|
|
Fan, W.; Zhang, P.; Xu, Z.; Wei, H.; Lu, N.; Wang, X.; Weng, B.; Chen, Z.; Wu, F.; Dong, X.
The process for reasonably evaluating the potential impacts of circular agriculture on the environment has become a key issue in the sustainable development of circular agriculture
. Based on this consideration, by using Life Cycle Assessment (LCA) and focusing on the circular agriculture industry company of Xingyuan, Fuqing, this paper evaluates the potential impacts of the pig farming industry-dragon fruit planting-forage planting-fishery industry-mushroom planting-biogas generating-organic fertilizer production circular agriculture model compared to a main agriculture industrial model, the pig farming industry, from environmental and environmental-economic perspectives. Moreover, this paper determines key elements that restrict the development of circular agriculture through a sensitivity analysis. The results show that if we simply consider the potential environmental impacts, circular agriculture does not produce better results than those of the main agricultural production model. In addition, if we consider reducing the potential environmental impact as well as improving the economic benefits from the perspective of a "reduction ring", we should consider removing mushroom planting and organic fertilizer from the circular agriculture framework. Moreover, if we want to reduce the potential environmental impact without changing the current recycling model, we should focus on the premix components, especially the three main components of corn, soybean meal, and whey protein concentrate. © 2018 by the authors
Read More
|
|
|
© 2018 by the authors
. In order to assess a concealed karst cave's influence on karst tunnel stability, an assessment model is proposed based on the analytic hierarchy process and a statistical analysis of relevant engineering projects. Major factors are studied and selected as impact factors of the assessment model based on a statistical analysis on a karst cave' s development conditions (karst hydrogeological and engineering geological conditions), construction conditions, and controlling measures. A weight analysis of factors shows that the surrounding rock grade, supporting measurement, formation lithology, unfavorable geology, construction methods, blasting techniques, advanced geological forecast, and groundwater level are the main controlling factors of the tunnel stability when there is a concealed karst cave in the tunnel. Topography and geomorphology, attitude of rocks, monitoring measurement, strata combination, and interlayer fissures are the minor influence factors. Tunnel section shapes, in situ stress, and geological logging are the least important factors. The proposed method is successfully applied to the assessment of a concealed karst cave's influence on the stability of the Huaguoshan Tunnel on the Enshi-Laifeng and Enshi-Qianjiang Expressways. The evaluation result agrees well with the construction site situation. In addition, the result provides good guidance with respect to the implementation of the treatment scheme and effectively avoids accidents in real-time
Read More
|
|
|
As the world’s largest urban area in both size and population, the rapid development of the Pearl River Delta (PRD) during past three decades has been accompanied by worsening water problems
. This paper examines the water-economy nexus of the PRD from the perspectives of both water use and water quality between 1999 and 2015, with a Logarithmic Mean Divisia Index decomposition model as well as an Environmental Kuznets Curve model, in order to assess the sustainable transition of the area. The results show that in this period, while the water dependency of economic development went down by a significant extent, the efficiency gains did not prevail over problems caused by economic scale expansion. However, at the city level, the 2008 financial crisis stimulated an economic transformation of the main economies from being scale-dominated to being efficiency-dominated. From 2009 to 2015, the sewage decreases driven by water dependency of Guangzhou, Shenzhen, and Dongguan outweighed the sewage increases driven by economic scale. While sewage discharge increased, the river water quality of the PRD kept improving. We found an inverted “U”-shaped relationship between GDP per capita and water quality of the PRD, with GDP per capita = ¥14,228.27 as the inflection point for river water quality. Once dubbed the “factory floor” of the world, the PRD has moved into a less environmentally impactful phase of development, with more expenditure on environmental protection and policy reform. However, given the huge and ever-increasing economic and population scales, ensuring a sufficient and safe water supply through industrial recycling and public education, along with even further pollution abatement, will be particularly important
Read More
|
|
|
© 2018 by the author
. The Yarlung Zangbo River Basin (YZRB) is an important transboundary river basin in Tibet, China with south Asian countries. Changes in precipitation are important driving factors of river flow changes. Extreme Precipitation Events (EPE), in particular, have serious impacts on human life and sustainable development. The objective of this study is to explore the temporal changes and the spatial distribution of EPE over the YZRB in recent decades using a precipitation product with a 5 km spatial resolution and the Mann-Kendall nonparametric statistical test method. A more thorough understanding of the spatial heterogeneity in precipitation was expected from using this high resolution dataset. At both basin and pixel scale, both annual precipitation amounts and number of rain days had significant upward trends, indicating that the increase in the number of rain days is one possible cause of the annual precipitation amounts increases. The annual precipitation and number of rain days increased significantly in 50.8% and 75.8% of the basin area, respectively. The areas showing upward trends for the two indexes mostly overlapped, supporting the hypothesis that the increasing number of rain days is one possible cause of the increases in annual precipitation in these areas. General precipitation intensity and EPE intensity increased in the Lhasa regions and in the southern part of the lower-reach region. However, the intensity of general precipitation and EPE decreased in the Nyangqu River Basin. A total of 43.0% of the area in the YZRB exhibits significant upward trends in EPE frequency. The contributions of EPE to total rainfall increase significantly in the Lhasa and Shannan regions. Overall, it was shown that the risk of disasters from EPE in the YZRB increases in the eastern middle-reach region and southern lower-reach region
