Long-term (2005-2015) trend analysis of PM precursor gas NO and SO concentrations in Taiwan.

Ground air monitoring stations have been installed in Taiwan since 1993 to ensure whether the criteria air pollutants meet the ambient air quality standards. In the present study, the data from the monitoring stations were used to evaluate long-term (2005-2015) trend of NO and SO in three metropolitan cities (northern Taipei, central Taichung, and southern Kaohsiung), two eastern coastal cities (Hualien and Taitung), and one agricultural city in west-central plain (Douliu); those cities essentially covered the entire region of Taiwan. The results indicate that SO and NO concentrations of all studied six cities meet the annual average standards of 30 and 50 ppb, respectively.

Abrupt state change of river water quality (turbidity): Effect of extreme rainfalls and typhoons.

River turbidity is of dynamic nature, and its stable state is significantly changed during the period of heavy rainfall events. The frequent occurrence of typhoons in Taiwan has caused serious problems in drinking water treatment due to extremely high turbidity. The aim of the present study is to evaluate impact of typhoons on river turbidity.

Tracking sinks of atmospheric methane using small world networks.

The present study uses small world network to highlight the key hubs for CH4 atmospheric pathways without considering rate constant of each reaction and concentrations of each species. The atmospheric methane sources and sinks were formulated into a well-organized network of 49 nodes and 302 links. In the network, reactions (including substrates and products) are considered as nodes and their pathways as links.

Multi-objective game-theory models for conflict analysis in reservoir watershed management.

This study focuses on the development of a multi-objective game-theory model (MOGM) for balancing economic and environmental concerns in reservoir watershed management and for assistance in decision. Game theory is used as an alternative tool for analyzing strategic interaction between economic development (land use and development) and environmental protection (water-quality protection and eutrophication control). Geographic information system is used to concisely illustrate and calculate the areas of various land use types.

Nonpoint source pollution loading from an undistributed tropic forest area.

Water quality and unit nonpoint sources (NPS) pollution load from a forest area were studied in a mountainous watershed in Taiwan. The flow rates were measured with rectangular weirs and samples taken for water quality analysis in both non-rainy and rainy days for 2 years. The subroutine of the Hydrological Simulation Program--FORTRAN was used to simulate runoff for additional 3 years.

Interactive fuzzy optimization for an economic and environmental balance in a river system.

An interactive fuzzy approach is applied to develop a water quality management plan in a river basin for solving multi-objective optimization problems involving vague and imprecise information related to data, model formulation, and the decision maker's preferences. This approach, originally proposed by Sakawa in 1983, is modified and presented as a sustainable water quality management strategy in which the decision makers and the environmental analysts put forward their views on three major economic and environmental factors: river water quality, assimilative capacity, and treatment cost of wastewater. This methodology is illustrated in a case study of multi-objective water quality management in the Tou-Chen River Basin in northern Taiwan.