Journal of Shaanxi Normal University(Natural Science Edition)

  • Experimental study on hydraulic characteristics of overland flow under different surface roughness

    ZHANG Yixuan;MA Lan;XUE Menghua;SUN Xu;WANG Fuxing;LI Haoyu;SONG Tianyi;The Metropolitan Area Forest Ecosystem Research Station, School of Soil and Water Conservation,Beijing Forestry University;Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University;Jixian Forest Ecosystem National Observation and Research Station, CNERN,Beijing Forestry University;

    To further explore the law of hydraulic properties of overland flow, the hydrodynamic characteristics of overland flow under different flow rates and slopes with different roughness(0.2~0.6 mm, 0.6~1 mm, 1~1.4 mm, 1.4~2 mm, 2~3 mm particle size and smooth control group) were studied by the indoor fixed-bed water scouring test. The results show that the increase of the underlying surface roughness slows down the overland flow velocity and increases the water depth. The flow velocity and water depth are well related to the flow, slope, and roughness factors as a power function. The Reynolds number reaches the maximum value in the control group, and the flow pattern tends to be slow flow with increasing roughness. The resistance coefficient positively changes with roughness and is in a good regression relationship with the power function of flow, slope, and roughness factors. The calculated runoff shear stress is well related to the measured runoff shear stress on the smooth underlying surface, and the increase of roughness has a certain effect on the increase of measured runoff shear stress. The results are significant for a deeper understanding of soil erosion mechanisms and slope erosion control.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 1593K]

  • Research on slope soil erosion of different textures on the Loess Plateau under slope control

    ZHANG Longqi ;JIA Guodong ;LYU Xiangrong ;LEI Ziran ;LIU Rui ;ZHANG Xiao ;Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University;The Metropolitan Area Forest Ecosystem Research Station, School of Soil and Water Conservation,Beijing Forestry University;

    Based on the simulated rainfall test, the mechanism of slope effect of soil erosion was discussed. The influence of slope in typical areas of the Loess Plateau on runoff depth and erosion modulus was analyzed by multiple linear regression with control covariates. The results showed that:(1) The slope effect of soil erosion was closely related to soil texture and slope erosion mode. On the sandy loam slope, soil infiltration and runoff were affected by the slope. The minimum infiltration and maximum runoff rate appeared on the 15° slope. For sandy clay loam, the 25° and 15° slopes had higher soil infiltration and lower runoff, while the 20° and 10° slopes had lower soil infiltration and higher runoff. On the clay loam slope, the infiltration on the 20° and 25° slopes was larger and the runoff was smaller, while the infiltration on the 10° and 15° slopes was lower and the runoff was higher. For loam clay slope, soil infiltration and runoff rate were approximately the same under different slopes, and soil infiltration was almost not affected by the slope.(2)There was a good linear relationship between the slope and erosion dynamic parameters. On sandy loam slope, the critical runoff shear force and power increased with the increase of slope. On sandy clay loam slope, the maximum critical runoff shear force and power appeard at 20° slope. The critical runoff shear force and power increased with the increase of slope on the clay slope.Moreover, the critical runoff shear force and power decreased with the increase of slope from 15° to 25° on the loamy clay slope. This paper provides theoretical support for soil erosion prevention and control and regional land use management on the Loess Plateau.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 2700K]

  • Accuracy evaluation of structure from motion (SfM) photogrammetry on the measurement of typical gullies in the Loess Plateau

    CHEN Xinyi;SHI Yangzi;YANG Yang;HUANG Tingting;LIU Yingna;ZHANG Guanghui;State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science,Beijing Normal University;School of Geography, Faculty of Geographical Science, Beijing Normal University;Monitoring Center of Soil and Water Conservation, Ministry of Water Resources;

    The structure from motion(SfM) photogrammetry was used to measure seven typical gullies in the Liudaogou catchment located in the Loess Plateau, and the accuracy in quantifying gully and gully erosion was evaluated via comparing the results to those acquired with the laser scanning(LS) and real-time kinematic(RTK) GPS. The DEM measured with SfM photogrammetry for each gully were similar with those obtained using LS and RTK GPS, and the average elevation differences ranged from-0.162 to 0.436 m when subtracting the former from the latter. SfM photogrammetry exhibited high precisions in quantifying the length, surface width, perimeter and area of each gully, and the corresponding relative errors barely exceeded ±7%. In contrast, the measurement errors of SfM photogrammetry were relatively greater for gully depth and volume, which ranged from-37.4% to 18.0%. Regarding gully erosion monitoring, both the spatial distribution of soil erosion and gully morphological parameter changes obtained by SfM photogrammetry were similar with those by RTK GPS. These results demonstrate that SfM photogrammetry can serve as a high-precision method for gully and gully erosion monitoring in the Loess Plateau.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 3626K]

