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Proper agricultural water management in arid regions is the key to tackling climatic risks. However, an effective assessment of the current response to climate change in agricultural water use is the precondition for a group adaptation strategy. The paper, taking the Tarim River basin (TRB) as an example, aims to examine the agricultural water use sustainability of water resource increase caused by climatic variability. In order to describe the response result, groundwater change has been estimated based on the Gravity Recovery and Climate Experiment (GRACE) and the Global Land Data Assimilation System (GLDAS)-Noah land surface model (NOAH) data. In order to better understand the relationship between water resource increase and agricultural water consumption, an agricultural water stress index has been established. Agricultural water stress has been in a severe state during the whole period, although it alleviated somewhat in the mid-late period. This paper illustrates that an increase in water supply could not satisfy agricultural production expansion. Thus, seasonal groundwater loss and a regional water shortage occurred. Particularly in 2008 and 2009, the sharp shortage of water supply in the Tarim River basin directly led to a serious groundwater drop by nearly 20 mm from the end of 2009 to early 2010. At the same time, a regional water shortage led to water scarcity for the whole basin, because the water consumption, which was mainly distributed around Source Rivers, resulted in break-off discharge in the mainstream. Therefore, current agricultural development in the Tarim River basin is unsustainable in the context of water supply under climatic risks. Under the control of irrigation, spatial and temporal water allocation optimization is the key to the sustainable management of the basin. [ABSTRACT FROM AUTHOR]

The southern margin of the Ordos Basin is covered by thick loess sediments. This area is typically characterized by frequent geologic hazards and is rich in energy resources. Identifying the velocity structure of the loess layer is of great significance for geologic hazard prevention and resource explorations in this area. In this paper, we utilize Rayleigh-wave data for imaging the shear-wave velocity (vs) of the loess sediments in the Dongjiahe area, in the southern margin of the Ordos Basin. The data collected in the Dongjiahe area is dominated by the higher-order mode Rayleigh-wave; the dispersive energy of the fundamental mode Rayleigh-wave is weak and suppressed in some frequency bands. An improved frequency–wavenumber (F-K) transform method which can enhance the dispersive energy and expand the frequency range of the weaker fundamental (or higher) mode Rayleigh-wave is proposed in this paper. Numerically simulated data are first utilized to show the processes and effectiveness of the improved F-K transform method. Then, we utilize the improved F-K transform to generate multi-mode dispersive spectrums and extract dispersion curves of the real-world data collected in the Dongjiahe area. Dispersion curves are inverted for vs structure using the Levenberg–Marquardt method. The pattern of the two-dimensional vs section of the study area indicates that the loess sediments mainly distributes as approximate flat layers with vs gradually increasing as the depth increases. In addition, the results also reveal the bedrock depth of some parts of the survey line. [ABSTRACT FROM AUTHOR]

The geological storage of CO2 is potentially one of the most effective methods to reduce the CO2 concentration in the atmosphere. Coalbeds are possibly suitable storage reservoirs, meaning that evaluating the suitability of individual coalbeds and associated engineering and construction is an important step in developing geological CO2 storage. This evaluation requires the development of a reasonable evaluation index system and associated weightings. This paper focuses on coal-bearing basins in China and outlines a technical process whereby the CO2 storage suitability of these basins can be comprehensively evaluated. This study uses an earth system science approach to determine the uncertainties involved in identifying ideal CO2 storage sites, develops an index that outlines the conditions related to the suitability of Chinese coal-bearing basins for geological CO2 storage, and incorporates this index into a hierarchical index system model for geological CO2 storage suitability that allows the comprehensive evaluation of coal-bearing basins and includes 5 aspects, 23 indexes, and 5 index levels. The weighting assigned to each evaluation index was determined using the analytic hierarchy process (AHP) and was subsequently incorporated into a fuzzy logic-based comprehensive evaluation approach. This approach was applied to assess the suitability of the Qinshui Basin for geological CO2 storage, revealing that this basin is indeed a suitable coalbed reservoir. The comprehensive geological CO2 storage evaluation model outlined here can also assess the CO2 storage suitability and capacity of other coal-bearing basins elsewhere in China and globally. [ABSTRACT FROM AUTHOR]

The East China Sea Shelf Basin (ECSSB) is a typical Meso-Cenozoic superimposed basin characterized by different tectonic frameworks, suffering multi-stage tectonism (e.g. the Indosinian, the Yanshanian and the Himalayan) since the Mesozoic. The Mesozoic ECSSB is a key place to our understanding of the tectonic evolution and dynamic mechanism in eastern South China and the subduction of the Izanagi Plate. Based on geological and geophysical results acquired over the last 10 years, this paper provides a summary of the distribution of Mesozoic strata, ascertains boundaries of the Mesozoic basin and proposes the division of the Mesozoic tectonic units in the ECSSB. The Mesozoic ECSSB was subdivided into the Western Fault Depression (WFD) characterized by dispersed Cretaceous half-grabens and the East Depression (ED) characterized by depressions at the early stage and grabens at the later stage. The WFD is composed of half-grabens formed under transtension, and the ED is composed of depression zones on the pre-Mesozoic basement under regional compression, indicating different dynamic mechanisms from the Cenozoic basins. Formation of the Mesozoic tectonic framework was controlled by the collision, compression and subduction of the Izanagi Plate and the Pacific Plate and also affected by the Indian Plate at a later stage. By comparison, this paper preliminarily proposes that the northern South China Sea and the ED of the ECSSB were originally a unified basin and jointly constituted a huge Mesozoic proto-basin in the East Asian continental margin. The Mesozoic tectonic unit division is helpful not only to discuss and resolve problems of ocean-continent differences and boundaries in southeastern South China but also to understand the tectonic nature of the East Asian continental margin, the dynamic mechanism of the Mesozoic basins and the transition of continental margin types. It also provides scientific support for petroleum exploration of the Mesozoic strata in the East China Sea. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Tectonic migration is a common geological process during basin formation and development. However, there are many disputes about the tectonic migration and its dynamic mechanism in the Bohai Bay Basin. By analysis of Cenozoic tectonic, sedimentation and magmatism migration processes in the Bohai Bay Basin, combined with previous studies, the Cenozoic tectonic migration law in the Bohai Bay Basin is summarized in this paper. Affected by the subduction of the Indian Plate to the Eurasian Plate, its far-field effect of the related eastward asthenospheric extrusion and the subduction of the Pacific Plate to the Eurasian Plate, the Cenozoic Bohai Bay Basin is characterized by the gradual northeastward and eastward/seaward migration of tectonic units. The tectonic migration is accompanied by eastward migrations and younging of faulting, depressions in the Bohai Bay Basin, depocentres and subsidence centres and magmatism. Finally, based on intraplate and plate marginal processes and mechanisms, the tectonic migration mechanism in the Cenozoic Bohai Bay Basin is discussed in this paper. The gradual migration of tectonic-sedimentary-basin-forming movements is younger and younger towards the east, resulting from the combined effect of the collision and subduction among the Indian Plate and the Pacific Plate to the Eurasian Plate. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The exploration achievements in the eastern‐central Ordos Basin have attracted tremendous attention in recent years. However, only a few studies were carried out on the relationship between formation pressure and distribution of natural gas in this area. The formation pressure of 293 wells, logging data of 154 wells, and fluid inclusion samples of 53 wells were analysed in this paper, and the results show that the mudstones from Permian Upper Shihezi Formation to Permian Taiyuan Formation are mostly undercompacted. Four gas‐bearing layers with significant differences in pressure profile can be further divided into Permian negative pressure system and Carboniferous normal pressure system. The distribution of current formation pressure is high in the east and north areas but low in the west and south areas. The sedimentary facies and distribution of formation pressure in Permian have a good consistency. The vertical development (zonation) of gas reservoirs is controlled by the undercompacted mudstone layers, and the reservoirs can be found in the “low pressure” areas of negative pressure strata in the Permian and “high pressure” regions of normal pressure strata in the Carboniferous. The pressure evolution and accumulation process can be divided into 3 stages: hydrocarbon‐generation supercharging accumulation during Late Jurassic—end of Early Cretaceous, sandstone resilience discharging accumulation during end of Early Cretaceous—Paleogene, and adjusting accumulation during Paleogene—Quaternary. The discovery of the relationship between formation pressure and gas reservoirs is significant to the future natural gas exploration in this area. [ABSTRACT FROM AUTHOR]

