No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Analysis of present situation of water resources and countermeasures for sustainable development in China
... As the aggravation of global warming, the ecological area of grain farmland worsens deeply such as the lack of irrigation water in grain, the pollution in water getting serious, more and more droughts in different areas and the continuous reduction of production. In present, the areas in droughts in our country reach 0.5 billion mu, is 3 times of that in 50's in last century [8][9]. There are huge pressure in water for irrigation and fighting the droughts in terms of the grain production system of weak foundation. ...
... At present, the amount of the available surface water and the groundwater freshwater is totally to 11,000 billion cubic meters, including groundwater resource for 2000 billion cubic meters. The per-capita water resource is only 800 cubic meters [9][10]. 70-90% of our country annual precipitation concentrates in June to September. ...
... Currently, there are 440khm 2 woodland being transferred to non-woodland in our country every year, 1654khm 2 forestland transfer to non-forest land, shrubbery and open forest. The degeneration of lawn is about 2 million hectare, the area of degeneration reaches up to 85 % [9][10]. The over destroy of the native vegetation lead to the declining in natural water storage and regulation ability noticeably. ...
... Water is essential for crop production because plants need water for growth and tissue expansion (Morison et al. 2008;Wilkinson and Davies 2010). However, China's water availability per capita is only one quarter of the world average (Wang et al. 2008b;Du et al. 2010). The outlook for water shortage is especially dire on the North China Plain, one of the main grain production areas in China (Kendy et al. 2003;Deng et al. 2006;Wang et al. 2008a;Hu et al. 2010b;Fan et al. 2012). ...
... These are likely to be due to the effect of nutrient placement on root growth (Fig. 5) and hence access to water (Fig. 7). Our study suggests that in regions which are likely to be water-limited Deng et al. 2006;Wang et al. 2008b;Fan et al. 2012), high rates of fertiliser application which over time result in deep nutrient-rich profiles, are likely to provide the least effective environment for water uptake by roots (Mi et al. 2010;Zhang et al. 2012). ...
Background and aimsWe were interested to determine the effects of horizontal stratification of nutrient-rich zones within different layers of the soil profile in water-limited environments on root growth and crop yield. This is practically relevant to large areas of China, many of which have been over-fertilized.Methods
We used soil-filled rhizotrons 1.4 m deep to grow wheat. Three different nutrient-rich horizontal stratifications were used at depths of 0–40, 60–100 and 0–140 cm. The soil was packed to a density of 1.5 g cm−3, at a matric potential of −10 kPa. The wheat was grown until it was at terminal drought. Low soil hydraulic conductance preserved the horizontal nutrient stratification.ResultsPlants grown in rhizotrons with a surface layer (0–40 cm) of nutrients had the greatest root growth, water uptake and yield. When nutrients were uniformly distributed throughout the rhizotron (0–140 cm), root growth was restricted to the surface layer. Measurements of soil moisture indicate this was because the roots became impeded.Conclusions
Nutrient enrichment of the surface layer was the most effective at promoting deep roots, higher water uptake and yield under water-limited conditions. Heterogeneous nutrient distribution can modify root growth and water uptake.
... China has abundant freshwater resources in terms of total availability, ranked as the world's sixth largest, however per capita volume is almost 2,000 m 3 p.a. which amounts to one-fourth of the global average. 1,2 China's water resources are unevenly distributed: northern China has only about 20% of the total water resources in China, but is supporting more than half the total population. Furthermore, widespread pollution has resulted in 75% of lakes and rivers and 50% of groundwater supplies becoming contaminated. ...
... Furthermore, widespread pollution has resulted in 75% of lakes and rivers and 50% of groundwater supplies becoming contaminated. 2 This situation has caused concern for the water abundant regions of China (e.g., South China) for the lack of available water even for agricultural use. To combat this, the Chinese Government has introduced a series of legislative instruments to conserve water resources and has invested substantially in constructing wastewater treatment plants servicing almost all large cities. 3 However, the level of aquatic pollution has not improved but has, in fact, worsened. ...
