Restoration Of Ecological Environment Research Articles

Research on Monitoring and Application of Ecological Restoration Engineering in Open Pit Backfilling Mines Based on Satellite Remote Sensing Data

Abstract. The restoration and management of mining ecological environment is an important component of China's ecological civilization construction. The implementation of restoration projects is to avoid the serious impact caused by the continuous deterioration of mining ecological structure, and is a key way to maintain regional ecological security and energy and mineral security. Therefore, efficient and rapid monitoring and evaluation of the effectiveness of mining ecological restoration is an essential and important link. With the rapid development of remote sensing technology, remote sensing monitoring has become an important means to objectively, quickly, and accurately obtaining changes in the mining environment. It can provide timely and long-term monitoring of mining and backfilling conditions in mining areas. This article uses the multi temporal stereo images of the Resource 3 satellite over four years to monitor the mining and backfilling situation of the Zhungeer open-pit coal mine area in Inner Mongolia. By reconstructing the Digital Surface Model (DSM) of the open-pit mining area, the changes and thresholds of the multi temporal DSM data are statistically analyzed to extract the mining and backfilling areas, and the earthwork volume is calculated. The results showed that from 2013 to 2016, the main large-scale mining faces in the study area of Zhungeer open-pit mining area had a total mining operation of about 563.5 million cubic meters, and a total backfilling operation of about 604.29 million cubic meters; During the period from 2016 to 2018, the main large-scale mining faces in the region had a total of approximately 721.71 million cubic meters of mining operations and a total of approximately 805.42 million cubic meters of backfilling operations. The overall operational intensity increased from 2016 to 2018. The research results show that based on satellite image data, it is convenient and efficient to obtain DSM and corresponding changes of multiple time periods in mining areas. Monitoring results can provide important support for regional environmental governance and protection, as well as safety production in mining areas.

An empirical examination of liability for ecological environment restoration in the context of the Civil Code of China

In environmental tort lawsuits, China has been overly focused on “punishing” violators and has neglected the value of ecological environment restoration. The Article 1234 of Civil Code of China in 2021 has provided an important institutional guideline for the restoration of ecological environment and sustainable development in China. This paper analyzes 512 cases of ecological environment restoration liability and identifies five challenges in the judicial context: the lack of sound legal regulation, the lack of liability allocation, the mismatch of liability subjects, the difficulty of identifying damage facts, and the difficulty of effective implementation of restoration. In the face of these difficulties, countries that attach importance to ecological environment restoration, such as the United States, Germany and Japan, have provided experience that can be drawn on for China's ecological environment restoration liability. Based on foreign experience, China's liability for ecological environment restoration should be improved in the following aspects: first, to improve the legal system from basic laws and specific laws; second, to expand the scope of subjects from both litigation request subjects and liability subjects; third, to improve the identification and assessment mechanism and innovate the identification and assessment procedures in accordance with China's national conditions; fourth, to determine the restoration methods based on the criterion of “utilization value and the differences in the objects. The ultimate goal is to help China's Civil Code to be better applied judicially on the one hand, and to contribute to the world ecological protection on the other.

Multi-Scenario Simulation and Eco-Environmental Effects Analysis of Land Use/Cover Change in China by an Integrated Cellular Automata and Markov Model