The southwestern area of the Ordos Basin, China, contains good oil/gas systems, similar to the main basin. However, no oil/gas reserves have been found because some magmatic rocks with different occurrences developed in the region, it resulted in the suspension of oil/gas exploration in the 1980s. By means of integrated research based on field investigation, geophysical interpretation, and data of drilling wells, this paper indicates that magmatic activities in the southwestern Ordos Basin display different properties over multiple periods. The Proterozoic and Palaeozoic magmatic rocks are mainly distributed as a large batholith in the Qinling Orogen, and the Qilian Orogen around the southwestern margin of the Ordos Basin. These Proterozoic and Paleozoic plutons have no effect on hydrocarbon source rocks and oil/gas generation in the Ordos Basin. However, the Mesozoic magmatic activities developed within the basin have obvious effects on oil/gas generation. Three kinds of exploration regions were selected within the southwestern Ordos Basin according to the distribution of hydrocarbon source and magmatic rocks as well as the thermal degree: (a) the marginal area of the basin, (b) the region of the Longmen Uplift distributed with concealed magmatic rocks within the basin, and (c) the region within the basin far away from concealed magmatic rocks. Three sets of gas source rocks, that is, the Upper Proterozoic algal dolostone, the Middle Ordovician dark shale, the Upper Paleozoic black mudstone of coal system, and one set of oil source rocks of the Upper Triassic lacustrine black mudstone and oil shale, are exposed in outcrops near the margin of the basin. They all display a low thermal degree with vitrinite reflectance (Ro) below 1.3%, and they do not contribute to oil/gas accumulation because of earlier tectonic uplift. The gas source rocks and oil source rocks, which occur within the basin area of the Longmen Uplift, where the concealed magmatic rocks, display an abnormal thermal degree of over maturation with Ro over 3.4% and underwent dry gas generation because of heating from magmatic activity, and they have gas exploration potential. The source rocks distributed within the basin area away from concealed magmatic rocks display a normal thermal degree and oil/gas generation. The Ro of the Upper Triassic oil source rock is 1.0–1.6%, which is under the thermal maturity stage of liquid oil generation, whereas that of the Upper Paleozoic gas source rocks is 2.0–2.5% under the thermal maturity stage of gas generation. Measured Ro and burial depth of source rocks in the region show a linear relationship, which indicate that source rocks experienced thermal evolution and oil/gas generation under the normal burial thermal condition rather than the magmatic activity. This region has the most potential for both oil and gas exploration. [ABSTRACT FROM AUTHOR]

Middle and eastern routes of the South-North Water Diversion Project (SNWDP) of China, which are approximately located within the area 28°-42°N and 110°-122°E, are being constructed. This paper investigates the past climatic variations on various time scales using instrumental and proxy data. It is found that annual mean surface air temperature has increased significantly during the past 50-100 years, and winter and spring temperatures in the northern part of the region have undergone the most significant changes. A much more significant increase occurs for annual mean minimum temperature and extreme low temperature than for annual mean maximum temperature and extreme high temperature. No significant trend in annual precipitation is found for the region as a whole for the last 50 and 100 years, although obvious decadal and spatial variation is detectable. A seesaw pattern of annual and summer precipitation variability between the north and the south of the region is evident. Over the last 100 years, the Haihe River basin has witnessed a significant negative trend of annual precipitation, but no similar trend is detected for the Yangtze and Huaihe River basins. Pan evaporation has significantly decreased since the mid-1960s in the region in spite of the fact that the trend appears to have ended in the early 1990s. The negative trend of pan evaporation is very significant in the plain area between the Yangtze and Yellow Rivers. There was a notable series of dry intervals lasting decades in the north of the region. The northern drought of the past 30 years is not the most severe in view of the past 500 years; however, the southern drought during the period from the 1960s to the 1980s may have been unprecedented. The dryness-wetness index (DWI) shows significant oscillations with periodicities of 9.5 and 20 years in the south and 10.5 and 25 years in the north. Longer periodicities in the DWI series include 160-170- and 70-80-yr oscillations in the north, and 100-150-yr oscillations in the south. The observed climate change could have implications for the construction and management of the SNWDP. The official approval and start of the hydro project was catalyzed by the severe multiyear drought of 1997-2003 in the north, and the operation and management of the project in the future will also be influenced by climate change-in particular by precipitation variability. This paper provides a preliminary discussion of the potential implications of observed climate change for the SNWDP. [ABSTRACT FROM AUTHOR]

The Banqiao area in the Bohai Bay Basin has experienced three stages of extensional deformation, leading to the formation of numerous fault-bound traps. Faults, acting as boundary conditions for these traps, play a crucial role in hydrocarbon accumulation. In this study, we conducted a 3D structural modeling of the area using high-resolution 3D seismic data and established a fault-reservoir database based on previous research. Our findings reveal four levels of faults in the Banqiao area: basin-controlling faults, boundary faults, derivative master faults, and secondary adjusting faults. The structural units can be categorized into subsag areas, slope areas, stress tran-sition zones, bifurcation and main incised fault zones, and southern block areas. The segmented growth of the main boundary faults controls the evolution of the subsags, with the subsidence center gradually shifting eastward from Rift Phase I to Rift Phase II, aligning with the distribution of source rocks. Fault-bound traps in the Banqiao area include single faults, intersecting faults, and side faults. Faults primarily act as barriers to lateral hydrocarbon migration during the process of hydrocarbon accumulation, while also providing pathways to a lesser extent. By integrating the fault-reservoir database with the fault system classification, we identified four types of fault-controlled hydro-carbon accumulation models: like-dipping fault barrier model, oppositely-dipping fault barrier model, intersecting fault barrier model, and reactivation-controlled secondary hydrocarbon ac-cumulation model. This structural geological model effectively demonstrates the spatial configuration of faults and their role in hydrocarbon accumulation in the Banqiao area. The fault control mechanisms presented in the model can also be applied to other blocks in the Bohai Bay Basin, laying a foundation for future petroleum exploration in continental rifted basins and facilitating the ap-plication of big data algorithms in various geoscientific research fields. [ABSTRACT FROM AUTHOR]

