摘要：
Predicting drought severity is essential for drought management and early warning systems. Although numerous physical model-based and data-driven methods have been put forward for drought prediction, their abilities are largely constrained by data requirements and modeling complexity. There remains a challenging task to efficiently predict categorial drought, especially for the U.S. Drought Monitor (USDM). Aiming at this issue, multiple Markov chains for USDM-based categorial drought prediction are successfully proposed and evaluated in this paper. In particular, this study concentrated on how the Markov order, step size, and training set length affected prediction accuracy (PA). According to experiments from 2000 to 2021, it was found that the 1-step and first-order Markov models had the best accuracy in predicting droughts up to 4 weeks ahead. The PA steadily dropped with increasing step size, and the average accuracy at monthly scale was 88%. In terms of seasonal variability, summer (July-August) had the lowest PA while winter had the highest (January-February). In comparison with the western region, the PA in the eastern United States is 25% higher. Moreover, the length of the training set had an obvious impact on the PA of the model. The PA in 1-step prediction was 87% and 78% under 20-and 5-yr training sets, respectively. The results of the study showed that Markov models predicted categorical drought with high accuracy in the short term and showed different performances on time and space scales. Proper use of Markov models would help disaster managers and policy makers to put mitigation policies and measures into practice.
摘要：
Promoting ratoon rice is a critical measure for ensuring food security in China. Understanding the mechanism underlying farmers' decision-making involving ratoon rice production may contribute to the design and implementation of extension policies. This study examined the impact of off-farm employment and outsourced machinery services on farmers' ratoon rice production behavior. We used a representative household survey of 1752 rice farmers in Hubei province in central China and a multinomial endogenous treatment effect model to address potential self-selection biases from both observable and unobservable factors. Our estimates suggest that the probability of ratoon rice production decreases by 17.2% for farmers with off-farm employment, while the probability of ratoon rice production increases by 78.9% and 57% for farmers with outsourced machinery services and those with simultaneous off-farm employment and outsourced machinery services, respectively. Moreover, we found that outsourced machinery services can mitigate the negative impact of agricultural labor aging and feminization on ratoon rice production to some extent. Outsourced machinery services have regional heterogeneity effects as farmers in non-plain areas are more likely to engage in ratoon rice production.
通讯机构：
[Yonglong Lu] S;State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China<&wdkj&>State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
关键词：
Energy Modeling;Energy management;Energy policy;Energy resources
摘要：
The flourishing logistics in both developed and emerging economies leads to huge greenhouse gas (GHG) emissions; however, the emission fluxes are poorly constrained. Here, we constructed a spatial network of logistic GHG emissions based on multisource big data at continental scale. GHG emissions related to logistics transportation reached 112.14Mt CO(2)-equivalents (CO(2)e), with seven major urban agglomerations contributing 63% of the total emissions. Regions with short transport distances and well-developed road infrastructure had relatively high emission efficiency. Underlying value flow of the commodities is accompanied by logistics carbon flow along the supply chain. The main driving factors affecting GHG emissions are driving speed and gross domestic product. It may mitigate GHG emissions by 27.50-1162.75 Mt CO(2)e in 15 years if a variety of energy combinations or the appropriate driving speed (65-70km/h) is adopted. The estimations are of great significance to make integrated management policies for the global logistics sector.
作者机构：
[Zheng, Wensheng; Xiong, Yajun; Wang, Xuzheng; Wang, Xiaofang; Zhou, Ying] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Zheng, Wensheng; Wang, Xiaofang] China Tourism Acad, Wuhan Branch, Wuhan 430079, Peoples R China.;[Zheng, Wensheng] Cent China Normal Univ, Hubei High qual Dev Inst, Wuhan 430079, Peoples R China.