Land use transitions play a critical role in ecological environmental restoration, but they are also plagued by ecological environmental problems caused by excessive land resource development. In this study, we propose a methodological framework for unveiling the nexus profile of land use/cover change (LUCC) and eco-environmental effects. This study explored the spatiotemporal evolution patterns of LUCC over a long time series based on high-precision land use data from 1990 to 2020. Then, the ecological values (EVs) of various cities were calculated to obtain the ecological contribution rate of different land use types in the process of change. Finally, the future development trends of land use and ecological environmental quality were predicted under multiple scenarios using the cellular automata–Markov model, and scientific policy recommendations were proposed. The results showed that the expansion trajectory of the construction land in the urban agglomeration mainly expanded inwards along the mouth of the Pearl River, and the conversion of cultivated land to construction land was the most significant type of land use change. The overall ecological environmental quality of the study area showed a downwards trend, with Shenzhen exhibiting the largest decrease in EVs. Cultivated land contributed significantly to improving regional ecological environmental quality, while the land use transition types with relatively large contributions to environmental quality deterioration were conversions to construction land. Under the scenario of coordinated protection, the degree of cultivated land area reduction was significantly reduced, and the area of forestland showed a positive growth trend, with the expansion trend of construction land being reversed. These research findings can enrich the theoretical research on the sustainable development of urban agglomerations and provide reliable data support for policy-making.

Evaluation of Ecosystem Services in Ruoergai National Park, China

This study utilizes ArcGIS10.8 and ENVI5.3 software and the InVEST model to analyze and operate field survey data and remote sensing image data from Ruoergai National Park. The work simulates the soil retention, carbon storage, water supply, and habitat quality of the park to evaluate and analyze its four major ecosystem services. Subsequently, important areas of ecosystem services are zoned based on the results, aiming to provide decision-makers with a theoretical and scientific basis for formulating ecological environment restoration, protection, and management measures in Ruoergai National Park. The results showed the following: (1) In the study area, the land use types, ranked from largest to smallest, are grassland, unused land, forest, water area, and construction land. (2) Soil retention and water supply show an increasing trend, while carbon storage shows a decreasing trend. Habitat quality remains relatively stable, with most areas maintaining a high level of quality. (3) The importance zoning of ecosystem services in the study area exhibited a trend of “four increases and one decrease”. Specifically, the areas classified as moderately important, highly important, and extremely important all increased, while the area designated as generally important decreased. The findings indicate that climate change, land use type changes, and human activities are the primary factors influencing changes in ESs. It is crucial to prioritize highly important and extremely important areas for protection and utilization within Ruoergai National Park. Moving forward, it will be essential to minimize human activities that disrupt the ecosystem, while also focusing on the conservation and sustainable use of forest and grassland.

The Spatiotemporal Variation Characteristics and Influencing Factors of Green Vegetation in China

Green vegetation is one of the main objects of ecological environment restoration and protection, objectively reflecting the quality of regional ecological environments. Studying its spatial distribution characteristics is of great significance to the formulation of ecological environment restoration policies. Based on data on urban green vegetation in China from 2000 to 2022, this study attempts to analyze the destruction and protection patterns of urban green vegetation in China from the perspectives of total changes in green vegetation contraction and growth and spatial evolution characteristics and trends, and it explores the driving factors affecting the change in green vegetation area. The results show the following: (1) Green vegetation growth and contraction occurred alternately in China from 2000 to 2022. Vegetation contraction showed a “point–line–plane” evolution pattern, forming a contraction stage of point-like aggregation, linear series, and planar spread. Vegetation growth has always presented a frontal pattern. (2) The growth and contraction of green vegetation in China showed a north–south differentiation phenomenon. The vegetation contraction phenomenon spread in the Central Plains urban agglomeration and its surrounding areas and showed an expanding trend. The growth trend is obviously moving northward, mainly concentrated in Inner Mongolia, Ningxia, Gansu, Xinjiang, and other northern provinces, which also coincides with the key ecological restoration policies in northern China in recent years. (3) City scale, economic level, population scale, agro-industrial structure, and water resources content have significant effects on the spatial distribution of green vegetation.

Has Green Finance Enhanced the Ecological Resilience Level in the Yangtze River Economic Belt?

