Water use efficiency and influence of management policies, analysis for the small-scale irrigation sector in South Africa

With the growing water scarcity, the need for more efficient water use has worldwide increased in importance. In addition, cost-recovery is now widely acknowledged as a cornerstone of sustainable water management. This research aims to contribute to improved water management in the small-scale irrigation sector in South Africa, which also faces these challenges. In a first analysis the economic production value of irrigation water was determined. Results show that without government subsidies on inputs, the profitability of many smallholders was low. Achieving full cost recovery therefore appears to be problematic for the current users. In the next part the concept of sub-vector efficiencies is introduced as a measure for water use efficiency. The analysis shows that smallholders fail to reach their overall technical efficiency levels when it concerns water use. Even using the current technologies the potential to reallocate irrigation water to other water demands is substantial. In a third part an innovative two-steps simulation model was developed to study the impact of water pricing. The model introduces a representation of the technology and smallholder efficiencies in a profit maximisation model. Farmers appear to be quite responsive to water charges and adjust their water use, even when the charge is relatively low. Pricing water can thus be used to provide incentives for efficiency improvement. However, the introduction of a water price is also shown to significantly decrease farm profit, particularly for smaller farms. The last part of the study investigates the impact of improving the water rights system in South Africa. Using a contingent ranking experiment the WTP of smallholders for specific interventions is estimated. The results show that farmers are prepared to pay considerably higher water prices if this is connected with advancements in the water rights system. This implies that such interventions would improve the efficiency of the small-scale irrigation sector. A higher WTP for water is also interesting in the light of the cost recovery, because it allows the government to increase water charges. In general, this research shows how economic analyses can be used to inform policy making to improve water management

Inventory management systems:Control and information issues

Abstract: This dissertation addresses the management of inventory systems. The thesis starts with an exposition on mathematical models that can be used in inventory theory. Then we deal with some information issues related to the demand process. Namely, how to control products that have intermittent demand. Moreover, we investigated the impact of data collection on the customer performance. Next, we investigated to what extend multiple-sourcing can lead to improvements of the inventory system. Finally two demand management strategies are investigated for smoothing demand. The first re-routes large customer orders to alternative stockpoint, whereas the second strategy splits a customer order in a time-phased delivery scheme.

Should we have a new engine? An automobile power systems evaluation. Volume 2: Technical reports

Alternative automotive powerplants were examined for possible introduction during the 1980-1990 time period. Technical analyses were made of the Stratified-Charge Otto, Diesel, Rankine (steam), Brayton (gas turbine), Stirling, Electric, and Hybrid powerplants as alternatives to the conventional Otto-cycle engine with its likely improvements. These alternatives were evaluated from a societal point of view in terms of energy consumption, urban air quality, cost to the consumer, materials availability, safety, and industry impact. The results show that goals for emission reduction and energy conservation for the automobile over the next 5-10 years can be met by improvements to the Otto-cycle engine and to the vehicle. This provides time for the necessary development work on the Brayton and Stirling engines, which offer the promise of eliminating the automobile as a significant source of urban air pollution, dramatically reducing fuel consumption, and being saleable at a price differential which can be recovered in fuel savings by the first owner. Specifically, the Brayton and Stirling engines require intensive component, system, and manufacturing process development at a funding level considerably higher than at present

Evaluating the sustainability of urban agriculture projects

Evaluating the sustainability of urban agriculture projects. 5. International Symposium for Farming Systems Design (AGRO2015

Future Computer Requirements for Computational Aerodynamics

Recent advances in computational aerodynamics are discussed as well as motivations for and potential benefits of a National Aerodynamic Simulation Facility having the capability to solve fluid dynamic equations at speeds two to three orders of magnitude faster than presently possible with general computers. Two contracted efforts to define processor architectures for such a facility are summarized

Impact Evaluation in Practice

The book is a comprehensive and accessible introduction to impact evaluation for policy makers and development practitioners. First published in 2011, it has been used widely across the development and academic communities. The book incorporates real-world examples to present practical guidelines for designing and implementing impact evaluations. Readers will gain an understanding of impact evaluations and the best ways to use them to design evidence-based policies and programs. The updated version covers the newest techniques for evaluating programs and includes state-of-the-art implementation advice, as well as an expanded set of examples and case studies that draw on recent development challenges. It also includes new material on research ethics and partnerships to conduct impact evaluation. The handbook is divided into four sections: Part One discusses what to evaluate and why; Part Two presents the main impact evaluation methods; Part Three addresses how to manage impact evaluations; Part Four reviews impact evaluation sampling and data collection. Case studies illustrate different applications of impact evaluations. The book links to complementary instructional material available online, including an applied case as well as questions and answers. The updated second edition will be a valuable resource for the international development community, universities, and policy makers looking to build better evidence around what works in development