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An assessment model for the satisfied degree of crop water requirements (CWR) on the grid scale, the CropWRA model, is developed to support precise management of agricultural water resources. On the grid scale, we urge that the CWR satisfied degree is not only rested with the abundance of water resources in a region, but also related to crop types, growing periods, water accessibility, etc. The CropWRA model also consists of corresponding indexes such as the CWR characteristics, crop planting combination and proportion, available water of agricultural production, water accessibility, etc. In this case study, the CWR satisfied degree of main food crops is evaluated with DEM data, hydrological data, meteorological and climate data, crop experiment and observation data, and statistical data in Hanjiang River Basin, China. In general, the results show that agricultural water resources can satisfy the CWR but the spatial differences are profoundly remarkable. The CropWRA index varies from -20% to 200%, and this difference is the comprehensive effects caused by the topography, river system, crop planting combination, land use, and water resources composition, etc. CropWRA model reveals the spatial differences in the relationships of CWR supply and demand and can provide the data support for precise water resource allocation.

City, urban systems and their evolution are classical interdisciplinary issues in urban studies. Most traditional classical theories have different drawbacks because of the inherent limitations of their basic disciplines. Therefore, a general theoretical framework is urgently needed to interpret city, urban systems and their evolution. This study proposed a novel theoretical framework of urban systems and their evolution (the GUSE theory) to explain the processes and features of origin, spatial pattern and evolution of regional urban systems. We firstly proposed definitions of coverage, city and urban system based on Graph Theory method; then built models and indices to interpret and evaluate growth and evolution of urban system by combining the model of spatial interaction flow with the “urban tree (UT)” hypothesis. Numerical simulation is finally conducted to illustrate the GUSE theory and verify the stability of the proposed models. The GUSE theory in this study can provide significant theoretical basis for regional research, such as urban system study and planning.

The integrated study on the evolution of the regional social-ecological system (RSES) is one of many complex and classical research topics. An innovative approach of conjugate analysis is introduced to describe the RSES evolution in this paper. We select land use intensity (L), bilateral dynamic change of land use types (S), landscape pattern index (P), ecological security index (Q), and the RSES composite index (T) to describe the RSES. We analyze and express the conjugacy of the RSES evolution: for the spatial correlations, they are revealed by variance analysis, spatial autocorrelation, and regionalized variable analysis; and for the temporal correlations, they are described by the analysis of spatiotemporal correlation. We use a case study of the Hanjiang River basin in Hubei province (China) to test the conjugate evolution of the RSES. We find that the RSES evolution in this region is driven by dual-source forces, both resource driven and economic power driven. These driving forces result in the spiral rise of the RSES evolution, where L, S, Q, P, and T have high self-autocorrelations, and there are remarkable and highly positive correlations and inheritance between the RSES and their subsystems. These results can corroborate the hypothesis about conjugate evolvement of the RSES. The spatial patterns of the RSES evolution are controlled by physical factors, especially geomorphology, where as its direction is guided by human activities, and its progress is pushed forward by human-environment interactions. The analysis of the RSES conjugate evolution can provide a new perspective for the RSES management, that is, the RSES management decisions should consider conjugate effects, because these effects can directly influence regional sustainable development.

Adaptability evaluation of reservoirs needs to be performed before natural gas flooding. However, the current evaluation methods consider the reservoir pressure and minimum miscible pressure (MMP) as separate parameters to evaluate the miscibility, which ignores the correlation between reservoir pressure and MMP. Also, the effect of reservoir pressure on injectivity is also neglected, while higher pressure than MMP may not improve the miscibility but increase the difficulty of gas injection. Furthermore, evaluation range of each index is inconsistent. Therefore, this paper proposes an improved evaluation system by introducing the miscible ability and optimizing the evaluation criteria to better evaluate the adaptability of natural gas flooding in enhancing oil recovery. The miscible ability is newly defined to evaluate the impact of reservoir pressure on miscibility, and multi-level evaluation model is further developed which includes 12 indexes based on reservoir/fluid/rock properties. The evaluation criteria are established by optimizing parameter intervals. The adaptability of BQ Oil field is assessed using Analytic Hierarchy Process (AHP) and fuzzy evaluation. Field application validates the reliability of the proposed evaluation system. It can be used to quickly evaluate the adaptability of natural gas flooding, which could improve success rate of natural gas flooding and reduce the costs.

