Water and nitrogen footprint assessment of integrated agronomic practice management in a summer maize cropping system

The footprints of water and nitrogen(WF and NF)provide a comprehensive overview of the type and quantity of water consumption and reactive nitrogen(Nr)loss in crop production.In this study,a field experiment over two years(2019 and 2020)compared three integrated agronomic practice management(IAPM)systems:An improved management system(T2),a high-yield production system(T3),and an integrated soil-crop management system(ISCM)using a local smallholder farmer’s practice system(T1)as control,to investigate the responses of WF,Nr losses,water use efficiency(WUE),and nitrogen use efficiency(NUE)to IAPM.The results showed that IAPM optimized water distribution and promoted water use by summer maize.The evapotranspiration over the whole maize growth period of IAPM increased,but yield increased more,leading to a significant increase in WUE.The WUE of the T2,T3,and ISCM treatments was significantly greater than in the T1 treatment,in 2019 and 2020respectively,by 19.8-21.5,31.8-40.6,and 34.4-44.6%.The lowest WF was found in the ISCM treatment,which was 31.0%lower than that of the T1 treatment.In addition,the ISCM treatment optimized soil total nitrogen(TN)distribution and significantly increased TN in the cultivated layer.Excessive nitrogen fertilizer was applied in treatment T3,producing the highest maize yield,and resulting in the highest Nr losses.In contrast,the ISCM treatment used a reduced nitrogen fertilizer rate,sacrificing grain yield partly,which reduced Nr losses and eventually led to a significant increase in nitrogen use efficiency and nitrogen recovery.The Nr level in the ISCM treatment was34.8%lower than in the T1 treatment while NUE was significantly higher than in the T1 treatment by 56.8-63.1%in2019 and 2020,respectively.Considering yield,WUE,NUE,WF,and NF together,ISCM should be used as a more sustainable and clean system for sustainable production of summer maize.

Carbon Footprint in Waste Sector of Hydropower Plant: A Case Study of Nam Theun 2 Hydropower Plant

While hydropower is generally considered a clean energy source, it is important to recognize that their waste can still contribute to greenhouse gas emissions (GHG). The purpose of this study is to assess the carbon footprint associated with the waste sector throughout the operational phase of the Nam Theun 2 hydropower plant in Laos. Understanding the environmental impact of the waste sector is crucial for ensuring the plant’s sustainability. This study utilizes the theoretical estimation method recommended in the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, as well as the Requirements for Specification with guidance at the organization level for quantification and reporting of GHG emissions and removals. We emphasize the significance of implementing sustainable waste management practices to reduce GHG emissions and minimize the environmental impact of hydropower operations. By conducting a comprehensive analysis, this paper also provides insights into the environmental implications of waste management in hydropower plants and identifies strategies to mitigate the carbon footprint in the waste sector. The findings contribute to a better understanding of the environmental sustainability of hydropower plants and provide valuable guidance for policymakers, energy producers, and environmental practitioners involved in hydropower plant design and operation.

The potential impact of increased whole grain consumption among Chinese adults on reducing healthcare costs and carbon footprint

Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.

Evaluation of Ecological Sustainable Development in the Yangtze River Delta Region Based on Ecological Footprint Theory

The ecological footprint was employed as a quantitative indicator of resource inputs,enabling a detailed account of the structure of biological resources and energy occupancy,as well as the variation of resource productivity in the Yangtze River Delta(YRD)Region.From 2004 to 2018,there were notable variations in the ecological productivity of different types of land on basis of China’s equilibrium factor across the three provinces and one city in the YRD region.Jiangsu Province exhibited the highest ecological productivity of arable land,while Anhui Province exhibited the highest ecological productivity of forest land.Shanghai City exhibited the highest ecological productivity of pasture land,while Zhejiang Province exhibited the highest ecological productivity of water area.In 2018,the proportion of arable land within the total ecological carrying capacity of the YRD region reached 74.35%.Furthermore,the contribution of Jiangsu and Anhui provinces to the YRD’s total ecological carrying capacity was 41.36%and 41.26%,respectively.In the construction of a new development pattern in the YRD region,which is dominated by the domestic cycle as the main body and mutually reinforced by domestic and international double-cycle,the YRD region should combine the utilization of natural forces with innovation in science,technology and cooperation mechanisms.Furthermore,the government should guide the concentration of social capital towards green industries.It is also recommended that the moderate reduction of ecological footprints should be encouraged,and that the security of biological resources and energy,the leadership in the field of cutting-edge science and technology should be ensured in YRD region.This will facilitate the formation of a new development pattern of higher-quality integration at the national level firstly.

