the slow release electron donors allowed a biological sulphate reduction > 82% either using carbohydrate based polymers or lignocellulosic bio-wastes, in batch bioreactors. The biological sulphate reduction was limited by the hydrolysis-fermentation rate and by the complexity of the slow release electron donors.

In the Eastern corridor of Northern region of Ghana, presence of high fluoride concentration in the groundwater has made many drilled boreholes unusable for drinking. Little is, however, known about the factors contributing to the occurrence of high fluoride in this part of Ghana and it's spatial distribution. Treatment of the fluoride-contaminated groundwater by adsorption is also hampered by the lack of suitable adsorbents that are locally available. Based on principal component analysis, and saturation indices calculations, this thesis highlights that, the predominant mechanisms controlling the fluoride enrichment probably include calcite precipitation and Na/Ca exchange processes, both of which deplete Ca from the groundwater, and promote the dissolution of fluorite. The mechanisms also include F-/OH- anion exchange processes, as well as evapotranspiration processes which concentrate the fluoride ions, hence increasing its concentration in the groundwater. Spatial mapping showed that the high fluoride groundwaters occur predominantly in the Saboba, Cheriponi and Yendi districts. The thesis further highlights that, modifying the surface of indigenous materials by an aluminium coating process, is a very promising approach to develop a suitable fluoride adsorbent. Aluminum oxide coated media reduced fluoride in water from 5. 0 +/- 0.2 mg/L to 1.5 mg/L (which is the WHO health based guideline for fluoride), in both batch and continuous flow column experiments in the laboratory. Kinetic and isotherm studies, thermodynamic calculations, as well as analytical results from Fourier Transform Infrared Spectroscopy and Raman spectroscopy, suggest the mechanism of fluoride adsorption onto aluminium oxide coated media involved both physisorption and chemisorption processes. Field testing in a fluoritic community in Northern Ghana showed that the adsorbent is also capable of treating fluoride-contaminated groundwater in field conditions, suggesting it is a promising defluoridation adsorbent. The adsorbent also showed good regenerability potential that would allow re-use, which could make it practically and economically viable. Additional research is, however, required to further increase the fluoride adsorption capacity of developed adsorbent.

Urban flood risks and their impacts are expected to increase as urban development in flood prone areas continues and rain intensity increases as a result of climate change while aging drainage infrastructures limit the drainage capacity in existing urban areas. Flood mitigation strategies are required as part of sound urban flood management plans to assess flood risk and identify technically feasible and cost-effective options to reduce the risk. Central to the development of flood mitigation strategies is the efficient prediction of flood propagation characteristics in urban areas. Detailed predictions of flood flows in urban areas require the use of high resolution topographic data. However, due to computational demand topographic data is often generalised to a more manageable resolution and floodplain models are built at much coarser resolutions. The research presented in this thesis addresses the problem of capturing small-scale features in coarse resolution urban flood models with the aim of improving flood forecasts in geometrically complex urban environments. The approach adopted in the research used a two-dimensional surface flow modelling system that can extract and incorporate useful information available in high resolution topographic data into coarse grid models. The thesis also presents modelling of the complex interaction between surcharged sewer and flows associated with urban flooding and incorporation of infiltration process in surface flow modelling tools. Case study results showed that the incorporating volume-depth and flow-area-depth relationships extracted from high resolution topographic data significantly improved the results of coarse grid urban flood models while taking the advantage of reduced computational time to ensure efficient prediction of urban flood characteristics.

Climate change, rapid population growth and urbanization are causing water shortage and pollution, especially in arid and semi-arid regions of the world due to the growing demand in different sectors and disposal of inadequately treated wastewater to water bodies. To tackle these challenges, further treatment and reuse of wastewater effluent using soil aquifer treatment (SAT) is an attractive cost-effective and environmentally friendly option that is employed with no intensive use of electricity and chemicals. This study highlights the prospects of using SAT for treatment and reuse of primary effluent (PE), especially in developing countries where wastewater is not treated to secondary and tertiary effluent levels due to lack of investment and operation costs to run sizable wastewater treatment plants (WWTPs). Coupled with experimental studies that show SAT efficiency to remove suspended solids, bulk organic matter, nutrients and pathogens indicators from PE, the thesis provides step-by-step tools that could be used for development of new SAT scheme. Furthermore, the study provides a water quality prediction model that estimates the potential contaminants removal which could be used to assess the need for reclaimed water post-treatment. This thesis is envisaged to contribute to the current knowledge on the necessity of water reuse.