  • Sheet erosion and its hydrodynamic parameters of extremely gentle loess slopes

    LIU Songbo;SUN Liying;HE Jijun;TIAN Lei;CAI Qiangguo;WANG Mingwei;State Key Laboratory of Urban Environmental Processes and Numerical Simulation, Beijing Laboratory of Water Resources Security, Capital Normal University;Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences;College of Resources and Environment, University Chinese Academy of Sciences;

    With the continued development of ecological civilization on the Loess Plateau, cultivated land on the very gentle slopes has become the most significant area affected by local production activities, its soil erosion should be paid enough attention.Based on this, indoor simulated rainfall test is adopted to study the sheet erosion characteristics and the variation rules of hydrodynamic parameters of the two soils(Ansai soil and Suide soil) under the condition of 90 mm/h rainfall intensity, two slopes(2.5° and 5°) and two slope lengths(5 m and 10 m). The results show that, compared with the Ansai soil, the Suide soil has a shorter runoff production time, a faster runoff increasing rate, a higher runoff with sediment content, and is prone to rill erosion. The average runoff and sediment content of Ansai soil ranged from 2.76 to 8.61 L/min and 0.80 to 9.26 g/L before runoff stabilization, and from 3.76 to 11.69 L/min and 0.46 to 2.88 g/L after runoff stabilization. The average runoff and sediment content of Suide soil before and after runoff stabilization was 3.94 to 12.75 L/min, 2.13 to 10.64 g/L and 4.51 to 15.02 L/min, 1.20 to 4.51 g/L, respectively. The relationship between sediment content and runoff can be characterized by a linear descent function with sediment content as a constant. In contrast, the Reynolds number and runoff power increase linearly with runoff with a clear and stable behavior. The runoff velocity and Froude number show a clear trend of increasing with runoff, but the fluctuations are large. The runoff shear force shows a large dispersion with runoff. Overall, for sheet erosion, Reynolds number and runoff power are the most suitable hydrodynamic parameters to characterize soil erosion, followed by runoff velocity and Froude number, and runoff shear force. The above results can provide a theoretical reference for optimizing soil erosion model parameters.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 1485K]

  • Response of sediment connectivity to land use change in Yanhe River Basin

    BIAN He;ZHU Bingbing;LI Heng;WANG Rong;TANG Xinyi;School of Geography and Tourism, Shaanxi Normal University;

    Sediment connectivity is an important parameter to characterize the physical cascade relationship of sediment between geomorphic units.It is of great significance to explore the response of sediment connectivity to land use change, which is helpful to reveal the dynamic of runoff and sediment load and evaluate the soil and water conservation capacity of different land use types. In this study, based on the data about land use, runoff and sediment load from 1990 to 2019, the index of connectivity(IC) was used to quantify the spatial and temporal variation characteristics of sediment connectivity and its relationship with runoff and sediment load under the background of land use change in Yanhe River Basin. The results showed that: 1) In recent 30 years, the land use change has been dominated by the Grain for Green, coupled with a small amount of the expansion of construction land in this basin. 2) From 1990 to 2019, the IC showed a downward trend as a whole, with a decrease of 17.85% in 2019. Grain for Green and the expansion of construction land could effectively reduce sediment connectivity, and the former also had long-term ecological benefits. 3) IC had obvious spatial distribution characteristics, which showed an increasing trend from south to north and east to west. Among them, the middle of the basin was the main region of Grain for Green and construction land expansion, and thus significantly reduced sediment connectivity. The northwest of the basin had higher sediment connectivity, and its decreasing extent became smaller with land use change.The sediment connectivity in the south of the basin was lower. 4) There was a significant positive correlation between IC and sediment load(P<0.05), and thus it was more suitable for the prediction of sediment load. The results can provide a scientific basis for the research of sediment transport process in the basin, and further provide a reference for the layout and optimization of land use.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 1954K]

  • Influence of environmental regulation on urban ecological resilience:a case study of urban agglomeration in the middle reaches of the Yangtze River

    SHI Caixia;HE Xiaorong;College of Tourism, Hunan Normal University;