China is a country with significant but unevenly distributed water resources. The water stressed North stays in contrast to the water abundant and polluted South defining China's current water environment. In this paper we use the latest available datasets and adopt structural decomposition analysis for the years 1992 to 2007 to investigate the driving forces behind the emerging water crisis in China. We employ four water indicators in China, i.e. freshwater consumption, discharge of COD (Chemical Oxygen Demand) in effluent water, cumulative COD and dilution water requirements for cumulative pollution, to investigate the driving forces behind the emerging crisis. The paper finds water intensity improvements can effectively offset annual freshwater consumption and COD discharge driven by per capita GDP growth, but that it had failed to eliminate cumulative pollution in water bodies. Between 1992 and 2007, 225 million tonnes of COD accumulated in Chinese water bodies, which would require 3.2 ~ 8.5 trillion m3 freshwater, depending on the water quality of the recipient water bodies to dilute pollution to a minimum re-usable standard. Cumulative water pollution is a key driver to pollution induced water scarcity across China. In addition, urban household consumption, export of goods and services, and infrastructure investment are the main factors contributing to accumulated water pollution since 2000.
... Although this water resource is large in absolute value, ranking sixth in the world, the per capita water resource is only 25% of the world average (Wang et al., 2008). China is listed as one of the 13 countries which are shortest of water. ...
... Of all China's environmental woes, the biggest threat to livelihoods and food security may be looming water shortages (Li, 2010, Peng, 2011 Although this water resource is large in absolute value, ranking sixth in the world, the per capita water resource is only 25% of the world average (Wang et al., 2008). China is listed as one of the 13 countries which are shortest of water. ...
In recent years, agricultural growth in China has accelerated remarkably, but most of this growth has been driven by increased yield per unit area rather than by expansion of the cultivated area. Looking towards 2030, to meet the demand for grain and to feed a growing population on the available arable land, it is suggested that annual crop production should be increased to around 580 Mt and that yield should increase by at least 2% annually. Crop production will become more difficult with climate change, resource scarcity (e.g. land, water, energy, and nutrients) and environmental degradation (e.g. declining soil quality, increased greenhouse gas emissions, and surface water eutrophication). To pursue the fastest and most practical route to improved yield, the near-term strategy is application and extension of existing agricultural technologies. This would lead to substantial improvement in crop and soil management practices, which are currently suboptimal. Two pivotal components are required if we are to follow new trajectories. First, the disciplines of soil management and agronomy need to be given increased emphasis in research and teaching, as part of a grand food security challenge. Second, continued genetic improvement in crop varieties will be vital. However, our view is that the biggest gains from improved technology will come most immediately from combinations of improved crops and improved agronomical practices. The objectives of this paper are to summarize the historical trend of crop production in China and to examine the main constraints to the further increase of crop productivity. The paper provides a perspective on the challenge faced by science and technology in agriculture which must be met both in terms of increased crop productivity but also in increased resource use efficiency and the protection of environmental quality.
... Presently, the scarcity of water resources is increasingly severe and agricultural water accounts for a significant proportion of the water resources in China [1][2][3]. Therefore, water-saving irrigation technology is extensively employed [4,5]. However, due to the high sediment content in diversion irrigation water, blockage and wear [6][7][8][9][10] are common issues faced by micro-irrigation system equipment. ...