通讯机构：
[Wensheng Zheng] C;College of Urban and Environment Science, Central China Normal University, Wuhan, China<&wdkj&>Wuhan Branch of China Tourism Academy, Wuhan, China<&wdkj&>Hubei High-quality Development Institute, Central China Normal University, Wuhan, China
期刊：
Global Change Biology,2023年29(8):2203-2226 ISSN：1354-1013
通讯作者：
Linchuan Fang
作者机构：
[Liu, Ji; Fang, Linchuan; Liu, Lanfa; Zhou, Baitao] Cent China Normal Univ, Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan, Peoples R China.;[Liu, Ji] Leibniz Inst Freshwater Ecol & Inland Fisheries, Dept Ecohydrol, Berlin, Germany.;[Fang, Linchuan; Qiu, Tianyi; He, Haoran; Cui, Qingliang] Northwest A&F Univ, Chinese Acad Sci, State Key Lab Soil Eros & Dryland Farming Loess Pl, Yangling, Shaanxi, Peoples R China.;[Sardans, Jordi; Penuelas, Josep] UAB, CSIC, Global Ecol Unit CREAF, Bellaterra, Catalonia, Spain.;[Sardans, Jordi; Penuelas, Josep] CREAF, Cerdanyola Del Valles, Catalonia, Spain.
通讯机构：
[Linchuan Fang] H;Hubei Province Key Laboratory for Geographical Process Analysis and Simulation, Central China Normal University, Wuhan, China<&wdkj&>State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Chinese Academy of Sciences, Northwest A&F University, Yangling, Shaanxi, China<&wdkj&>School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, China
摘要：
Crop residues coupled with inorganic fertilizers balance soil ecological stoichiometry and thus improve soil carbon, nitrogen, and phosphorus sequestration. Subsequently, environmental effects are mitigated and grain yields are increased. Abstract Although soil ecological stoichiometry is constrained in natural ecosystems, its responses to anthropogenic perturbations are largely unknown. Inputs of inorganic fertilizer and crop residue are key cropland anthropogenic managements, with potential to alter their soil ecological stoichiometry. We conducted a global synthesis of 682 data pairs to quantify the responses of soil carbon (C), nitrogen (N), and phosphorus (P) and grain yields to combined inputs of crop residue plus inorganic fertilizer compared with only inorganic fertilizer application. Crop residue inputs enhance soil C (10.5%–12%), N (7.63%–9.2%), and P (2.62%–5.13%) contents, with an increase in C:N (2.51%–3.42%) and C:P (7.27%–8.00%) ratios, and grain yields (6.12%–8.64%), indicating that crop residue alleviated soil C limitation caused by inorganic fertilizer inputs alone and was able to sustain balanced stoichiometry. Moreover, the increase in soil C and C:N(P) ratio reached saturation in ~13–16 years after crop residue return, while grain yield increase trend discontinued. Furthermore, we identified that the increased C, N, and P contents and C:N(P) ratios were regulated by the initial pH and C content, and the increase in grain yield was not only related to soil properties, but also negatively related to the amount of inorganic N fertilizer input to a greater extent. Given that crop residual improvement varies with soil properties and N input levels, we propose a predictive model to preliminary evaluate the potential for crop residual improvement. Particularly, we suggest that part of the global budget should be used to subsidize crop residue input management strategies, achieving to a win‐win situation for agricultural production, ecological protection, and climate change mitigation.
