Ecological Environment Evaluation Research Articles

A WebGIS-Based System for Supporting Saline-Alkali Soil Ecological Monitoring: A Case Study in Yellow River Delta, China

The monitoring and evaluation of soil ecological environment is very important to ensure the saline-alkali soil health and the safety of agricultural products. It is of foremost importance to, within a regional ecological risk-reduction strategy, develop a useful online system for soil ecological assessment and prediction to prevent people from suffering the threat of sudden disasters. However, the traditional manual or empirical parameter adjustment causes the mismatch of the hyperparameters of the model, which cannot meet the urgent needs of high-performance prediction of soil properties using multi-dimensional data in WebGIS system. For the end, this study aims to develop a saline-alkali soil ecological monitoring system for real-time monitoring of soil ecology in the Yellow River Delta, China. The system applied advanced web-based GIS, including front-end and back-end technology stack, cross-platform deployment of machine learning models, and a database embedded in multi-source environmental variables. The system adopts a five-layer architecture and integrates functions such as data statistical analysis, soil health assessment, soil salt prediction and data management. The system visually displays the statistical results of air quality, vegetation index and soil properties in the study area. It provides users with ecological risk assessment functions to analyze soil heavy metal pollution. Specially, the system introduces a tree structured Parzan estimator (TPE) optimized machine learning model to achieve accurate prediction of soil salinity. The TPE-RF model had the highest prediction accuracy (R2 = 94.48%) in the testing set in comparison with the TPE-GBDT model, which exhibited the strong ability for the nonlinear relationship between environmental variables and soil salinity. The system developed in this study can provide accurate saline-alkali soil information and health assessment results for government agencies and farmers, which is of great significance for agricultural production and saline-alkali soil ecological protection.

Comprehensive comparison of two models evaluating eco-environmental quality in Fangshan

It is crucial to employ scientifically sound models for assessing the quality of the ecological environment and revealing the strengths and weaknesses of ecosystems. This process is vital for identifying regional ecological and environmental issues and devising relevant protective measures. Among the widely acknowledged models for evaluating ecological quality, the ecological index (EI) and remote sensing ecological index (RSEI) stand out; however, there is a notable gap in the literature discussing their differences, characteristics, and reasons for selecting either model. In this study, we focused on Fangshan District, Beijing, China, to examine the differences between the two models from 2017 to 2021. We summarized the variations in evaluation indices, importance, quantitative methods, and data acquisition times, proposing application scenarios for both models. The results indicate that the ecological environment quality in Fangshan District, Beijing, remained favorable from 2017 to 2021. There was a discernible trend of initially declining quality followed by subsequent improvement. The variation in the calculation results is evident in the overall correlation between the RSEI and EI. Particularly noteworthy is the significantly smaller correlation between EI and the RSEI in 2021 than in the other two years. This discrepancy is attributed to shifts in the contribution of the evaluation indices within the RSEI model. The use of diverse quantitative methods for evaluating indicators has resulted in several variations. Notably, the evaluation outcomes of the EI model exhibit a stronger correlation with land cover types. This correlation contributes to a more pronounced fluctuation in RSEI levels from 2017 to 2021, with the EI model's evaluation results in 2019 notably surpassing those of the RSEI model. Ultimately, the most prominent disparities lie in the calculation results for water areas and construction land. The substantial difference in water areas is attributed to the distinct importance assigned to evaluation indicators between the two models. Moreover, the notable difference in construction land arises from the use of different quantification methods for evaluation indicators. In general, the EI model has suggested to be more comprehensive and effectively captures the annual comprehensive status of the ecological environment and the multiyear change characteristics of the administrative region. On the other hand, RSEI models exhibit greater flexibility and ease of implementation, independent of spatial and temporal scales. These findings contribute to a clearer understanding of the models' advantages and limitations, offering guidance for decision makers and valuable insights for the improvement and development of ecological environmental quality evaluation models.