The East China Sea Shelf Basin (ECSSB), the Pearl River Mouth Basin (PRMB) and the Taixinan Basin (TXNB) in the northern continental margin of the South China Sea (SCS) are important oil- and gas-bearing basins on the Western Pacific Continental Margin. During the Paleocene to Late Miocene, their strata can be compared, and the lithofacies were continuous from the TXNB, via the Taixi Basin (TXB) to the ECSSB. The lithologies mainly consist of interbedded shale, sandstone and mudstone layers. In addition, these basins have similar tectonic and sedimentation features. The three basins had similar marine-terrigenous facies in the Paleocene and marine-lacustrine-fluvial facies during the Eocene and Late Miocene. The basins experienced several coeval tectonic movements and episodes, and they developed a series of NE- and NNE-trending faults during the Paleocene and Eocene, which controlled the structure of the basins. During the Early Oligocene and Middle Miocene, they developed a series of NW- and WNW-trending strike-slip faults, reverse folds and flower-like strike-slip faults. However, there were obvious differences in sedimentary and tectonic evolution since the Late Miocene. The TXNB and TXB developed marine facies after the Late Miocene, while in the Quaternary, open marine facies replaced the Pliocene terrigenous facies in the ECSSB. Since the Late Miocene, the south of the ECSSB developed into a subsidence stage, and fault activity stopped. The TXB and TXNB developed some inverse structures and then developed into a thermal subsidence episode after the Dongsha Movement. Thus, this paper proposes that the ECSSB and the Cenozoic basins in the SCS were originally a unified basin and then subsequently separated into two basins as a result of the indentation of the Philippine Sea Plate (PSP) and the arc-continent collision between the Luzon Arc and the Eurasian Plate. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Thirteen ichnogenera and seventeen ichnospecies were recognised in carbonate rocks from the Lower Permian Taiyuan Formation in North China Basin. Based on the composition, occurrence and diversity of ichnofossils, intensity of bioturbation, lithologic characteristics, especially on the variation of individual size and the filling colour diversities of theZoophycosburrows, four types of ichnofabrics were recognised, that is (1) epigenic tiering ichnofabric – mainly appeared on or near the bedding plane and formed in restricted bay or lagoon sedimentary environments; (2) shallow tiering ichnofabric – developed less than 15 cm under the bedding plane and occurred in the upper shallow-marine environment; (3) medium tiering ichnofabric – mainly distributed from 15 to 20 cm under the bedding plane and generated in the mid-upper shallow sea (restricted–open platform); (4) deep tiering ichnofabric – distributed from 25 to 30 cm under the bedding plane and occurred in lower shallow sea (open platform) far from shore. Based on ichnological and sedimentological analyses above four types of ichnofabrics, the sedimentary environment model of the ichnofabrics in carbonate rocks from the Taiyuan Formation in North China Basin is proposed in this paper. [ABSTRACT FROM AUTHOR]

One of the potential impacts of global warming is likely to be experienced through changes in flood frequency and magnitude, which poses a potential threat to the downstream reservoir flood control system. In this paper, the downscaling results of the multimodel dataset from phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5, respectively) were coupled with the Variable Infiltration Capacity (VIC) model to evaluate the impact of climate change on the Feilaixia reservoir flood control in the Beijiang River basin for the first time. Four emissions scenarios [A1B and representative concentration pathway (RCP) scenarios RCP2.6, RCP4.5, and RCP8.5] were chosen. Results indicate that annual distribution and interannual variability of temperature and precipitation are well simulated by the downscaling results of the CMIP3 and CMIP5 multimodel dataset. The VIC model, which performs reasonably well in simulating runoff processes with high model efficiency and low relative error, is suitable for the study area. Overall, annual maximum 1-day precipitation in 2020-50 would increase under all the scenarios (relative to the baseline period 1970-2000). However, the spatial distribution patterns of changes in projected extreme precipitation are uneven under different scenarios. Extreme precipitation is most closely associated with extreme floods in the study area. There is a gradual increase in extreme floods in 2020-50 under any of the different emission scenarios. The increases in 500-yr return period daily discharge of the Feilaixia reservoir have been found to be from 4.35% to 9.18% in 2020-50. The reservoir would be likely to undergo more flooding in 2020-50. [ABSTRACT FROM AUTHOR]

The Junggar Basin is one of the main oil basins in Northwest China, and the north‐west part of the basin is a significant petroleum exploration target. Mesozoic structural activity had an important influence on the present structural characteristics of the north‐west Junggar Basin. In this paper, we discuss the tectonic evolution of the Junggar Basin by studying the structural characteristics of the Ke‐Bai Fault. Our results suggest that the Ke‐Bai Fault has obvious strike‐slip characteristics and that it is an important basin‐controlling fault that has controlled the tectonic evolution of the north‐west Junggar Basin. The Junggar Basin was a rift basin in the Early Permian, but it experienced a tectonic reversal during the Middle Permian to the Triassic. The Ke‐Bai Fault changed from a normal fault into a thrust fault from the Early Permian to the Triassic. During the Jurassic, dextral strike‐slip structures developed along the Ke‐Bai Fault, horsetail splay faults developed in its north segment, and there is evidence that it was under WNW–ESE compression. The dextral strike‐slip faulting of the Ke‐Bai Fault is consistent with tectonic movement along the Kelameili, Sangequan, Wu‐Xia, Hong‐Che, and North Tianshan fault systems in the Junggar Basin. We therefore infer that counterclockwise rotation occurred in the Junggar Basin in the Jurassic. [ABSTRACT FROM AUTHOR]

Heavy rainfall hit the Yangtze-Huai Rivers basin (YHRB) of east China several times during the pro-longed 2007 mei-yu season, causing the worst flood since 1954. There has been an urgent need for attaining and processing high-quality, kilometer-scale, hourly rainfall data in order to understand the mei-yu pre-cipitation processes, especially at the mesoß and smaller scales. In this paper, the authors describe the construction of the 0.07°-resolution gridded hourly rainfall analysis over the YHRB region during the 2007 mei-yu season that is based on surface reports at 555 national and 6572 regional automated weather sta-tions with an average resolution of about 7 km. The gridded hourly analysis is obtained using a modified Cressman-type objective analysis after applying strict quality control, including not only the commonly used internal temporal and spatial consistency and extreme value checks, but also verifications against mosaic radar reflectivity data. This analysis reveals many convectively generated finescale precipitation structures that could not be seen from the national station reports. A comprehensive quantitative as-sessment ensures the quality of the gridded hourly precipitation data. A comparison of this dataset with the U.S. Climate Prediction Center morphing technique (CMORPH) dataset on the same resolution suggests the dependence of the latter's performance on different rainfall intensity categories, with sub-stantial underestimation of the magnitude and width of the mei-yu rainband as well as the nocturnal and morning peak rainfall amounts, due mainly to its underestimating the occurrences of heavy rainfall (i.e., >10mmh-1). [ABSTRACT FROM AUTHOR]

Poyang Lake in Jiangxi Province is the largest freshwater lake in China and is historically a region of significant floods. Maximum annual lake stage and the number of severe flood events have increased during the past few decades because of levee construction that reduced the area available for floodwater storage. The most severe floods since 1950 occurred during 1954, 1973, 1983, 1995, and 1998. Each of these floods followed El Niño events that influence the Asian monsoon and that are directly linked to rainfall in the Changjiang (Yangtze River) basin. The 1954 flood was the largest ever recorded until the 1990s. That year the peak Changjiang stage at Hukou was 21.6 m, which was 1.6 m above the previous record high. The last major flood on the Changjiang was during 1998, when the peak Changjiang stage reached 22.5 m, higher than during 1954, even though peak discharge was lower. The most severe floods, including those in 1954 and 1998, require both 1) high rainfall and tributary discharge into Poyang Lake and 2) high Changjiang discharge and stage at Hukou that backflows into the lake or slows Poyang Lake drainage. Since gauging stations were established on the Changjiang, these conditions always occurred following an El Niño. [ABSTRACT FROM AUTHOR]