The potential of green manure to increase soil carbon sequestration and reduce the yield-scaled carbon footprint of rice production in southern China

Green manure(GM)has been used to support rice production in southern China for thousands of years.However,the effects of GM on soil carbon sequestration(CS)and the carbon footprint(CF)at a regional scale remain unclear.Therefore,we combined the datasets from long-term multisite experiments with a meta-analysis approach to quantify the potential of GM to increase the CS and reduce the CF of paddy soils in southern China.Compared with the fallow-rice practice,the GM-rice practice increased the soil C stock at a rate of 1.62 Mg CO_(2)-eq ha^(-1) yr^(-1) and reduced chemical N application by 40%with no loss in the rice yield.The total CF varied from 7.51 to 13.66 Mg CO_(2)-eq ha^(-1) yr^(-1) and was dominated by CH_(4) emissions(60.7-81.3%).GM decreased the indirect CF by 31.4%but increased the direct CH_(4) emissions by 19.6%.In the low and high CH_(4) emission scenarios,the CH_(4) emission factors of GM(EF_(gc))were 5.58 and 21.31%,respectively.The greater soil CS offset the increase in GM-derived CF in the low CH_(4) scenario,but it could not offset the CF increase in the high CH_(4) scenario.A trade-off analysis also showed that GM can simultaneously increase the CS and reduce the total CF of the rice production system when the EF_(gc) was less than 9.20%.The variation in EF_(gc) was mainly regulated by the GM application rates and water management patterns.Determining the appropriate GM application rate and drainage pattern warrant further investigation to optimize the potential of the GM-rice system to increase the CS and reduce the total CF in China.

An analysis of energy consumption and carbon footprints of cryptocurrencies and possible solutions

There is an urgent need to control global warming caused by humans to achieve a sustainable future.CO_(2) levels are rising steadily,and while countries worldwide are actively moving toward the sustainability goals proposed during the Paris Agreement in 2015,we are still a long way to go from achieving a sustainable mode of global operation.The increased popularity of cryptocurrencies since the introduction of Bitcoin in 2009 has been accompanied by an increasing trend in greenhouse gas emissions and high electrical energy consumption.Popular energy tracking studies(e.g.,Digiconomist and the Cambridge Bitcoin Energy Consumption Index(CBECI))have estimated energy consumption ranges from 29.96 TWh to 135.12 TWh and 26.41 TWh to 176.98 TWh,respectively for Bitcoin as of July 2021,which are equivalent to the energy consumption of countries such as Sweden and Thailand.The latest estimate by Digiconomist on carbon footprints shows a 64.18 MtCO_(2) emission by Bitcoin as of July 2021,close to the emissions by Greece and Oman.This review compiles estimates made by various studies from 2018 to 2021.We compare the energy consumption and carbon footprints of these cryptocurrencies with countries around the world and centralized transaction methods such as Visa.We identify the problems associated with cryptocurrencies and propose solutions that can help reduce their energy consumption and carbon footprints.Finally,we present case studies on cryptocurrency networks,namely,Ethereum 2.0 and Pi Network,with a discussion on how they can solve some of the challenges we have identified.

Carbon footprints in minimally invasive surgery:Good patient outcomes,but costly for the environment

Advancements in technology and surgical training programs have increased the adaptability of minimally invasive surgery(MIS).Gastrointestinal MIS is superior to its open counterparts regarding post-operative morbidity and mortality.MIS has become the first-line surgical intervention for some types of gastrointestinal surgery,such as laparoscopic cholecystectomy and appendicectomy.Carbon dioxide(CO_(2))is the main gas used for insufflation in MIS.CO_(2)contributes 9%-26%of the greenhouse effect,resulting in global warming.The rise in global CO_(2)concentration since 2000 is about 20 ppm per decade,up to 10 times faster than any sustained rise in CO_(2)during the past 800000 years.Since 1970,there has been a steady yet worrying increase in average global temperature by 1.7℃ per century.A recent systematic review of the carbon footprint in MIS showed a range of 6-814 kg of CO_(2)emission per surgery,with higher CO_(2)emission following robotic compared to laparoscopic surgery.However,with superior benefits of MIS over open surgery,this poses an ethical dilemma to surgeons.A recent survey in the United Kingdom of 130 surgeons showed that the majority(94%)were concerned with climate change but felt that the lack of leadership was a barrier to improving environmental sustainability.Given the deleterious environmental effects of MIS,this study aims to summarize the trends of MIS and its carbon footprint,awareness and attitudes towards this issue,and efforts and challenges to ensuring environmental sustainability.