Ecological environment restoration has become an important strategy for the high-quality development of the Yangtze River Economic Belt, and green finance is indispensable to supporting industrial transformation and green innovation. It is of great importance to clarify the internal relationship between green finance and ecological resilience construction. This paper introduces the concept of resilience into the field of ecological construction and constructs an ecological resilience index system from three dimensions of “resistance-adaptability-resilience”. On this basis, it focuses on the different aspects of green finance, such as green credit, green securities, green investment, green insurance, etc., and examines the role of green financial development on the ecological resilience of the Yangtze River Economic Belt. The results of the study showed that (1) during the study period, the overall ecological resilience level of the Yangtze River Economic Belt improved significantly and there were significant differences in the ecological resilience of the economic belts but such spatial differences are converging; (2) green insurance has a significant positive influence on ecological resilience, while green credit, green securities, and green investment have a significant negative influence on ecological resilience; (3) green credit and green securities have a significant positive effect on the resistance to ecological resilience, green credit and green investment inhibit the adaptability of ecological resilience, and green insurance significantly improves the resilience of ecological resilience. Green financial policies should be further optimized, and innovative all-round and multi-level products and services should be provided. It is necessary to leverage social capital to promote green transformation and technological innovation in high-pollution industries. By combining resource endowment and location advantages, we can explore the benign interaction between green finance and ecological civilization construction.

Evaluation of ecological carrying capacity and construction of ecological security pattern in West Liaohe River Basin of China

The West Liaohe River Basin (WRLB) is a typical agro-pastoral interlaced zone in Northeast China where excessive economic development activities brought great pressure on the ecosystem and caused a series of ecological problems, having a negative effect on regional ecological carrying capacity (ECC). The rational construction of ecological security pattern (ESP) is an effective way to improve regional ECC and alleviate the contradiction between ecological protection and economic development. In this study, taking the WLRB as an example, spatiotemporal changes of ECC in the WLRB from 2000 to 2020 were explored by using spatial principal component analysis (SPCA). Furthermore, ecological sources were determined by coupling ECC evaluation results with important ecological patches such as natural protected areas, and the minimum cumulative resistance (MCR) model combined with the circuit theory method were employed to identify ecological security zoning, ecological corridors and key ecological nodes. Then a comprehensive ESP of the basin was constructed. The results show as follows: 1) The ECC of the overall WLRB was at medium carrying level, yet was spatially differentiated, which decreased from the periphery to the center of the basin in general. ECC showed a fluctuating upward trend from 2000 to 2020. 2) The ecological source area of the WLRB was 21926.91 km², accounting for 17.33% of the total study area. The ecological sources were seriously fragmentated and mainly distributed in the mountain area. The area of ecological conservation zone, optimized buffer zone, ecological transition zone, ecological prevention and control zone were 55672.69 km², 32662.24 km², 23862.84 km² and 12021.04 km², accounting for 44.82%, 26.29%, 19.21% and 9.68%, respectively. We also extracted 95 ecological corridors (with a total length of 3130.97 km), 49 ecological pinch points (with a total area of 200.33 km²) and 30 ecological barrier points (with a total area of 318.30 km²), constituting a “points-lines-planes” comprehensive ecological security pattern. This research can provide scientific reference for the protection and restoration of ecological environment and regional sustainable development.

Advanced flow simulations of estuarine water resources responding to changes in societal demands

Water resources of rivers and estuaries have traditionally been managed for local societal demands, including municipal, agricultural, and industrial usages, as well as for transportation as navigational channels. However, as societal demands have changed including urban expansion, economic growth, cultural transition, etc., the land uses also should be changed, and the civil necessities of water have been diversified, and this has raised concerns about the ecology, environment, and water quality issues. This study attempted to address three water resource management issues in South Korean rivers and estuaries, which occurred recently due to the changes in societal demands for water and explained how the most advanced scientific research techniques had been applied. The main issues were 1) agricultural water security and ecological environment restoration in Nakdong River Estuary, 2) water and soil quality degradation due to industrial effluents in Hyeongsan River Estuary, and 3) utilization of rivers as waterways and water quality and ecology issues in the ARA waterway. To find solutions to conflicts of water resources, the series of numerical simulations validated by the field observations allowed 1) assessments of the impact and extent of salt intrusion upon the opening of estuary dam gates, 2) estuarine physical processes to investigate the influence of industrial effluent, and 3) analysis water quality variations resulting from changes in the function of artificial channels. These analyses are expected to provide appropriate and science-based strategies of regional water management.