Urban informal settlements or slums are growing rapidly in cities in sub-Saharan Africa. Most often, a sewer system is not present and the commonly-used low-cost onsite wastewater handling practices, typically pit latrines, are frequently unplanned, uncontrolled and inefficient. Consequently, most households dispose of their untreated or partially treated wastewater on-site, generating high loads of nutrients to groundwater and streams draining these areas. However, the fate of nutrients in urban slums is generally unknown. In excess, these nutrients can cause eutrophication in downstream water bodies. This book provides an understanding of the hydro-geochemical processes affecting the generation, fate and transport of nutrients (nitrogen and phosphorus) in a typical urban slum area in Kampala, Uganda. The approach used combined experimental and modeling techniques, using a large set of hydrochemical and geochemical data collected from shallow groundwater, drainage channels and precipitation. The results show that both nitrogen-containing acid precipitation and domestic wastewater from slum areas are important sources of nutrients in urban slum catchments. For nutrients leaching to groundwater, pit latrines retained over 80% of the nutrient mass input while the underlying alluvial sandy aquifer was also an effective sink of nutrients where nitrogen was removed by denitrification and anaerobic oxidation and phosphorus by adsorption to calcite. In surface water, nutrient attenuation processes are limited. This study argues that groundwater may not be important as regards to eutrophication implying that management interventions in slum areas should primarily focus on nutrients released into drainage channels. This research is of broad interest as urbanization is an ongoing trend and many developing countries lack proper sanitation systems.

Population growth in the Blue Nile Basin has led to fast land-use changes from forest to agricultural land, which resulted in speeding up the soil erosion processes producing highly negative impacts on the local soil fertility and agricultural productivity. The eroded sediment is transported downstream by water and sinks in the lower basin where it significantly reduces reservoir storage and irrigation canals capacity. The only effective solution to mitigate the sedimentation problem is to limit the sediment inputs from upstream by locally implementing erosion control practices. However, given the vastness and remoteness of the involved areas, this first requires the knowledge of the most critical zones. The book identifies the sources of the sediment depositing in the Lower Blue Nile Basin and quantifies the amounts involved providing essential information for the planning and implementation of any interventions aiming at reducing soil erosion. The methods used consist of extensive field work covering most of the basin, watershed, hydrodynamic and morphodynamic modelling and, for the first time, the mineralogical analysis of the sediment at the sources and sinks. The method is successful in indentifying the areas providing most of the transported sediment, where it is recommended to start with erosion control practices.

The prospects for the future are clear. Agriculture will have to respond to changing patterns of demand for food and combat food insecurity and poverty amongst marginalized communities. In so doing, agriculture will have to compete for scarce water with other users and reduce pressure on the water environment. Moreover, water managers have to unlock the potential of agricultural water management practices to raise productivity of water, spread equitable access to water, and conserve the natural productivity of the water resource base. This PhD thesis presents field tests combined with modelling work on the cultivation of irrigated Teff (Eragrostic Tef) in the Awash Rift Valley of Ethiopia. The field experiments were conducted during the dry season for two years. The results of these studies revealed that dealing with improvement of water productivity is closely related to the irrigation practice of regulated deficit irrigation and has a direct effect on yield, as the amount of water applied decreases intentionally the crop yield drops. Overall, this research has demonstrated the potential and the limitations of combining experimental fieldwork with modelling to optimize agricultural water productivity for Teff cultivation. Focusing on only experimental fieldwork is a single approach, and is hardly ever sufficient for achieving the best solutions to current water management problems. New guidelines on using the combined effort of experimental work in the field to produce field experimental data and using models are clearly needed. It is to these needs as well as to the required increase of Teff production under water scarce conditions that this research provides its main contribution.

The rate of global increase in water abstraction for irrigation has been declining since the 1970's due to declining potentials for large and medium-scale irrigation developments, and is expected to further decline in the next decades. As such the significant proportion of the expected increase in production would have to be supplied from existing irrigated and /or cultivated lands. This in turn could be achieved by enhancing land and water productivity through improved performance and optimal operation and maintenance. With less than 15% of over 5 million ha irrigation potential harnessed, irrigation devolvement in Ethiopia remained low. Over 70% of the developed irrigation in the country belongs to small-scale irrigation serving smallholder farmers. While accelerated development of new irrigation, particularly of large and medium-scale schemes is relevant in Ethiopia, ensuring the performance and sustainability of existing schemes is also equally important. The existing irrigation schemes in Ethiopia are generally characterized by an overall performance and technical sustainability levels of below expectation. This thesis evaluates the performance of two large-scale (Wonji-Shoa and Metahara) and two community-managed (Golgota and Wedecha) irrigation schemes located in the Awash River Basin of Ethiopia. The study focussed on hydraulic/water delivery performance in the large-scale schemes, and on comparative and internal irrigation service (utility) evaluation in the community-managed schemes. Water delivery performance was evaluated using routine data and hydrodynamic modelling. Farmers' utility was evaluated using qualitative responses of water users. Major performance challenges in each category of schemes were addressed and operational/water management options for improvement were identified.