Highway Ecological Environmental Assessment Based on Modified Remote Sensing Index—Taking the Lhasa–Nyingchi Motorway as an Example

The Lhasa to Nyingchi Expressway in Xizang made efforts to protect the ecological environment during its construction, but it still caused varying degrees of damage to the fragile ecosystems along the route. Accurately assessing the process of change in the ecological environment quality in this region holds significant research value. This study selected the Linzhi-to-Gongbo’gyamda section of the Lhasa-to-Nyingchi Expressway as the research area. Firstly, based on the remote sensing ecological index (RSEI), this study constructed an ecological environmental quality evaluation system for the Xizang region. Subsequently, using the Google Earth Engine (GEE) platform, sub-indicators were extracted, and the combination weighting method of game theory was employed to determine indicator weights. This process resulted in the calculation of the MRSEI for the study area from 2012 to 2020. Finally, by utilizing the spatial distribution of the MRSEI, monitoring the level of MRSEI changes, and employing the transition matrix, this study analyzed the changing trend of the ecological environmental quality from 2012 to 2020. The results indicate that the MRSEI are 0.5885, 0.5951, 0.5296, 0.6202, 0.59, 0.5777, 0.5898, 0.5703, and 0.5987, showing a gradual increasing trend with an initial decrease followed by an ascent. This trend is mainly attributed to concentrated road construction and subsequent ecological restoration, leading to an improvement in the restoration effect. Simultaneously, the ecological environmental quality remains relatively stable, with 69.5% of the region showing no change, and the remaining 30.5% experiencing improvement exceeding degradation. Specifically, there were significant improvements in the land with ecological quality levels categorized as poor, fair, moderate, and good. The types of degradation primarily involved lands originally classified as excellent and good degrading to good and moderate levels, respectively. The above results serve as a theoretical reference for the ecological restoration project of the Lhasa-to-Nyingchi Expressway.

Comprehensive evaluation of urban talent ecological environment and diagnosis of barrier factors: An analysis of 16 cities in Shandong Province

Based on the personal-environment matching theory and urban comfort theory, the paper constructs an evaluation index system for urban talent ecological environment. The entropy-weighted-TOPSIS method was used to measure the urban talent ecological environment in Shandong Province from 2018 to 2021, the Gini coefficient was used to explore regional differences in the urban talent ecological environment, and the obstacle factor model was used to determine the obstacle factors affecting the urban talent ecological environment. The results show that the talent ecological environment of cities in Shandong Province can be divided into 4 tiers. Qingdao city is in the leading tier, Jinan city is in the challenging tier, Yantai city and other 4 cities are in the catching up tier, and Dezhou city and other 10 cities are in the improving tier. The urban talent ecological environment shows the spatial distribution of “ East Shandong > Central Shandong > Southwest Shandong > Northwest Shandong ”. Per capita gross regional product, foreign direct investment, general public budget income, per capita urban road area, number of patent applications granted, number of research and experimental development personnel, education expenditure, housing expenditure and other indicators are the main obstacles factors affecting urban talent ecological environment.

Retracted: Analysis and Evaluation of Ecological Environment Monitoring Based on PIE Remote Sensing Image Processing Software

Retracted: Analysis and Evaluation of Ecological Environment Monitoring Based on PIE Remote Sensing Image Processing Software

Urban ecological environment evaluation and influencing factors analysis at the residential quarter-level in Xi'an, China