Application of MSPA-MCR models to construct ecological security pattern in the basin: A case study of Dawen River basin

Building an ecological security pattern (ESP) can safeguard and improve the structure, functions and services of regional ecosystems. Furthermore, it is also one of the significant spatial methods to mitigate the conflict between ecological conservation and economic growth. Most previous researches on the construction of ESP have directly utilized extensive regions of forestland, grassland, water area or nature reserves as ecological sources (ESs) without weighing the habitat quality (HQ) and ecological protection red line (EPRL). The ES of the Dawen River basin (DRB) was identified through morphological spatial pattern analysis (MSPA) and landscape connectivity index. By employing the minimum cumulative resistance model (MCR), the potential ecological corridor (EC) was identified, and its importance was evaluated by gravity model. Simultaneously, the spatial properties of HQ and ecological resistance (ER) were analyzed. Finally, this paper proposed an optimization strategy for ESP in accordance with the EPRL. The results indicate that: (1) The DRB contained 15 important ESs, mainly concentrated in water and mountain forest areas. (2) 105 ECs were extracted by MCR and gravity model, including 35 level 1 corridors and 70 level 2 corridors, which were primarily concentrated in the eastern region of the basin. (3) Based on the spatial characteristics of HQ and ER, as well as the EPRL in the research, the ESP of “one axis, two belts and five zones” in the DRB was constructed and control strategies were proposed. This research offers some reference for ecological environment protection and restoration and regional sustainable development in the Yellow River basin.

Evolution and Optimization of an Ecological Network in an Arid Region Based on MSPA-MCR: A Case Study of the Hexi Corridor

Under the background of climate change, the problems of water resource allocation and desertification in arid areas are becoming increasingly prominent, which seriously threatens the sustainable development of society. Constructing an ecological network is an important measure to improve the ecological environment and maintain ecological service function. This study takes the Hexi Corridor as an example and relies on land use data from 2000 to 2020, and comprehensively applies methods, such as morphological spatial pattern analysis (MSPA), the minimum cumulative resistance model (MCR), and the network evaluation index to construct and optimize the ecological network of the Hexi Corridor. Our results show: (1) the spatial distribution of the landscape elements in the Hexi Corridor was not uniform and that the ecological foundation in the north was poor; (2) the resistance surface was “low in the south and high in the north”, with low-value areas mainly located to the south of Jiuquan City, Zhangye City, and Wuwei City, and the high-value areas were mainly located in the middle and to the north of Jiuquan City and Wuwei City; (3) the ecological source areas, corridors, and nodes showed a fluctuating upward trend, and they were mainly located to the southwest of Zhangye City, Jiuquan City, and Wuwei City; (4) the network closure (α), line point rate (β), and network connectivity (γ) showed a W-shaped change trend; (5) after the ecological network optimization, 22 new ecological source areas, 78 new corridors, and 61 new nodes were added, as a result, the α, β, and γ indices all increased. Our results provide a reference for ecological environment restoration research and serve as a regionally balanced means of sustainably developing the Hexi Corridor.

Agroecosystem transformation and its driving factors in karst mountainous areas of Southwest China: The case of Puding County, Guizhou Province

