滑移岩石边坡治理的稳定性分析

位于山西省境内的祁临(祁县—临汾)高速公路灵石—霍州段(K86+534.466～K93+263.977),座落在一个地质构造复杂、岩体破碎的滑坡群区域内,在施工过程中,先后有多处地段出现了较大规模的滑坡。为确保工程的正常进行,针对这一区域的实际情况,采取了分段治理、稳定整体的边坡治理方式,将滑坡群分为3个不同的治理段,分别采用了中高压注浆、预应力锚杆、底锚、挂网喷浆、肋柱式钢筋混凝土挡墙、回填土“反压坡”、浆砌石挡士墙等多种加固方式,并将多种加固方式结合在一起,形成了一个有机整体。根据加固设计,选取Ⅰ区段中的K86+145断面作为计算模型,采用FLAC^2D有限差分法计算软件对加固结构的性能和边坡的稳定性进行了分析。分析结果表明,这一复合式加固方法是非常有效的,加固结构体和边坡都表现出了较好的稳定性。同时,提出对其中一些区域的预应力锚杆要施加二次“补偿张拉”,而对底锚则不必施加预应力。

An Experimental Analysis of Water and Soil Conservation Effected by Micro-landscape Structure

[Objective] This comparative experiment was to explore the soil loss con- trol effects under cultivation combination of different soil and vegetation types, and to provide scientific basis for the upcoming pilot project of ecological recovery. [Method] Both the rudiment of water locomotion functioned by micro-landscape structures and different spatial combinations of various landscape constituents are considered, thus, the combination of multi-soil type, crop species and site conditions is designed in three different experimental sites. [Result] Soil loss estimates in experiments in South Wello significantly depended on various soil type, slope, vegetation and type of con- servation structure; grass cover tremendously reduces soil loss; legume cultivation performed better than cereal cultivation in soil loss control. [Conclusion] By conduct- ing the data analysis of the experiment, a scientific reference is proposed to the agri- culture planting and protective mode for the alleviation of water and soil loss in Amhara Region, Ethiopia.

Efficiency Pattern and Spatial Strategy of Ports in Yangtze River Delta Region

This paper measures the efficiency of ports in the Yangtze River Delta Region(YRDR) in 2008 and 2013 using port berth quantity, quay length, and human resources as input indicators, using cargo and container throughput as output indicators, and considering traditional(foreign trade dependence and industrialization level) and modern environmental factors(traffic line density, financial development level, and informatization level). To achieve such aim, this study constructs a multi-stage data envelopment analysis model(DEA) that identifies effective port decision-making units(DMUs) and generates a highly accurate conclusion by eliminating the interference from the exogenous environment and random errors. First, the external environment significantly affects port efficiency, with the traditional environmental factors showing huge fluctuations and the modern environmental factors producing great benefits. Second, the efficiency of ports in YRDR has increased from 2008 to 2013 primarily because of their pure technical efficiency. Third, the weighted standard deviation ellipse(SDE) analysis results reveal that the efficiency pattern of ports significantly deviates from their throughput pattern, while the center of SDE of port efficiency moves from the eastern coastal regions to the northwest regions. Based on these findings, this paper proposes spatial development strategies for YRDR, such as creating an unblocked environment where spatial elements can freely circulate, intensifying port-city joint development, implementing differentiated policies, and focusing on the spatial collaboration of port efficiency.

Taxonomic revision of Gelidium tsengii and Gelidium honghaiwanense sp. nov. (Gelidiales, Rhodophyta) from China based upon molecular and morphological data analyses