Read More
|
|
|
© 2018 by the author
. This study investigated the influence of the proximity to wet markets and supermarkets on urban household dietary diversity in Nanjing. Based on the data collected through a citywide survey in 2015 and the map data of wet markets and supermarkets, the Poisson regression model was deployed to examine the correlations between geographical proximity to supermarkets and wet markets and household dietary diversity. The result shows that the coefficients for the distance to the nearest wet market are not statistically significant. Although the coefficients for the distance to nearest supermarket are statistically significant, they were too minor to reach a practical importance. We argue, however, that the insignificant correlations reflect exactly the high physical accessibility to food outlets and the extensive spatially dense food supply network constituted by wet markets, supermarkets and small food stores in Nanjing, due in part to the food infrastructure development planning in Nanjing that has ensured relatively equal and convenient access to wet markets or supermarkets for all households. Our findings are verified by the survey data that more than 90% of households purchased fresh food items within their neighborhoods or in walking distance. In addition to the densely distributed food outlets, various other factors contributed to the non-significant influence of the distance to the nearest wet market and supermarket, in particular, the numerous small food stores within or close to residential communities, the prevalence of three-generation extended household structure and the high household income
Read More
|
|
|
An integrated modelling approach is developed to simulate ecological economics processes of mountainous watershed of Heihe river basin, northwest China
. The objectives are 1) a hydrologic unit model HLM_HMU was developed; 2) the impacts of LUCC on the hydrological processes based on different scenarios were simulated respectively; and 3) the Payment for Ecosystem Services (PES) curve of prohibition grazing is given. The hydrological results show that the observed and simulated data have a good fit, in which the Nash–Sutcliffe efficiency, balance error, and explained variance are 0.69, -0.13, and 0.62, respectively; the model can simulate the majority of peaks well; the source code of Spatial Modelling Environment (SME) needs to be deeply understood to improve the algorithms of interpolation and conflux; the PES result shows that prohibition grazing will occur completely when the price of PES reached to 17.42 yuan, and the increased amount of ecosystem services is 2.13 × 108 m3.The main purpose of this paper is to build a better understanding of developing a meaningful integrated model in the study area to solve its ecological and economic problems
Read More
|
|
|
Summary The Tibetan Plateau (TP) is the “water tower of Asia” and strongly influences both the hydrology and climate of southern and eastern Asia
. Exploring the impact of climate change on the runoff of TP rivers is critical to improve water resources management. However, thorough studies on the runoff response to climate change are seldom conducted on large TP river systems. To complement the current body of work, this study uses two rainfall–runoff models (SIMHYD and GR4J) to simulate the monthly and annual runoff across the Yarlung Tsangpo River (YTR) basin in the southeastern TP (i.e., upstream of the Brahmaputra) under historical (1962–2002) and future (up to approximately 2030) climate conditions. The future climate series are obtained by using 20 Global Climate Models (GCMs) outputs from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) to reflect a 1 °C increase in the global average surface air temperature. The two rainfall–runoff models successfully simulate the historical runoff for the eight catchments in the YTR basins with median monthly runoff Nash–Sutcliffe Efficiencies (NSE) of 0.86 for SIMHYD and 0.83 for GR4J. The mean annual future precipitation and runoff across the region are projected to increase by most of the modeling results. The mean annual precipitation changes obtained from the 20 GCMs are −15%, 7% and 16% for the 10th percentile, median and 90th percentile of GCM outputs, respectively, and the corresponding changes in the simulated mean annual runoffs are −24%, 13% and 29% for the SIMHYD model outputs and −22%, 11% and 26% for the GR4J model outputs. The projected increase in the runoff at the median percentile mainly occurs in the middle reaches of the YTR and its two tributaries, the Lhasa River and the Nyangqu River, with a 12% increase in annual runoff that mainly occurs in the wet season from May to September. The present work is the first comprehensive study on the hydrological response to climate change covering the entire upstream area of the Brahmaputra, and the results found in this study are not only helpful for local water resource management but also for the lower reaches of the Brahmaputra
Read More
|
|
|
Mulligan, M.; Fisher, M.; Sharma, B.; Xu, Z. X.; Ringler, C.; Mahé, G.; Jarvis, A.; Ramírez, J.; Clanet, J.-C.; Ogilvie, A.; Ahmad, M.-U.-D.
In this article the authors assess the potential impacts of projected climate change on water, livelihoods and food security in the Basin Focal Projet basins
. The authors consider expected change within the context of recently observed climate variability in the basins to better understand the potential impact of expected change and the options available for adaptation. They use multi-global circulation model climate projections for the AR4 SRES A2a scenario, downscaled and extracted for each basin. They find significant differences in the impacts (both positive and negative impacts) of climate change, between and within basins, but also find large-scale uncertainty between climate models in the impact that is projected
Read More
|
email alert
or subscribe to the 
RSS feed.