The apatite (U-Th)/He thermochronometry has been used to study the tectono-thermal evolution of mountains and sedimentary basins for over ten years. The closure temperature of helium is important for the apatite (U-Th)/He thermochronometry and has been widely studied by thermal simulation experiments. In this paper, the apatite He closure temperature was studied by establishing the evolutionary pattern between apatite He ages and apatite burial depth based on examined apatite He ages of natural samples obtained from drillholes in the Tarim basin, China. The study showed that the apatite He closure temperature of natural samples in the Tarim basin is approximately 88±5°C, higher than the result (∼75°C) obtained from the thermal simulation experiments. The high He closure temperature resulted from high effective uranium concentration, long-term radiation damage accumulation, and sufficient particle radii. This study is a reevaluation of the conventional apatite He closure temperature and has a great significance in studying the uplifting events in the late period of the basin-mountain tectonic evolution, of which the uplifting time and rates can be determined accurately. [ABSTRACT FROM AUTHOR]

Abstract: Increasing inter-sectoral virtual water trade has organized the world into a huge web and different trade sectors will impact each other directly and indirectly through productions or services. It is hard to make reasonable virtual water policies before understanding the interdependency between different trade sectors in virtual water production and consumption. This paper introduces a method, named ecological network analysis, to show the independence and interaction between different trade sectors. A virtual water trade network model of the Baiyangdian Basin was built as an example of how this approach provides insights into the trade system. Control, utility, unit environ and final contribution ratio methods of network analysis were used to identify the quantitative dependency relations, distinguish the beneficiary and the contributor, detect fate of boundary input and output in any component and explore the contribution of each compartment to virtual water trade system. Results showed these methods could well depict the mutual relations in trade system and direct, observable relations may differ from integral ones. This paper revealed ways to optimize virtual water trade structure by adjusting the relationships among compartments, thereby demonstrating how ecological network analysis can be used in future basin water resources management. [Copyright &y& Elsevier]

Abstract: In the paper, Authors separately used analytical hierarchy process, expert scoring method, principal component and BP network to establish the weights of ecological vulnerability evaluation Index system in the Hengyang Basin as a case, and used hierarchical-comprehensive index -clustering model, principal component-comprehensive index- clustering analysis model, expert scoring-composite index-clustering analysis model, BP artificial neural network model to evaluate separately the reality vulnerability in 2000. The results shows that study area are moderate weak, and the results broadly similar. Authors think that Principal component and artificial neural network model can avoid subjective factors, and taking the way of the expert group judgment is to reduce the error of ecological vulnerability assessment. With the impact of global change and the strengthening of fragile ecosystems, China has carried out many researches and practices on vulnerability assessments [1,14].Although Vulnerability assessment in many ways, not yet formed a unified evaluation method, this paper draw on previous evaluation methods based on [1,11], using AHP, principal component analysis, BP neural network and expert scoring method on quantitative assessment and analysis, then clustering the results by comparison to determine which method to evaluate the most accurate.Authors analysis the Hengyang Basin reality vulnerability in 2000,attempting to explore a more suitable and easy erosion in hilly areas degraded fragile vulnerability assessment method. [Copyright &y& Elsevier]

Abstract: The study has put forward a water pollution management model as a GIS tool in the long-term water projects regulating process and pollution control plan for the Huaihe River Basin in China. In this paper, we applied GIS network analysis technology to water pollution management, which established digital stream network model and river water environmental database, integration and manage of water projects regulating related data resource. This paper designed a stream network analysis platform based on GIS support. Based on algorithms provided in the GIS foundational software such as shortest path analysis, connectivity component analysis, upstream/downstream trace and buffer analysis, we built an algorithm library including water projects regulating-oriented algorithms for upstream/downstream tracking of water pollution. [Copyright &y& Elsevier]

Abstract: This paper introduces the development of a dynamic parallel algorithm for conducting hydrological model simulations. This new algorithm consists of a river network decomposition method and an enhanced master–slave paradigm. The decomposition method is used to divide a basin river network into a large number of subbasins, and the enhanced master–slave paradigm is adopted to realize the function of this new dynamic basin decomposition method through using the Message-Passing Interface (MPI) and C++ language. This new algorithm aims to balance computation load and then to achieve a higher speedup and efficiency of parallel computing in hydrological simulation for the river basins which are delineated by high-resolution drainage networks. This paper uses a modified binary-tree codification method developed by to code drainage networks, and the basin width function to estimate the possible maximum parallel speedup and the associated efficiency. As a case study, with a hydrological model, the Digital Yellow River Model, this new dynamic parallel algorithm is applied to the Chabagou basin in northern China. The application results reveal that the new algorithm is efficient in the dynamic dispatching of simulation tasks to computing processes, and that the parallel speedup and efficiency are comparable with the estimations made by using the basin width function. [Copyright &y& Elsevier]

Large areas of the Tibetan plateau are only covered by a sparse network of ground snow sampling stations, while the snow cover is highly heterogeneously distributed due to wind, topography etc. Nevertheless, the snow accumulation and spatial patterns play an important role in the hydrological cycle. It releases moisture during the dry spring period before the onset of the monsoon season. Widely used MODIS snow cover products have been available globally since 2002. The understanding of the temporal and spatial distribution of snow cover in a given region calls for a comprehensive data representation method. In this paper a method to visualize both spatial and temporal aspects of snow cover distribution from MODIS 8-day composite data is presented. It is based on RGB display of the snow cover data which is grouped according to season. The RGB syntheses of snow cover distribution (RSD) were generated for the Nam Co Basin in the central part of the Tibetan Plateau during the years of 2002-2009. An alternating pattern of monsoon and autumn snow cover was identified in the western part of the basin which corresponds to the biennial character of the variations of the Indian monsoon. Monsoon snow cover was found in RSD images for the years 2002, 2004 and 2008 whereas in years 2003 and 2009 the autumn snow cover is dominant. The eastern part of the basin does not follow this general pattern since it is affected by the so called ?lake effect?, which is a snow fall induced by the passing of dry and cold westerlies over the lake surface during the winter months. The years 2002, 2006 and 2007 were identified as years with a particularly strong lake effect from the RSD images. Areas with permanent snow cover and areas that were snow free were both found to be relatively stable. Comparison of the lake effect at Nam Co with nearby Siling Co, where the lake effect is smaller or absent, suggests that the presence of an effective barrier on the opposite side of the lake is a prerequisite for the occurrence of the strong lake effect. [ABSTRACT FROM AUTHOR]

The sediment loads of many of the world's major rivers have changed significantly in recent years due to land-use change, reservoir construction, and other human impacts on their drainage basins. For many rivers, the loads have decreased, whereas for others, they have increased. Such changes can have important implications for both the natural functioning of the system as well as for human exploitation of the river system. This paper considers the evidence for recent changes in the sediment load of the Mekong River. The available data have a number of limitations in terms of both sampling frequency and the period of coverage, but they have been processed to provide a basis for considering the changes in the sediment load of the river over the period extending from the early 1960s to 2002. Although there is evidence of increasing loads at some measuring stations, the overall trends show little evidence of major changes, and the system provides evidence of buffering through storage. As of 2002, the construction of major dams on the headwaters in China appears to have had little impact on the sediment load, although as further larger dams are commissioned, the sediment load of the Mekong can be expected to decrease. [ABSTRACT FROM AUTHOR]