The Abay / Upper Blue Nile basin contributes the largest share of discharge to the river Nile. However, the basin exhibits large spatio-temporal variability in rainfall and runoff. Moreover, human activities also impact hydrological processes through intensive agriculture, overgrazing and deforestation, which substantially affect the basin hydrology. Thus, understanding hydrological processes and hydro-climatic variables at various spatio-temporal scales is essential for sustainable management of water resources in the region. This research investigates the hydrology of the basin in depth using a range of methods at various spatio-temporal scales. The methods include long-term trend analysis of hydroclimatic variables, hydrologic responses analysis of land cover change, stable isotope techniques and process based rainfallrunoff modelling. A combination of field investigations with new measurements of precipitation, water levels and stable isotopes as well as existing hydro-climatic data offered gaining new insights about runoff generation processes in headwater catchments. The use of rainfall-runoff modelling in two meso-scale catchments of the Abay basin depict that a single model structure in a lumped way for the entire Abay basin cannot represent all the dominant hydrological processes. The results of the different approaches demonstrated the potential of the methods to better understand the basin hydrology in a data scarce region.

The Gezira Scheme is Sudan's oldest and largest gravity irrigation system. The scheme has played an important role in the economic development of the country, and is a major source of foreign exchange. The farming system of the Gezira Scheme is dominated by crop production. The main crops grown are sorghum, wheat, groundnut and the oilseed crop sesame. Sunflower (Helianthus annuus L.) is an important oil crop in the world and a new edible oil crop in Sudan. Knowledge of the effects of irrigation scheduling on sunflower production and water productivity under water stress conditions is becoming increasingly important. Irrigation scheduling is particularly important since many field crops are more sensitive to water deficit at specific phonological stages. Sunflower has several growth stages: emergence, vegetative, reproductive, flowering, seed formation and maturity. Water stress in each stage results in reduction in seed yield and oil content. The treatments in the test plots, which were conducted to study the effect of water stress at different growth stages, showed that sunflower was significantly affected by water stress that occurred in the sensitive flowering and seed formation stages. Highest seed yield was obtained when water stress was avoided during these stages. The AquaCrop model was used to simulate the seed yield and water productivity. The model was able to precisely simulate seed yield, but overestimated water productivity under different irrigation treatments.

Constructed Wetlands (CWs) are among the few natural treatment systems that can guarantee an efficient wastewater treatment and an appealing green space at the same time. However, they require large areas for their construction, which is not available in many cases. In this thesis, two domestic wastewater treatment options were designed and studied with the purpose of having a low space requirement: the Duplex-CW and the Constructed Wetoof (CWR). The Duplex-CW is a hybrid CW composed of a vertical flow CW on top of a horizontal flow filter. The stacked arrangement is the key for reducing the CW footprint. The CWR is a shallow HF CW placed on the roof of a building, thus it does not occupy any land. Several modifications and improvements have been tested, in addition to the study of the treatment performance, in order to select the most appropriate Duplex-CW and CWR design. Overall, this thesis contributes to the development of two efficient domestic wastewater treatment technologies. The Duplex-CW area requirement is still higher than many CWs and therefore further improvements are necessary. The CWR is the foremost option to save land areas since it requires 0 m2 of land per person equivalent.