The taxonomic relationship of Chinese GeBdium tsengii and Gelidium johnstonii was ambiguous. For almost 20 years they have been regarded as distinct taxa and until 2002 G.johnstonii was considered as a misapplied name of G. tsengii. In this study, herbarium specimens that initially attributed to G. tsengii and fresh G. tsengii specimens were used to address the taxonomic issues. In phylogenetic studies, G. tsengii from Dayawan, China, near the type locality of G. tsengii and G.johnstonii from Sonora, Mexico, the type locality of G. johnstonii, formed a monophyletic group with maximum support in rbcL and COl genes analyses, indicating that they were genetically identical. In morphological studies, G. tsengii was similar to G. johnstonii in branching pattern, inner structures and fructiferous organs. Consequently, we considered that semi-circular outline of G. tsengii could no longer be treated as a discrimating fea^re. G.johnstonii had priority of publication and according to the International Code of Botanical Nomenclature, G. tsengii was proposed as a synonym of G. johnstonii. Gelidium honghaiwanense sp. nov. was described from Guangdong, China on the basis of morphological and molecular data. For vegetative structures, it was characterized by flattened upright frond, regular two-three times branches pinnate or alternate and clavate ultimate branchlets. For reproductive structures, the tetrasporangial sori were in the apical part of branches and the tetrasporangial branchlets were distichously distributed along second order branches. The present study clarified the relationship between G. tsengii and G. johnstonii from Guangdong and added a new Gelidium species to the Chinese algal flora.

Using multispectral landsat and sentinel-2 satellite data to investigate vegetation change at Mount St. Helens since the great volcanic eruption in 1980

Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based measurements. Contrarily, spatially continuous observations of succession dynamics over extended areas and timeperiods are sparse. Here, we applied a change vector analysis(CVA) to investigate vegetation succession dynamics at Mount St. Helens after the great volcanic eruption in 1980 using Landsat. We additionally applied a supervised random forest classification using Sentinel-2 data to map the currently prevailing vegetation types. Change vector analysis was performed with the normalized difference vegetation index(NDVI) and the urban index(UI) for three subsequent decades after the eruption as well as for the whole observation time between 1984 and 2016. The influence of topography on the current vegetation distribution was examined by comparing altitude, slope angles and aspect values of vegetation classes derived by the random forest classification. WilcoxRank-Sum test was applied to test for significant differences between topographic properties of the vegetation classes inside and outside of the areas affected by the eruption. For the full time period, a total area of 516 km2 was identified as re-vegetated, whereas the area and magnitude of re-growing vegetation decreased during the three decades and migrated closer to the volcanic crater. Vegetation losses were mainly observed in regions unaffected by the eruption and related mostly to timber harvesting. The vegetation type classification reached a high overall accuracy of approximately 90%. 36 years after the eruption, coniferous and deciduous trees have established at formerly devastated areas dominating with a proportion of 66%, whereas shrubs are more abundant in riparian zones. Sparse vegetation dominates at regions very close to the crater. Elevation was found to have a great influence on the reestablishment and distribution of the vegetation classes within the devastated areas showing in almost all cases significant differences in altitude distribution. Slope was less important for the different classes-only representing significantly higher values for meadows, whereas aspect seems to have no notable influence on the reestablishment of vegetation at Mount St. Helens. We conclude that major vegetation succession dynamics after catastrophic events can be assessed and characterized over large areas from freely available remote sensing data and hence contribute to an improved understanding of succession dynamics.

Effects of Normalized Difference Vegetation Index and Related Wavebands′ Characteristics on Detecting Spatial Heterogeneity Using Variogram-based Analysis

Spatial heterogeneity is widely used in diverse applications, such as recognizing ecological process, guiding ecological restoration, managing land use, etc. Many researches have focused on the inherent scale multiplicity of spatial heterogeneity by using various environmental variables. How these variables affect their corresponding spatial heterogeneities, however, have received little attention. In this paper, we examined the effects of characteristics of normalized difference vegetation index （NDVI） and its related bands variable images, namely red and near infrared （NIR）, on their corresponding spatial heterogeneity detection based on variogram models. In a coastal wetland region, two groups of study sites with distinct fractal vegetation cover were tested and analyzed. The results show that： l） in high fractal vegetation cover （H-FVC） area, NDV! and NIR variables display a similar ability in detecting the spatial he- terogeneity caused by vegetation growing status structure; 2） in low fractal vegetation cover （L-FVC） area, the NIR and red variables outperform NDVI in the survey of soil spatial heterogeneity; and 3） generally, NIR variable is ubiquitously applicable for vegetation spatial heterogeneity investigation in different fractal vegetation covers. Moreover, as variable selection for remote sensing applications should fully take the characteristics of variables and the study object into account, the proposed variogram analysis method can make the variable selection objectively and scientifically, especially in studies related to spatial heterogeneity using remotely sensed data.