    From the perspective of spatiotemporal interaction, the evolution characteristics of environmental regulation and ecological resilience in the middle reaches of the Yangtze River urban agglomeration from 2005 to 2020 were analyzed, and the spatial econometric model was used to clarify the impact of environmental regulation on urban ecological resilience. The results show that: 1)The intensity of environmental regulation in urban agglomeration in the middle reaches of the Yangtze River increased from 0.167 in 2005 to 0.903 in 2020, and the ecological resilience increased from 0.227 to 0.747, both systems showed a fluctuating upward trend. The local spatial structure of urban environmental regulation intensity was relatively stable, and its ecological resilience was strongly dependent on the direction of spatial evolution, and presented a certain degree of spatio-temporal competition. 2) There was a significant inverted U-shaped relationship between environmental regulation intensity and urban ecological resilience. Although the implementation of environmental regulation had a positive spillover effect on the surrounding cities, it had a more obvious effect on the improvement of local ecological resilience. 3) Environmental regulation of sub-urban agglomerations had a positive and direct effect on the improvement of local ecological resilience, and the impact on surrounding areas was different. The environmental regulation of Wuhan urban area showed a negative spatial spillover effect, the indirect effect of the urban agglomeration around Poyang Lake was positive, and the impact of environmental regulation of the urban agglomeration of Changsha-Zhuzhou-Xiangtan on the surrounding area was not significant.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 3342K]

  • Coupling coordination and driving factors of urban resilience and land use efficiency in the Yangtze River Delta urban agglomeration

    YUAN Jiade;ZHANG Jie;WANG Yuchun;School of Public Policy & Management, Anhui Jianzhu University;

    Based on the panel data of 26 cities in the Yangtze River Delta urban agglomeration from 2010 to 2020, the coupling coordination level, spatial agglomeration characteristics and driving factors of urban resilience and land use benefit are analyzed by using the models of coupling coordination, spatial autocorrelation and geographical detector. The results show that the urban resilience and land use benefit of the Yangtze River Delta urban agglomeration continue to rise, but there are obvious differences in spatial distribution. The coupling coordination of the two systems is also increasing year by year. The coordination types are mainly mild imbalance, near imbalance, primary coordination and intermediate coordination. In the east-west direction, it has always presented the spatial distribution characteristics of “high in the east and low in the west”. In the north-south direction, it has evolved from the spatial differentiation pattern of “prominent in the middle and collapsed in the north and south” to “high in the middle, followed by the south and lowest in the north”. Moreover, the spatial agglomeration effect of coupling coordination degree is not strong, and the spatial heterogeneity of local areas does not change much with time. The level of economic development, government regulation ability and labor factor are the main driving factors affecting the coordinated development of the two systems. Among them, the interaction between government regulation ability and other factors is the strongest. The research on the correlation between urban resilience and land use benefit is helpful to provide a reference for the Yangtze River Delta urban agglomeration to do a good job in risk prevention and control, intensive land use, and to provide relevant experience for the sustainable development of other regions in China.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 1654K]

  • Transformation performance and obstacle factors of coal resource-exhausted cities

    YE Changlong;YIN Jiangbin;WANG Zixuan;NAN Yurui;School of Geography and Tourism, Shaanxi Normal University;Northwest Land and Resource Research Center, Shaanxi Normal University;Global Regional and Urban Research Institute, Shaanxi Normal University;

    Accelerating the transformation of resource-based cities is an inevitable requirement for achieving high-quality economic development. In combination with the energy consumption structure of “coal is the largest” in China, 15 coal resource-exhausted cities were selected as the research objects, a three-dimensional indicator system of economic development, social welfare and ecological environment was built, the transformation performances of 15 cities during the planning period of the 《National Sustainable Development Plan for Resource based Cities(2013-2020)》(hereinafter referred to as the Plan) were quantitatively evaluated, and the obstacle factors affecting urban transformation were analyzed. The results indicated that: 1) There was a significant spatiotemporal difference in transformation performances. In terms of space, the overall performance was generally lower than the average value of the national and provincial performance, and there were significant regional differences before and after the transformation. In the early stage, the western and northeastern regions were higher, while in the end, the central and eastern regions were higher. In terms of time, the overall performance showed a slow growth trend, but the dimensions of economic development were generally negative, while the dimensions of social welfare and ecological environment were generally positive.2) The transformation process could be divided into four categories, that is, economic dominance, balanced development, social welfare dominance, and ecological environment dominance.3) During the planning period of the four types of cities, there were differences and similarities in the obstacle factors. The six significant obstacle factors all cover three dimensions, and the ecological environment was the biggest pain point for transformation and development. It showed that the Plan had achieved remarkable results, but the transformation of coal resource-exhausted cities had not been completely completed, and follow-up policy support was still needed.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 1510K]

  • Spatio-temporal evolution and influencing factors of the integration development level of culture and tourism industry in the Yangtze River Economic Belt

    WANG Zhaofeng;LIANG Zhiqiang;College of Tourism, Hunan Normal University;