Carbon, Water, Ecological Footprints, Energy and Nutritional Densities of Omnivore and Vegan Culinary Preparations

This study aimed to evaluate energy and nutritional densities, water, carbon and ecological footprints, cost, of omnivorous and vegan main courses served in a university restaurant in the city of Rio de Janeiro. A cross-sectional, analytical study was conducted with 40 main dish-type preparations, 20 of which are omnivorous and 20 vegans, served at lunch, to assess energy and nutritional densities, carbon, water and ecological footprints and cost of preparations. We propose a healthy and sustainable preparation index (HSPI) to evaluate from the list, the best preparation options considering the nutritional quality combined with the impact that the food causes on the environment. Preparations with the highest HSPI were considered the best options because they have a good relation between the nutritional profile and the environmental impact. Results: Regarding energy (ED), nutritional (ND) densities and water, carbon and ecological footprints, omnivorous preparations presented much higher values when compared to the vegan ones. The omnivorous preparations had the highest average cost (R$ 3.44). Regarding the HSPI, vegan preparations showed better rates than omnivorous preparations. Food services should promote healthy and sustainable choices by offering menus with low energy density preparations, high nutritional density, and low environmental impact, considering local realities and customer needs. Conclusion: This study was able to evaluate the best preparation options, considering the nutritional profile and the food impact on the environment, using health and sustainable indicators. Obtaining indicators of preparations regarding healthiness and sustainability, in practice, translates environmental aspects in menu planning, which contribute to changes in food consumption patterns in food services, in addition to contributing to the reduction of the environmental impact. In this way, they can be used as tools added to the menu planning process for the analysis of the environmental impact of menus, in addition to nutritional and qualitative aspects.

Carbon and Water Footprint Evaluation of 120Wp Rural Household Photovoltaic System: Case Study

This study uses the Life Cycle Analysis (LCA) to evaluate the magnitude of the environmental impact, in terms of global warming potential, and water footprint throughout the 20 years of useful life of a rural electrical energy concession comprised of 120Wp Households photovoltaic systems (HPS) in the isolated communities of San Martin, in the Peruvian Amazon region. On the other hand, due to the particular conditions of the system (installation, operation, maintenance, monthly tariff collection), it is necessary to know its real impact and sustainability;not only through the aforementioned environmental impact indicators, but also by energy intensity values required by the system throughout its life cycle. Therefore, this paper used the Cumulative energy demand (CED) method to determine the amount of energy taken from natural resources for each process involved in the LCA and calculated with this, i.e., the Energy Payback Time (EPBT) of the whole system. Likewise, the HPS has been environmentally compared to other case studies and the Peruvian Energy Mix, revealing a lower impact in the latter case and results within the range for stand-alone systems. Besides, the HPS shows a strong relation between energy production and O&M condition. Additionally, this study allows a further promotion of the use of this type of system in isolated areas, as well as the diversification of electricity generation in Peru.

Can food security and low carbon be achieved simultaneously?——An empirical analysis of the mechanisms influencing the carbon footprint of potato and corn cultivation in irrigation areas

Irrigated agriculture has tripled since 1950,accounting for 20%of the global arable land and 40%of food production.Irrigated agriculture increases food security yet has controversial implications for global climate change.Most previous studies have calculated carbon emissions and their composition in irrigated areas using the engineering approach to life-cycle assessment.By combining life cycle assessment(LCA)-based carbon emissions accounting with econometric models such as multiple linear regression and structural equation modeling(SEM),we conducted an interdisciplinary study to identify the influencing factors and internal mechanisms of the carbon footprint(CFP)of smallholder crop cultivation on irrigation reform pilot areas.To this end,we investigated corn and potato production data in the 2019–2020 crop years for 852 plots of 345 rural households in six villages(two irrigation agriculture pilot villages and four surrounding villages as controls)in Southwest China.The crop CFP in the irrigation agriculture pilot areas was significantly lower than in non-reform areas.Irrigation reforms mainly impacted the crop CFP through four intermediary effects:the project(implementation of field irrigation channels),technology(improving adoption of new irrigation technologies),management(proper irrigation operation and maintenance),and yield effects.All effects inhibited the CFP,except for the project effect that promotes carbon emissions.Among them,yield increase has the greatest impact on reducing CFP,followed by management and technology effects.Furthermore,planting practices,individual characteristics,and plot quality significantly impacted the crop CFP.This study has policy implications for understanding the food security–climate nexus in the food production industry.