With the rapid socioeconomic development and urbanization, global agroecosystems (AESs) have undergone varying degrees of transformation, and conducting an in-depth study on how AESs are transforming in karst mountainous areas (KMAs) is essential. To further reveal the transformation process of AESs in KMAs, we proposed a theoretical framework for the transformation of AESs in KMAs. Following a “theory construction–empirical analysis–pattern evolution–mechanism revelation” research methodology, we studied the trend of AES evolution in “typical study area—typical landforms of the study area,” summarized the transformation patterns of AESs in different karst landforms, and analyzed the influencing factors of their transformation. The study found that (1) a large amount of productive land (PL) was abandoned as ecological land (EL) on steep slopes at high altitudes in KMAs, while river valleys are dominated by the transformation of PL into ecological and economic land (EEL), and the spatial distribution structure has evolved into a coordinated distribution of EL–EEL–PL, with the dominance of the production function transformed into the dominance of ecological and eco-economic functions and the living function strengthened. (2) The transformation of AESs in different karst landscapes can be summarized into four types: eco-economic development, food supply, ecological conservation, and living service. (3) The transformation of AESs is influenced by various factors, including the region's particular natural environment and socioeconomics. This study also shows that traditional extensive agriculture is moving toward modern intensive agriculture with remarkable ecological and economic win–win benefits. Our study provides theoretical guidance for land remediation, ecological environment restoration, and agricultural transformation in KMAs and similar mountainous areas to alleviate regional human–land conflicts and promote sustainable agricultural development in KMAs.

Driving factors analysis of spatial-temporal evolution of vegetation ecosystem in rocky desertification restoration area of Guizhou Province, China.

The investigation of the temporal-spatial characteristics and driving factors of vegetation ecosystem (VE) alterations held significant practical implications for the evaluation of the efficacy of rocky desertification management initiatives and safeguarding the ecological environment in the rocky desertification restoration region of Guizhou. We computed the comprehensive ecological quality index (Q) of vegetation based on the normalized difference vegetation index (NDVI) and net primary productivity (NPP). Combined with temperature, precipitation, sunshine duration, rocky desertification grade, land use, and the time series of various regions being included in national ecological functional zones, we analyzed the spatial-temporal distribution characteristics of VE changes and their response to climate change (CC) and ecological engineering (EE) by using partial derivative analysis method and scenario setting method in rocky desertification restoration areas in Guizhou. Results demonstrated that (1) the average values of NDVI, NPP, and Q all showed a fluctuating upward trend since 2000. Although the VE status of rocky desertification area was obviously worse than that of no rocky desertification area, it has a higher growth rate, especially the growth rates of NDVI, NPP, and Q in severe rocky desertification area were as high as 0.0050 year-1, 9.0733 g C m-2 year-1, and 0.7829 year-1, and the area with high recovery degree accounted for 93.19%, followed by the middle rocky desertification area. (2) CC was the main driving factor for NDVI and Q recovery, and EE was the main driving factor for NPP recovery. The contribution of EE to NPP and Q recovery increased with the increase of rocky desertification, as high as 82.13% and 30.31% in severe rocky desertification area. (3) The more serious the rocky desertification was, the more dependent the vegetation restoration was on ecological engineering, and the more difficult the restoration was. It was urgent to solve the ecological environmental problems. (4) EE played a greater role in the restoration of VE in the early stage of implementation. Its role gradually decreased in the later stages of implementation, while the role of CC increased. We provide a scientific basis for the follow-up treatment of rocky desertification, ecological environment restoration, and ecological protection effectiveness evaluation in Guizhou.

A multifunctional synergy development evaluation model of the impact of the cascade reservoir construction sequence on basins

Considering the mass reservoirs construction, it is important to study the cascade reservoir construction sequence, which directly affects the water and sediment resource allocation, ecological environment restoration, and socioeconomic development of the basin. Thus, we constructed an evaluation index system by comprehensively considering the basin water and sediment discharge index, basin ecological and environmental maintenance index, and basin social and economic development index. The evaluation model was established to assess the impact of the cascade reservoir construction sequence on basin multifunctional synergy development index. The model was applied to evaluate the cascade reservoir construction sequence in the Yangtze and Yellow River Basin of China. The results revealed that: (1) The basin water and sediment discharge index, basin social and economic development index, and basin multifunctional synergy development index benefits gradually increased, the basin ecological and environmental maintenance index benefits progressively decreased in the Yangtze and Yellow River Basin. (2) The basin water and sediment discharge index, and basin ecological and environmental maintenance index of the planned cascade reservoir construction sequence ranked top in the Yellow River Basin; the basin water and sediment discharge index, and basin social and economic development index of the planned cascade reservoir construction sequence ranked top in the Yangtze River Basin. (3) The cascade reservoir construction sequence focused more on basin social and economic development index benefits when the level of national economic development was low, and more on basin water and sediment discharge index benefits when it was high. (4) Reservoir capacity and installed capacity were the main factors influencing the cascade reservoir construction sequence in the Yangtze and Yellow River Basin, respectively. These findings provide useful information regarding the cascade reservoir construction sequence.