Ground fissures are a geological hazard with complex formation mechanisms. Increasing amounts of human activity have created more ground fissures, which can destroy buildings and threaten human security. Some ground fissures indicate potentially devastating earthquakes, so we must pay attention to these hazards. This paper documents recently discovered ground fissures in the Hetao basin. These ground fissures are located along the frontal margins of the terraces of the Sertengshan piedmont fault. These fissures are 600–1600 m long, 5–50 cm wide, and at most 1 m deep. These ground fissures emerged after 2010 and ruptured newly constructed roads and field ridges. The deep geodynamic mechanisms within this extensional environment, which is dominated by NE-SW principal compressive shear, involve N-S tensile stress, which has produced continuous subsidence in the Hetao basin and continuous activity along the Sertengshan piedmont fault since the late Quaternary. Trenches across the ground fissures reveal that the fissures are the latest manifestation of the activity of preexisting faults and are the result of creep-slip movement along the faults. The groundwater level in the Hetao basin has been dropping since the 1960s because of overexploitation, resulting in subsidence. When the tensile stress exceeds the ultimate tensile strength of the strata, the strata rupture along preexisting faults, producing ground fissures. Thus, the Sertengshan piedmont fault planes are the structural foundation of the ground fissures, and groundwater extraction induces the development of ground fissures. [ABSTRACT FROM AUTHOR]

With the acceleration of the Yinchuan Basin’s rapid economic and social development and urbanization, humans are continually enhancing the production of some services at the expense of others. This paper aimed to estimate the changes in ecosystem service and the relationship between carbon sequestration, wind prevention and sand fixation and water retention in the Yinchuan Basin of China.These ecosystem service were of great importance to healthy development of the study area and the least-square fitting of the orthogonal polynomials was applied to evaluate the relationship between these ecosystem service. The results suggest that the highest carbon sequestration, wind prevention and sand fixation, and water retention value were distributed in the middle of the Yinchuan Basin. Water retention was the main water source for farmland, and wind prevention and sand fixation were generally enhanced during 1993–2014. Futhuemore, there were synergistic relationships between carbon sequestration, wind prevention and sand fixation, and water retention under three ecosystem services. [ABSTRACT FROM AUTHOR]

This paper provides insights into the allocation of benefits derived from joint wastewater treatment in the Lake Tai Basin of China and the acceptability and stability of different cost allocation schemes in a trans-jurisdictional water system context. First, the wastewater treatment cost function is estimated and coalition costs are compared to the cost of stand-alone wastewater treatment in each province. Second, two standard and five game theoretical cost allocation schemes are applied to the grand coalition. Results suggest that a cost savings of US $46.46 million can be obtained by forming a grand coalition. All allocation schemes were found to be acceptable. Results also suggest that both Shanghai and Jiangsu Province would prefer a proportional allocation scheme based on pollutant discharge, because it would offer them the largest cost savings. But this allocation scheme is the least stable one. Based on the criterion of stability, the Nash-Harsanyi scheme emerges as providing the optimal allocation. Finally, calculation of power and stability indexes suggests Jiangsu Province as an agent is critical to the success of grand coalition formation. [ABSTRACT FROM AUTHOR]

The Wufeng–Longmaxi Formation in northern Guizhou Province is the dominant shale gas exploration and development strata in China. This study investigates the Shixi and Daozhen synclines, which are located in the basin margin transition zone. This region experienced complex tectonic stages and superimposed transformations, resulting in heterogeneous preservation conditions and shale reservoir pressure evolution in different tectonic units of the Wufeng–Longmaxi Formation. Based on fluid inclusion analysis, the types of fluid inclusion and the fluid filling stages of the Wufeng–Longmaxi shale reservoir were determined by laser Raman analysis and homogenization temperature and salinity tests. It was found that the fluid inclusion density and paleopressure in each filling stage were then restored. The results confirm that: ① Both the Shixi syncline and Daozhen syncline Wufeng–Longmaxi shale reservoirs experienced two fluid filling phases, in the early Yanshanian and late Yanshanian–Himalayan, respectively. In the course of tectonic evolution, the Wufeng–Longmaxi Formation in the Shixi and Daozhen synclines experienced pressure relief to some extent during the two aforementioned key fluid charging periods but remained in overpressurized states overall; ② The Wufeng–Longmaxi Formations of the Shixi and Daozhen synclines are characterized by high-density methane inclusions; ③ Based on the differences in the structural preservation conditions, the pressure evolution mechanisms of the Wufeng–Longmaxi Formation Shales during the important tectonic evolution period in northern Guizhou Province were revealed. Furthermore, differential enrichment and accumulation models of shale gas were established and named "facing thrust structural sealing type (Shixi syncline)" and "reverse fault lateral blocking type (Daozhen syncline)". [ABSTRACT FROM AUTHOR]

The ecological footprint (EF) is an accepted worldwide method for the evaluation of environmental sustainability. However, its utility is limited by the existence of a series of shortcomings in the methodology such as the only-partial inclusion of human generated wastes. To improve the ability of the footprint method to evaluate environmental sustainability, a new footprint-based indicator – the ‘Waste Absorption Footprint’ (WAF) – has been proposed. The purpose of this paper is to test this methodological approach by evaluating the sustainability of the water environment in the Taihu Lake Basin, in densely populated eastern China. Applying the WAF method indicates that anthropogenic discharges of wastes have imposed an absorption pressure on the local water system such that the local water environment is increasingly unsustainable . Furthermore, nitrogen and phosphorus are identified as more critical wastes than organic substances, while domestic discharges are shown to be more important sources compared with those from industry and agriculture, which therefore should be the focus of environmental management and pollution control initiatives. It is demonstrated that the WAF method can provide a wealth of information that can be used for reference by local water environmental management authorities. [ABSTRACT FROM AUTHOR]

This paper describes a new species of the genusAdocus(A. inexpectatus, sp. nov.), based on an almost complete shell from the upper Eocene Youganwo (= Youkanwo) Formation of the Maoming Basin, China. The inclusion ofA. inexpectatusin a phylogenetic analysis of Adocusia resulted in a polytomy withAdocus aksaryandA. amtgai(both from the Upper Cretaceous of Asia). This clade formed a polytomy with the North American species ofAdocus. Like other ‘true’Adocus,A. inexpectatushas overlapping of the marginals onto the costals in the middle and posterior parts of the carapace and sculpturing of the shell surface with small grooves and pits. Thus,A. inexpectatusrepresents the first ‘true’Adocusfrom the Paleogene of Asia. Other specimens from the Paleogene of Asia that have been referred toAdocus, characterized by shell sculpturing with small dots and unknown condition of the marginal/costal overlapping, are distinct from ‘true’Adocusand herein referred to as ‘Adocus’ spp. Here we also report the presence of ‘Adocus’ from the Paleocene of North America. Our study indicates that the evolutionary and biogeographic history of the Adocidae was more complicated than considered previously, including previously unrecognized dispersal events between Asia and North America. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]

Based on the analysis of field observation, drilling data and geophysical data, this paper interpreted the structural deformation characteristics of Lower Yangtze region and its preservation potential for shale gas. The results show that the deformation characteristics of Lower Yangtze region vary in different areas. The structural style is not only different from south to north, but also from east to west. To the east of Maoshan, the structure style is mainly controlled by decollement folding, which was caused by the Indosinian-Yanshan movement. The following extension and reversion movements greatly are destroyed the previous structures. So it still has good shale gas preservation conditions for shale gas and not very hard to explore. The west Maoshan region, however, is strongly reworked by strong reverse and tension movements since the Indosian-Yanshan movement, and as a result a serious of extensional and faulted basins and volcanic basins were formed, which are very negative for the shale gas preservation and explorations. [ABSTRACT FROM AUTHOR]