Biomass estimation of Shorea robusta with principal component analysis of satellite data

Spatio-temporal assessment of the above ground biomass （AGB） is a cumbersome task due to the difficulties associated with the measurement of different tree parameters such as girth at breast height and height of trees. The present research was conducted in the campus of Birla Institute of Technology, Mesra, Ranchi, India, which is predomi- nantly covered by Sal （Shorea robusta C. F. Gaertn）. Two methods of regression analysis was employed to determine the potential of remote sensing parameters with the AGB measured in the field such as linear regression analysis between the AGB and the individual bands, principal components （PCs） of the bands, vegetation indices （VI）, and the PCs of the VIs respectively and multiple linear regression （MLR） analysis be- tween the AGB and all the variables in each category of data. From the linear regression analysis, it was found that only the NDVI exhibited regression coefficient value above 0.80 with the remaining parameters showing very low values. On the other hand, the MLR based analysis revealed significantly improved results as evidenced by the occurrence of very high correlation coefficient values of greater than 0.90 determined between the computed AGB from the MLR equations and field-estimated AGB thereby ascertaining their superiority in providing reliable estimates of AGB. The highest correlation coefficient of 0.99 is found with the MLR involving PCs of VIs.

Ecological variables influencing the diversity and distribution of macrolichens colonizing Quercus leucotrichophora in Uttarakhand forest

Ecological variables play a significant role in determining the diversity and distribution of any living organism on earth. Lichens are not exceptional and are quite sensitive in comparison to other organisms; hence the present study focuses on the impact of ecological variables on the diversity and distribution of epiphytic macrolichens colonizing Quercus leucotrichophora across eight different sites(50 m × 50 m) in Thal Ke Dhar forest, Kumaun Himalaya, Uttarakhand, India. For sampling of macrolichens, 200 trees(25 trees from each site) of Q.leucotrichophora were selected from each site and five quadrats of 5 cm × 10 cm(1000 quadrats in totality) were drawn at the tree trunk. From all the sampled trees, a total of 54 species of epiphytic macrolichens belonging to 18 genera and five families were recorded. Various ecological variables, namely altitude, aspect, slope, diameter at breast height(DBH), and lopping percent(partial cutting of the twigs as disturbance), were also analyzed to investigate their influence on macrolichen species composition and distribution pattern in the study area. For the determination of relationships between these variables, statistical analysis, namely Pearson's Correlation Coefficient, Polynomial regression analysis and Principal Component Analysis(PCA)were performed. Out of all variables, lopping was significantly correlated to species richness of epiphytic macrolichens(0.712~*, p<0.05) and it was confirmed by Pearson's Correlation Coefficient.Despite of having high anthropogenic pressure or impact through lopping, the maximum number of macrolichen species was recorded at elevation 2267 meter above sea level(m asl). The present study revealed that besides other ecological variables,lopping practices can act as a key parameter incontrolling the diversity and distribution not only of epiphytic macrolichens but also of other life forms such as bryophytes, pteridophytes, insects, birds etc.and can be either negatively or positively correlated.

Analysis of Urban Environmental Conditions Based on Satellite Remote Sensing and Socioeconomic Conditions Based on StatisticsmA Case Study of Semarang Municipality, Indonesia

In this study, urban environmental condition using Terra ASTER （advanced spaceborne thermal emission and reflection radiometer） remotely sensed satellite imagery was estimated and compared to statistically derived socioeconomic condition data from Semarang Municipality in Central Java Province： Indonesia. From satellite imagery： U1 （urban index） and NDVI （normalized difference vegetation index） were calculated and used that information to construct urban density and vegetation distribution maps of the study area. Urban density and vegetation distribution were combined to estimate urban environmental condition; then compared to socioeconomic conditions. The results revealed that the Semarang Municipality had a higher percentage of developed or urbanized areas （49%） compared to the percentage of area covered by vegetation （42%）. In general, southern Semarang had a higher quality urban environment and socioeconomic condition compared to northern Semarang, which had a higher urban density, lower quality urban environment and lower socioeconomic condition. The indicate that socioeconomic condition can be determined using satellite-derived urban and vegetation indices even in places like Semarang Municipality, where the population settlement was sparse and unorganized.