Fences and hydropower:Important but overlooked Human Footprint

Human activities have impacted 77%of the terrestrial ecosystems(excluding Antarctica),and the remaining areas are becoming increasingly endangered.Mapping spatiotemporal dynamics of Human Footprint has been used to evaluate the cumulative interference on terrestrial environments globally.However,fences and hydropower,two widespread and rapidly expanding infrastructures,have not been considered regarding Human Footprint,despite their complicated and extensive effects on ecosystem functioning and species survival.Previous work has proved that fences increase habitat fragmentation,disrupt migratory routes,inadvertently trap and kill wildlife,and hinder genetic exchange.Hydropower construction also caused habitat loss,fragmentation,and degradation.These impacts have received global concern,but fences around the world are difficult to be detected due to the limitations of current cartographic technologies.Furthermore,the effect of hydropower on the terrestrial environment has been underestimated,making the research on this topic at a global scale still in its infancy.Therefore,building an observation network of global fences and hydropower is a necessary step to move forward in the assessment of the impact of human activities on our planet,but also to better provide scientific support for policy-making regarding global biodiversity conservation,the identification of protected areas,and the prioritization of ecological restoration areas.

煤矿充填固碳理论基础与技术构想

在国家“双碳”目标背景下,如何减少煤炭行业的碳排放、实现碳封存已成为亟待解决的难题。煤炭行业作为高碳化石能源生产者和主体碳排放源提供者,在生产和消费过程中引发的大宗固废堆存、大型采空区形成和大量CO_(2)排放是制约煤炭可持续开发利用与绿色健康发展的瓶颈所在。为协同解决二氧化碳封存与矿山固废消纳问题,将大宗固废处置、固废高值化利用、CO_(2)封存、采空区利用有机结合,提出了二氧化碳充填的理念,从碳汇能力评估角度界定了二氧化碳充填的3种类型。具体开展工作包括:①分析了CO_(2)充填料浆输运过程和矿化反应过程涉及到的基础理论,给出了各个过程的数学方程以及碳封存量计算公式,指出了温度、湿度等因素对矿化反应机理、碳封存量和充填体强度的影响规律。②总结了现阶段CO_(2)矿化的工艺方法、主要碱性工业固废的CO_(2)封存能力和CO_(2)矿化强化措施。在此基础上提出了基于直接湿法矿化和间接矿化的2种CO_(2)充填材料制备工艺,满足矿井充填的流动性、凝固特性和强度要求。③针对CO_(2)充填过程中的CO_(2)物理封存问题,提出了窄条带式胶结充填和综采架后胶结充填2种技术路径,前者通过在弱充填条带中构筑多贯通孔隙的充填体CO_(2)物理封存,后者借助充填支架和链式自行充填挡板在长壁工作面采空区中间断构筑充填带,控制顶板垮落,形成CO_(2)物理化学封存空间。④为了评估CO_(2)充填的碳平衡效果,依据全生命周期法界定了CO_(2)充填中碳足迹及碳消纳的计算边界。然后,梳理了CO_(2)充填过程中的碳足迹及碳消纳,分别考虑了CO_(2)的来源、用量、损耗、转化等因素。给出了包括原料运输、充填料浆制备、井下注入与充填等过程中的碳足迹及碳消纳计算方法。研究成果有望降低CO_(2)封存的能耗及成本,对煤炭绿色开采及其可持续开发利用具有深远的意义。

Thoughts and Prospects for Promoting Energy-Saving and Carbon Footprint Reduction in the Non-Ferrous Metal Industry

As the upstream of high-energy consumption industries such as metallurgy and chemical enterprises, the “carbon neutrality” ability of mining and mining enterprises can have a strong influence on the progress of China’s non-ferrous metal industry to achieve the “double carbon” goal. According to the Global Mining Development Report 2021, although mining occupies an important position in global economic development, it also accounts for 4% to 7% of global greenhouse gas emissions. Therefore, as an important part of promoting China’s economic development and energy structure transformation, mining will also face scale adjustment. By investigating and studying the carbon emission sources of mining enterprises at the current stage at home and abroad, the carbon neutrality method that has been implemented in mines, and the future low-carbon technologies to be developed, this paper provides the thoughts and prospects for promoting the development of green mines, as well as the reference value for the transformation of China’s mining industry.

