Role of Hydrological Process Representation on Erosion, Deposition, and Sediment Yield Estimate

Soil erosion by water is a major driven force causing land degradation. Laboratory experiments, on-site field study, and suspended sediments measurements were major fundamental approaches to study the mechanisms of soil water erosion and to quantify the erosive losses during rain events. The experimental research faces the challenge to extent the result to a wider spatial scale. Soil water erosion modeling provides possible solutions for scaling problems in erosion research, and is of principal importance to better understanding the governing processes of water erosion. However, soil water erosion models were considered to have limited value in practice. Uncertainties in hydrological simulations are among the reasons that hindering the development of water erosion model. Hydrological models gained substantial improvement recently and several water erosion models took advantages of the improvement of hydrological models. It is crucial to know the impact of changes in hydrological processes modeling on soil erosion simulation.

This dissertation work first created an erosion modeling tool (GEOtopSed) that takes advantage of the comprehensive hydrological model (GEOtop). The newly created tool was then tested and evaluated at an experimental watershed. The GEOtopSed model showed its ability to estimate multi-year soil erosion rate with varied hydrological conditions. To investigate the impact of different hydrological representations on soil erosion simulation, a 11-year simulation experiment was conducted for six models with varied configurations. The results were compared at varied temporal and spatial scales to highlight the roles of hydrological feedbacks on erosion. Models with simplified hydrological representations showed agreement with GEOtopSed model on long temporal scale (longer than annual). This result led to an investigation for erosion simulation at different rainfall regimes to check whether models with different hydrological representations have agreement on the soil water erosion responses to the changing climate. Multi-year ensemble simulations with different extreme precipitation scenarios were conducted at seven climate regions. The differences in erosion simulation results showed the influences of hydrological feedbacks which cannot be seen by purely rainfall erosivity method.

The Philippines in the Aerospace Global Value Chain

This report uses the Duke CGGC Global Value Chain (GVC) framework to examine the role of the Philippines in the global aerospace industry and identify opportunities for the country to upgrade. The Philippines is a newcomer to the growing global aerospace manufacturing industry. Although the country has been host to a major flight controls manufacturer since 1985, the industry really only began to expand within the past five to ten years. During this recent period (2007-2014), the country has rapidly ramped up its aerospace manufacturing exports, reaching US$604 million in 2014 and more than tripling employment. The industry now employs 3,000 full time and 3,000 part time workers. Although still a very small player, accounting for less than 0.15% of the global industry, this incipient growth is promising. Both foreign firms and local suppliers that have established operations in the industry have already achieved some degree of upgrading within a short timeframe. These include expanding the product lines served, obtaining essential process certifications and upgrading beyond basic assembly operations to undertake additional manufacturing processes such as machining as well as initiating procurement and engineering functions in country.

China in Global Value Chains: Implications for Industrial Policy and Development

Rapid technological advances and liberal trade regimes permit functional reintegration of dispersed activities into new border-spanning business networks variously referred to as global value chains (GVCs). Given that the gains of a country from GVCs depend on the activities taking place in its jurisdiction and their linkages to global markets, this study starts by providing a descriptive overview of China’s economic structure and trade profile. The first two chapters of this paper demonstrate what significant role GVCs have played in China’s economic growth, evident in enhanced productivity, diversification, and sophistication of China’s exports, and how these economic benefits have propelled China’s emergence as the world’s manufacturing hub in the past two decades. However, benefits from GVC participation – in particular technological learning, knowledge building, and industrial upgrading – are not automatic. What strategies would help Chinese industries engage with GVCs in ways that are deemed sustainable in the long run? What challenges and related opportunities China would face throughout the implementation process? The last two chapters of this paper focus on implications of GVCs for China’s industrial policy and development. Chapter Three examines how China is reorienting its manufacturing sector toward the production of higher value-added goods and expanding its service sector, both domestically and internationally; while Chapter Four provides illustrative policy recommendations on dealing with the positive and negative outcomes triggered by GVCs, within China and beyond the country’s borders. To the end, this study also hopes to shed some light on the lessons and complexities that arise from GVC participation for other developing countries.