Characteristics of Spatial and Temporal Vegetation Index Variability and Its Responses to Temperature and Precipitation in Mongolia

The Mongolian Plateau,a vital ecological barrier in northern China,is of great importance for studying vegetation dynamics in Mongolia against the background of climate warming.Such studies can enhance our understanding of regional vegetation responses to global warming and contribute to the establishment of a stronger ecological barrier in northern China.Here,we analyzed the spatial and temporal characteristics of the NDVI(normalized difference vegetation index)in Mongolia using 8 km resolution GIMMS NDVI3g data from 1990 to 2022,along with temperature,precipitation,and elevation data.Trend analysis and correlation methods were used to examine the relationships between the NDVI and temperature,as well as precipitation.The results showed four important aspects of these relationships.(1)The NDVI in Mongolia increased significantly from 1990 to 2022 at a rate of 0.0015 yr^(-1)(P<0.05).(2)Mongolia’s NDVI increased from 1990 to 2022 in 60.73%of the country.Of this total,the area with a significant increase accounted for 31.67%and was concentrated on the eastern and western edges.The area experiencing a significant decrease accounted for 15.67%and was mainly located on the southwestern edges.(3)The NDVI analysis revealed significant increasing trends in all regions except for those at elevations of 1500-2000 m.The greatest rate of increase was observed between 500 and 1000 m,and the increasing trend weakened as elevation continued to increase before gradually becoming significant again.Additionally,the NDVI increased significantly across different slopes,and the rate of increase decreased as the slope increased.(4)From 1990 to 2022,Mongolia’s NDVI was mostly negatively correlated with temperature.This occurred over 66.75%of the total land area,with 17.21%of the region exhibiting a significant negative correlation,mainly in the southwest.Conversely,the NDVI demonstrated a positive correlation with precipitation,encompassing 86.71%of the total land area.Approximately 40.44%of the region had a significant positive correlation,primarily in the southwest.In conclusion,throughout the experimental period,the vegetation state in Mongolia improved.However,due to the warming and drying climate,more attention should be paid to vegetation degradation in the south-central region.

Temporal Variations in Growth and Aboveground Biomass of Phragmites australis and EVI Analysis in Jiaozhou Bay Coastal Salt Marshes, China

To better ascertain leaf, stem and flower traits, and analyze aboveground allocation during the vegetation period, three sampling vegetation transects were settled and reed samples were collected at intervals to determine morphological parameters and dry and wet weights in Jiaozhou Bay wetland. Remote sensing data were also combined to evaluate regional biomass through EVI regression models. Results show that growth dynamics of leaves and stems changed during the vegetation period. Stem length increased rapidly and peaked in September（194.40 ± 23.89 cm）, whereas leaf width peaked in July. There was a significantly negative correlation between stem length and stem diameter with a value of-0.785. Stem biomass was higher than that of leaves, and the maximum value of aboveground biomass was 27.17 ± 3.56 g. F/C exhibited a tendency to increase and values ranged from 0.37–0.76. The aboveground biomass of sample plots reached a peak of 2356 ± 457 g/m^2 in September. EVI was 0.05–0.5; EVI and biomass had a better fitting effect using the power-exponent model compared with other models and its function was y = 4219.30 x^0.88（R^2 = 0.7810）. R^2 of the other three models ranked as linear function〉 polynomial function 〉exponent function, with the values being 0.7769, 0.7623 and 0.6963, respectively. EVI can be used to estimate vegetation biomass, and effectively solved the problems of the destructive effect to sample plots resulting from traditional harvest methods.

The measurement and model construction of complex permittivity of vegetation

The complex permittivity of targeted objects is an important factor that influences its microwave radiation and scattering characteristics.In the quantitative research of microwave remote sensing,the study of the dielectric properties of the vegetation to establish the relationship between its specific physical parameters and complex permittivity is fundamental.In this study,six categories of vegetation samples were collected at the city of Zhangye,a key research area of the Heihe watershed allied telemetry experimental research.The vector network analyzer E8362B was used to measure the complex permittivity of these samples from 0.2 to 20 GHz by the coaxial probe technique.The research focused mainly on the corn leaves,and an empirical model was established between the gravimetric moisture and the real/imaginary parts of complex permittivity at the main frequency points of microwave sensors.Furthermore,the empirical model and the classical Debye-Cole model were compared and verified by the measured data collected from the Huailai County of Hebei Province.The results show that the newly- established empirical model is more accurate and more practical as compared to the traditional Debye-Cole model.