The Olifants River is one of the major tributaries of the Limpopo River. Approximately 3,400,000 people live in its catchment and a considerable proportion of South Africa’s mining, power production and agricultural activities are concentrated there. The catchment also encompasses important tourist destinations (e.g., the Kruger National Park). Consequently, in terms of the national economy it is one of the country’s most significant waterways. The catchment is one of the first in South Africa for which a Catchment Mangement Agency (CMA) is planned.
This study aims at improving the hydrological process understanding of the semi-arid and transboundary Incomati river basin to enable better water management. Comprehensive statistical and trend analysis of rainfall and streamflow were conducted, and the Indicators of Hydrological Alteration tool was deployed to describe the streamflow regime and trends over time. Land use and land cover change, particularly the conversion of natural vegetation into forest plantation, the expansion of irrigated agriculture and the flow regulation due to dam operation were identified as critical drivers of flow regime alteration. Hydrograph separation using long-term hydrochemical data at seasonal scale, and hydrochemical and isotope data at event scale were performed to quantify runoff components. A novel methodology to calibrate recursive digital filters using routinely collected water quality data was developed and tested in the catchment. This method allows for estimation of daily baseflow from readily available daily streamflow data. Dominant runoff generation zones were mapped using the Height Above Nearest Drainage approach. The hydrological model STREAM was then employed, informed by the runoff generation zones mapping and the process understanding gained in the catchment, as well as remote sensing data. The study provides the basis for better operational water management in the catchment.
Forest ecosystems include a great variety of communities of organisms interacting with their physical environment: multi-aged natural forests, even-aged monocultures, and secondary forests invaded by foreign species. The challenge is to sustain their ability to function, by adapting to changing climates and satisfying a multitude of human demands. Our first chapter sets the scene with a discussion about the effects of forest management on ecosystem services. Details about forest observational infrastructures are introduced in the second chapter. The third chapter presents methods of analysing forest density and structure. Models for estimating the shape and growth of individual forest trees are introduced in chapter 4, models of forest community production in Chapter 5. Methods and examples of sustainable forest design are covered in chapter 6. New scientific contributions continue to emerge as we are writing, and this work is never finished. We hope to continue with regular updates replacing obsolete sections with new ones, but the general aim remains the same, to introduce a range of methods that will assist those interested in sustaining forest ecosystems.
The report evaluates the impacts of climate change on the hydrological regime and water resources of the Blue Nile River Basin in Ethiopia. It starts from the construction of the climate change scenarios based on the outcomes of several general circulation models (GCMs), uses a simple hydrological model to convert theses scenarios into runoff, and examines the impacts by means of a set of indices. The results, however uncertain with existing accuracy of climate models, suggest that the region is likely to have the future potential to produce hydropower, increase flow duration, and increase water storage capacity without affecting outflows to the riparian countries in the 2050s.
To conserve water, one of the most valuable and vital resources in the world, management and public strategies, processes to reduce water consumption in industrial/commercial applications, and methods such as smart irrigation systems have been proposed. Local authorities have focused on infrastructure operations to prevent water losses and flow measurements have begun to be followed more closely. The use of greywater for partial recycling of water for household purposes and rainwater harvesting systems are being encouraged. In addition, there is more research on water conservation, its smart use, and recycling of used water being conducted. This book presents valuable scientific research on water and land management, groundwater management, and water/wastewater treatment applications for the conservation of water.
Water resource development has played a significant role in the expansion of agriculture and industry in the Olifants River Catchment. However, currently water deficit is one of the major constraints hampering development in the catchment; both the mining and agricultural sectors are producing below optimal levels because of their reliance on insufficient supplies. In this study, the Water Evaluation and Planning (WEAP) model was used to evaluate scenarios of historic, current and future water demand in the catchment. For each scenario, the WEAP model was used to simulate demand in five different sectors (rural, urban, mining, commercial forestry and irrigation) over a 70-year period of varying rainfall and hydrology. Levels of assured supply were estimated for each sector and the economic cost of failing to provide water was predicted. For the future scenarios, the impact of infrastructure development and water conservation measures were assessed. The study illustrates how a relatively simple model can provide useful insight for resource planning and management.