摘要：
以2007～2021年CNKI及Web of Science核心合集数据库共1874篇中英文文献为支撑，采用文献计量可视化方法，针对文献发表的时间分布、机构组成、代表团队、引用期刊、研究热点及技术手段等方面综述了生物炭对土壤性质、入渗和蒸发等水循环要素过程影响的现状研究进展及未来趋势。结果表明，相关研究发文量呈高速增长趋势；研究机构集中在中国科学院、美国农业部和西北农林科技大学等；高引期刊主要包括GEODERMA、CHEMOSPHERE和SCIENCE OF THE TOTAL ENVIRONMENT；研究热点集中在量化生物炭添加对土壤物理和水力学特性要素指标的影响大小，并关注上述影响对入渗和蒸发等水循环过程及其对作物生长和产量的互馈作用；技术手段主要包括实验研究和Meta分析方法两种。未来亟需集成实验数据，关注尺度转换，将不同环境条件下生物炭添加对要素过程的影响，融入水文模型水循环模拟计算模块，完善模型功能。
摘要：
This study utilized Trichoderma and activated sludge to construct combined activated sludge (TAS). The metagenomic approach was employed to examine the shifts in microbial community structure and function of TAS under amoxicillin stress and investigate the mechanism underlying the reduction of β-lactam antibiotic resistance genes (β-ARGs). The findings demonstrated that the elevated aundance of glpa, glpd, ugpq, glpq, and glpb were primarily responsible for the reduction in total phosphorus (TP) removal by TAS. The increased abundance of Proteobacteria and Verrucomicrobia led to enhanced expression of ugpb, phnd, and phne, thereby improving the TP removal of TAS. Furthermore, antibiotic inactivation has gradually become the primary antibiotic resistance mechanism in TAS. Specifically, an increase in the abundance of OXA-309 in TAS will decrease the probability of amoxicillin accumulation in TAS. A decrease in β-ARGs diversity confirmed this. This study presents a novel approach to reducing antibiotic and ARG accumulation in sludge.
期刊：
Journal of Environmental Management,2023年327:116880 ISSN：0301-4797
通讯作者：
Guangming Yu
作者机构：
[Gu, Yinxue; Xu, Lili; Zhang, Chenlei; Chen, Xiaoxu; Yu, Guangming; Tu, Zhenfa] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Yu, Guangming] Kashi Univ, Coll Life & Geog Sci, Kashi 844000, Peoples R China.;[Xu, Lili; Tu, Zhenfa] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Yang, Jian] Hubei Univ Arts & Sci, Fac Resource Environm & Tourism, Xiangyang 441053, Peoples R China.
通讯机构：
[Guangming Yu] C;College of Urban and Environmental Sciences, Central China Normal University, Wuhan, 430079, China<&wdkj&>College of Life and Geographic Sciences, Kashi University, Kashi, 844000, China
关键词：
Citizen water use;Han river basin;SHRD model;Water accessibility;Water price
摘要：
Water resource, with properties of scarcity, is one of the vital resource endowments. Like land resources, the prices of these resource endowments should be correlated to their locations to follow fair and reasonable principles. The current water price systems are mainly policy-oriented fixed regimes. And the water use was charged according to the regional-average situation with scarce consideration of the fine-scale geographical water accessibility. With a combination of the water accessibility and the current water pricing regime, this paper first proposed a novel water pricing model, the Water Price at Grid-scale (WPG) model, to dynamically allocate water prices to fine grids for urban residents. The WPG model was examined in the case study of the Han River Basin in the Hubei province of China. The specific results were: (1) the P(grid) of Tier I is between 0.66 and 3.94 yuan/m³, the P(grid) of Tier II is between 0.57 and 5.44 yuan/m³, and the P(grid) of Tier III is between 0.47 and 6.94 yuan/m³ in the study area. (2) the grids with more water acquisition generally have lower water prices than others and vice versa. (3) the average water prices in tiers obtained by the WPG model are generally higher than that derived from the current water pricing system. The results proved that the proposed WPG model spatially allocates the three-tier water prices into grids of urban areas. The WPG framework can be adopted in any society by involving its water price regimes and adjusting the scale of grids and the pricing year. This study provided a new viewpoint of domestic water pricing involving fine-scale water accessibility. The WPG model has great potential to ease water shortage pressure in water-limited societies and can be utilized and loaded into the current smart-city network for efficient and fine-scale water resource management.
作者机构：
[Xu, Baodong; Wei, Haodong; Xu, Zilu; Yang, Jingya; Cai, Zhiwen] Huazhong Agr Univ, Macro Agr Res Inst, Coll Resources & Environm, Wuhan 430070, Peoples R China.;[Hu, Qiong; He, Zhen] Cent China Normal Univ, Coll Urban & Environm Sci, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[You, Liangzhi] Huazhong Agr Univ, Coll Econ & Management, Wuhan 430070, Peoples R China.;[You, Liangzhi] Int Food Policy Res Inst, 1201 1 St NW, Washington, DC 20005 USA.;[Chen, Yunping] Huazhong Agr Univ, Coll Plant Sci & Technol, Wuhan 430070, Peoples R China.