In this paper, the relationship between the dynamic surface subsidence and overburden separated strata has been studied under the condition of sedimentary coal measure strata. When the underground coal seam is mined, the ground surface subsidence will be caused. The surface subsidence is caused by the goaf clearance passing along the overlying strata up to the surface. During the course, the bed-separation space would be generated and its size directly affected the value of mining goaf passing up to the ground - the surface subsidence. It shows that the surface subsidence is closely related with overburden separated strata. Therefore, the research on the dynamic development law of overburden separated strata contributes to recognition and prediction of surface dynamic subsidence, which is the important basis for the control of mining subsidence damage. In this paper, the whole processes form cracking, propagation, to closure of the mining overburden separated strata are analyzed in the first chapter. The various steps of surface dynamic subsidence, from the initial step, the active step, and then to the recession are researched. And then the corresponding relationship between the surface dynamic subsidence and overburden separated strata is studied and its model is established for analyzing factors of geological and mining that influenced this relationship. At last, a similar material model for coal measure strata in sandy shale is established and carried on the excavation experiment of coal seam. Then by use of the test, the development law of mining overburden separated strata is studied, and the space-time corresponding rule of the surface subsidence and overburden separated strata is analyzed. And on this basis, we find the relationship between the surface subsidence and overburden separated strata. Based on allometric growth of mining overburden separated strata, which would provide a new research and analysis method for control and prevention of mining subsidence damage, we establish the model of mining subsidence.

The origin, spatial pattern, and evolution of urban system have been hot research issues in the field of urban system. In this study, the theory of “urban tree (UT)” was proposed to address these issues. The spatial pattern of urban system can be expressed by the phrase UT and the growth of the UT reflects the origin, spatial pattern, and evolution of urban system. Analysis of the UT growth can reveal the evolutionary mechanisms of the urban system. We present an UT resistance model to determine spatial extension in the evolutionary processes of urban system. The Thiessen polygon method and spatial re-mapping were used to construct the UT. Data collected in 1995, 2000, 2005 and 2010 from cities in the Huai River Basin were used to construct the UT model to analyze the origin, spatial pattern, and evolution of urban system in this region. Xuzhou City was the UT “tree root” and the UT growth the followed four paths. Growth of cities on the nodes of these paths promoted the evolution of urban system. The UT theory expresses the spatial pattern and evolution of urban system in an intuitive way and helps to explain the origin and evolution mechanisms of urban system. Empirical research supported the UT theory. Because of the operational and visual expression, this theory has broad application prospects in the urban system research.

The article focuses on proposing a new hybrid time-Laplace domain response calculation method for symmetrical floating structures by solving Cummins equation, which is depending on the state–space model identified from transfer function. Different from a time or frequency domain method, the proposed approach estimates the state–space model of a floating structure system from the transfer function in the Laplace domain and calculates the response by considering the exciting forces as an input of the state–space model. Implementing complex exponential decomposition to the retardation functions, the retardation functions in the Laplace domain are expressed using a series of poles and the corresponding residues, which avoids the numerical integral of the convolution terms in the Cummins equation and greatly improves the computational efficiency during the process of a dynamic response analysis. Three examples are applied to investigate the validity of the proposed method. The first is a simple single degree of freedom mathematical model excited by an irregular wave. Studies have shown that the response calculated by the proposed method matches well with that of a traditional Newmark- β method. Meanwhile, this approach is insensitive to the interval time of the calculation and consumes less calculation time, which means that the proposed method has higher precision and computational efficiency. The last two examples are a spar-type offshore wind turbine and a semi-submersible platform model (SEMI) in SESAM, which extend the proposed method to solve the response estimation problem of marine structures. The results of the spar-type floating structure show that the estimated responses when using the proposed method are in good agreement with the results of the traditional time domain method. By studying the response calculation of SEMI, the following conclusions can be obtained: (1) the estimated responses match well with the traditional time domain method and WASIM code of SESAM, and (2) the calculation time of the new approach is reduced significantly compared with the Newmark- β method especially under a long simulation time.

