Sustainability2016, 8(7), 609; doi:10.3390/su8070609 (registering DOI) - published 28 June 2016 Show/Hide Abstract
Abstract: Land conversion to cropland is one of the major causes of severe soil erosion in Africa. This study assesses the current cropland extent and the related soil erosion risk in Rwanda, a country that experienced the most rapid population growth and cropland expansion in Africa over the last decade. The land cover land use (LCLU) map of Rwanda in 2015 was developed using Landsat-8 imagery. Based on the obtained LCLU map and the spatial datasets of precipitation, soil properties and elevation, the soil erosion rate of Rwanda was assessed at 30-m spatial resolution, using the Revised Universal Soil Loss Equation (RUSLE) model. According to the results, the mean soil erosion rate was 250 t·ha−1·a−1 over the entire country, with a total soil loss rate of approximately 595 million tons per year. The mean soil erosion rate over cropland, which occupied 56% of the national land area, was estimated at 421 t·ha−1·a−1 and was responsible for about 95% of the national soil loss. About 24% of the croplands in Rwanda had a soil erosion rate larger than 300 t·ha−1·a−1, indicating their unsuitability for cultivation. With a mean soil erosion rate of 1642 t·ha−1·a−1, these unsuitable croplands were responsible for 90% of the national soil loss. Most of the unsuitable croplands are distributed in the Congo Nile Ridge, Volcanic Range mountain areas in the west and the Buberuka highlands in the north, regions characterized by steep slopes (>30%) and strong rainfall. Soil conservation practices, such as the terracing cultivation method, are paramount to preserve the soil. According to our assessment, terracing alone could reduce the mean cropland soil erosion rate and the national soil loss by 79% and 75%, respectively. After terracing, only a small proportion of 7.6% of the current croplands would still be exposed to extreme soil erosion with a rate >300 t·ha−1·a−1. These irremediable cropland areas should be returned to mountain forest to foster environmental sustainability or further sustainable alternative erosion control techniques may be applied, such as applying Vetiver Eco-engineering Technology due to its economical soil erosion control and stabilization of steep slopes and the construction of erosion control dams to absorb and break down excess runoff from unusually intense storms in various parts of the watersheds.
Sustainability2016, 8(7), 601; doi:10.3390/su8070601 (registering DOI) - published 28 June 2016 Show/Hide Abstract
Abstract: As the subject of how economic development affects the quality of the natural environment has gained great momentum, this paper focuses on examining the extent to which the openness of a market economy and the quality of the institution affect environmental performance. The majority of the current studies focus on the Environmental Kuznets Curve and the level of economic growth. This paper addresses this question by relating environmental (“Environmental Performance Index”) to macroeconomic (Gross Domestic Product per capita, “Open Markets Index”) and governance indicators (“Worldwide Governance Indicators”). The sample consists of 75 countries, including all G20 and EU members, comprising “more than 90% of global trade and investment”. Findings show that the Environmental Performance Index is positively correlated to each of the (institutional) indicators, so as to confirm that the selected indices are consistent with previous studies, suggesting that environmental performance increases in line with economic development and that good governance increases a country’s levels of environmental protection. By applying factor analysis, an empirical model of the Environmental Performance Index is estimated, suggesting that there is a significant positive correlation between a country’s economic growth, the openness of an economy, high levels of effective governance, and its environmental performance.
Sustainability2016, 8(7), 605; doi:10.3390/su8070605 (registering DOI) - published 28 June 2016 Show/Hide Abstract
Abstract: The main objective of this study is to investigate the causal relationship between tourism development and economic growth in Gulf Cooperation Council (GCC) countries in a multivariate model, using panel data for the period 1995–2012. The study adopts a panel Granger causality analysis approach to assess the contribution of tourism to economic growth in GCC countries as a whole, and in each individual country. In the case of GCC countries as a whole, the results show a one-way Granger causality, from economic growth to tourism growth. Furthermore, Kuwait, Saudi Arabia, Qatar, and the United Arab Emirates follow the path of economy-driven tourism growth, as hypothesized. The reverse hypothesis (i.e., tourism-led growth hypothesis) holds true for Bahrain, while there is no causal relationship between tourism and economic growth in the case of Oman.
Sustainability2016, 8(7), 602; doi:10.3390/su8070602 (registering DOI) - published 28 June 2016 Show/Hide Abstract
Abstract: Rural depopulation and the disappearance of villages in rural Russia occurred as part of the historical process of urbanization and industrialization. Rural depopulation also occurred for structural reasons having to do with village location, and for behavioral reasons whereby villagers react to primitive living conditions and poor economic prospects. Three possible strategies for addressing the problem of sustainable villages are considered. The government is attempting to improve rural living conditions, but rural depopulation is likely to continue. Characteristics of sustainable villages are outlined. Agro-tourism is analyzed for its potential to support sustainable villages.
Sustainability2016, 8(7), 607; doi:10.3390/su8070607 (registering DOI) - published 28 June 2016 Show/Hide Abstract
Abstract: Electric vehicles play a key role for developing an eco-sustainable transport system. One critical component of an electric vehicle is its battery, which can be quickly charged or exchanged before it runs out. The problem of electric vehicle dispatching falls into the category of the shortest path problem with resource renewal. In this paper, we study the shortest path problems in (1) electric transit bus scheduling and (2) electric truck routing with time windows. In these applications, a fully-charged battery allows running a limited operational distance, and the battery before depletion needs to be quickly charged or exchanged with a fully-charged one at a battery management facility. The limited distance and battery renewal result in a shortest path problem with resource renewal. We develop a label-correcting algorithm with state space relaxation to find optimal solutions. In the computational experiments, real-world road geometry data are used to generate realistic travel distances, and other types of data are obtained from the real world or randomly generated. The computational results show that the label-correcting algorithm performs very well.
Sustainability2016, 8(7), 606; doi:10.3390/su8070606 (registering DOI) - published 28 June 2016 Show/Hide Abstract
Abstract: The influence of globalization on sports has turned out to be a popular issue widely discussed by researchers. Improvement to the sustainability of sports industry policy is an important and challenging issue, and related are inherently multiple attribute decision making (MADM) problems that can be strategically important to economic systems. The purpose of this study is to set up a new sustainability sports industry policy evaluation model that addresses the main causal factors and amends the priorities. A MADM model is combined with DEMATEL, DANP, and VIKOR for the evaluation and improvement of the sustainability of sports industry policy. The improvement priorities according to the domain expert interviews are in the following order: promotion and assistance of government policy (A), sports venues and facilities (D), enterprise sponsorship of sports quality (E), expert human resources (B), and finally sports competitions and events (C).