Residential quarters are a critical component of urban areas, which significantly affects people's health and quality of life. In recent decades, the high-density and crowded residential quarters have become the mainstream organizational model of construction in China, because of the rapid and massive urbanization in many cities. This results in the contradiction between the eco-environment needs and the accommodation needs. Therefore, a systematic evaluation of the eco-environment in residential quarters is urgently needed to address the drawbacks of current residential quarters' planning and design. This paper aims to explore ways to improve the eco-environment with residential quarters from the perspective of China. We first used the Remote Sensing Ecological Index (RSEI) to evaluate the eco-environmental quality of 3, 756 residential quarters in the main urban areas of Xi 'an, China. Then, we quantitatively analyzed the landscape patterns of the impervious surfaces in these residential quarters. Finally, we characterized the impacts of residential quarters layout on the ecological environment by using the vegetation coverage (FVC), the normalized difference bare soil index (NDBSI), building density (BD), the residential density (RD), and the population density (PD) as main factors. The results are as follows: (1) Only 20.5 % of residential quarters with good eco-environments were distributed between the Second and Third Ring Road, indicating the need for improvement in creating livable eco-environments. (2) The shape of the impervious surface of excellent ecological quarters is complex and broken, the average patch area is smaller, and the degree of aggregation and combination of patches is lower compared to residential quarters with poor ecological quality. Therefore, it is recommended to reduce the connectivity of the impervious surface to improve the eco-environment of residential quarters. (3) Among the factors affecting RSEI of residential quarters, FVC, and NDBSI contribute more than other factors. For the construction of excellent eco-environments in residential quarters, we suggest that vegetation coverage should be no less than 0.4, the impervious surface coverage should be no more than 0.53, the building density should be between 0.28 ∼ 0.35, residential density should be no more than 0.22, and the population density of residential quarter should be under 0.29. Overall, for open and low-density residential quarters, the living environment can be improved by enriching vegetation and reducing impervious surfaces, while compact, high-density residential quarters can create a livable eco-environment by optimizing the impervious surface landscape patterns.

Coupling analysis of ecological environment evaluation and urbanization using projection pursuit model in Xi'an, China

With rapid urbanization, more people are migrating to cities, making it an inevitable trend. However, urbanization has significant impacts on the ecological environment. To address this, a sustainable development model is crucial to harmonize urbanization with the ecological environment. Previous studies have focused on selecting assessment indicators, but often overlooked the objective evaluation of component weights. In this study, we developed an assessment model and index system for the urban ecological environment, considering climate, vegetation, air pollution, human activities, and disaster-prone environments based on ecological evaluation theory. The projection pursuit (PP) model was employed to integrate these indicators simultaneously. Using night light data, we evaluated the coordination between the quality of the ecological environment and the current urbanization status of Xi'an, providing recommendations for the city's sustainable development The findings indicate that: 1) The overall ecological environment of Xi'an has shown improvement over time. There has been a noticeable north–south extension of human activity. To protect the urban ecology, it is crucial to establish the Qinling-Lishan Mountain ecological corridor as a significant barrier. This corridor will play a vital role in maintaining and enhancing the ecological balance in the region. 2) Comprehensive Night Light Index of Xi'an increased significantly during the four-year period, indicating accelerated urbanization. The city's expansion towards the west and north will be accelerated, eventually connecting with Xianyang and forming a larger Xi-Xian metropolitan circle. 3) We analyzed the coordinated growth pattern between the city and ecology in Xi'an and provided suggestions for urban ecological environment governance. These findings offer a decision-making framework for future sustainable development.

Suspended sediment change along the Zhejiang-Fujian coast revealed using MODIS 250-m imagery

Suspended sediment concentration (SSC) is one of the important parameters in the ecological environment evaluation of marine water bodies, as it provides an important basis for research on the ecological environment of nearshore sea areas, shoreline beach erosion and deposition, water quality of coastal zones and nearshore sedimentation zones. In recent years, the amount of sediment carried by the Yangtze has declined dramatically due to the Three-Gorges Dam (TGD), which might change the sediment supply to the sea and thus affect sediment transport to the coasts of Zhejiang and Fujian. This study aims to both develop specific algorithms and reveal the interannual and seasonal dynamics of the suspended sediment belt from the Yangtze Estuary to the Zhejiang-Fujian provincial shoal using MODIS 250 m data from 2000 to 2020. MODIS time-series analysis shows that the suspended sediments were originally from the Yangtze Estuary and formed a suspended sediment belt in the winter season. Moreover, driven by monsoon winds and coastal current dynamics, the sediment belt has obvious seasonality. Furthermore, we also suggest that the coastal sediment area has a tendency to shrink in winter, and the lifetime of the sediment belt also shortens, showing early disconnection in spring and delayed recovery in autumn, in response to the decline in sediment discharge from the Yangtze River basin to the sea. Impressively, the impact of the TGD in 2003 led to a drop in the sediment concentration in the coastal area. In addition, further analysis confirms that a sudden decrease in suspended sediment concentration was observed at Zhoushan (S2), Wenling (S4), Minjiang River Mouth (S7), Pingtan Island (S8), and many other stations along the coast in 2003, and the closer to the Yangtze Estuary, the more serious this phenomenon becomes, on the basis of monthly SSC analysis. These findings can assist us in better understanding the new pattern of the sediment belt from the Yangtze Estuary to the Zhejiang-Fujian coastal area. The findings of this study have theoretical and practical implications for the study of the hydrological sediment field in offshore areas, the protection of the marine ecological environment, changes in the shoreline and mudflats, and the maintenance of waterways and ports in estuaries.

