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As the most widely distributed river form in the world, meandering river is of great significance for stabilizing the physical structure of the river and maintaining ecosystem. To quantitatively study the positive effects of meandering rivers, the Chishui River, a natural tributary of the Yangtze River in Southwest China, is selected as the research area, and two typical river sections with different meandering degrees are selected as the research objects.Based on the field survey data, the local endemic fishWith the change in discharge, a positive correlation is observed between the maximum velocity and depth of the meandering river and the discharge, whereas the WUA and hydraulic unit index of the meandering river have relatively small changes. Under low discharge, the distribution of pool-riffle sequences can be seen in the meandering reach, which is essential to improve the ecological suitability and stability of the river.This study provides scientific sustentation for river restoration and fish conservation.

In the process of urban agglomeration, water-food security can be deemed as a key to support urban development and human living, but which can be challenged by expanded population growth, accelerated industrialization, unbalance regional economic development and diversity of weather (due to climate changes). In this study, a water resources allocation and food production (WF) optimization is developed for regional sustainability under multiple uncertainties. A hybrid two-stage fuzzy programming with Laplace criterion (TSFL) is proposed into a WF optimization to handle hybrid indeterminacies, which can increase the robustness of decision-making. The WF optimization with proposed TSFL method can be applied to a practical case of Beijing-Tianjin-Hebei (BTH) region. The obtained results associated with water deficits, optimal water allocations, inadequate capacities of food production, rational irrigation schedules, sound livestock scales, optimized agricultural possessing layouts and system benefits under various population-economy regulation scenarios can be obtained. The results can reflect the tradeoff between economic development and water-food safety; meanwhile, they can display risk violation of WF plan under various credibility levels and Laplace criterions (based on TSFL method). All above results can facilitate to produce an optimized water-food plan to support the synergetic development of BTH region in a robust manner.

Herein, a kind of Fe3O4@C@Ru hybrid nanocomposites was successfully synthesized by a three-step process. The as-prepared products were characterized by X-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, UV–visible diffuse reflectance spectrometry and photoluminescence emission spectrometry. The Ru nanoparticles loaded on the surface of carbon shell on Fe3O4@C nanospheres were nearly spherical with an average diameter of less than 5 nm. The photodegradation of methylene blue (MB) was carried out under the irradiation of simulated visible light to investigate the catalytic activity of the introduced nanomaterial. The results showed that the catalytic activity of Fe3O4@C@Ru nanocomposites in the MB photodegradation was higher than that of Fe3O4 nanospheres or of Fe3O4@C nanospheres, as they could degrade 92.70% of the dye in 140 min of simulated sunlight irradiation without any other oxidant or reductant. The photodegradation reaction was first-order with the rate constant of 0.0176 min−1 at room temperature. The degradation rate of Fe3O4@C@Ru nanocomposites decreased very slightly after five cycles. Furthermore, they could be easily separated and recycled by using an external magnet. It indicated that the magnetically recoverable Fe3O4@C@Ru nanocomposites had a very broad application prospect in the field of environmental protection.

The method of random forest was used to classify the heavy mineral assemblages of 2 418 Jurassic samples in the southern Junggar Basin, and determine the distribution of the heavy mineral assemblages from the same provenance systems. Based on the analysis of heavy minerals assemblages, ZTR index, sedimentary characteristics, U-Pb zircon ages, whole-rock geochemical and paleocurrent direction analysis, the study reveals that five important provenances were providing sediments to the southern Junggar Basin in the Jurassic period: The North Tianshan (NTS), Central Tianshan (CTS), Bogda Mountains, Zhayier Mountains and Kalamaili Mountains. During the Early Jurassic, NTS-CTS, Kalamaili Mountains and Zhayier Mountains are primary provenances, Bogda Mountains started to uplift and supply clastic materials in the Middle Jurassic. There are three sedimentary area in the Jurassic of southern Junggar Basin: the western part, the central part and the eastern part. In the western part, the clastic materials of the Early Jurassic was mainly from NTS blocks and Zhayier Mountains, and the sediments were dominantly derived from the Zhayier Mountains during the Middle–Late Jurassic. In the central part, the main provenance of the Early Jurassic switched from NTS to CTS. In the Xishanyao Formation, the main source went back to NTS again. The NTS was the primary provenance during the sedimentary periods of Toutunhe Formation and Qigu Formation. In the eastern part, the contribution of CTS and Kalamaili Mountains were considered as major provenances in the Early Jurassic−Xishanyao Formation, small proportion of sediments were from NTS. The Bogda mountains uplifted and started to provide sediments to the Junggar Basin in the sedimentary period of Xishanyao Formation, and became the major source during the Toutunhe Formation period, with small amount of sediments from CTS. The provenance from CTS was hindered during the sedimentary period of Qigu Formation owing to the uplifting of the Bogda mountains, and the sediments were mainly from the Bogda mountains and NTS. Key words: southern Junggar Basin, Jurassic, source to sink system, provenance, heavy minerals assemblages, random forest

