兰州大学机构库研究单元&专题: 资源环境学院
http:///ir.lzu.edu.cn/:80/handle/262010/113463
2024-03-28T17:09:52Z
2024-03-28T17:09:52Z
Holocene climate changes and paleoecology on the Tibetan Plateau: recent advances
Hou, Juzhi
http:///ir.lzu.edu.cn/:80/handle/262010/584057
2024-03-19T01:04:52Z
2024-03-19T01:04:51Z
题名: Holocene climate changes and paleoecology on the Tibetan Plateau: recent advances
作者: Hou, Juzhi
2024-03-19T01:04:51Z
Simultaneous immobilization of multiple heavy metal(loid)s in contaminated water and alkaline soil inoculated Fe/Mn oxidizing bacterium
Wu, Yi
Wang, Shengli
Xu, Jun
Zang, Fei
Long, Song
Wu, Yining
Wang, Yuqing
Nan, Zhongren
http:///ir.lzu.edu.cn/:80/handle/262010/583794
2024-03-20T07:10:12Z
2024-03-15T02:28:20Z
题名: Simultaneous immobilization of multiple heavy metal(loid)s in contaminated water and alkaline soil inoculated Fe/Mn oxidizing bacterium
作者: Wu, Yi; Wang, Shengli; Xu, Jun; Zang, Fei; Long, Song; Wu, Yining; Wang, Yuqing; Nan, Zhongren
摘要: <p>Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened. The surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II) and Mn(II) by Pseudomonas taiwanensis (marked as P4) and Pseudomonas plecoglossicida (marked as G1) contains rich reactive oxygen functional groups, which play critical roles in the removal efficiency and immobilization of heavy metal(loid)s in co-contamination system. The isolated strains P4 and G1 can grow well in the following environments: pH 5-9, NaCl 0-4%, and temperature 20-30°C. The removal efficiencies of Fe, Pb, As, Zn, Cd, Cu, and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system (the initial concentrations of heavy metal(loid) were 1 mg/L), approximately reaching 96%, 92%, 85%, 67%, 70%, 54% and 15%, respectively. The exchangeable and carbonate bound As, Cd, Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil, thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)s. This research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s. © 2023</p>
2024-03-15T02:28:20Z
Characteristics of the impact pressure of an outburst debris flow: Insights from experimental flume tests
Yang, Yunpeng
Chen, Guan
Meng, Xingmin
Chong, Yan
Shi, Wei
Bian, Shiqiang
Jin, Jiacheng
Yue, Dongxia
http:///ir.lzu.edu.cn/:80/handle/262010/583792
2024-03-15T02:28:15Z
2024-03-15T02:28:14Z
题名: Characteristics of the impact pressure of an outburst debris flow: Insights from experimental flume tests
作者: Yang, Yunpeng; Chen, Guan; Meng, Xingmin; Chong, Yan; Shi, Wei; Bian, Shiqiang; Jin, Jiacheng; Yue, Dongxia
摘要: Debris flows generated by landslide dam failures are highly destructive and can result in rapid, large-scale landscape changes. Understanding the formation and impact dynamics of an outburst debris flow is essential for effective hazard mitigation. In this study, we conducted a series of experiments to investigate the flow dynamics and the impact against an obstacle of outburst debris flows by measuring the flow properties, seismic signals, and impact forces. The results show that the impact of an outburst flow is strongly affected by the evolution of the landslide dam and the internal flow dynamics, which influence its motion and govern its rheology. For an outburst flow with a high sediment concentration caused by intensive dam erosion, the matrix structure can provide cohesive strength for the suspension of coarse particles in the flow. This significantly enhances the stationary mean impact force of the outburst flow. Furthermore, the solid inertial stress, which is a crucial factor representing particle agitation and reflecting flow properties, exhibits a positive power-law correlation with the impact force and a positive linear correlation with seismic energy. This indicates that seismic monitoring can reveal the bulk flow characteristics, internal flow dynamics and their impact characteristics. The seismic energy level increases with the velocity and bulk density of the outburst flow, while its frequency of the seismic data increases with the rate of particle impacts but decreases in the presence of a dampening layer. Our findings provide a scientific perspective for understanding the impact dynamics of an outburst debris flow that could improve the design of measures to mitigate debris-flow hazards. © 2024 Elsevier B.V.