The Coupling and Coordination Relationship between Leisure Tourism and Ecological Environment: The Case of Ili Region in Xinjiang Province

There is no doubt that a coupling relationship between leisure tourism and the ecological environment exists, but how to realize their coordinated development on that basis is much less clear. In this paper, taking Xinjiang’s Ili region as the research object, we first established a leisure tourism and ecological environment evaluation index system using the mean-variance method to assign its weighting and then built a coupling coordination model. In this way, the coupling and coordination relationship between leisure tourism and the ecological environment of the Ili region over a recent 20-year period (2001–2020) was analyzed in depth. Our results show that the economic benefit of leisure tourism and the efficiency of ecological environment protection contribute most, respectively, to the leisure tourism and ecological environment subsystems. During the study period, the coupling and coordination of leisure tourism and ecological environment system in the Ili area could be divided into five types, namely, “serious disorder-system balanced development”, “moderate disorder-leisure tourism lags”, “near disorder-leisure tourism lags”, “barely coordination-leisure tourism lags’, and “primary coordination-system balanced development”. The comprehensive development level of leisure tourism has exceeded that of the ecological environment, and prominent ecological and environmental problems have gradually arisen. Therefore, when vigorously developing leisure tourism, we should pay more attention to the ecological environment’s problems so as to realize the sustainable, coordinated development of the two.

Analysis on the coupling characteristics of urban ecological structure and local economy in the Yellow River Basin

The Yellow River Basin is an important part of China's ecological protection areas, but the stable development of the Yellow River Basin cannot be guaranteed due to the unreasonable setting of the local ecological structure and the slow pace of economic development. Many scholars at home and abroad have researched the ecological structure and urbanization level of the Yellow River Basin, but there is still a lack of work to analyze the coupling characteristics of the two. In this paper, the entropy weight method is used to study the coupling characteristics of economic development and ecological structure in the Yellow River Basin. The ecological environment, urbanization evaluation system and the ecological environment and urbanization coupling coordination characteristic evaluation system are constructed. The results show that the comprehensive evaluation coefficient of urbanization has increased by 276.2% from 2011 to 2020. The annual average increase of the comprehensive evaluation index of the ecological environment is over 35%. The degree of matching between the level of urban modernization and the ecological environment is basically above 95%.

Monitoring and Analysis of the Driving Forces of Changes in the Ecological Environment of a Mining Area of Western China from 1986 to 2022

The remote sensing ecological index (RSEI) has been widely used in the rapid monitoring and evaluation of the regional ecological environment; however, the research on the main factors that cause changes in RSEI and the impact of human activities in the mining area on RSEI is not often explored. To this end, this paper selected the Landsat (TM/OLI) series of remote sensing images from 1986 to 2022; extracted the four important indicators of the normalized difference vegetation index (NDVI), the wetness component of the tasseled cap transformation (WET), normalized difference built-up and soil index (NDBSI), and land surface temperature (LST); calculated the remote sensing ecological index (RSEI) based on the principal component analysis method; monitored and evaluated the ecological environment changes in the Shendong Mining Area for a period of 36 years; and analyzed the driving forces that cause these ecological environment changes. The results show the following: (1) The ecological status of the study area has shown an overall upward trend during the 1986–2022 period. (2) From 1986 to 2022, the area of RSEI with a grade of 0.4–0.6 increased by 1142.74 km2, that with a grade of 0.6–0.8 increased by 124.09 km2, and that with a grade of 0.8–1.0 increased by 0.73 km2. (3) In the past 36 years, the proportion of RSEI with a positive grade difference was 97.52%, and the proportion of regions with a negative grade difference was 6.20%. (4) Rainfall is the main factor that causes changes in the regional ecological environment. By analyzing the main driving factors of ecological environment change and the relationship between human activities and RSEI, reference can be provided for the formulation of environmental protection policies and environmental planning in mining areas.