With increasing water scarcity, pressure to re-allocate water from agriculture to other uses mounts, along with a need to put in place institutional arrangements to promote 'higher value' uses of water. Many developing countries are now experimenting with establishing new institutional arrangements for managing water at the river basin level.This book, based on research by IWMI and others, reviews basin management in six developed and developing countries. It describes and applies a functional theory of river basin management, based on the idea that there is a minimum set of functions required to manage basins effectively and a set of basic conditions that enable effective management institutions to emerge. The book examines the experiences of both developed and developing countries in order to see what lessons can be learned and to identify what constitutes the core of a 'theory of river basin management'. It concludes that although it is difficult for developing countries to adopt approaches and institutional designs directly from developed countries, basic principles and lessons are transferable.
The Olifants catchment is one of 19 Catchment Management Areas in South Africa. Different water users (i.e., rural, urban, mining, subsistence and commercial irrigated agriculture, commercial forestry, industry and power generation) are present in the catchment. Rising population andincreasing water provision in rural areas, in conjunction with the development of the mining industry, the construction of new power generation plants, the implementation of environmental flows andthe need to meet international flow requirements are going to greatly exacerbate the complexity of future water resources management in what is already a water-stressed catchment. Being able to assess the ability of the catchment to satisfy potential water demands is crucial in order to plan for the future and make wise decisions. In this study, a scenario analysis approach was used in conjunction with the Water Evaluation And Planning model, in order to assess the impacts of possible water demands on the water resources of the Olifants catchment in 2025. Foreach scenario, the water resource implications were compared to a 1995 “baseline.” The model enabled analyses of unmet water demands, streamflows and water storage for each scenario. The model results show that for the different scenarios considered in this study the implementation of the Environmental Reserve (an instream requirement to guarantee the health of the riverine ecosystems) will increase the shortages for other sectors. The construction of the main water storage infrastructure proposed by the Department of Water Affairs and Forestry, in conjunction with the application of Water Conservation and Demand Management practices, can reduce the unmet demands and shortfalls to levels lower than, or similar to, those experienced in the 1995 baseline. However, in all cases these interventions will be insufficient to completely meet the demands of all the sectors. A tight control of the growth in future demands is essential, although this may be difficult in a rapidly developing country like South Africa.
Water resources are under extreme pressure today all over the world. The resulting problems have given rise to many activities which reflect the growing concern about them and the importance of effective management.As water increasingly becomes a precious resource on which the well-being of future generations depends, it is essential to discuss issues concerning quality, quantity, planning and other related topics.Containing papers presented at the Fourth International Conference on Water Resources Management, this book examines the recent technological and scientific developments associated with the management of surface and sub-surface water resources. The wide variety of subjects covered are as follows: Water Resource Management and Planning; Waste Water Treatment and Management; Water Markets and Policies; Urban Water Management; Water Quality; Storm Water Management; Water Security Systems; Pollution Control; Irrigation Problems; Reservoirs and Lakes; River Basin Management; Hydrological Modelling; Flood Risk; Decision Support Systems; Groundwater Flow Problems and Remediation Technologies; Coastal and Estuarial Problems; Soil and Water Conservation and Risk Analysis.
This book presents results of scientific studies ranging from hydrological modelling to water management and policy issues in the Nile River basin. It examines the physical, hydrometeorological and hydrogeological description of the basin along with analysis in understanding the hydrological processes of the basin under the changing land-use stemming from population pressure and increased natural resources tapping. The book discusses the increased impact of climate change on the river flows, and such issues as water availability and demand, management and policy to offset the imbalance between demand and available resources. This book will be of interest to researchers, practitioners, water resources mangers, policy makers as well as graduate and undergraduate students. It is a useful reference text for ecohydrology, arid zone hydrology, hydrology of transboundary rivers and similar courses.