2024-03-15T02:28:14Z
Increasing deep soil water uptake during drought does not indicate higher drought resistance
Yin, Dingcai
Gou, Xiaohua
Liu, Jie
Zhang, Dingyun
Wang, Kai
Yang, Haijiang
http:///ir.lzu.edu.cn/:80/handle/262010/583788
2024-03-15T02:28:08Z
2024-03-15T02:28:07Z
题名: Increasing deep soil water uptake during drought does not indicate higher drought resistance
作者: Yin, Dingcai; Gou, Xiaohua; Liu, Jie; Zhang, Dingyun; Wang, Kai; Yang, Haijiang
摘要: Understanding the water use patterns of different tree species and their adaptability to drought is urgently needed due to global warming. In this study, we investigated the seasonal water uptake patterns of Pinus tabulaeformis and Picea wilsonii on the eastern Tibetan Plateau using stable isotope methods. In addition, tree ring width data was used to evaluate the radial growth resistance of the two species to drought in 2022. The focus was on identifying species differences in water uptake patterns during drought spells and radial growth resistance to drought. The results showed that although Pinus tabulaeformis could increase water uptake from deeper soil layers during drought spells, the radial growth resistance to drought was significantly lower (p © 2024 Elsevier B.V.
2024-03-15T02:28:07Z
Exploring future trends of precipitation and runoff in arid regions under different scenarios based on a bias-corrected CMIP6 model
Wang, Qingzheng
Sun, Yunfan
Guan, Qingyu
Du, Qinqin
Zhang, Zepeng
Zhang, Jun
Zhang, Erya
http:///ir.lzu.edu.cn/:80/handle/262010/583784
2024-03-15T02:28:01Z
2024-03-15T02:28:00Z
题名: Exploring future trends of precipitation and runoff in arid regions under different scenarios based on a bias-corrected CMIP6 model
作者: Wang, Qingzheng; Sun, Yunfan; Guan, Qingyu; Du, Qinqin; Zhang, Zepeng; Zhang, Jun; Zhang, Erya
摘要: Precipitation and runoff changes play a very important role in ecosystems and human well-being. Predicting its changes is critical for water resource management and coping with climate change. However, corresponding studies in arid regions are limited by lack of data and poor spatial distribution of meteorological stations. Therefore, this study identified the applicability of multi-source meteorological data in a typical arid region, the Shiyang River Basin, by comparing its variability with measured precipitation. Then, the best applicable precipitation product was selected to correct the data of CMIP6, and to predict the change of precipitation and runoff under the scenarios of SSP126/245/585 by 2100. The results showed that the CMADS dataset was more consistent with the measured data than TRMM and CFSR. Through Taylor diagram analysis and equidistant cumulative distribution functions matching (EDCDF) method bias correction, the GFDL-ESM4 model was more suitable for arid regions in terms of precipitation and temperature. During 2015–2100, the annual precipitation and average annual temperature under each scenario all showed an increasing trend. However, the monthly precipitation from May to October showed a decreasing trend, indicating an increase in precipitation during spring and winter, and a decrease during summer and autumn. The average temperature for all months from January to December showed an increasing trend. However, in arid regions, the temperature increase is more pronounced during colder months (1–3) compared to hotter months (6–9). The average annual runoff of SSP126 scenario showed an increasing trend from 2015 to 2100 (SSP126: 0.004/yr), while the runoff from the SSP245 and SSP585 scenarios showed a decreasing trend (SSP245: −0.031/yr; SSPSSP585: −0.084/yr). This is primarily attributed to a small increment of precipitation and a larger increment of temperature, an early melting of glacial snow and an increasing of evapotranspiration, which in turn leads to a reduction in annual runoff. The research can help achieving sustainable development, effective management of water resources in arid regions, and provide a reference and example for related research in high-resolution. © 2024 Elsevier B.V.