Construction of Ecological Landscape Environment in Guanzhong Traditional Villages from the Perspective of Rural Revitalization

In order to supplement and improve the landscape evaluation system of traditional villages and play a positive guiding role in the specific protection and development of village landscape, this paper proposes the ecological landscape environment evaluation of traditional villages in Guanzhong from the perspective of rural revitalization. First of all, the relevant national and provincial evaluation standards are deeply studied, and the comprehensive evaluation system of the traditional village landscape in the Guanzhong region is constructed by using expert scoring and an analytic hierarchy process, which includes 6 criteria and 25 indicators. Three typical villages of different types and different development stages, namely, village A, village B, and Village C, were selected for landscape investigation and comprehensive evaluation. The results show that the weight of village location and landscape pattern is the largest, that is, the most important. The second is architectural landscape, with a weight of 0.236, accounting for a high proportion. Then, it is the natural landscape and street landscape, with a weight of 0.1-0.2. Finally, it is the intangible cultural landscape and landscape style protection, with a weight of less than 0.1. The alpha value of the comprehensive evaluation questionnaire of the village A is 0.984. The alpha value of the comprehensive evaluation questionnaire of village B is 0.941. The alpha value of the comprehensive evaluation questionnaire for the landscape of village C is 0.986, which is greater than 0.8. Conclusion. This study makes a comprehensive evaluation of the landscape of typical traditional villages.

Evaluation and prediction of ecological environment of karst world heritage sites based on google earth engine: a case study of Libo–Huanjiang karst

The assessment and prediction of ecological quality can help to quickly and systematically understand the ecological status of World Natural Heritage and assist with developing appropriate strategies to ensure the sustainable and healthy development of that heritage. Using the google earth engine platform, the remote sensing ecological index (RSEI) is rapidly constructed based on principal component analysis to evaluate the spatial and temporal distribution characteristics and the main impact indicators of the ecological environment, and the cellular automata (CA)-Markov model are used to simulate and predict the ecological quality, taking the Libo–Huanjiang karst world natural heritage site as the study area. The results show that: (a) the contribution rate of the four ecological indicators on the first principal component (PC1) are more than 90%. The construction of RSEI based on PC1 are applicable in karst world nature heritage sites and can be used to monitor and evaluate the spatial and temporal variation characteristics of the ecological environment. (b) The mean values of RSEI of the Libo–Huanjiang heritage site during 2000, 2007, 2013 and 2020 were 0.5435, 0.5465, 0.6009 and 0.5101, The overall ecological quality is mainly moderate and good, but in the eastern part of the heritage site the ecological quality is poor. (c) The evolution of the ecological environment quality during 20 years is mainly divided into the development trend of rapidly getting better, slowly getting better, and maintaining stability. (d) In the analysis of the relationship between RSEI and altitude, it is found that the ecological environment quality is mainly inferior, less favorable and moderate in areas with altitudes below 600 m, and there is a positive relationship between ecological quality level and altitude. (e) By analyzing the apparent spatial aggregation between the ecological environment quality, and then simulating the ecological grades in 2027 and 2033 using CA-Markov model, it is predicted that the area of medium and excellent ecological grades will increase in the future, but the ecological environment quality still needs to be improved in the eastern region due to the development of the tourism industry. Overall, the remote sensing ecological index is an effective model for evaluating and monitoring the ecological environment quality of karst heritage sites; the ecological environment quality of the Libo–Huanjiang heritage site is in a steady state of improvement, and the conservation measures of relevant departments are beginning to bear fruit; further coordination between conservation and development is needed to promote the sustainable development of heritage sites and to provide effective solutions for monitoring other karst-like heritage sites.

