Journals AtoZhttp://hdl.handle.net/20.500.12424/932024-03-19T05:06:13Z2024-03-19T05:06:13ZLandscape pattern optimization of small watershed based on water purification (Danjiangkou reservoir area, China)Bojun MaKun SunXiaoshuang WangJigen LiuGuanhua ZhangPengcheng WangWenfeng DingJinquan HuangYu ZhangZhixiang Zhouhttp://hdl.handle.net/20.500.12424/43056732024-03-16T20:00:22Z2024-06-01T00:00:00ZLandscape pattern optimization of small watershed based on water purification (Danjiangkou reservoir area, China)
Bojun Ma; Kun Sun; Xiaoshuang Wang; Jigen Liu; Guanhua Zhang; Pengcheng Wang; Wenfeng Ding; Jinquan Huang; Yu Zhang; Zhixiang Zhou
In recent years, landscape pattern optimization has been regarded as a cutting-edge science in various fields, and basin hydrology is no exception. Its effect on basin water purification has also been focused on. Based on the analysis of land use types and landscape patterns in the Danjiangkou Reservoir Basin, and combined with the determination of water quality indicators in the Danjiangkou Reservoir Basin, the relationship between the spatial pattern of Landscape Morphology and water quality was studied; It is found that among the basic characteristic indicators of many basins, the main influencing factors of water quality with high Variable importance for the projection (VIP>1) are IJI (Interspersion and Juxtaposition Index), COHE (Patch Cohesion Index), AI (Aggregation Index), PD (Patch Density), ED (Edge Density); Using PLSR (Partial Least Squares Regression) analysis, the main influencing factors of water quality were discussed. It was found that there was a significant negative regression relationship (Rc < 0) with CODMn (permanganate index), TP (Total Phosphorus), TN (Total Nitrogen) and NH4+-N (ammonia nitrogen) in the basin, and the influencing factors were topographic humidity index, topographic relief, slope, and forest area; The landscape patch connectivity index was used to determine the ecological source areas in the Danjiangkou reservoir basin that have improved connectivity and need to be protected; The priority of ecological corridor construction and protection was determined; With the help of the minimum cumulative resistance model, the ecological corridor between various ecological sources is constructed; The ecological grips on the ecological corridor are identified. In order to provide technical support for the optimization of landscape configuration for the purpose of water quality purification in Danjiangkou reservoir area.
2024-06-01T00:00:00ZEconomic evaluation of the removal of hydropower damsKristina EkElin SpegelJesper Stagehttp://hdl.handle.net/20.500.12424/43056722024-03-16T20:00:19Z2024-06-01T00:00:00ZEconomic evaluation of the removal of hydropower dams
Kristina Ek; Elin Spegel; Jesper Stage
Stricter environmental regulations (e.g. the EU’s Water Framework Directive) will entail many environmental improvement measures in waters that have been affected by hydropower, and dam removals are becoming a more common measure. This paper reviews economic evaluations of dam removals, primarily drawing on studies in the USA, and identifies key, frequently recurring, issues that future evaluations will likely need to consider. The paper also reports on an ex-ante evaluation of the recent removal of the Marieberg Hydropower Plant in the Mörrum River in Sweden. An environmental valuation survey carried out as a key part of this evaluation was conducted as a replication of a previous study, where the policy context was different but the expected ecological outcome similar. The replication study produced comparable results to those of the previous study.
2024-06-01T00:00:00ZAnnual consumption and types of synthetic nitrogen fertilizers: Ammonia emission indicators for mitigation strategies in the European UnionYuncai HuUrs Schmidhalterhttp://hdl.handle.net/20.500.12424/43056712024-03-16T20:00:15Z2024-06-01T00:00:00ZAnnual consumption and types of synthetic nitrogen fertilizers: Ammonia emission indicators for mitigation strategies in the European Union
Yuncai Hu; Urs Schmidhalter
Anthropogenic ammonia (NH3) emissions are primarily derived from agricultural activities. NH3 emissions from synthetic nitrogen (N) fertilizers are associated with the annual consumption of various N fertilizers. In this study, the annual consumption of different types of synthetic N fertilizers in the EU countries, derived from the database of the International Fertilizer Association, was analyzed, and the implementation of mitigation measures for NH3 emissions at the national level was assessed. NH3 emissions were estimated using the emission factors of different N fertilizers in cool, temperate and hot climates, and low- and high-pH soils, as the European Environment Agency proposed. The results revealed that the annual consumption of various synthetic N fertilizers (average values from 2016 to 2020) varied markedly in different EU countries. France, Germany, Poland, Spain, and the United Kingdom had the largest annual consumption of synthetic N fertilizers. NH3 emissions from urea-based fertilizers are the highest in most EU countries. The annual NH3 emissions were associated with the type of synthetic N fertilizer consumed. For example, although the annual synthetic N fertilizer consumption in Germany was 38% and 41.5% higher than those in Spain and Italy, the annual NH3 emissions in Germany were 63% and 20% lower than those in Spain and Italy, respectively, due to the high proportion of urea-based fertilizers with the highest emission factor among the synthetic N fertilizers in Spain and Italy. Thus, mitigation strategies should be tailored to specific types of N fertilizers with high emission factors and proportions to minimize NH3 emissions. Since the NH3 emissions from urea-based fertilizers are the highest in the EU countries, especially in the top five countries, we recommend the addition of urease inhibitors to urea fertilizers as one important strategy for mitigating NH3 emissions.
2024-06-01T00:00:00ZMetals and metaloid preserved in marine sediments of an industrial complex of central Chile. Environmental assessment using different background valuesJorge Valdés SaavedraEduardo Quirogahttp://hdl.handle.net/20.500.12424/43056702024-03-16T20:00:11Z2024-06-01T00:00:00ZMetals and metaloid preserved in marine sediments of an industrial complex of central Chile. Environmental assessment using different background values
Jorge Valdés Saavedra; Eduardo Quiroga
This work examines the distribution of metals(oid) in coastal sediments of the Concon-Quintero industrial complexes (central Chile), and evaluates the environmental condition of this zone, using some environmental indexes and different global and local background values.The Index of geoaccumulation and the Enrichment Factor were different depending on the background values used to calculate them. Only Mo and Pb, simultaneously show both an enrichment, and some degree of pollution problem, with all backgrounds utilized. Three of the four background values used in this work to calculates the Pollution Load Index suggests a polluted condition of the bottom environment. The spatial distribution, the results of environmental indices and the comparison with local environmental legislation suggests that Pb is introduced to the marine system by industrial activities. The result of both, SQG and m-ERM-Q suggest that metals preserved in the sediments are a threat to the benthic life, especially in the Concon-Ritoque zone, where the highest values were recorded.These results suggest a notorious influence of the Aconcagua river on the metal accumulation in the coastal zone.
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