2024-03-15T02:28:00Z
Photo-Reactivity of dissolved black carbon unveiled by combination of optical spectroscopy and FT-ICR MS analysis: Effects of pyrolysis temperature
Li, Liangyu
Cheng, Wan
Xie, Xiaoyun
Zhao, Ranran
Wang, Yaodong
Wang, Zhaowei
http:///ir.lzu.edu.cn/:80/handle/262010/583782
2024-03-15T02:27:57Z
2024-03-15T02:27:56Z
题名: Photo-Reactivity of dissolved black carbon unveiled by combination of optical spectroscopy and FT-ICR MS analysis: Effects of pyrolysis temperature
作者: Li, Liangyu; Cheng, Wan; Xie, Xiaoyun; Zhao, Ranran; Wang, Yaodong; Wang, Zhaowei
摘要: Dissolved black carbon (DBC) has high photoactivity, which plays an important role in contaminants photodegradation. However, it is unclear how pyrolysis temperatures would affect the composition and photo-reactivity of DBC at the molecular level. Herein, we combined complementary techniques to study the characteristics of DBC pyrolyzed at 200 - 500 ℃, as well as the photoproduction of reactive species and the photodegradation of tetracycline (TC). Bulk composition characterization found that condensed aromatic carbonyl compounds (ConAC) with narrow molecular weights in DBC experienced an increase from 200 to 500 °C, which enhanced the photoproduction of 3DBC*,1O2, and ·OH. Molecular-level data suggested that 3DBC* and 1O2 were both related to the same DBC compounds. Comparatively, the patterns for ·OH were less pronounced, implying its precursor was not 3DBC* and had more complexity. Plentiful CHOx species of ConAC in DBC400 and DBC500 (DBCT, where T = pyrolysis temperature) accelerated the generation of 3DBC* and 1O2, enhancing the photodegradation of TC, and mainly triplet states of quinones reacted with TC. In contrast, DBC200 and DBC300 exhibited inhibition since massive CHOx species in lignin-like reduced 3TC* to TC. Our data revealed the diverse photochemical behavior mechanisms of DBC pyrolyzed at 200 – 500 ℃ at the molecular level and the implications for aquatic contaminants photochemistry. © 2024 Elsevier Ltd
2024-03-15T02:27:56Z
Modeling the impacts of 2D/3D urban structure on PM2.5 at high resolution by combining UAV multispectral/LiDAR measurements and multi-source remote sensing images
Lyu, Rongfang
Zhang, Jinming
Pang, Jili
Zhang, Jianming
http:///ir.lzu.edu.cn/:80/handle/262010/583779
2024-03-15T02:27:50Z
2024-03-15T02:27:49Z
题名: Modeling the impacts of 2D/3D urban structure on PM2.5 at high resolution by combining UAV multispectral/LiDAR measurements and multi-source remote sensing images
作者: Lyu, Rongfang; Zhang, Jinming; Pang, Jili; Zhang, Jianming
摘要: Understanding the impacts of 2D/3D urban structure on PM2.5 is critical for protecting resident health and sustainable development. However, accurate understanding is limited by the lack of high-resolution PM2.5 simulation in cities with sparse monitoring stations and the simultaneously consideration of different landscape types both in 2D and 3D directions. Using Yinchuan City as a case study, an integrated simulation model combining satellite AOD, NDVI and meteorological data was developed using random forest (RF) algorithm to simulate city-scale PM2.5 variation at 30 m resolution. Then, the most critical 2D/3D urban metrics in altering PM2.5 and their impacts were explored through RF analysis. Finally, optimal urban structure was identified using Bayesian Network and multi-scenario analysis. The results indicated that 1) the established RF model could effectively simulate within-city variation of PM2.5 at 30 m with an R2 of 0.75. Thus, it is feasible to use the abundant temporal information and high-resolution AOD to map city-scale PM2.5 and overcome the limitation of spare monitoring stations. 