Economics of Sustainable Natural Resource Management

Can existing patterns of human activity safely and sensibly continue unaltered over the long term, or will continuing these patterns lead to unacceptable consequences? This is the central issue underlying current discussions of sustainability. There is no denying that human activity remains completely dependent on natural resources and on the larger environment in which we function, so sustainable human systems require careful management of natural resources over the long term. This dissertation contributes to the understanding of sustainable economic development. To be specific, it focuses on certain renewable natural resources that are thought to be a key element of sustainability. The dissertation consists of three separate studies: two empirical case studies and one theoretical modeling study. The first study develops an economic model to address water allocation issues between upstream and downstream cities, then applies this model to the Nakdong River basin in South Korea. The second study focuses on soil erosion problems in developing countries, examining the role of public intervention in farmer adoption of soil conservation practices. Using two-period panel data collected from Salvadorian farmers, the study offers new insights into farmer adoption behaviors, and suggests ways to improve soil conservation programs. The last study develops an intertemporal resource allocation that combines bequest motives and Rawls’ maximin principle with the undiscounted utilitarian criterion. Our model provides an optimal path for sustainability by meeting two conditions: guaranteeing the highest sustainable utility level for future generations by following the GGR, and being acceptable for present generations by unburdening their excessive hardship

Is Sustainable Watershed Management Feasible under Climate Change? An Economic Appraisal of the Nile River

Historically, the Nile, a well-known transboundary river, has been a major contributor to Egyptian economic growth in many ways but has suffered from sediment accumulation. Since anthropocentric activities on the Nile delta heavily rely on nutrient-rich sediment from the Ethiopian highland, sediment control schemes in the Aswan High Dam not only prolong the life of the dam but also increase the economic value of the watershed. The purpose of our study is to use an economic optimization approach to evaluate the feasibility of sustainable management of the Nile concerning climate change. The model considers significant anthropocentric effects on the reservoir as well as the impacts of climate change on the entire watershed. Moreover, the social planner’s model is developed to unravel somewhat numerous externalities. The results indicate that among the various technically feasible sediment removal schemes, the hydro-suction sediment removal system (HSRS) is the only desirable solution under severe climate change. In order to control the negative externalities in the watershed, the in-stream flow control should be applied. By implementing appropriate management schemes simultaneously, the life of the AHD can be extended, and the total economic benefits of the entire watershed can be maximized to approximately $272 billion USD

Impacts of Climate Change on Reservoir Management and Downstream Watershed

Although it is well known that sedimentation may reduce the storage capacity of a dam, there is relatively modest amount of economic research on the subject. Furthermore, there is no economic literature as yet on the important relationship between climate change and reservoir management. This paper attempts to address both issues in the context of a dynamic optimization model that maximizes social welfare by allowing for periodic sediment removal from a dam in a way that is responsive to changing climatic conditions and the needs of downstream users. The model is applied to the Aswan High Dam in Egypt. The reservoir of this dam impounds 90 km3 of water from two main Nile Rivers. The dam provides substantial economic benefits to Egypt in terms of hydropower, irrigation, and flood control. However, the dam’s storage capacity is being reduced over time due to sedimentation, and climate change is also likely to significant impact it’s future net benefits by altering evaporation and precipitation rates. Our model computes effective storage capacity of a reservoir by considering sedimentation, evaporation, and precipitation rates simultaneously. Reservoir-level sediment removal is our control variable and this allows us to influence downstream agriculture productivity, which is also determined in part by climate change. Hydrologic data of the Aswan High Dam is obtained from the International River and Lake Network and regional agricultural data is obtained from the FAO. Climate change forecasting data for the Nile River Basin is based on IPPC reports. Our simulation results indicate that, without climate change, optimal sediment control increases reservoir life indefinitely and social welfare by 36%, compared to the situation with no sediment control. With climate change that involves relatively high evaporation rates, however, optimum reservoir life is curtailed to 319 years and social welfare is reduced by 21%

Economics of Integrated Watershed and Reservoir Management

A dynamic optimization framework is used to analyze integrated watershed management and suggest appropriate policies. Soil conservation, reservoir level sediment release, downstream water allocation and water quality are subject to control. Application of the model to the Aswan Dam watershed illustrates the need for international cooperation to manage shared watersheds

EFFECTS OF VIBRATION IN STORAGE-RING OF POHANG LIGHT-SOURCE

Effects of vibrations in a storage ring are described. For convenience, vibrational sources are categorized as internal and external sources depending on their locations. Internal sources are likely to cause a random vibration of magnets, and their effects on the motion of a circulating beam are described well by the conventional closed orbit amplification factor. External sources cause all or some magnets to vibrate in a coherent manner, and their effect on the beam motion requires separate treatment. In this paper, we discuss the effects of both internal and external vibrational sources on the motion of a stored beam in a storage ring. The results are applied to the Pohang Light Source (PLS) 2 GeV storage ring, currently under construction in Pohang, Korea. Some recent measurement results of the PLS storage ring floor vibration are also presented.X110sciescopu

Road-Aware Trajectory Prediction for Autonomous Driving on Highways

For driving safely and comfortably, the long-term trajectory prediction of surrounding vehicles is essential for autonomous vehicles. For handling the uncertain nature of trajectory prediction, deep-learning-based approaches have been proposed previously. An on-road vehicle must obey road geometry, i.e., it should run within the constraint of the road shape. Herein, we present a novel road-aware trajectory prediction method which leverages the use of high-definition maps with a deep learning network. We developed a data-efficient learning framework for the trajectory prediction network in the curvilinear coordinate system of the road and a lane assignment for the surrounding vehicles. Then, we proposed a novel output-constrained sequence-to-sequence trajectory prediction network to incorporate the structural constraints of the road. Our method uses these structural constraints as prior knowledge for the prediction network. It is not only used as an input to the trajectory prediction network, but is also included in the constrained loss function of the maneuver recognition network. Accordingly, the proposed method can predict a feasible and realistic intention of the driver and trajectory. Our method has been evaluated using a real traffic dataset, and the results thus obtained show that it is data-efficient and can predict reasonable trajectories at merging sections

Characteristics and Socio-Demographic Distribution of Precarious Employment Among Korean Wage Workers: A Proposition of Multidimensional Approach Using a Summative Score

Introduction: There is a growing global interest in the issue of precarious employment. We aimed to analyze the characteristics and socio-demographic distribution of precarious employment using a summative score approach. Methods: To operationalize precarious employment, we utilized data from the Korean Working Conditions Survey and focused on three distinct dimensions: employment insecurity, income inadequacy, and a lack of rights and protections. By constructing a summative scale ranging from -16 to 2, with lower scores indicating higher precariousness, we measured employment precariousness among Korean wage workers. To compare employment precariousness according to survey participant characteristics, we employed the Wilcoxon Rank Sum Test. Results: We analyzed a weighted number of 38,432 workers. The overall sample showed a median (Q1, Q3) summative scale score of -3 (-6, -1). The median summative score was lower for women compared to men (men: -2; women: -5; p < 0.001), as well as for young or older workers compared to middle-aged workers (young: -4; middle-aged: -2; older: -5; p < 0.001). Similarly, workers with lower educational levels (middle school or below: -8; high school: -5; college or above: -2; p < 0.001) and non-white collar workers (blue collar: -5; service/sales worker: -6; white collar: -2; p < 0.001) experienced higher levels of employment precariousness. Conclusion: Our findings indicate that certain vulnerable groups, such as women, young or older adults, workers with low educational attainment, and caregiving or low-skilled elementary workers, are disproportionately exposed to high employment precariousness. Active policy interventions are needed to improve the employment quality of vulnerable groups