Non-point source (NPS) pollution simulation in control units can identify critical pollution source areas and make Best Management Practices (BMPs) more effective for the responsible parties. In this study, the control unit division method is introduced, and the spatial and temporal distribution characteristics of NPS pollution in the Guishui River Basin of Northern China are analyzed using the Soil Water Assessment Tool (SWAT) model. In addition, five BMP scenarios were designed for environmental and cost-benefit analyses. The results show that the loss of total nitrogen (TN) and total phosphorus (TP) is concentrated in the rainy season, and the loss of TN and TP is mainly distributed in the middle and lower reaches of the main stream of the Guishui River. This area accounts for 22.34% of the basin area. The vegetated filter strips (VFS) scenario had the best environmental benefits with average TN and TP reduction efficiencies of 63.4% and 62.6%, respectively. The Grassed Waterway was the most cost-effective scenario measure, cost-benefit (CE) values of TN and TP were 1798.13 g/&euro, and 601.56 g/&euro, Generally, research on NPS pollution using control units can more clearly identify the critical source areas of pollution than other methods, and provides technical support for watershed management decision makers.

Diversion-type hydropower stations play an important role in energy and power generation. However, they also substantially alter the natural hydrological situation of the river section through the formation of dewatered river sections between water-retaining structures and the power plant, which have a series of associated effects on the habitats of living organisms, thereby affecting the health of the water ecosystem. Therefore, it is of practical importance to study and analyse the ecological flow of the dewatered river section. Maintaining a certain ecological flow is considered to be an effective solution, but at the same time it can also affect the socio-economic benefits of hydropower plant operation. To reconcile the relationship between the two, this paper proposes a new method for calculating ecological flow in dewatered river sections, an optimal method for the phased habitat demand (OMPHD) of key species, in which key species are selected and explored in stages, giving priority to the key elements of each stage. Organisms have different life stages and these stages require a series of different habitats; habitats with a high geomorphological diversity have the best habitat suitability. In this study, basic data were obtained through inductive sorting, data collection, and a field survey of the Houxi River (a secondary tributary of the Yangtze River) and the endemic fish Schizothorax prenanti was selected as a key species. The hydrodynamic and fish effective habitats were calculated and simulated using relevant hydraulic formulae; a geomorphological diversity index (GDI) was introduced, and the target fish habitat area and geomorphological units, such as water depth and flow velocity, were analysed comprehensively to determine the ecological flow in the downstream dehydrated river section of the diverted small hydropower station. Flows of 17.5 m3/s and 5 m3/s were established during the spawning and non-spawning periods, respectively. This information provides a basis for the ecological restoration of river sections.

The path of economic reform with Chinese characteristics consists of not only the transition from agriculture to industry but also the transformation from a planned economy to a market economy. The reform of forest property institution is an important part of this dual transformation.

In this study, a wetland reallocation (WR) plan based on water-indicator is designed to confront various ecological crisis and flood risks on Yonding River Floodplain, China, where converting farmland to wetland (CFW) and water diversion (WD) can be considered to balance the tradeoff between manual land utilization and wetland conservation. A risk-simulation based two-stage stochastic fuzzy (RTF) method is developed for handling multiple uncertainties in a WR issue, which cannot only map various risks (including water shortage, soil loss, flood and pollution) through Geographic Information System (GIS), but also deal with objective / subjective uncertainties in a two-stage context. Through risk-simulation, numbers of risk maps have been obtained based on various WD scenarios, which displayed that ecological risk would be the lowest when water diversion reached 200 x 106m3, while flooding risk would increase. Meanwhile, based on WR optimization, natural-artificial wetland reallocations would decrease ecological loss about US$ 0.92 x 106 at highest. Moreover, the optimized land utilizations under various CFW and WD scenarios have been obtained. This study is useful for policymakers of floodplain to adjust current land utilization strategies with consideration of artificial regulations in a sustainable manner.

