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Influences of rock fragments on the hydraulics and erosion of concentrated runoff in steep spoil heaps on the Loess Plateau of China

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International Journal of Sediment Research 2022年第5期37卷 553-562页

作者： Wenzhao Guo Hongliang Kang Xiao Yu Wenlong Wang Pei Tian State key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Water and Soil Conservation Northwest Agriculture & Forestry University Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province Central China Normal University

The soil-rock mixed spoil heaps are prone to severe soil erosion during heavy rain, causing severe land degradation and ecological and environmental damage. Nevertheless, past research on the erosion on spoil heaps has focused on soil particles that were readily eroded and disregarded the rock fragments(RF) that were not readily eroded. To explore the effect of the RF embedded in spoil heaps on the hydraulics of and erosion caused by concentrated runoff, scour-erosion experiments were implemented on three types of spoil heaps: RF = 7%, RF = 45%, and RF = 69%. The RF clearly reduced runoff and erosion on steep spoil heaps. As the RF increased from 7% to 69%, the runoff intensity and runoff coefficient decreased by 72.9%-79.1% and 83.2%-84.1% respectively, and the sediment concentration, soil denudation rate, and total soil loss decreased by 36.0%-47.8%, 83.7%-87.1%, and 87.0%-92.3%, respectively.Narrow rills were generated during the experiments, and the RF distinctly influenced the rill characteristics. High contents of RF restrained rill retreating and undercutting, and promoted rill widening. With an increase in RF, the flow shear stress and stream power gradually decreased, and the Darcy-Weisbach roughness coefficient increased. These findings imply that the RF dissipated the flow energy and reduced soil detachment capacity and sediment transport capacity. Soil detachment is strongly related to the Darcy-Weisbach roughness coefficient, Reynolds number, and runoff intensity,which may be the preferred descriptors of soil detachment. The current findings indicate that embedded rock fragments could effectively reduce soil loss on steep spoil heaps.

关键词： Soil erosion Runoff Rock fragments (RF) Rills Chinese loess plateau

Unique landslides (loess slide-flows) induced by an extreme rainstorm in 2018 on the Loess Plateau: A new geological hazard and erosion process

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International Journal of Sediment Research 2023年第2期38卷 228-239页

作者： Li Luo Wen-Zhao Guo Pei Tian Yi-li Liu Shao-Kun Wang Jia-Wei Luo State key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau/College of Water Resources and Architectural Engineering Northwest Agriculture and Forestry University State key laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province Central China Normal University

Currently, the vegetation has recovered well in most areas of the Loess Plateau in China, and soil erosion has significantly decreased. However, the heavy rainfall event in July 2018 triggered many instances of a unique type of loess landslides(i.e., slide-flows) on the gully-slopes with vegetation recovery in the Nanxiaohegou Basin on the Loess Plateau. This rainfall event was unusual and was a persistent heavy rainfall. The accumulated rainfall from 24 June to 10 July was 232.2 mm, which comprised 42% of the mean annual rainfall. A loess slide-flow is characterized by combining two movement types of the slide and flow. The loess slide-flows first slide on the gully-slopes and then turn into long run-out earthflows moving downstream, delivering vast amounts of sediment to the river. The average landslide erosion rates were 110.8-134.9 kg/m2. These loess slide-flows generally did not occur individually but in groups,which were characterized by large numbers, high density, small scale, and shallow depth. The changes of vegetation characteristics and soil characteristics both had a significant impact on the scale of the landslides. Grass with high coverage had an adverse effect on the occurrence of shallow landslides. The adverse hydrological effects of the plant may offset the weak root reinforcement. Loess slide-flows have become a new geological hazard and erosion process on the Loess Plateau. Loess slide-flows are a prominent ecological and environmental problem after vegetation restoration, and more attention should be paid to loess slide-flows in the future.