Coupling Coordination Development of Urbanization and Ecological Environment in the Urban Agglomeration on the Northern Slope of the Tianshan Mountains, China

With rapid urbanization and increasingly prominent environmental issues, objective evaluation of the quality of the ecological environment is crucial for environmental protection and sustainable development. Most remote sensing ecological indices (RSEI) used for ecological environmental quality evaluation include only four indicators (greenness, humidity, heat, and dryness), and many studies have ignored the impact of air quality on urban ecological environmental quality in arid areas. This study used the urban agglomeration on the northern slope of the Tianshan Mountains (UANSTM), China, as the research area based on the Google Earth Engine platform via Landsat remote sensing images and NPP/VIIRS data to establish a new remote sensing ecological index (RSEInew) and compounded night light index of urbanization level. The coupling coordination degree model was used to quantitatively analyze the characteristics of the coordinated development of the ecological environment and urbanization in UANSTM and major cities from 2015 to 2020. The results showed that: (1) compared to RSEI, RSEInew is more suitable for assessing the ecological quality of arid zones because it accounts for air quality; (2) the RSEInew value for the eco-environmental quality of UANSTM from 2015 to 2020 improved and then deteriorated with an overall declining trend. The variation in the RSEInew rating was between “strongly bad” and “neutral,” and there were differences in the quality of the ecological environments among cities; (3) the level of urbanization in the economic zone of UANSTM from 2015 to 2020 increased significantly, and the degree of coordination between urbanization and ecological environmental quality coupling steadily increased but remained moderately imbalanced. The results of this study provide a scientific reference for the economic development and ecological environmental protection of the study area.

Dynamic Monitoring and Driving Factors Analysis of Ecological Environment Quality in Poyang Lake Basin

The ecological environment of Poyang Lake basin is an important part of the construction of ecological civilizations in the south of China. Based on the Landsat satellite remote sensing images, using the principal component analysis (PCA) method to construct the remote sensing ecological index (RSEI) as an evaluation index of ecological environment quality, introducing the Geodetector model to quantitatively detect the explanatory power of different influencing factors on the spatial divergence of the ecological environment, and exploring the changes in ecological environment quality in the Poyang Lake basin from 1990 to 2020 and the impact of different driving factors. The results of the study showed that there were obvious regional differences in the ecological environment quality in the basin. The areas with bad and poor ecological quality were mainly distributed in the central and northern plains; the areas with high and good quality grades were mainly distributed in the hilly and mountainous region of the southwestern part of the basin; the overall ecological environment of the Poyang Lake basin has been improving over the past 30 years; and the improved areas were mainly distributed in low-altitude areas. Geodetector results showed that population density was the factor with the highest explanatory power for the spatial divergence of ecological environment quality in the Poyang Lake basin. Among different natural factors, topographic factors (slope, aspect) had a higher driving force than meteorological factors (temperature, precipitation). The night light index factor showed an increasing yearly trend, indicating that the ecological environment quality of the Poyang Lake basin was gradually increased due to the influence of urbanization development. The construction of the RSEI model based on Google Earth Engine could not only effectively ensure the accuracy of ecological environment quality evaluation in different years but could also quickly realize image preprocessing and index calculations, which greatly improved the efficiency of ecological environment evaluation. These research results can provide a theoretical basis and scientific data support for the ecological environment protection work in the Poyang Lake basin.

Has green finance improved China's ecological and livable environment?

Green finance can promote economic transformation and technological innovation and play a key role in solving the ecological environment and energy crisis. This paper constructs a comprehensive ecological livable environment evaluation system based on the provincial panel data in China from 2011 to 2019. At the same time, the panel mediation effect and spatial econometric model are used to test the impact of green finance on the ecological and livable environment. The main research conclusions include the following: (1) green finance has significantly improved China's ecological and livable environment; (2) green finance improves the ecological and livable environment by improving the level of technological innovation; (3) the impact of green finance on the ecological livable environment has regional heterogeneity, and green finance in the central provinces has a better effect on the improvement of the ecological livable environment; and (4) the ecological livable environment among Chinese provinces has a significant positive spatial correlation. Among them, green finance has significantly improved the local ecological livable environment but reduced the ecological livable environment of surrounding provinces. Based on the above conclusions, this paper suggests that the government should pay more attention to green finance and technological innovation and coordinate the development of the ecological livable environment among provinces. The research results provide empirical evidence for better developing green finance and improving the ecological livable environment and also provide certain theoretical guidance for China's coordinated regional development and high-quality economic development.