Research progress on ecology and sustainable development of Guilin Lijiang River Basin, China, based on bibliometric analysis.

Guilin is a typical representative of karst landform in South China. Because of its unique geographical landform and hydrological environment, Lijiang River Basin has received a certain degree of attention in field of ecology and sustainable development. Explore and visualize the hotspots and frontiers of Guilin Lijiang River Basin Ecology and Sustainable Development (GLRBESD) by using bibliometrics, CiteSpace, and VOSviewer. Results showed that number of published papers was in a fluctuating upward trend from 1992 to 2022 and from 2011 to 2022, respectively. Work of scholars in this field has been continuously strengthened and deepened, and overall scientific research results show an increasing trend. Research objects and topics are mainly aimed at the water resources, climate, and environment of GLRB Landscape ecology and SDG index construction. Research of GLRBESD-published documents has the characteristics of multi-disciplinary and interdisciplinary integration. High-frequency keywords in research field focus on ecotourism, ecological restoration, and sustainable development, mainly based on the research of ecotourism development. Impact of environmental factor changes and human activities on land use change in different periods is an important research topic. Core research field of GLRBESD on macro-scale can be divided into ESV and function, ecological compensation and ecotourism, ecological environment and ecological restoration, ecological network and ecological risk assessment, and sustainable development. This research provides systematic scientific research basis for enhancing sustainable development ability and ecosystem functions and services of World Natural Heritage Site.

Discussion on the Application of Coal Gangue in Soil Remediation in Plateau Areas

Soil remediation is an important part of ecological environment restoration, especially important in the harsh environmental conditions in the high and cold plateau. Adding special materials to improve the soil environment can improve the soil quality, which is conducive to vegetation growth and ecological improvement. As a solid waste in the process of coal resource development and utilization, coal gangue is also a new type of soil remediation and improvement material, which has natural advantages and great potential in controlling contaminated soil, improving soil quality and improving ecosystem. In this work, Junba Village in the plateau area affected by desertification was taken as the observation location of the restoration test, and two groups of sample plots were set up in the area for comparison tests. One group with coal gangue materials (water retaining agent 120g and coal gangue) was taken as the No. 1 plot, and the control group without coal gangue materials (water retaining agent 120g) was taken as the No. 2 plot. After longterm observation and measurement, the development quantity of vegetation in sample No. 1 (98 dominants and 97 dominants) was obviously better than that in sample No. 2 (38 dominants and 24 dominants) , and the growth status was also better than that in sample No. 1 (0. 6 cm in leaf width of alkali-grass) and that in sample No. 2 (0. 3 cm in leaf width of alkali-grass) . Thus, it can be shown that coal gangue has a positive and effective role in soil remediation in the plateau areas, and it is suggested to popularize the use of soil remediation in other similar environments.