The Enhanced Biological Phosphorus Removal (EBPR) process is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by Phosphate-Accumulating Organisms (PAO) and subsequent removal through wastage of excess sludge. Although many studies have demonstrated the existence of different PAO clades, the functional differences among these clades and potential implications for the process performance remained unclear. Furthermore, the salinity effects on the EBPR process had not been properly investigated, which is necessary to assess its applicability for the treatment of saline wastewaters. The first part of the thesis focuses on the functional diversity among PAO clades. It demonstrates significant functional differences in the main characteristics of the anaerobic metabolism of two different PAO clades and provides fundamental insight in the metabolic response of PAO to different influent P/C ratios. In addition, it shows how these functional differences provide competitive advantages to specific PAO clades in a selection study and discusses their potential implications on process performance, in particular for combined biological and chemical systems for nutrient removal and recovery. The second part of the thesis describes the salinity effects on the metabolism of PAO and their competitors that do not contribute to phosphorus removal; the so-called Glycogen-Accumulating Organisms (GAO). It shows how salinity affects the different metabolic processes (kinetics and stochiometry) of PAO and GAO and provides a model that describes the salinity effects on their kinetic rates. Finally, it discusses the potential implications of sudden saline shocks in wastewater treatment systems that are not regularly exposed to salinity.

The aim of this book is to contribute to understanding risk knowledge and to forecasting components of early flood warning, particularly in the environment of tropical high mountains in developing cities. This research covers a challenge, taking into account the persistent lack of data, limited resources and often complex climatic, hydrologic and hydraulic conditions. In this research, a regional method is proposed for assessing flash flood susceptibility and for identifying debris flow predisposition at the watershed scale. An indication of hazard is obtained from the flash flood susceptibility analysis and continually, the vulnerability and an indication of flood risk at watershed scale was obtained. Based on risk analyses, the research follows the modelling steps for flood forecasting development. Input precipitation is addressed in the environment of complex topography commonly found in mountainous tropical areas. A distributed model, a semi-distributed model and a lumped model were all used to simulate the discharges of a tropical high mountain basin with a paramo upper basin. Performance analysis and diagnostics were carried out in order to identify the most appropriate model for the study area for flood early warning. Finally, the Weather Research and Forecasting (WRF) model was used to explore the added value of numerical weather models for flood early warning in a paramo area.

The Ning-Meng reach of the Yellow River basin is located in the Inner Mongolia region at the Northern part of the Yellow River. Due to the special geographical conditions, the river flow direction is towards the North causing the Ning-Meng reach to freeze up every year in wintertime. Both during the freeze-up and break-up period, unfavourable conditions occur which may cause ice jamming and ice dam formation leading to dike breaching and overtopping of the embankment. Throughout history this has often led to considerable casualties and property loss. Enhanced economic development and human activities in the region have altered the characteristics of the ice regime in recent decades, leading to several ice disasters during freezing or breaking-up periods. The integrated water resources management plan developed by the Yellow River Conservancy Commission (YRCC) outlines the requirements for water regulation in the upper Yellow River during ice flood periods. YRCC is developing measures that not only safeguard against ice floods, but also assure the availability of adequate water resources. These provide the overall requirements for developing an ice regime forecasting system including lead-time prediction and required accuracy. In order to develop such a system, numerical modelling of ice floods is an essential component of current research at the YRCC, together with field observations and laboratory experiments. In order to properly model river ice processes it is necessary to adjust the hydrodynamic equations to account for thermodynamic effects. In this research, hydrological and meteorological data from 1950 to 2010 were used to analyse the characteristics of ice regimes in the past. Also, additional field observations were carried out for ice flood model calibration and validation. By combining meteorological forecasting models with statistical models, a medium to short range air temperature forecasting model for the Ning-Meng reach was established. These results were used to improve ice formation modelling and prolong lead-time prediction. The numerical ice flood model developed in this thesis for the Ning-Meng reach allows better forecasting of the ice regime and improved decision support for upstream reservoir regulation and taking appropriate measures for disaster risk reduction.

Mountains are water towers of our world, but their role in global water resources may be altered due to changing climate. This book provides an integrated assessment of the spatial and temporal variability of both recent and future climate change impacts in the Yellow River source region (YRSR) with specific focus on extremes. The book is structured across four different topics from detecting contemporary hydro-climatic changes, comparing three different statistical downscaling methods, assessing elevation dependency of expected changes in temperature, and projecting future climate-induced hydrologic changes in the YRSR. The detection of historical hydro-climatic changes in recent decades indicates that climate change may already be happening and may pose a serious threat to water availability in this region. However, an ensemble of climate change projections for the periods 2046-2065 and 2081-2100 based on two GCMs and three emission scenarios demonstrates that the future water availability of this region would increase due to climate change. This discrepancy suggests that contemporary hydro-climatic experience based on past records alone may not always provide a reliable guide to the future. This study makes an important contribution toward an improved understanding of climate change impacts in the YRSR. The knowledge generated has major implications for water resources management in the Yellow River and will be instructive for climate change impacts studies in other mountain areas.