关键词： Loess plateau Landslide Soil erosion Vegetation Rainfall

Influence of vegetation type and topographic position on volumetric soil water content dynamics and similarity among surface and deep soil layers

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International Soil and Water Conservation Research 2023年第1期11卷 183-196页

作者： Muxing Liu Qiuyue Wang Jun Yi Hailin Zhang Ji Liu Wei Hu key laboratory for geographical process analysis&simulation Hubei ProvinceWuhan430079China College of Urban and Environmental Sciences Central China Normal UniversityWuhan430079China The New Zealand Institute for Plant and Food Research Limited Private Bag 4704Christchurch8140New Zealand

Clarifying the mechanisms governing volumetric soil water content(VSWC)dynamics in soil profiles is essential,as it can help to elucidate soil water transport processes and improve the prediction accuracy of soil hydrological processes.Using Spearman's rank correlation and wavelet coherence analysis methods,similarity in soil profile VSWC dynamics and factors governing VSWC soil profile dynamics in upslopes and downslopes under three vegetation types(evergreen forest[EG],secondary deciduous forest mixed with shrubs[SDFS],and deforested pasture[DP])at different time scales(hourly,daily,weekly,and monthly)and in different seasons were analyzed.The results revealed significant similarity in the VSWC of different soil depths(Pweekly(42.8%)>daily(21.8%).The effects of soil properties(e.g.,texture,saturated hydraulic conductivity),rainfall,and potential evapotranspiration(ET_(p))on VSWC similarity were related to the time scale and season in which VSWC monitoring took place.Soil properties had apparent effects on VSWC similarity at longer time scales(i.e.,monthly),with a high SCA.In contrast,the effects of rainfall and ET_(p) on VSWC similarity were concentrated at weekly and daily scales,with a relatively low SCA.Rainfall and ET_(p) dominated VSWC dynamics in the summer and fall,respectively.These results imply the use of measured VSWC at one soil depth to predict the VSWC at other soil depths was a reliable method.While the in-fluence of time scale effects and seasonal variations on prediction accuracy of VSWC should be considered.

关键词： Volumetric soil water content Wavelet analysis Significant coherence area Time scale Vegetation type Slope postion

Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020

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Chinese geographical Science 2024年第1期34卷 181-194页

作者： ZHU Yuanyuan ZHANG Yan ZHU Xiaohua key laboratory of Geographic process analysis&simulation hubei province Central China Normal UniversityWuhan430079China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing100101China

Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.

关键词： dietary structure structural evolution carbon emission effects carbon neutrality China

Mapping winter wheat using phenological feature of peak before winter on the North China Plain based on time-series MODIS data

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Journal of Integrative Agriculture 2017年第2期16卷 348-359页

作者： TAO Jian-bin WU Wen-bin ZHOU Yong WANG Yu JIANG Yan key laboratory of Agri-informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province/School of Urban and Environmental Sciences Central China Normal University

By employing the unique phenological feature of winter wheat extracted from peak before winter （PBW） and the advantages of moderate resolution imaging spectroradiometer （MODIS） data with high temporal resolution and intermediate spatial resolution, a remote sensing-based model for mapping winter wheat on the North China Plain was built through integration with Landsat images and land-use data. First, a phenological window, PBW was drawn from time-series MODIS data. Next, feature extraction was performed for the PBW to reduce feature dimension and enhance its information. Finally, a regression model was built to model the relationship of the phenological feature and the sample data. The amount of information of the PBW was evaluated and compared with that of the main peak （MP）. The relative precision of the mapping reached up to 92% in comparison to the Landsat sample data, and ranged between 87 and 96% in comparison to the statistical data. These results were sufficient to satisfy the accuracy requirements for winter wheat mapping at a large scale. Moreover, the proposed method has the ability to obtain the distribution information for winter wheat in an earlier period than previous studies. This study could throw light on the monitoring of winter wheat in China by using unique phenological feature of winter wheat.

关键词： time-series MODIS data phenological feature peak before wintering winter wheat mapping

Evaluation, simulation, and optimization of land use spatial patterns for high-quality development: A case study of Zhengzhou city, China

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Journal of geographical Sciences 2023年第2期33卷 266-288页

作者： ZHU Wenchao JIANG Zhimeng CEN Luyu WU Hao College of Urban and Environmental Sciences Central China Normal UniversityWuhan 430079China hubei province key laboratory for geographical process analysis and simulation Central China Normal UniversityWuhan 430079China