Microagroecosystem models and their landscape ecological risk evolution in karst mountainous areas

Micro-spatial agroecosystem (AES) changes in karst mountain areas are a response to the human-land relationship of the human activity center. However, the changes and linkages between AESs and landscape ecological risks (LER) from a micro perspective in karst mountain areas (KMA) have not yet attracted in-depth attention from the academic community. This paper proposes the concept of microagroecosystems (MAESs) and constructs the MAES model based on the landscape development intensity (LDI) to evaluate the systematic landscape evolution rules and the LER intensity, which reflects the human-land relationship in KMA. We used the buffer ring with a 200 m cultivation range interval to categorize the MAES model into six models, namely, High-Mid-Low, High-Low-Medium, Medium-High-Low, Medium-Low-High, Medium-High-High, Low-Medium-High and Low-Medium-High, and the different models not only reflect the regional conditions but also represent the different stages of the evolution of AESs in KMAs. We found that AESs in karst mountainous areas are transforming from traditional food crop systems to economic fruit forest ecosystems, and at the same time, the gravity center of human activities is migrating from high to low altitude areas, and the ecological vitality of MAESs is showing a trend of enhancement. In addition, the regions with high altitudes and steep slopes in karst mountainous areas have a single landscape structure and are dominated by traditional food cultivation, while the regions with low altitudes and gentle slopes have a diverse landscape structure and are dominated by modern and sustainable agricultural development. Finally, we reveal that the LER in KMAs shows a trend of initial increase followed by subsequent decrease, the influence of the human-land relationship on the LER in the micro perspective is significant, and the coordination and trade-off between agricultural development and environmental protection is the key direction of development in the future. The study results can provide a reference for the rational allocation of landscape, ecological environment restoration, and optimization of regional human-land relationships in KMAs worldwide.

Simulation of the Spatial Flow of Wind Erosion Prevention Services in Arid Inland River Basins: A Case Study of Shiyang River Basin, NW China

Wind erosion is a key global environmental problem. As an important protective measure to provide services to the ecosystems in wind-eroded areas, the wind erosion prevention service is of great significance to the management of wind and sand hazards and ecological environment restoration in the wind-eroded areas and the neighboring areas. Taking the Shiyang River basin as the study area, the quality of supplies for wind erosion prevention services was estimated using the RWEQ model for the years 2005, 2010, 2015, and 2020; the trajectories of air masses at wind speeds higher than the sand-causing wind speeds were simulated based on the forward trajectory module of the HYSPLIT model for a 24 h period; the spatial simulation of the flow of wind erosion prevention services on a daily scale with Minqin Station as the sand source was carried out; and the beneficiary areas of wind erosion prevention services were identified. Based on the RWEQ model, the spatial patterns of potential wind erosion, actual wind erosion, and wind and sand stabilization services were obtained, and the supply areas were divided. From 2005 to 2020, the wind erosion prevention service flow in the Shiyang River basin was distributed along a northwest–southeast direction, with a radial decrease from the center to the periphery, and with an extremely strong extraterritorial effect. The amount of wind erosion in the basin has a variable downward tendency over time and a spatial distribution pattern of high in the north and low in the south. The area of higher sand fixation is distributed in the eastern oasis area and desert junction zone. The HYSPLIT model was used to simulate the transport paths of wind and sand within 24 h during 2005–2020, the transmission paths of the wind erosion prevention service flow were obtained to be 59–134, and the flows were 2.55 × 104–3.85 × 106 t, displaying a changing trend of first decreasing, then increasing, and then decreasing. Gansu Province, Ningxia Hui Autonomous Region, and Inner Mongolia Autonomous Region are the most important areas benefiting from the wind erosion prevention service flow in the Shiyang River basin. The wind erosion prevention service flows in the basin benefit 47 cities in 9 provinces.