The field of ecohydraulics integrates hydrodynamic and eco-dynamic processes. While hydrodynamic processes are usually well described by partial differential equations (PDE's) based on physical conservation principles, ecosystem dynamics often involve specific interactions at the local scale. Because of this, Cellular Automata (CA) are a viable paradigm in ecosystem modelling. All cells in a CA system update their states synchronously at discrete steps according to simple local rules. The classical CA configuration consists of uniformly distributed cells on a structured grid. But in the field of hydrodynamics, the use of unstructured grids has become more and more popular due to its flexibility to handle arbitrary geometries. The main objective of this research is to identify whether the CA paradigm can be extended to unstructured grids. To that end the concept of Unstructured Cellular Automata (UCA) is developed and various UCA configurations are explored and their performance investigated. The influence of cell size was analyzed in analogy with the Finite Volume Method. A characteristic parameter -min distance of UCA- was put forward and tested by numerical experiments. Special attention was paid to exploring the analogies and differences between the discrete CA paradigm and discrete numerical approximations for solving PDE's. The practical applicability of UCA in ecohydraulics modelling is explored through a number of case studies and compared with field measurements.

The relationship between environmental agencies and polluters is especially challenging in the context of micro and small sized enterprises (McSEs) in developing countries. The focus is mainly at end-of-pipe solutions that are usually unaffordable for McSEs. In order to engage them in achieving national environmental policy goals, this thesis reflexively combines the theoretical fields of Action Research and Negotiation/Conflict Resolution to fill the gaps in knowledge. A methodology was developed that is problem-driven and iterative by using longitudinal data collection rather than snap-shots. Along with a comparative study of two regional tannery cases, a new approach based on Action Research named SASI (Systematic Approach for Social Inclusion) was designed and tested for six years on cleaner production (CP) implementation with a third tannery case. The results highlight how institutional barriers in Colombia negatively affect the McSEs. The research shows that CP implementation needs comprehensive, systemic mechanisms based on participatory approaches that take into account the concerns and contexts of McSEs. Doing Action Research through SASI generated both theoretical insight and positively changed the lives of the tanners engaged in the research. It contributed to breaking the cycles of their exclusion and simultaneously facilitated innovation and use of local knowledge.

Human beings strongly depend on the sustainable availability of resources, such as food, water and energy. The continued supply of these resources can only be assured by sustainable land uses but these are easily threatened by inappropriate human activities. Human behavior is intermingled with hydrological, biogeochemical, atmospheric and ecological processes through land use and land cover change (LULCC). LULCC is a locally pervasive and globally significant environmental trend and has become a process of paramount importance to the study of global environmental change. This thesis investigates LULCC and its links with soil hydrology, soil degradation and climate variability through combining results from fieldwork, laboratory work and Remote Sensing. Seasonal, inter-annual and broad timescale land transitions are analyzed for a robust identification of biophysical change. The determinants of LULCC are determined using spatially explicit statistical modelling of most systematic land transitions. This thesis explores soil hydrological impacts of LULCC for a better soil water management. The thesis further explores the climatic factors leading to the observed trends in vegetated land cover for improved understanding of the link between climate and carbon fixation and water use by vegetation.

Providing an introduction to the crucially important topic of groundwater, this text covers all major fields of hydrogeology and includes outlines of the occurrence of groundwater in various rock types, the movement and storage of groundwater, the formulation of groundwater balances, the development of groundwater chemistry, as well as the practical application of hydrogeology for groundwater development. Following a unique systems approach to describe and connect its various elements, the text also explores a large selection of examples of groundwater cases from various parts of the world. In addition, theoretical sections and examples are illustrated with a number of drawings, photos and computer printouts. Suitable for education in hydrogeology at postgraduate and graduate level, the text is also a useful reference tool for professionals and decision-makers involved in water or water-related activities. In the revised paperback edition more attention is paid to the processes in the unsaturated zone, especially those relating to groundwater recharge. Also, the investigation methods are highlighted in the sections where the related theory is dealt with, and they are not presented in the last chapter on groundwater management. The References and Bibliography section is also extended, some figures are improved, and the inevitable 'typing errors' are corrected as well. In the third edition, a more formal basis for the hydro-chemical processes described in the chapter on groundwater chemistry has been added. Mass balances and the principles of dispersion and retardation are introduced. Additional illustrations are provided, also explaining the processes occurring along streamlines. Consult: http://introductiontohydrogeology.nl/ for additional information on the book, the author and available software.