A comparison of the modern condition with the Permian-Triassic Boundary (PTB) times was made to estimate how severe the modern biotic crisis is. About the global changes, the two periods are correlative in carbon dioxide concentration and carbon isotope negative excursion, UV strengthening, temperature increase, ocean acidification, and weathering enhancement. The following tendencies of biotic crises are also correlative: acceleration of extinction rates accompanied by parabolic curve of extinction with a turning interval representing the critical crisis; decline of the three main ecosystems: reefs, tropical rain forests and marine phytoplankton. It is also interesting to note that certain leading organism in both periods undergo accelerated evolution during the crisis. The comparison shows that the modern crisis is about at the turning point from decline to decimation. The extinction curve is now parabolic, and the extinction rate has been accelerated, but the decimation is not yet in real. This is also justified by the modern situation of the three main ecosystems. Modern biotic decline may worsen into decimation and mass extinction but may also get better and recover to ordinary evolution. Since human activities are the main cause of the deterioration of environments and organisms, mankind should be responsible and able to strive for the recovery of the crisis. For the future of mankind, Homo sapiens may become extinct, i.e., disappear without leaving descendants, or evolve into a new and more advanced species, i.e., disappear but leave descendants. For a better future, mankind should be conscious of the facing danger and act as a whole to save biodiversity and harmonize with the environments.

Late Permian reefs developed widely on shallow marine carbonate platforms in South China but disappeared far below the main mass extinction level of the latest Permian. The collapse of reef ecosystem may be related to the enhanced volcanism at the end of Late Permian. Notably, some colony corals and reef-building sponges were found to occur near the mass extinction boundary, inferring the eclipse of reef ecosystem is ahead of the disappearance of reef-building organisms, and the triggers would be present long before the main mass extinction. As the primary producers, the calcareous algae are rich in platform limestones of Late Permian and played a very important role in maintaining the shallow benthic ecosystems. The calcareous algae were found to disappear synchronously with the great reduction of foraminifers, which were ecologically associated with these algae. The extinction of Late Permian calcareous algae greatly reduced the biodiversity of primary producers in the shallow marine environment and destroyed in part the structure and the base of the shallow marine ecosystems, which in turn cause the extinction of ecologically associated metazoan. Microbialites developed on carbonate platforms immediately after the end-Permian mass extinction, representing a simple and unique microbial ecosystem. Widespread occurrence of microbialites symbolized the deterioration of marine environmental conditions and the dramatic revolution of marine ecosystems. As the new primary producers instead of the extinguished calcareous algae, cyanobacteria in the microbialites were an important base of this peculiar ecosystem and contributed greatly to the survival of the remnant faunas after the mass extinction. Widespread occurrence of microbialites in shallow marine environment is suggested to be related to the elevated level of volcanism-induced greenhouse gases and enhanced evaporation and hypersaline condition in addition to the decrease of metazoan grazing pressure. The change from calcareous algae and reef ecosystem to the cyanobacteria-dominated microbial ecosystem documented in the shallow marine sequences in South china is the ecological feedback to the deterioration of the marine environmental conditions probably induced by volcanism.

The pattern and causes of Permo/Triassic biotic crisis were mainly documented by faunal and terrestrial plant records. We reviewed herein the geomicrobiological perspective on this issue based on the reported cyanobacterial record. Two episodic cyanobacterial blooms were observed to couple with carbon isotope excursions and faunal mass extinction at Meishan section, suggestive of the presence of at least two episodic biotic crises across the Permian-Triassic boundary (PTB). The two episodes of cyanobacterial blooms, carbon isotope excursions and faunal mass extinction were, respectively, identified in several sections of the world, inferring the presence of two global changes across the PTB. Close associations among the three records (cyanobacterial bloom, shift in carbon isotope composition, and faunal extinction) were subsequently observed in three intervals in the Early Triassic, the protracted recovery period as previously thought, inferring the occurrence of more episodes of global changes. Spatiotemporal association of cyanobacterial blooms with volcanic materials in South China, and probably in South-east Asia, infers their causal relationship. Volcanism is believed to trigger the biotic crisis in several ways and to cause the close association among microbial blooms, the carbon isotope excursions and faunal mass extinctions in four intervals from the latest Permian to the Early Triassic. The major episodes of the well-known Siberian flood eruption are proposed to be responsible for the extinctions in the Early Triassic, but their synchronicity with the end-Permian extinction awaits more precise dating data to confirm. Geomicrobial records are thus suggestive of a long-term episodic biotic crisis (at least four episodes) lasting from the latest Permian to the end of the Early Triassic, induced by the global volcanic eruptions and sea level changes during Pangea formation.

Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus (B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and then, it declined. Supplemented with bacteria only, the concentration could increase on the second day. By contrast, the arsenic concentration in the treatment supplemented with sodium citrate or glucose was kept very low. These results indicate that bacterial activities promoted the release of arsenic in the sediments. Bacterial activities also influenced other geochemical parameters of the aqueous phase, such as pH, Eh, and the concentrations of dissolved Fe, Mn, and Al that are important controls on arsenic release. The removal of Fe, Mn, and Al from sediment samples was observed with the presence of B. cereus. The effects of microbial activities on Fe, Mn, and Al release were nearly the same as those on As mobilization. The pH values of the treatments inoculated with bacteria were lower than those without bacteria, still at alkaline levels. With the decrease of Eh values in treatments inoculated with bacteria, the microcosms became more reducing and are thus favorable for arsenic release.

This study presents an application of a well-calibrated integrative hydro-ecological model to examine water resources management in the upper and middle parts of the Yellow River basin, an arid and semiarid area in northwestern China. The hydro-ecological model was developed to simulate dynamic and accumulative hydrologic, ecologic, and economic variables at different spatial units. Four water management scenarios based on water use priorities, a business-as-usual scenario, an ecological scenario, an irrigation use efficiency scenario and water use scenario were designed and modeled over the period of 2011–2020 to reflect alternative water management pathways to the future. Water resource conditions were assessed in terms streamflow, actual evapotranspiration, soil water, groundwater yield, overall water yield, and derived indicator of drought index. Unit crop yield was to assess ecological production, and monetary values of crop productivity and water productivity were used to assess economic output. Scenario analysis results suggested that water stress would continue in the study region under both current water use patterns and ecological scenarios of river flow being fully satisfied. Water use scenarios would result in decreased water availability and ecosystem degradation in the long run. Improving irrigation use efficiency would be the most efficient approach in securing long-term water and food supply. The simulation results from this study provided useful information for evaluating long-term water resources management strategies, and will contribute to the knowledge of interdisciplinary modeling for water resources management in the study region.

A stratigraphical unit was proposed before as the “anthropocene” over the Holocene to characterize the anthropogenic activities. We argue here for the great significance of that proposal. The human-induced geological processes, including anthropogenic weathering, denudation, transportation, and accumulation, are getting more and more important in modern environments. These processes are intensive, rapid, and extensive and, at some cases, even exceed the natural geological process in intensity. The anthropogenic geological processes, which are definitely distinctive from the natural processes that occurred before in the geological history, have both positive and negative effects on the Earth surface system. Adding a chronostratigraphical unit favors the investigation of anthropogenic activities, which concerns both natural and social science. A flooding sediment profile with some anthropogenic fingerprints is clearly identifiable at the top of the Holocene sediments, enabling the three subdivisions of the whole Quaternary sediments in the middle reaches of Yellow River. It is thus necessary to add the chronostratigraphic unit of the “anthropocene” over the Holocene.

Reef-associated beachrocks from Rameswaram and Keelakkarai group of islands (Holocene) were studied to assess the depositional environment and faunal assemblages. The samples were collected from marine terraces and reef platforms. Granulometrically, they are coarse to medium grained, moderately to very well sorted and fine to very fine skewed in character. The fine-skewed nature of the sediments suggests the prevalence of the environmental condition of low energy. The microfaunas associated in beachrock reflect the reefal environment of deposition. Bivariant plots show that the sediments were predominantly deposited under beach environment. The C-M pattern indicates that the sediments are deposited by rolling and graded suspension. The Visher diagram of the study area samples clearly shows the presence of a dominant single saltation, lack of population and no surface creep population. The low diversity and fair preservation of faunas reflect the transgressive phase and the shallow marine environmental condition. The commonly preserved species such as Quinqueloculina sp. and Triloculina sp. indicate the low-energy environmental conditions.