Spatiotemporal variations of eco-environmental vulnerability in Shiyang River Basin, China

Eco-environmental vulnerability reflects the unfavorable degree of the ecological environment presented by external disruptions. The Shiyang River Basin, as a typical desert interior river basin in Northwest China, plays crucial ecological roles. Exploring eco-environmental vulnerability's spatial and temporal evolution is vital to maintaining ecosystem stability. We utilized the ecological sensitivity-resilience-press (SRP) model to create a complete evaluation index system of eco-environmental vulnerability using meteorological, remote sensing, and statistical data. The cloud theory improved analytic hierarchy process (CM-AHP) was used to calculate the subjective weights, the entropy weight method (EWM) was used to estimate the objective weights, and the comprehensive weights of the indicators were determined using the least square method, which combined the subjective and objective weights. From 2000 to 2020, the spatial-temporal features of eco-environmental vulnerability in the research area were analyzed. The results indicate that surface temperature, land use, and monthly precipitation are key factors impacting the state of eco-environmental vulnerability. The basin's potential-vulnerable and light-vulnerable areas are predominantly located in the south and southwest, whereas the northern and eastern areas are classified as severe-vulnerable and extreme-vulnerable. Extreme-vulnerable areas declined from 8.59% in 2000 to 4.3% in 2020, while potential-vulnerable areas climbed from 2.11% in 2000 to 8.08% in 2020. The eco-environmental vulnerability as a whole has evolved in a benign direction. The research results can serve as a theoretical groundwork for the restoration of the Shiyang River Basin's ecological environment and long-term development.

Enhancing Uranium Removal with a Titanium-Incorporated Zirconium-Based Metal-Organic Framework.

The urgent need to efficiently and rapidly decontaminate uranium contamination in aquatic environments underscores its significance for ecological preservation and environmental restoration. Herein, a series of titanium-doped zirconium-based metal-organic frameworks were meticulously synthesized through a stepwise process. The resultant hybrid bimetallic materials, denoted as NU-Zr-n%Ti, exhibited remarkable efficiency in eliminating uranium (U (VI)) from aqueous solution. Batch experiments were executed to comprehensively assess the adsorption capabilities of NU-Zr-n%Ti. Notably, the hybrid materials exhibited a substantial increase in adsorption capacity for U (VI) compared to the parent NU-1000 framework. Remarkably, the optimized NU-Zr-15%Ti displayed a noteworthy adsorption capacity (∼118 mg g-1) along with exceptionally rapid kinetics at pH 4.0, surpassing that of pristine NU-1000 by a factor of 10. This heightened selectivity for U (VI) persisted even when diverse ions exist. The dominant mechanisms driving this high adsorption capacity were identified as the robust electrostatic attraction between the negatively charged surface of NU-Zr-15%Ti and positively charged U (VI) species as well as surface complexation. Consequently, NU-Zr-15%Ti emerges as a promising contender for addressing uranium-laden wastewater treatment and disposal due to its favorable sequestration performance.

Experimental study on the development mode and evolution mechanism of sodium silicate solidified sand under different temperatures and curing paths

Water glass, which can be cured by rapid dehydration, is an ideal environmentally friendly material for engineering grouting solidification and ecological environment restoration. The curing efficiency of water glass at room temperature was low, the curing mechanism and strength characteristics at high temperature were not clear, and the engineering applicability and optimal curing methods were to be explored. In this paper, 10 curing paths were designed within 100 °C. The mechanical and acoustic characteristics of water glass-cured sandy soils were tested by uniaxial compressive tests and acoustic emission (AE). The relationship between strength, wave velocity and curing age was established based on the “logistics” model. The characteristic parameter “Q” value was proposed based on the AE characteristic value. Combined with the results of scanning electron microscopy (SEM), the solidification evolution process was revealed in terms of gel structure, crystal morphology and pore space. The process of water glass curing sandy soil was divided into a “strength rising period” and a “strength deterioration period”. The enhancement and weakening effects of high temperature on the gel layer were stronger than those at room temperature. The longer the room temperature curing time is, the weaker the effect of high temperature on the specimen. After high-temperature curing, the maximum strength of the specimens increased by 107.85 %, and the strength growth rate and strength deterioration rate increased by 586.34 % and 3738.79 %, respectively. The conversion rate of the gel under high temperature conditions determined the strength of the specimen. The rate of strength deterioration of the specimen was determined by the hardening effect of the undehydrated gel and the excessive dehydration effect of the rigid gel.