甘肃温室葡萄生产的能量利用与碳足迹研究

【目的】探明甘肃温室葡萄生产的能量投入和碳足迹构成,识别主要的碳排放贡献因子,为温室葡萄清洁生产提供依据。【方法】以甘肃温室葡萄为研究对象,将温室葡萄栽培区分为兰州市永登县及武威市凉州区、古浪县、天祝县华藏寺镇和天祝县哈溪镇5个不同海拔区域,通过农户调查获得2019年葡萄生产数据,核算温室葡萄生产各环节的能量输入、能量输出和碳排放,对比分析不同海拔区域温室葡萄生产的能量利用效率、能量生产率、净能量、比能和碳足迹。【结果】甘肃温室葡萄生产的能量输入为273862~434421 MJ/hm^(2),能量输出为170723~327962 MJ/hm^(2),葡萄产量为14460~27793 kg/hm^(2),属于高投入高产出型。甘肃温室葡萄生产的能量利用效率为0.45~1.13,能量生产率为0.038~0.096 kg/MJ,净能量为-263798~2496 MJ/hm^(2),比能为13.51~44.85 MJ/kg;直接能量投入和可再生能量投入占比低,间接能量投入和不可再生能量投入占比高。单位面积碳足迹和单位产量碳足迹分别为32959~55075 kg/hm^(2)和1.59~5.70 kg/kg,碳足迹很大程度上来源于氮肥的投入,其占比达45.5%~62.4%。不同区域相比,天祝县哈溪镇温室葡萄生产的能量输入低,能量输出和产量较高,能量利用效率和能量生产率也较高,净能量最大且为正值,比能最小,单位面积碳足迹和单位产量碳足迹均最小;天祝县华藏寺镇能量利用指标最差,碳足迹最大。【结论】甘肃温室葡萄生产的能量利用效率较低,碳足迹较高,能量利用效率的提高和碳足迹的降低空间均较大。因此应采取降低氮肥使用量、优化氮肥与有机肥配比等科学合理的管理措施,提高甘肃温室葡萄生产的能量利用效率,降低碳足迹,改善其环境效应。

淮河流域谷物生产水足迹及用水效率研究

为研究淮河流域水稻、小麦、玉米三大谷类粮食作物生产用水总量和用水效率,保障粮食安全,促进粮食生产可持续发展,本研究以淮河及沂-沭-泗水系的35个地级市为研究对象,基于2000-2019年谷物生产、水资源、气候等数据,采用PenmanMonteith模型、探索性空间数据分析(ESDA)模型、空间杜宾模型,对流域谷物生产水足迹强度进行测度以反映其用水效率,并分析其时空演变特征及影响因素。结果表明,2000-2019年淮河流域谷物生产水足迹逐渐趋于稳定,谷物生产水足迹强度整体下降82.86%。水足迹强度空间集聚显著,集聚状态逐渐稳定。社会经济条件、农业生产投入、农业生产条件、自然条件与资源禀赋对谷物生产水足迹强度影响显著。淮河流域谷物生产用水总量整体增加,用水效率总体不断提升。淮河流域谷物生产用水效率存在显著的空间差异,效率较高的区域为淮河干流下游及沂-沭-泗水系,效率较低的区域为淮河干流安徽段。农村经济发展水平、科技发展水平与有效灌溉面积等因素的提升能促进谷物生产用水效率的提升,城镇化水平、化肥施用量、年日照时长、年平均气温等因素的提升则会对其产生抑制作用,农村经济发展水平、城镇化水平、年平均气温等因素通过要素流动、技术转移等产生空间溢出效应。

水力发电生命周期评价及碳足迹区域化分析

基于生命周期评价方法,对我国典型水电站水力发电生命周期碳足迹及其他环境影响进行了评估,并分析讨论了不同区域水力发电碳足迹的差异性及原因。结果显示,三峡水电站单位水电碳足迹(以CO_(2)当量计)为12.7 g/(kW·h),主要来源于运行阶段,造成其他环境影响的主要阶段为土建工程阶段,其次为机电设备制造阶段;我国不同省级行政区单位水电碳足迹差距较大,与全国平均值相差±20%以上的省级行政区有24个;各省级行政区运行阶段碳足迹占比为47.94%~96.82%,占比超过80%的省级行政区有19个。研究结果可以为我国及省级发电清单编制与电网结构调整提供数据支撑。