2) The emission-related metric of distance to polluting enterprise and city center had the largest impacts on PM2.5, followed by NDVI, building height, impervious surface area and shape, and UGS green volume, area, shape and connectivity. Optimized 3D urban structure for reducing PM2.5 was proposed from the three aspects of emission source location, UGS pattern and impervious surface. This study deepens the understanding of how 2D/3D urban structure impact PM2.5 and provides scientific references for optimization possibility of urban air quality in both horizontal and vertical directions. © 2024 Elsevier Ltd
2024-03-15T02:27:49Z
Legacy effects of extreme drought and wetness events on mountain grassland ecosystems and their elevation dependence
Du, Qinqin
Guan, Qingyu
Sun, Yunfan
Wang, Qingzheng
Zhang, Jun
Xiao, Xiong
Liu, Hanqi
Yang, Xinyue
Zhang, Erya
http:///ir.lzu.edu.cn/:80/handle/262010/583778
2024-03-15T02:27:49Z
2024-03-15T02:27:48Z
题名: Legacy effects of extreme drought and wetness events on mountain grassland ecosystems and their elevation dependence
作者: Du, Qinqin; Guan, Qingyu; Sun, Yunfan; Wang, Qingzheng; Zhang, Jun; Xiao, Xiong; Liu, Hanqi; Yang, Xinyue; Zhang, Erya
摘要: Extreme climate currently has significant impacts on global carbon cycling, ecosystem services, and biodiversity, and these impacts will continue in the future. The effects of extreme drought on terrestrial ecosystems have been extensively researched. Mountain regions are undergoing more pronounced climate change compared to the global average. However, the differential responses of mountain grassland ecosystems to extreme drought and wetness remain unclear. Therefore, this study focuses on grasslands in the Qilian Mountains (QLMs) and utilizes the normalized difference vegetation index (NDVI) and the standardized precipitation evapotranspiration index (SPEI) to compare and analyze the legacy effects of extreme drought and extreme wetness events on grassland ecosystems. The results indicate that between 2000 and 2018, extreme drought generally has one-year negative legacy effects on grassland ecosystems, particularly in alpine meadow. Conversely, extreme wetness predominantly exhibits positive legacy effects on grassland growth. The acceleration of growth caused by extreme wetness (wet compensation effect) can compensate for 143 % of the drought legacy effect. This compensatory effect is particularly evident in temperate typical meadow, highlighting the asymmetrical response of grassland vegetation to extreme drought and wetness events. Furthermore, the legacy effects of extreme drought and wetness events are spatially heterogeneous and demonstrate clear elevation dependence. For alpine meadow and alpine steppe, the most significant positive and negative legacy effects occur at high and low elevations, while mid-elevations (3300–3800 m) experience the smallest legacy effects. These findings provide crucial guidance for understanding the impacts of extreme climate events on the structure and functioning of mountain grassland ecosystems. © 2024 Elsevier B.V.