Study of the spectral characters–chlorophyll inversion model of Sabina vulgaris in the Mu Us Sandy Land

As the dominant shrub community plant in the Mu Us Sandy Land, S. vulgaris is the key factor of ecological environment restoration in the Mu Us Sandy Land, It is of great significance to explore the estimation and inversion of content based on spectrum for ecological environment evaluation and intervention in Mu Us Sandy Land. The SVC HR-1024 portable feature spectrometer and SPAD 502 chlorophyll meter were used to study Mu Us Sandy Land of S. vulgaris. The best band is screened by correlation matrix method, the best vegetation index is screened by Structural Equation Modeling model, and then the best inversion model is established by different mathematical modeling methods. Results revealed that the vegetation indices and chlorophyll content were correlated, combining the six vegetation indices revealed that 610–690nm and 700–940 nm were the bands with the highest correlation. In the selection of optimal vegetation index, NDVI, ratio vegetation index and mNDVI perform best and are suitable for subsequent modeling. Of the four models, the partial least squares model had the best fitting effect (R2 > 0.91). The univariate linear regression model had the simplest processing procedure, but its accuracy was unstable (R2 = 0.1–0.9). multivariate stepwise regression accuracy is also appropriate (R2 > 0.8). The stability of BP neural network modeling is not high. Compare the four methods, PLS and multivariate stepwise regression have their own advantages, and the accuracy is higher, you can make a choice according to the demand as the late modeling method.

‍Enhanced remote sensing ecological index and ecological environment evaluation in arid area

‍Enhanced remote sensing ecological index and ecological environment evaluation in arid area

An evaluation of rural ecological environment carrying capacity under rural land commercial development

In order to improve the accuracy and efficiency of rural eco-environmental carrying capacity assessment, this paper proposes a new rural eco-environmental carrying capacity assessment method under rural land commercialisation development based on combined weighting method. Firstly, the weighted average method is used to calculate the rural surface runoff coefficient covering the whole area and determine the soil erodibility factor. Secondly, by realising the weighting of the rural ecological environment carrying capacity using principal component analysis (PCA), and calculating the subjective weight of each evaluation index by an analytic hierarchy process, a multi-level evaluation index system is established. The PCA weighting and subjective weighting is then combined to form combined weighting. Finally, the objective function of maximising the carrying capacity of rural ecological environment resources is constructed to realise the evaluation of carrying capacity. The experimental results show that the evaluation accuracy of this method is as high as 99.68%; and the evaluation time is short.

Study on Ecological Environmental Impact Assessment Index System of UHV AC Transmission and Transformation Engineering-A Case Study of 1000kv UHV Transmission and Transformation Engineering from Zhangbei to Xiongan

Ultra-high voltage (UHV) power grid is a new transmission and transformation technology, which has the advantages of large transmission capacity, long transmission distance, low line loss, saving land resources and obvious economic benefits. Taking the Zhangbei-xiongan 1000kv AC high voltage power transmission and transformation project as an example, this paper constructs the eco-environmental index system of the UHV transmission and transformation project by using the pressure-state-response model, and constructs a set of 18 indexes eco-environmental index system, it mainly includes three aspects: the eco-environmental pressure index caused by the construction behavior in different construction stages of power transmission and transformation projects, and the eco-environmental state index given by on-the-spot investigation and study of projects, based on the construction unit on the ecological environment impact management response measures given indicators. The index system provides a basis for comprehensive and systematic evaluation of the impact of power transmission and distribution projects on the ecological environment, and finally draws the corresponding project construction evaluation conclusions. In this paper, the eco-environmental impact assessment index system of power transmission and transformation engineering has certain universality, and it has certain reference and guiding significance for the ecological environment evaluation of power transmission and transformation engineering.