Abstract: This paper analyzes the large-scale accumulation conditions and distribution characteristics of medium-low abundance hydrocarbon resources in China. Large-scale development of accumulation elements and their change in scale are the material basis of large scale oil and gas accumulation, determining the regional nature of oil and gas distribution. Liquid hydrocarbon dispersed in marine source rocks being cracked to form a large volume of gas and coal measure source rocks expelling gas during uplift are two important factors for the formation of large-scale hydrocarbon accumulation, which control the scale of source rocks that enter the main gas-generating stage. Volume flow and diffusive flow are the main migration-accumulation mechanism for the large-scale hydrocarbon accumulation, which ensures the sufficiency of hydrocarbon supply. Pancake, layer-like, and cluster are three main accumulation forms of large-scale hydrocarbon accumulation, which ensure the scale of hydrocarbon accumulation. Middle to low abundance hydrocarbon resources are characterized by near-source distribution, main-body play, late accumulation stage and single accumulation type. The periclinal area of palaeo-highs in marine craton basins, the lower slopes and sags in an intra-continental depression basin, and the gentle slopes of foreland basins are the most likely areas for the development of large-scale hydrocarbon accumulation, and they have two types of accumulation, large area and large scope. The proposal of the large-scale accumulation of middle to low abundance hydrocarbon resources in China improves the hydrocarbon discovering potential in middle to deep layers of superimposed basins and in the lower slopes and sags in depression basins, enlarges the exploration scale, and extends the hydrocarbon exploration from local second-order structure zones to the whole basin with the main source rock as the center, and from middle layers to deep, even super-deep, layers. [Copyright &y& Elsevier]

Variability and availability of water resources under changing environment in a regional scale have been hot topics in recent years, due to the vulnerability of water resources associated with social and economic development. In this paper, four subbasins in the Dongjiang basin with a significant land use change were selected as case study. Runoffs of the four subbasins were simulated using the SCS monthly model to identify the quantitative impacts of land use and climate change. The results showed that (1), in the Dongjiang basin, temperature increased significantly, evaporation and sunlight decreased strongly, while precipitation showed a nonsignificant increase; (2) since the 1980s, land uses in the Dongjiang basin have experienced a significant change with a prominent increase inurbanareas, amoderate increase in farmlands, anda greatdecrease inforest areas; (3) the SCSmonthlymodel performed well in the four subbasins giving that the more significant land use change in each subbasin, the more runoff change correspondingly; (4) overall, runoff change was contributed half and half by climate change and human activities, respectively, in all the subbasins, in which about 20%~30% change was contributed by land use change. [ABSTRACT FROM AUTHOR]

Abstract: Taking the littoral-facies clastic reservoir of Donghe sandstone in HD4 oil field, Tarim Basin, NW China as an example, this paper analyzes the effect of different reservoir architecture pattern on oil well production performance. There are three types of reservoir architecture patterns in the target layers of the study area, parallel, groove and oblique. The dynamic response characteristics of different reservoir architecture patterns were discussed by establishing the conceptual model of different reservoir architecture patterns, in conjunction with numerical reservoir simulation results and actual production performance of the study area. Based on the numerical simulation, together with analysis of geologic factors and performance evaluation, a performance evaluation method for clastic reservoir architecture of littoral facies was put forward, in turn, the distribution scopes of different reservoir architecture patterns in the study area were identified by this method. The research results show that the parallel reservoir architecture only affects oil well production in vertical direction, the oblique reservoir architecture has the strongest effect on oil well production performance, reflected in both vertical and lateral direction, the effect of groove reservoir architecture on oil well production is mainly in vertical direction, relatively weak in lateral direction. Different adjustment measures should be adopted for the distribution areas of different reservoir architecture patterns. [Copyright &y& Elsevier]

Abstract: The superimposed basins in the Tarim Basin are characterized by multiple source-reservoir-caprock combinations, multiple stages of hydrocarbon generation and expulsion, and multi-cycle hydrocarbon accumulation. To develop and improve the reservoir forming theory of superimposed basins, this paper summarizes the progress in the study of superimposed basins and predicts its development direction. Four major progresses were made in the superimposed basin study: (1) widely-distributed of complex hydrocarbon reservoirs in superimposed basins were discovered; (2) the genesis models of complex hydrocarbon reservoirs were built; (3) the transformation mechanisms of complex hydrocarbon reservoirs were revealed; (4) the evaluation models for superimposed and transformed complex hydrocarbon reservoirs by tectonic events were proposed. Function elements jointly controlled the formation and distribution of hydrocarbon reservoirs, and the superimposition and overlapping of structures at later stage led to the adjustment, transformation and destruction of hydrocarbon reservoirs formed at early stage. The study direction of hydrocarbon accumulation in superimposed basins mainly includes three aspects: (1) the study on modes of controlling reservoir by multiple elements; (2) the study on composite hydrocarbon-accumulation mechanism; (3) the study on hydrocarbon reservoir adjustment and reconstruction mechanism and prediction models, which has more theoretical and practical significance for deep intervals in superimposed basins. [Copyright &y& Elsevier]

Abstract: Upper Paleozoic coal measures in the Ordos Basin consist of dark mudstone and coal beds and are important source rocks for gas generation. Gas accumulations include coal-bed methane (CBM), tight gas and conventional gas in different structural areas. CBM accumulations are mainly distributed in the marginal area of the Ordos Basin, and are estimated at 3.5 × 1012 m3. Tight gas accumulations exist in the middle part of the Yishan Slope area, previously regarded as the basin-centered gas system and now considered as stratigraphic lithologic gas reservoirs. This paper reviews the characteristics of tight gas accumulations: poor physical properties (porosity < 8%, permeability < 0.85 × 10−3 μm2), abnormal pressure and the absence of well-defined gas water contacts. CBM is a self-generation and self-reservoir, while gas derived from coal measures migrates only for a short distance to accumulate in a tight reservoir and is termed near-generation and near-reservoir. Both CBM and tight gas systems require source rocks with a strong gas generation ability that extends together over wide area. However, the producing area of the two systems may be significantly different. [Copyright &y& Elsevier]

Abstract: This paper presents the end Late Paleozoic tectonic stress field in the southern edge of Junggar Basin by interpreting stress-response structures (dykes, folds, faults with slickenside and conjugate joints). The direction of the maximum principal stress axes is interpreted to be NW–SE (about 325°), and the accommodated motion among plates is assigned as the driving force of this tectonic stress field. The average value of the stress index R′ is about 2.09, which indicates a variation from strike-slip to compressive tectonic stress regime in the study area during the end Late Paleozoic period. The reconstruction of the tectonic field in the southern edge of Junggar Basin provides insights into the tectonic deformation processes around the southern Junggar Basin and contributes to the further understanding of basin evolution and tectonic settings during the culmination of the Paleozoic. [Copyright &y& Elsevier]

Abstract: According to the comparison of biomarkers in source rocks and crude oil, fluid inclusion analysis, and basin modeling, this paper discusses the oil source, hydrocarbon accumulation period and reservoir forming model of the Chang 9 and Chang 10 oil-bearing formations, Yanchang Formation, Ordos Basin. The crude oil of Chang 9 in the Longdong and Jiyuan areas can be divided into two types, type I crude oil originated from the source rocks within Chang 7, while type I crude oil came from the source rocks within Chang 9. The crude oil of Chang 10 in Northern Shaanxi originated mainly from the source rocks of Chang 9. The Chang 9 oil reservoirs in both the Longdong and Jiyuan areas experienced two periods of hydrocarbon injection. The former reached the peak period of hydrocarbon injection in the first period (the depositional period of Middle Jurassic Zhiluo Formation), while the latter in the second period (the depositional period of Lower Cretaceous Zhidan Formation). There are two periods of continuous hydrocarbon injection in Chang 10 of Northern Shaanxi, generally from the early depositional period of the Middle Jurassic Zhiluo Formation to the middle-late depositional period of the Cretaceous Zhidan Formation. There are three types of hydrocarbon accumulation models in Chang 9 and Chang 10, i.e. “upper generation and lower storage”, “adjacent generation and lateral storage” and “self-generation and self-storage”. [Copyright &y& Elsevier]