2024-03-15T02:27:48Z
Evaluation of heavy metal speciation distribution in soil and the accumulation characteristics in wild plants: A study on naturally aged abandoned farmland adjacent to tailings
Dong, Suhang
Li, Longrui
Chen, Weijie
Chen, Zhaoming
Wang, Yufan
Wang, Shengli
http:///ir.lzu.edu.cn/:80/handle/262010/583776
2024-03-15T02:27:41Z
2024-03-15T02:27:40Z
题名: Evaluation of heavy metal speciation distribution in soil and the accumulation characteristics in wild plants: A study on naturally aged abandoned farmland adjacent to tailings
作者: Dong, Suhang; Li, Longrui; Chen, Weijie; Chen, Zhaoming; Wang, Yufan; Wang, Shengli
摘要: Heavy metal composite pollution is widespread in the surrounding environment of tailings ponds in arid and semi-arid regions, leading to the abandonment of substantial agricultural land. This study investigates the speciation distribution and plant accumulation characteristics of heavy metals in abandoned farmland with different durations of natural aging. The aim is to comprehend the local heavy metal behavior pattern in the soil-plant system and offer insights for environmental remediation. Our findings reveal that Cd stands out as the primary heavy metal pollutant in this area. The mobility ranking of heavy metals is Cd > Pb > Zn > Cu, with Cd and Pb mobility decreasing along the basin. Notably, active Pb exhibits a higher affinity for soil binding compared to other metals. The predominant plant species in the region are primarily small shrubs, herbaceous plants, and semi-shrubs that demonstrate tolerance to drought and salt. Most plant samples showed elevated levels of Cd, Pb, and Zn, surpassing the maximum tolerance levels for dietary minerals in livestock. This elevated metal content poses potential threats to the health of local livestock and wildlife, yet it is also considered a potential for phytoremediation. Selected dominant plant species from the current study include Kalidium foliatum & gracile which shows potential as a Cd accumulator and indicator. Neotrinia splendens and Reaumuria songarica demonstrate potential as Cd excluders, with the latter exhibiting higher tolerance to Cd (62.9 mg/kg). Additionally, our observations indicate that different plant parts exhibit distinct responses to heavy metals, and Zn synergistically influences the aerial part accumulation of Cd. This study holds significant importance in understanding the complex behavior patterns of multi-metal pollutants in the natural environment. The identification of native plants with remediation potential is valuable for phytoremediation of environment pollution in mining area. © 2024
2024-03-15T02:27:40Z
Field experiment on the spatiotemporal evolution of soil moisture in a rainfall-induced loess landslide: Implications for early warning
Chen, Guan
Bian, Shiqiang
Ma, Jianhua
Meng, Xingmin
Shi, Wei
Wu, Jie
Zhang, Yi
Li, Yajun
http:///ir.lzu.edu.cn/:80/handle/262010/583773
2024-03-15T02:27:35Z
2024-03-15T02:27:34Z
题名: Field experiment on the spatiotemporal evolution of soil moisture in a rainfall-induced loess landslide: Implications for early warning
作者: Chen, Guan; Bian, Shiqiang; Ma, Jianhua; Meng, Xingmin; Shi, Wei; Wu, Jie; Zhang, Yi; Li, Yajun
摘要: Rainfall can increase the moisture content of a slope, which changes its mechanical properties and thus acts as an important mechanism to trigger landslides. However, it is unclear how moisture contents vary in space and time during rainfall-induced slope movements, and which soil-wetting patterns precede landslide events. Here, we used point sensors and time-lapse 3D electrical resistivity tomography (tl-3D-ERT) technology to monitor the spatiotemporal evolution of the hydrology and movement within a rainfall-induced loess landslide. We observed that movement of the slope involved a semi-continuous process of initiation, acceleration, and deceleration to stabilization. The slope hydrology evolution suggested that initial saturation, dominant flow, and changes in slope recharge and drainage owing to internal seepage and erosion are important factors that affect moisture changes. The movement accelerated when the average saturation value and spatial variation in moisture distribution within the slope increased; however, the movement decelerated when both parameters did not change significantly with time. The accumulation and dissipation of pore water pressure within the slope owing to uneven humidification may be the underlying cause of changes in landslide movement. Our study demonstrates the potential of tl-3D-ERT for monitoring the spatiotemporal variability of moisture evolution within rainfall-induced landslides to determine landslide deformation trends and develop a landslide early warning system. © 2024 Elsevier B.V.
2024-03-15T02:27:34Z