The trophic state index (TSI) and trophic level index (TLI) are commonly used methods for evaluating the eutrophication state of lakes and reservoirs. However, they are unable to overcome uncertainties such as calculation errors and spatial heterogeneity of evaluation indicators. To comprehensively evaluate the eutrophication state of a region, we introduce a probability density function and propose the stochastic trophic level index model (STLI). The probability density function of each trophic level is derived through the principle of maximum entropy, and membership vector F (F1, F2, F3, F4, F5) for each trophic level is established to quantify the risk of regional eutrophication. We utilized STLI to evaluate the eutrophication status of Songhua Lake, China, and determined that the method can be used for uncertainty and risk assessment. Our results show that the Jiaohe River backwater area has the highest eutrophication level (light eutropher), with a 0.12 probability of further deterioration to middle eutropher. The eutrophication status of the Main Scenic Area of the Songhua Lake Scenic Resort was shown to be mesotropher, with 0.26 and 0.08 probabilities of further deterioration to light eutropher and middle eutropher, respectively. Finally, the eutrophication status of the Songhua River Three Lakes Reserve Experimental Area was shown to be mesotropher, with a 0.24 probability of further deterioration to light eutropher. Overall, the Songhua River Three Lakes Reserve Experimental Area is the most promising for the lowest level of eutrophication. We recommend that the management department take effective targeted measures against the Jiaohe River backwater area first. The probability density and membership vector of STLI can effectively solve the uncertainties presented by traditional methods for evaluating regional eutrophication status.

The static calculation of ecological service value is the main basis for determining the value of water ecological service function in a river basin. The reasonable ecological service value calculation is the premise to determine the limit value of ecological compensation standard. Based on the types and calculation methods of watershed water ecological service value, on the basis of comprehensive comparison of the applicable scope and reliability of calculation results of various calculation methods, combined with the landscape characteristics of the study area, the ecological value assessment method of watershed forest system was given. Taking the Shanxi reservoir area in the Feiyun River basin as an example, the ecological value of the four service functions of supply, regulation, culture and support services was calculated, and the total ecological service value of the reservoir area was determined to be 7.062 billion yuan/a. The ecological services value of the forest in Shanxi reservoir area in terms of water retention, environmental purification, and reduction of soil waste requires cost inputs from the people upstream of the reservoir area. In order to achieve the overall equitable, coordinated and sustainable development of the basin, the beneficiaries of the downstream ecological service value of the basin should compensate the upstream 1.498 billion yuan/a, which is about 21% of the ecological service value.

According to the characteristics of groundwater and the requirements of groundwater protection, the ecological compensation standard of groundwater is discussed. Based on the study of groundwater characteristics at home and abroad, combined with the existing ecological compensation research, the ecological compensation standard of groundwater is discussed based on fair water use. Based on the determination of water distribution, pollutant discharge permission and water use income, and based on the social equity mechanism and the cooperative game, the upper limit of agricultural water demand in Cheng’an County under the current development mode is calculated to be 400 million m3, the lower limit to be 34 million m3, and the average to be 32 million m3. The people’s Government of Cheng‘an county shall compensate the farmers for their water saving. The compensation standard is based on the economic benefits of agricultural water use. The total compensation amount is 236 million yuan. The compensation standard is 6720 ¥/ha according to the accounting of 35 thousand ha farmland area. The calculation results of the groundwater ecological compensation model are reasonable and easy to implement, which provides a theoretical basis for the implementation of groundwater ecological compensation in Beijing Tianjin Hebei region.

Hydrological condition is of great significance to river ecosystems. Alteration in hydrological conditions can directly or indirectly affect ecosystems, causing changes in river ecological health, species habitats, and water-sand relationships. In this paper, the Index of Hydrologic Alteration-Range of Variability Approach method (IHA-RVA) method was used to evaluate the alteration of hydrological condition in Yuanshui river from 1959 to 2010 under the combined action of climate change and human activities. We have reached the conclusion that the current hydrological condition alteration in the Yuanshui River Basin is moderately changing; Regardless of the water diversion, the contribution rates of natural runoff changes and cascade reservoir operations to hydrological change is 58% and 42% respectively, which were quantified by the multi-series contribution rate segmentation method. It can be seen that the natural runoff change was the leading cause of the change of the overall hydrological situation, and the operation of the cascade reservoir was an important cause of the hydrological situation change.