Landslide hazard is one of the major environmental hazards in geomorphic studies in mountainous areas. For helping the planners in selection of suitable locations to implement development projects, a landslide hazard zonation map has been produced for the Golmakan Watershed as part of Binaloud northern hillsides (northeast of Iran). For this purpose, after preparation of a landslide inventory of the study area, some 15 major parameters were examined for integrated analysis of landslide hazard in the region. The analyses of parameters were done by geo-referencing and lateral model making, satellite imaging of the study area, and spatial analyses by using geographical information system (GIS). The produced factor maps were weighted with analytic hierarchy process (AHP) method and then classified. The study area was classified into four classes of relative landslide hazards: negligible, low, moderate, and high. The final produced map for landslide hazard zonation in Golmakan Watershed revealed that: 1) the parameters of land slope and geologic formation have strong correlation (R² = 0.79 and 0.83, respectively) with the dependent variable landslide hazard (p<0.05). 2) About 18.8% of the study area has low and negligible hazards to future landslides, while 81.2% of the land area of Golmakan Watershed falls into the high and moderate categories.

The rift lacustrine basin is characterized by a variety of sediment sources, multiple sedimentary systems, and complex filling, and its sediment supply is largely influenced by climate change. The sedimentary filling and its controlling factors have always been the focuses in basin analysis. This paper first reviews the recent advancement in rift lacustrine basin investigations with an emphasis on the structural controlling on lacustrine configuration, accommodation, and directly structural controlling on basin filling characteristics. The paleogeography resulted from spatial configuration of structural styles, and the sediment supplies synergically determine the types and distribution of depositional systems. The sedimentary filling characteristics of the fourth-order sequence record the evolution of cyclic climate. The case studies are followed on the basis of the sedimentary filling analysis in typical Nanpu sag and Qikou sag in Huanghua rift lacustrine basins in East China. The comparison of sedimentary fillings within sequence stratigraphic frameworks in the two sags shows the different episodic tectonic activities, and their resulting structural frameworks mainly controlled the different sequence stratigraphic developments, their internal architectures, and depositional systems distribution. Qikou sag has more complicate sedimentary filling controlled by episodic activities of boundary and intrabasin secondary faults and sediment supplies. Based on the studies from our own and the formers, we suggest that the sedimentary filling study in rift lacustrine basin should be under the guidance of sequence stratigraphy, use high resolution seismic and all available geological data, combine tectonic evolution and structural styles to build the sequence framework, and then reconstruct the paleo-structure and paleogeography. Studying the relationship between paleogeography and paleo-sedimentary filling can favor the understanding of the characteristics of sedimentary systems development and help in predicting the potential reservoir distribution. The result of this work can be applied directly to the exploration of energy resources.

Inter-city relation, though of great importance in the context of an increasingly globalized society, has rarely been addressed quantitatively compared to the structure and function within the city due to the difficulties when acquiring and disposing the relational data between cities. In this study, we presented a conceptual model for quantifying the inter-city relation in ecological and economic contexts based on emergy analysis, which is recognized as a promising approach to evaluating various city flows on a common basis. Emergy diagram of an urban system was constructed explicitly, and the related relational data indices were selected from the ecological and economic aspects, respectively, to form two indicator systems for emergy analysis, incorporating the transfer of labor, material and currency, etc. After that, the inter-city interaction intensity and sustainability were formulated to identify the sustainable conditions between the two cities, and hopefully, it could reveal potential complementarity or competition between the cities over time. With the introduction of emergy analysis, this study may provide a new way to quantify city interaction.

Low-carbon economy is becoming a new approach to optimize economic development, ensuring energy security and coping with climate change. As one of the important emission sources of greenhouse gases (GHG), the industrial sector should be prioritized in the development of low-carbon economy. In this study, the carbon emission from industrial energy use of Chongqing is accounted. On basis of industrial carbon emission (ICE) accounting, main factors responsible for industrial CO₂ emission are identified and quantitatively analyzed using the Log-Mean Divisia Index method. The factors influenc- ing ICE include energy mix, energy intensity, industrial structure and industrial output. It is found that the industrial output is the main driving force of ICE. The energy structure performs as a negative factor in carbon emission growth. By means of decomposing the influenc- ing factors, several policy proposals were suggested for policy makers to build a low carbon city.