Abstract: A water resources vulnerability (WRV) assessment is important to maintain water resources safety in a basin. In this paper, an index system, including four subsystems -- the hydrological subsystem, the socioeconomic subsystem, the eco-environment subsystem and the hydraulic engineering subsystem, is constructed for an integrated WRV assessment of the Zhangjiakou region of the Guanting Reservoir Basin, North China. The parametric-system (PS) method based on background value is used for the quantitative WRV assessment of each subsystem and of the integrated water resources system. The results of the calculations show that the degree of vulnerability of Guanting Reservoir Basin is quite serious, with Zhangjiakou City being extremely vulnerable, and Yanqing County and Zhuolu County mildly vulnerable. The assessment process and results, as well as the characteristics of the method used, have been compared with those of the fuzzy optimization (FO) method and the grey relational analysis (GRA) method. The parametric-system (PS) method is appropriate for level classification and rank analysis of many samples in the system, with the obvious advantage of employing the simple process of linear calculation for both the assessment and reference systems. In practical calculation, multiple methods should be used comprehensively, so as to provide a more rational decision-making basis for water resources management. [Copyright &y& Elsevier]

Abstract: According to the latest drilling data, the geologic survey of surrounding outcrops and the laboratory test results of rock samples, this paper studies the regional distribution, geochemical and reservoir characteristics and gas concentration of organic-rich shales to reveal the shale gas generation and potential of the Lower Cambrian Qiongzhusi Formation of the Southern Sichuan Basin. The study area features high organic content (with TOC between 0.55% and 25.7%, average of more than 2%), great net shale thickness (of 60–300 m), high brittle mineral content (over 40%), abundant micro- and nanometer-sized pores and micro-fractures, and high gas content (0.27–6.02 m3/t, average of 1.90 m3/t), which is in favor of the generation and accumulation of shale gas. The Lower Cambrian Qiongzhusi Formation is one of the most favorable strata which has frequent gas show and industrialization breakthrough during drilling, and the Weiyuan and Xunyong-Junlian areas are two most realistic and favorable targets for shale gas exploration and development. [Copyright &y& Elsevier]

Abstract: It is key issue to predict the rainfall-runoff process on the Kuronagi River before the joint sediment flushing and sluicing of Dashidaira and Unazuki dams at the downstream of the Kurobe River. In this paper, the ArcGIS system is used to produce the digital basin of the Kuronagi River, the distributed Kinematic Wave hydrological model is used to calculate the rainfall-runoff process on the Kuronagi River, and the results are in good agreement with the observations. The results show that with the progress of rainfall observation techniques and computational methods, the development of digital land information and the effective application of GIS technology, a relatively simple rainfall-runoff model can get higher precision results. [Copyright &y& Elsevier]

Abstract: In this paper, three historical biodiversity datasets (from 1940s, 1980–1999 and 2000–2004) and results from the recent inventory are used to trace the long-term changes of the mollusks in the eutrophic Lake Dianchi. Comparison of the obtained results with those of earlier investigations performed during the period of 1940s and 1980–1999 as well as 2000–2004 showed that changes have occurred in the interval. There were 31 species and 2 sub-species recorded prior to the 1940s, but the species richness decreased from a high level of 83 species and 7 sub-species to 16 species and one sub-species from 1990s to the early of 21st century in lake body. Species from the genera of Kunmingia, Fenouilia, Paraprygula, Erhaia, Assiminea, Galba, Rhombuniopsis, Unionea and Aforpareysia were not found in Dianchi basin after 2000. The species from the genera Lithoglyphopsis, Tricula, Bithynia, Semisulcospira and Corbicula were only found in the springs and upstream rivers. Anoxia and the changing of substrates and fish species composition could explain why molluscan community composition changed in eutrophic Lake Dianchi. Additionally, the different sampling methods and ignore of the specific groups in earlier studies are cause for Sphaerium and Pisidium first found in our study. This study is first time to enlarge the investigation region to the Dianchi basin. Although some endemic species disappeared in the lake body, they still distribute in the springs and upstream rivers. The springs and upstream rivers are important refuges for mollusks. [Copyright &y& Elsevier]

Abstract: The tight sandstone gas accumulation is mainly driven by overpressure arising from the gas generation in source rocks. This paper proposes a quantitative computation model for the pressurization from gas generation in source rocks, establishes a dynamic equilibrium equation and a modeling process for tight sandstone gas accumulation, and simulates the gas generation quantity and source rock overpressure history in the Hechuan-Tongnan area of the Sichuan Basin. The modeling reveals that: (1) The gas generation intensity determines the degree of pressurization from gas generation, whereas the reservoir property determines the distribution of gas reservoirs; the conventional gas reservoir is complementary with the tight sandstone gas reservoir in terms of horizontal and vertical distribution, the former is mainly distributed at the top of reservoir with porosity over 7% on local structural highs while the latter is mainly distributed at the bottom of reservoir on local structural lows near source rocks of large gas generation quantity. (2) During the uplifting process from the maximum burial depth (65 Ma) to the current burial depth, because of the pressure drop of formation water and the increase of gas-water pressure difference, the tight sandstone gas migrates farther and increases in accumulation quantity; however, the conventional gas does not migrate basically and has no increase in accumulation quantity; (3) The quantity of the tight sandstone gas in the T3x2 is 5.9 times that of the conventional gas, and the undiscovered resource is mainly tight sandstone gas distributed in northeast of Hechuan, and north and southeast of Tongnan. [Copyright &y& Elsevier]

Abstract: Natural gas exploration and discovery of hydrocarbons in the Xujiahe Formation in the Sichuan Basin are mainly concentrated in the Xu-2, 4 and 6 Members. The discovered gas reservoirs are characterized by a low filling degree, high water saturation in lower intervals, low levels of produced reserves and a limited number of gas-bearing reservoirs. The Xu-1, 3 and 5 Members are identified as source rocks. Based on the study of natural gas accumulations and several gas production wells in the Xu-1, 3 and 5 Members, this paper proposes that large scale sand bodies are developed in the Xu-1, 3 and 5 Members in the northwest, southwest and central parts of the Sichuan Basin. In each member, the favorable gas bearing area is about 5 000-11 000 km2, the reservoir rocks have good continuity with single layer extensions of up to 15-20 km. It is believed that these sand bodies have favorable conditions for gas accumulation within source kitchens to form lithologic or structural-lithologic gas reservoirs and have better accumulation potential and higher gas-bearing abundance than that of the Xu-2, 4 and 6 Members. Exploration practices have revealed that economic gas reserves may be generated. It is suggested that more efforts be made to study the gas accumulation conditions in the Xu-1, 3 and 5 Members (especially the Xu-3 and Xu-5 Members) and more exploration work be conducted in these strata. [Copyright &y& Elsevier]