High-intensity land use and resource overloaded-induced regional land use spatial pattern(LUSP)are essential and challenging for high-quality development.The empirical studies have shown that a scientific land uses spatial layout,and the supporting system should be based on a historical perspective and require better considering the double influence between the current characteristics and future dynamics.This study proposes a comprehensive framework that integrates the resource environment carrying capacity(RECC)and land use change(LUC)to investigate strategies for optimizing the spatial pattern of land use for high-quality development.China’s Zhengzhou city was the subject of a case study whose datasets include remote sensing,spatial monitoring,statistics,and open sources.Three significant results emerged from the analysis:(1)The RECC has significant spatial differentiation but does not follow a specific spatial law,and regions with relatively perfect ecosystems may not necessarily have better RECC.(2)From 2020 to 2030,the construction land and farmland will fluctuate wildly,with the former increasing by 346.21 km^(2) and the latter decreasing by 295.98 km^(2).(3)The study area is divided into five zones,including resource conservation,ecological carrying,living core,suitable construction,and grain supply zones,and each one has its LUSP optimization orientation.This uneven distribution of RECC reflects functional defects in the development and utilization of LUSP.In addition,the increase in construction land and the sharp decline of farmland pose potential threats to the sustainable development of the study area.Hence,these two elements cannot be ignored in the future high-quality development process.The findings indicate that the LUSP optimization based on dual dimensions of RECC and LUC is more realistic than a single-dimension solution,exhibiting the LUSP optimization’s effectiveness and applicability.

关键词： land use spatial pattern resource environment carrying capacity land use change spatial optimization high-quality land development Zhengzhou city

Climatic Fluctuation of Marine Isotope Stage 9: A Case Study in the Southern Margin of the Chinese Loess Plateau

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地球科学学刊:英文版 2023年第5期34卷 1556-1566页

作者： Tieniu Wu Antai Cheng Henry Lin Hailin Zhang Yi Jie key laboratory for geographical process analysis&simulation Hubei ProvinceCentral China Normal UniversityWuhan 430079China Department of Ecosystem Science and Management The Pennsylvania State UniversityUniversity ParkPA 16802U.S.A. College of Urban and Environmental Sciences Central China Normal UniversityWuhan 430079China

Marine Isotope Stages(MIS) 9 has been proposed as an analog for the present warm period. However, detailed studies of this geological time period are rare in loess-paleosol sequence. In the Chinese Loess Plateau(CLP), the corresponding stratum is the third paleosol layer(S3). Here, we report the terrestrial reconstruction of climatic fluctuations during MIS 9 by analyzing the paleo-climate indexes of S3 with high sampling density. Our results showed that:(1) During the period of MIS 9, the main climatic sub-cycle was 29 ka;(2) MIS 9 could be divided into five sections, MIS 9a, 9b, 9c, 9d, and 9e. Among them, MIS 9a, 9c, and 9e were warm stages, while MIS 9b and 9d were cool intervals;and 3) There were also three swift warm-wet events and one cool-dry event, which occurred around 332 –331, 324–323, 311–310, and 331–329 ka BP, respectively. The overall trend of paleo-climate fluctuation correlated approximately with SPECMAP, LR04 stack and Iberian margin deep-sea cores. This study suggested that the paleosol records in the southern margin of the CLP have global significance and contain more detailed climatic signals than marine deposits.

关键词： MIS 9 climatic fluctuation Paleosol S3 Chinese Loess Plateau environmental geology

中国植物性饮食结构调整具有显著的耕地资源效应

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Science Bulletin 2024年第6期69卷 737-740页

作者：朱晓华张燕朱媛媛李裕瑞 Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China key laboratory of Geographic process analysis&simulation hubei province Central China Normal UniversityWuhan 430079China

Food systems are already a major contributor to land degradation,and changes in global diets will exacerbate this situation[1].Population growth and affluent dietary patterns result in changes in land demand and land-use patterns,and up to 40% of global arable land and more than 30% of global food-crop production are used for animal feed[2].Furthermore,food-feed competition can result in an inadequate food supply[3].

关键词：耕地资源 arable food

Evolution process of Urban Spatial Pattern in hubei province Based on DMSP/OLS Nighttime Light Data

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Chinese geographical Science 2016年第3期26卷 366-376页

作者： ZHENG Wensheng RUN Jiying ZHUO Rongrong JIANG Yupei WANG Xiaofang key laboratory for geographical process analysis & simulation Hubei Province Central China Normal University Wuhan 430079 China Academy of Wuhan Metropolitan Area Hubei Development and Reform Commission & Central China Normal University Wuhan 430079 China Chongqing Geomatics Center Chongqing 401121 China

This paper intends to investigate the urban spatial patterns of hubei province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in hubei province, the viewpoint of ′point-axis-area′ in the ′point-axis system′ theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of ′Wuhan Metropolitan Area′, ′Yichang-Jingzhou-Jingmen City Group′ and ′Xiangyang-Shiyen-Suizhou City Group′, which are defined by local development strategy in hubei province, are different from the above three urban groups.

关键词：城市空间格局湖北省演变连接网络灯光城市节点夜间光照指数模型