通讯机构：
[Baodong Xu] M;Macro Agriculture Research Institute, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China<&wdkj&>State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Aerospace Information Research Institute, Chinese Academy of Sciences and Beijing Normal University, Beijing, 100101, China
关键词：
Ratoon rice;Potential northern limits;Potential planting areas;Climate conditions;MaxEnt model
摘要：
Ratoon rice has emerged as a promising rice cropping system to improve grain production and reduce labor costs compared with traditional single/double rice in China. However, the potential planting areas of ratoon rice in China remain unclear. This research investigated the potential northern limits and promotion extent of ratoon rice in China by considering its climatic suitability based on the optimized maximum entropy (MaxEnt) model as well as terrain and land use conditions. The MaxEnt model derived by all environmental variables yielded a good performance, with average AUC (area under the curve) and TSS (true skill statistic) over the validation dataset of 0.940 and 0.825, respectively. The comparison with field samples and previous studies revealed the reliability of the derived potential promotion areas. Potential northern limits contained a closed curve surrounding the Sichuan Basin, and the other curve ran from Yunnan Province to Jiangsu Province. Safe promotion areas of ratoon rice in China were 472,003 km2, mainly located in Sichuan, Hubei, Guangxi and Hunan. Risky promotion areas were 74,150 km2, which were dominant in Henan, Anhui and Yunnan. Our study provides crucial infor-mation for rice planting pattern adjustment to alleviate national food insecurity caused by the loss of double rice.
作者：
Zheng, Jiangpeng;Huang, Zhou;Zhou, Xiao;Scheuer, Bronte;Wang, Han
期刊：
Sustainable Cities and Society,2023年99:104976 ISSN：2210-6707
通讯作者：
Huang, Z
作者机构：
[Huang, Zhou; Zheng, Jiangpeng; Huang, Z; Scheuer, Bronte] Peking Univ, Inst Remote Sensing & Geog Informat Syst, Sch Earth & Space Sci, Beijing 100871, Peoples R China.;[Huang, Zhou; Zheng, Jiangpeng; Scheuer, Bronte] Peking Univ, Beijing Key Lab Spatial Informat Integrat & Its Ap, Beijing 100871, Peoples R China.;[Zhou, Xiao] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Wang, Han] Univ Hong Kong, Fac Architecture, Div Landscape Architecture, Future Urban & Sustainable Environm FUSE Lab, Hong Kong, Peoples R China.
通讯机构：
[Huang, Z ] P;Peking Univ, Inst Remote Sensing & Geog Informat Syst, Sch Earth & Space Sci, Beijing 100871, Peoples R China.
关键词：
CO2 emissions;Bus smart card;Spatiotemporal characteristics;Per person-kilometer;Emission reduction potential
摘要：
Human activities, primarily carbon dioxide emissions, have undeniably caused global warming. The transportation sector contributes about a quarter of global CO2 emissions. While replacing traditional buses with electric ones has reduced emissions, it is crucial to consider the indirect emissions resulting from electricity consumption. This study proposes a framework for modeling bus emissions using smart card data, integrating spatiotemporal distribution characteristics and emission reduction potentials. Our analysis reveals that routes spanning 10-30 km contribute to 81% of total bus emissions, with an average emission rate of 56.2 gCO2/per-km for residents traveling by bus. Bus emissions also exhibit cyclical variations during holidays, weekdays, and weekends, indicating spatial clustering and trends. Although the area within Beijing's 4th Ring Road constitutes only 13% of the total area within the 6th Ring Road, it generates almost half of the CO2 emissions. With urban expansion, total bus emissions increase gradually, but emission intensity decreases. This study emphasizes the potential for reducing emissions through improved public transportation operations. It recommends fully electrifying the bus fleet and employing low grid emission factors, which could reduce emissions by up to 71% compared to diesel options. Electrification of buses and optimizing power generation on the grid are essential priorities for emission reduction.