    Promoting the integration of culture and tourism industries is conducive to enhancing a nation's soft power and meeting the increasingly growing spiritual and cultural demands of its people. By utilizing coupled coordination models, priority models for tourism development, and exploratory spatial data analysis, this study assesses the spatiotemporal evolution patterns of the cultural and tourism industry integration level in 11 provinces and cities along the Yangtze River Economic Belt from 2008 to 2022. Quantile regression is also employed to explore the influencing factors of the coupled coordination index. Findings indicate that: 1)From 2008 to 2022, the average level of cultural and tourism industry development along the Yangtze River Economic Belt exhibited a cyclical pattern of rise and fall, divided into five phases with the years 2012, 2013, 2019, and 2020 as turning points. Spatially, the development level of the cultural and tourism industry generally followed the pattern of being higher in the eastern region, followed by the central region, and then the western region. 2)The mean value of the coordination degree of the culture and tourism industry from 2008 to 2022 showed an overall trend of fluctuating increase. Although the overall coordination level was relatively low, the level structure gradually improved over time. There were significant inter-provincial differences in coordination values, with the gap between high and low values gradually narrowing. 3)Different provinces and cities exhibited various types of spatial clustering in the development of cultural and tourism industry integration. H-H(high-high) agglomeration areas were primarily represented by the eastern regions with Shanghai and Zhejiang as examples, but their positive spillover effects needed enhancement. L-L(low-low) agglomeration areas were mainly represented by western regions with Guizhou as an example, and breaking the “Matthew effect” stalemate is necessary. 4)Infrastructure, human capital, industrial structure, and technological innovation all had positive effects on the cultural and tourism industry integration level along the Yangtze River Economic Belt at different quantile points. However, market supply exerted inhibitory effects, and policy systems did not pass the significance test.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 2153K]

  • Spatial structure and node role evolution of the related transaction network of Chinese listed cultural and tourism enterprises

    WANG Zhao;WANG Huan;College of Tourism, Hunan Normal University;

    Enterprise networks provide an innovative perspective on the deep-seated mechanisms and diversified trends of the evolution of economic spatial linkages in the cultural and tourism industry. As an important form of characterization of business transactions among enterprises, the related transaction network has the dual attributes, horizontal links among enterprises and vertical links among subsidiaries and parent companies. According to the data of related transactions of listed cultural and tourism enterprises from 2000 to 2021, the spatial structure of related transaction networks of cultural and tourism enterprises as well as their evolution characteristics are revealed, and the status and roles of network nodes are identified. The study finds that the overall related transaction value of listed cultural and tourism enterprises from 2000 to 2021 experienced staggering growth, and the industries involved in the cultural and tourism industry had been enriched, the leasing and business services industry being mainly related parties. With the increase of related transaction volumes, expansion of network's spatial coverage, and growth of long-distance connections across regions, the overall network evolves from a simple “radial” structure to a complex “network” one, with a few nodes of high centrality playing the role of “hubs”. The level of node shift centrality and shift control increases, and obeys the one-dimensional distribution of high-high and low-low. Beijing and Shanghai have always been the leading and core cities of the network, while Hangzhou, Shenyang, and Changsha have played the role of center or power portal at different times, and a large number of nodes in Midwest China have taken on the role of crony edges in the network.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 2490K]

  • Spatial network structure and influencing factors of tourism flow in Northwest China based on online ordering data

    SUN Yiming;LIU Peixue;ZHANG Jianxin;WEI Ruibing;School of Geography and Ocean Science, Nanjing University;School of Business Administration, Nanjing University of Finance and Economics;

    Big data helps to reveal the migration patterns and spatial characteristics of tourists in the destination area in detail. Northwest China is the main destination region of China's “Silk Road”. Based on extensive travel route data obtained from online booking platforms, this paper employs social network analysis to study the network and spatial characteristics of tourist flows and connections between destinations in Northwest China. It aims to uncover regional community structures and analyze the factors influencing touring route. The results indicate that the tourist flow network in Northwest China is loose and unbalanced, with distinct core and peripheral areas. The peripheral areas are mainly located in western Xinjiang, most of Shaanxi, and southern Gansu, while the core areas are mainly distributed in Hexi Corridor. In Northwest China, a small number of nodes possess absolute network power, demonstrating clear hierarchical levels. Nodes at all levels are highly dependent on core nodes such as Lanzhou, Xi'an, and Urumqi. The Northwest tourism network is composed of 3 secondary communities and 8 tertiary communities around the core nodes. These communities demonstrate strong regional proximity and administrative regionalism within their internal structures. Tourism flow in Northwest China is influenced by various factors, including the tourism resources endowment, tourism reception capacity, regional economic levels, transportation infrastructure, and more. Finally, taking into consideration the characteristics of the Northwest China tourist flow network and the factors influencing it, this paper offers relevant recommendations for tourism enhancement and regional development.

    2023 06 v.51;No.210 [Abstract][OnlineView][Download 2200K]