中国燃煤发电水足迹时空特征研究

中国燃煤发电行业需要消耗大量水资源。基于生命周期方法,建立了中国燃煤发电水足迹评估模型。该模型包括煤炭开采、煤炭加工、煤炭运输、燃煤发电和电力输送五个阶段,水足迹不仅考虑了直接水足迹,还有间接水足迹。基于该模型,定量分析了2000—2020年中国燃煤发电整个生命周期的用水量和废水排放对环境的影响,中国各省份燃煤发电的水足迹以及跨省煤电运输所产生的虚拟水的时空变化特征。结果显示:从时间上看,2000—2020年,中国燃煤发电总水足迹逐年上升,从160亿立方米增加到661亿立方米。单位水足迹处于先上升后下降的趋势,2015年达到最大值15.6 m3/MW·h。期间,灰水足迹占比较大,为76%~83%。整个生命周期中,间接水足迹占总水足迹的36%~45%。从空间上看,2020年,内蒙古、安徽、宁夏、陕西和新疆是主要虚拟水输出省份,而内蒙古、山西、山东和新疆是2000—2020年水足迹增长最多的省份。研究结果以期为我国煤炭和水资源高效利用以及水环境管理提供重要借鉴。

黄河流域关中平原城市群水资源利用效率与公平性评价

为提高黄河流域城市群水资源利用效率与公平性,推动黄河流域生态保护与高质量发展,以关中平原城市群为例,在采用水足迹与水行星边界方法分析水资源可持续利用水平的基础上,运用超效率SBM模型与GML指数探讨了城市群的水资源利用效率,并利用基尼系数与贡献系数评价了用水公平程度对城市群的影响。结果表明:2010—2019年,关中平原城市群水足迹、水赤字和灰水足迹分别下降了4.52%、3.62%和59.79%,水资源的不可持续性和水污染状况得到改善;水资源利用效率不高且未呈现增长趋势,技术效率与技术进步之间未实现良性互动;水资源占用相对公平,但水污染同城市发展及水资源承载能力之间的公平程度均有明显下降。

基于BP-DEMATEL的山西省冬小麦水足迹影响因素识别

针对山西省冬小麦水足迹历史演变及关键影响因素识别问题,分析了1993—2021年山西省冬小麦水足迹历史演变规律,利用BP神经网络-决策实验室(BP-DEMATEL)模型对冬小麦水足迹演变的关键影响因素进行识别,将其分为驱动型因素及特征型因素,并揭示了影响因素之间的作用机制。结果表明:1993—2021年山西省冬小麦水足迹及单位水足迹均呈下降趋势;2021年山西省冬小麦总水足迹为27亿m^(3)(蓝水占比57%),单位水足迹为1 122 m^(3)/t,与前期高点相比分别下降38%(较1994年)和21%(较1993年);气温、相对湿度和灌溉面积为冬小麦水足迹演变的关键驱动型因素,化肥施用量和农业机械总动力为关键特征型因素。

绿色矿山建设碳源/汇与减排增汇研究进展

为应对长期以来矿业开采导致的环境问题,绿色矿山理念及配套政策逐步发展。碳达峰碳中和目标导向下,绿色矿山倡导低碳化生产、生态开采等新的发展要求。为探究新时期绿色矿山建设在节能减排目标下的重要方向和关键问题,助力碳中和目标与绿色矿山建设的协同发展,该研究以绿色矿山、碳源/汇与减排增汇为关键词开展文献计量分析,总结“双碳”目标下绿色矿山建设内涵与要求,分析绿色矿山建设背景下碳源/汇与减排增汇研究进展,梳理矿区碳源与碳汇核算方法,探究绿色矿山减排增汇策略。得出:绿色矿山在理论与应用方面均具有较为丰富的研究及实践成果,具有良好基础以面对新的发展挑战;绿色矿山现存管理方案与考评体系成果完整,整体偏定性和基础推荐性要求;矿山碳足迹核算中,基于生命周期理念、采用排放因子法的核算模式已较为成熟,但在生命周期划分与核算因子选取过程中仍需慎重,注意加强因子的本地化选取;针对减排增汇目标,绿色矿山在策略上需重视能源与技术视角。在“双碳”目标下,当前绿色矿山相关验收标准在减排方面的关注度有待增强,指标体系的定量化程度与执行力有待提高;煤炭矿山的碳足迹核算与减排潜力分析是未来绿色矿山研究的重点之一;矿山减排研究中,由复垦产生的碳源与碳汇核算及矿山全生命周期的减排方案设计需得到更多关注。