Abstract: This paper examines the spatial variation of sediment yield in the Yangtze basin in China, a large basin with complex geology, climate, land-use history, and extensive sediment monitoring. 287 stations with drainage area less than 10,000km2 were used to study the scale effects of sediment yield. In order to develop scale relations for regional sediment yield, the whole study area was divided into eight sub-basins. Relation between specific sediment yield and drainage basin area was built for each sub-basin. Regional scaling relation was analyzed based on landforms, geology, lithology and land-use of each sub-basin. Three regional trends were identified in relation to the drainage area: (1) a declining trend, due to soil erosion on heavily cultivated steep land and the storage of sediment in floodplains; (2) a flat trend, due to mass movement on the upper reach and heavy agricultural disturbance on the middle and lower reaches; and (3) an increasing trend, due to downstream recruitment of sediment from land downstream where slope farming and deforestation occurred. Using these developed relations, areally adjusted sediment yield maps were created over the entire Yangtze basin. [Copyright &y& Elsevier]

Abstract: The storage potential of selected sites within the Bahaiwan Basin was evaluated, the storage capacity estimated and the selection criteria considered for the COACH project. This paper examines the two methods used during the project for calculation of the storage capacity in the Shengli oilfield complex within the Bahaiwan Basin. Both methodologies were used to quantify the potential CO2 storage capacity of the depleted oil hydrocarbon reservoirs of the Shengli oilfield complex. They can both be considered as “simple” equation models which try to capture an “approximation” of a possible storage capacity. Nevertheless, between these models several differences exist. The CSLF methodology works with replacement of oil, gas or formation water, but does not incorporate dissolution of CO2 in formation water. The EOR methodology of CUPB developed from methodology of Tanaka et al. on the other hand includes dissolution of CO2 into the formation water, but does not consider the time period needed for the dissolution. [Copyright &y& Elsevier]

Abstract: 24 new recently measured heat flow data of Bohai bay basin are reported firstly here, combining all the heat flow data available of this region, the distribution pattern of present-day heat flow and its tectonic implications are presented in this paper. Generally, the heat flow data of the Bohai bay basin is still representative and the value ranges from 45mW/m2 to 90mW/m2, although the sites of measurement are sparse spatially and not cover the whole region well. Diverse statistical analysis is applied to this heat flow dataset for calculating the mean value and the results show that the average heat flow varies between 64 and 66mW/m2 by different methods. The mean heat flow of the Bohai bay basin is 64.4±8.1mW/m2 calculated by quality weighting mean square deviation statistics with 0.5°×0.5° geodetic coordinates. The distribution pattern of heat flow of the Bohai bay basin is characterized by high in the northeast and central parts but low in the southwest area, and the value within basin is higher than those of the surrounding mountain areas; we propose that this pattern is related with the crustal differential thinning and activities of the large ultra-crustal fault zones in this region. Additionally, the present-day heat flow of the Bohai bay basin is obviously larger than those of the western areas of the North China Craton (NCC), indicating the different thermal regime and thermodynamics of lithosphere in the eastern and western parts of the NCC. As the latest heat flow compilation of the Bohai bay basin, the results presented here provide some geothermal constraints on the destruction of the North China Craton. [Copyright &y& Elsevier]

Abstract: With Sichuan Basin as focus, this paper introduces the depositional environment, geochemical and reservoir characteristics, gas concentration and prospective resource potential of three different types of shale in China: marine shale, marine-terrigenous shale and terrigenous shale. Marine shale features high organic abundance (TOC: 1.0%–5.5%), high-over maturity (R o: 2%–5%), rich accumulation of shale gas (gas concentration: 1.17–6.02 m3/t) and mainly continental shelf deposition, mainly distributed in the Paleozoic in the Yangtze area, Southern China, the Paleozoic in Northern China Platform and the Cambrian-Ordovician in Tarim Basin; Marine-terrigenous coalbed carbonaceous shale has high organic abundance (TOC: 2.6%–5.4%) and medium maturity (R o: 1.1%–2.5%); terrigenous shale in the Mesozoic and Cenozoic has high organic abundance (TOC: 0.5%–22.0%) and mid-low maturity (R o: 0.6–1.5%). The study on shale reservoirs in the Lower Paleozoic in Sichuan Basin discoveried nanometer-sized pores for the first time, and Cambrian and Silurian marine shale developed lots of micro- and nanometer-sized pores (100–200 nm), which is quite similar to the conditions in North America. Through comprehensive evaluation, it is thought that several shale gas intervals in Sichuan Basin are the practical targets for shale gas exploration and development, and that the Weiyuan-Changning area in the Mid-South of Sichuan Basin, which is characterized by high thermal evolution degree (R o: 2.0%–4.0%), high porosity (3.0%–4.8%), high gas concentration (2.82–3.28 m3/t), high brittle mineral content (40%–80%) and proper burial depth (1500–4500 m), is the core area for shale gas exploration and development, the daily gas production for Well Wei 201 is 1×104–2×104 m3. [Copyright &y& Elsevier]

Abstract: Based on discussions about the tectonic background and the relationship between faulting and petroleum accumulation in Chinese continental basins, this paper introduces the basic concepts, principles, scientific foundation, an exploration of fault controlling hydrocarbon theory as well as the differences between fault controlling hydrocarbon theory and other viewpoints about fault controlling petroleum. The geologic tectonic backgrounds of compression from three directions, continental facies basin, extension in east and compression in west, developed faults and frequent tectonic movement suggests that faulting is the main reason for various geological processes that influence petroleum generation, migration, accumulation and distribution in Chinese oil-bearing basins. The exploration concept based on fault controlling hydrocarbon theory is: take faults as the main control factor, find hydrocarbon controlling faults such as source-controlling faults and trap-controlling faults as well as seal faults, analyze their petroleum migration and accumulation potential, evaluate trap properties and determine the exploration targets. [ABSTRACT FROM AUTHOR]

The Zhada basin is a large Neogene extensional sag basin in the Tethyan Himalaya of southwestern Tibet. In this paper we examine environmental changes in the Zhada basin using sequence stratigraphy, isotope stratigraphy, and lithostratigraphy. Sequence stratigraphy reveals a long-term tectonic signal in the formation and fi lling of the Zhada basin, as well as higher-frequency cycles, which we attribute to Milankovitch forcing. The record of Milankovitch cycles in the Zhada basin implies that global climate drove lake and wetland expansion and contraction in the southern Tibetan Plateau from the Late Miocene to the Pleistocene. Sequence stratigraphy shows that the Zhada basin evolved from an overfi lled to underfi lled basin, but continued evolution was truncated by an abrupt return to fl uvial conditions. Isotope stratigraphy shows distinct drying cycles, particularly during times when the basin was underfi lled. A long-term environmental change observed in the Zhada basin involves a decrease in abundance of arboreal pollen in favor of nonarboreal pollen. The similarity between the long-term environmental changes in the Zhada basin and those observed elsewhere on and around the Tibetan Plateau suggests that those changes are due to global or regional climate change rather than solely the result of uplift of the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Abstract: On the basis of high-resolution sequence stratigraphy, this paper establishes a sequence stratigraphic frame, and predicts reservoirs by analyzing velocity field, seismic inversion, and seismic attributes. In the case study of the Jurassic Toutunhe Formation braided river delta reservoir of Shinan 21 well block, middle of the Junggar Basin, space variant velocity field inversion and reservoir prediction were carried out based on the sequence stratigraphic frame and the reservoir prediction accuracy was improved. Comparing the prediction results with the real drilling shows that, when the burial depth of bed of interest is 2 500 m, the maximum prediction error of depth is only 10 m, and the average relative prediction error is 0.16%; for appraisal wells with an average effective sandstone of 13 m, the maximum prediction error of sandstone thickness is only 5 m. The structure mapping and reservoir prediction constrained by the sequence stratigraphic frame achieved success. [Copyright &y& Elsevier]