A year-long field study on the seasonal characteristics of fine particulate matter (PM 2.5 ) was conducted at the Qilian Shan Station of Glaciology and Ecologic Environment (QSS), a remote site on the northeast edge of the Tibetan Plateau. The PM 2.5 samples were collected weekly using a low volume (16.7 L/min) sampler, and then analyzed by ion chromatography for the water soluble ionic species (WSIs). The annual average mass loading of PM 2.5 , retrieved from co-located measurement on aerosol size distribution, was 9.5 ± 5.4 μg m − 3 with WSIs accounting for 39 ± 2%. The WSIs were dominated by SO 4 2 − (39%), CO 3 2 − (19%), Ca 2 + (16%), NO 3 − (10%), and NH 4 + (6%), suggesting important contributions from both anthropogenic aerosol and mineral dust. The mass loading of total WSIs showed a seasonal variation with higher concentrations in spring (6.3 μg m − 3 ) and summer (5.1 μg m − 3 ) and lower concentrations in winter (2.2 μg m − 3 ) and fall (1.7 μg m − 3 ). A linear regression of ammonium versus sulfate by equivalent concentration showed a slope of 0.51, suggesting an excess of acids. The excess sulfuric and nitric acids likely reacted with mineral dust, as evidenced by the tight correlation between [Ca 2 + + NH 4 + ] and [SO 4 2 − + NO 3 − ]. The oxidation ratios of nitrogen and sulfur estimated based on the datasets of SO 2 and NO 2 from the closest air quality station at Jiayuguan (~ 150 km from sampling site) showed that the gas-particle partitioning of nitrogen on dust was more efficient than that of sulfur. The size distribution of SO 4 2 − showed a dominant accumulation mode, with a mode diameter ( D p ) ranging from 0.18 to 0.56 μm. In comparison, NO 3 − and Ca 2 + showed a prominent coarse mode with D p ranging from 1 to 10 μm. The results of air mass trajectory cluster and potential source contribution function analysis demonstrated that the source regions of the mineral dust were located in the arid areas of northwest China while the anthropogenic aerosol was likely from urban areas in the low elevation areas to the east of QSS. The effects of meteorological parameters on the particle mass loading were also evaluated.

Data resources and assessment frameworks are two keys to ecosystem health assessment (EHA). Application of the land use database together with the Pressure–State–Response (PSR) model in EHA provides better precision relative to traditional data resources and assessment frameworks for EHA at the county scale. The raw data are taken from The Anlu County Annals, The Soil Records of Anlu County, and The Statistical Yearbook of National Economy in Anlu County. The spatial and attribute data are partly extracted from the database of current land use in Anlu City using the MAPGIS platform. Based on the results from principal component analysis (PCA), a total of eleven indicators were selected to build an indicator system designed to assess the ecosystem health at the county scale. According to the PSR model, the scores from three indices (press index, state index, and response index) and a comprehensive assessment index (CAI) were calculated, and an assessment map was constructed. The results from the index scores and spatial analysis display a large range for the state of ecosystem health due to the evolution of natural ecosystems and human activities at the county scale. The precision of the current land use database (scale of 1:10,000) makes it a better candidate for evaluating ecosystem health than the traditional data resources. This study also demonstrates the numerous benefits of combining land use databases with GIS functions to assess ecosystem health at the county scale.

A new Co-base superalloy 22Co–21Ni–23Fe–29Cr–2.2Nb (Co22 for short) was developed, and the influence of a trace amount of rare earth (RE) on the oxidation resistance was investigated. Isothermal oxidation behaviour of this Co-base superalloy was investigated at 1050–1250 °C in air, analyzed with scanning electronic microscopy and X-ray diffraction. The results show that oxidation mass gain of the samples with or without RE elements obeyed secondary parabolic law, and the effect of 0.03 wt.% RE on oxidation resistance is small. The oxidation rate constant of the 0.03 wt.% RE added Co22 alloy decreases by about 6.1% to 9.0% compared to that of the Co22 alloy without RE. Oxidation at 1050–1250 °C for 100 h results in the formation of MnCr 2 O 4 , Cr 2 O 3 and SiO 2 . A continuous and protective MnCr 2 O 4 spinel layer forms as outer layer. The continuous middle oxide layer is confirmed to be Cr 2 O 3 , and the innermost layer consists of discontinuous SiO 2 . The outer and middle layers strongly improve oxidation resistance and oxide layer adhesion because of their continuity and compactness, and the innermost SiO 2 layer forms a diffusion barrier to prevent further oxidation. Formation and growth mechanisms of oxide layers were also discussed.