Considering the differences of fault characteristics in the process of fault diagnosis, the paper proposes power grid fault diagnosis method based on integrated fault degree. This method firstly, the wavelet transform is used for electric parameters amplitude and energy characteristics of the information analysis, extract the key indicators; then, according to the amount of the digital information from remote communication system, calculating coding similarity by using fault coding theory; finally, determine integrated fault degree by using the improved D-S evidence theory and finding finally fault line by improved k-means clustering method. The simulation results show that the proposed scheme improves the accuracy of diagnosis, and has good application prospects.

In order to effectively solve the problem of over-exploitation of groundwater in Hebei Province and achieve the balance of groundwater recovery, Hebei Province began to conduct pilot research on comprehensive management of groundwater over-exploitation in 2014. Taking Linyi County in the south of Hebei Province as an example, this paper studies the effect of pressure extraction on groundwater over-exploitation comprehensive treatment of water conservancy projects in 2015, analyzes and summarizes the experience, deficiencies and improvement measures of groundwater pressure mining work, in order to follow the groundwater pressure mining work. Provide guidance for reference. The results show that: Linyi County’s 2015 water conservancy project achieved a pressure recovery capacity of 4.02 million m3, and the water-saving pressure mining effect was remarkable. Among them, the sprinkler irrigation water-saving facilities have an average water saving capacity of 105 m3/mu, and the water-saving efficiency is obvious. In addition, the next stage of work should pay attention to the study of water-saving measures based on water-saving management and regional agriculture represented by crop planting structure adjustment. Irrigation pattern, implementation of field engineering work, to form a regional scale, intensive water-saving irrigation pattern, promote the promotion and application of groundwater over-exploitation comprehensive treatment in Hebei Province.

Based on information of ecology, environment and socio-economics over the Hutuo River Basin from 2000, we analyzed factors influencing ecosystem health, used entropy method to develop index weighting scheme of ecosystem health assessment, and evaluated ecosystem health in this basin. Finally, based on the ecological regionalization, some measures for different ecological function sub-region were advanced to protect the basin ecology and recover basin ecosystem. Evaluation results are consistent with the actual situation, indicating that our method is suitable for ecosystem health assessment in the Hutuo River Basin. The resulting data provide scientific basis for integrative ecosystem management of the Hutuo River Basin, so as to provide theoretical and technical support to promote watershed ecological protection and restoration.

Much uncertainty exists in the phosphorus (P) cycle in the marshes of the intertidal zone. This study explored the P cycling in the two Suaeda salsa marshes [middle S. salsa marsh (MSM) and low S. salsa marsh (LSM)] of the Yellow River estuary during April 2008 to November 2009. Results showed seasonal fluctuations and vertical distributions of P in different S. salsa marsh soils, and variations in P content in different parts of plants due to water and salinity status. The N/P ratios of the different S. salsa were 9.87 +/- A 1.23 and 15.73 +/- A 1.77, respectively, indicating that plant growth in MSM was limited by N, while that in LSM was limited by both N and P. The S. salsa litter in MSM released P to the environment throughout the year, while that in LSM immobilized P from the environment at all times. The P absorption coefficients of S. salsa in MSM and LSM were very low (0.0010 and 0.0001, respectively), while the biological cycle coefficients were high (0.739 and 0.812, respectively). The P turnovers among compartments of MSM and LSM showed that the uptake amounts of roots were 0.4275 and 0.0469 g m(-2) year(-1) and the values of aboveground parts were 1.1702 and 0.1833 g m(-2) year(-1), the re-translocation quantities from aboveground parts to roots were 0.8544 and 0.1452 g m(-2) year(-1), the translocation amounts from roots to soil were 0.0137 and 0.0012 g m(-2) year(-1), the translocation quantities from aboveground living bodies to litter were 0.3157 and 0.0381 g m(-2) year(-1), and the annual return quantities from litter to soil were less than 0.0626 and -0.0728 g m(-2) year(-1) (minus represented immobilization), respectively. P was an important limiting factor in S. salsa marshes, especially in LSM. S. salsa was seemingly well adapted to the low-nutrient condition and the vulnerable habitat, and the nutrient enrichment due to the import of N and P from the Yellow River estuary would be a potential threat to the S. salsa marshes.