Stable lead (Pb) isotopic fingerprints provide opportunities to trace natural and anthropogenic Pb sources in the environment. In order to evaluate Pb deposition from different sources over mountainous areas of western China, Pb isotopic compositions were characterized from modern aeolian dust in 15 snowpit samples collected from 13 typical mountain glaciers between 2008 and 2010. Most of the snowpits sampled cover more than a whole year of accumulation and overlap with each other on deposition date. Pb isotopic variability among all the samples is small, varying in the range of 18.1399-18.9199 for Pb-206/Pb-204, 15.5979-15.8743 for Pb-207/Pb-204, 38.2272-39.9453 for Pb-208/Pb-204, 1.1605-1.2009 for Pb-206/Pb-207 and 2.4433-2.5182 for Pb-208/Pb-207. Three isotopic plots of the different Pb isotope ratios (Pb-207/Pb-204 vs. Pb-206/Pb-204, Pb-208/Pb-204 vs. Pb-206/Pb-204, and Pb-208/Pb-207 vs. Pb-206/Pb-207) in all the samples show identical geographic trends, with more radiogenic in the south and less in the north. This trend is consistent with the distribution of natural dust sources and supports the interpretation of a regional/local source for insoluble particles (IP) to snow/glaciers in this region. Comparison with the Pb isotope results from potential dust sources, however, it shows that the Pb isotopic compositions of IP samples in snow samples are relatively less radiogenic. Parts of these less-radiogenic Pb isotopes are comparable with the ice core results during recent decades, which are shown to be influenced by anthropogenic sources. At sites located along the periphery of western China, the Pb isotopic compositions are much closer to anthropogenic results. Natural and anthropogenic Pb sources are roughly assessed using a simple binary model. The sites with a high anthropogenic fraction are at lower elevations and are relatively close to population centers. (C) 2013 Elsevier Ltd. All rights reserved.

The concentration and size distribution of aerosol particles in the range of 0.25-32 mu m was monitored with an optical particle counter from 2009 to 2011 at the Qilian Shan Station of Glaciology and Ecologic Environment (QSS) (39.50N, 96.51E

The purpose of this study is to identify and classify the ecological risks in land consolidation, and to develop a framework of the theory and method to assess the change of ecological risk degree before and after land consolidation. Environmental impacts and ecological risks of land consolidation have recently drawn much attention, and there are two opposing viewpoints to assess these impacts and risks in the academia of China. Both viewpoints result from the bias of assessment anticipation. Land consolidation includes four main engineering aspects in China, and ecological succession from start of land consolidation to ecosystem stabilization should pass three phases. Different ecological impacts and risks of land consolidation rise from different phases of ecological successions. According to the climax theory of ecology, we developed a framework of the ecological risk assessment based on the anticipation of ecosystem stabilization (ERABAES) for land consolidation. We applied analytical hierarchical processing (AHP) method to the data resources from the land consolidation project in Southern China to allocate weightings to the indices of ecological risk (ER), and to set up an integrated index system for the ecological risk identification. This integrated index system encompasses the ecological risks with three factors (water, soil and biology) and 14 indices. The results of the project show: (1) The ER is reduced from 58.02 to 28.8 after land consolidation and the degree of ecological risk is down from Degree III to Degree IV. (2) According to the element analysis, the water ER is reduced from 21.53 to 6.16, its contribution to reduce the ecological risk is 53%; the reduced ERs of soil and biology are respectively 12.79 and 1.06, their contribution of ecological risk reduce is lower than water.