To examine the influence of plate shapes and quantities on the sedimentation performance of a linear sedimentation tank, experimental research was conducted using tanks featuring five distinct plate structures. The findings reveal that when subjected to an inflow rate ranging from 60 to 100 m3/h and with median particle sizes of 571.110 μm and 162.254 μm, for sediment particles in water containing sediment, the flow field distribution in the arc-plate sedimentation tank facilitates the effective settling of sediment particles. Comparative analyses indicate that incorporating eight arc plates in the sedimentation tank, as opposed to an equal number of inclined plates, results in a notable reduction in surface sediment concentration within the plate region, ranging from approximately 8 to 34%. Additionally, the mass percentage of sediment particles with sizes less than 0.05 mm at the tank bottom increases by about 5–7%. Moreover, in comparison to tanks lacking plates and those equipped with four arc plates, the surface sediment concentration experiences a significant decrease, ranging from approximately 33% to 60% and 18% to 44%, respectively. Concurrently, the mass percentage of sediment particles with sizes less than 0.05 mm shows an increase of about 25–32% and 10–20%. The arc-plate sedimentation tank exhibits superior sedimentation efficiency with an inflow rate of 60 m3/h and the installation of eight arc plates. Additionally, the study concludes that increasing the number of plates and reducing the inflow rate enhance sediment settling. The research findings offer valuable insights for the design and advancement of sedimentation tanks.
... The traditional transport methods on which material transport is based are unable to meet the growing demand for transport. At present, the commonly used transportation methods have problems [1][2][3] such as high energy consumption and high pollution. The emergence of the hydraulic transport technology of the barrel-loading pipeline [4,5] provides a new direction for the transport of materials. ...
It is of great significance to explore the flow velocity characteristics of piped cars when they are started under different loads. In this paper, the flow velocity characteristics of the water flow around a piped car when it is started in the straight pipe section are studied through physical experiments. The masses of the piped cars are 1.5 kg, 1.9 kg, and 2.3 kg, respectively. The results show that, with the increase in the load of the pipeline car, the axial flow velocity in the front section increases, the absolute values of radial flow velocity and circumferential flow velocity increase, and the gradient of flow velocity increases. The positive radial flow velocity and negative circumferential flow velocity regions increase, and the distribution of positive and negative radial flow velocities and circumferential flow velocities is obvious. The gradients of axial, radial, and circumferential flow velocities in the annular section all increase, and the contour spacing becomes smaller and more densely distributed. The absolute values of the radial and circumferential flow velocities increase. The regional demarcation of axial flow velocity in the rear section is more obvious, and the average value of axial flow velocity in the high-flow-velocity area behind the vehicle increases. Additionally, the gradient of flow velocity increases. The absolute values of radial velocity and circumferential velocity increase, the gradient of velocity increases, and the velocity distribution is obviously regional. This study supplements and improves the theoretical study of a piped car when it is started and has certain reference value for the research and application of the hydraulic transport technology of the barrel-loading pipeline.
... 3 China accounts for 20% of the world's population and 7% of the world's freshwater resources, resulting in a per capita water resource possession equivalent to only one-fourth of the world average. 4 The disparity in the spatial distribution of water resources and the human population exacerbates the local water scarcity. 5 In addition to insufficient water quantity, pollution exacerbates a region's water scarcity by rendering water unsuitable for different uses and reducing freshwater availability. ...
... Although northwestern China (NWC) accounts for 17% of the land area of China, the total annual water storage is only approximately 3% of the total water storage in China . Coupled with serious wastage and pollution of water due to human activities, water shortages have become one of the most important factors restricting the economic development of NWC (Deng et al. 2002;Wang et al. 2008). Studying the distribution and variation of regional water storage can provide scientific reference for the development and utilization of water resources (Li et al., 2019a;,b, 2022Yang et al., 2022). ...
... China's total water resources are 2.8 trillion m 3 , accounting for 6% of the global water resources, ranking fourth in the world. However, the per capita water resources are only 2300 m 3 , which is only a quarter of the world average level, ranking 110th in the world, and listed by the United Nations as one of the 13 countries with the poorest per capita water resources in the world [1,2]. With the rapid development of China's economy and society, the demand for water in various industries has increased significantly. ...
Optimal allocation of water resources is an effective way to solve the supply and demand contradiction between water resources and water users. Recently, the rapid economic and social development of Handan has significantly increased water demand in various industries. Superimposed on the reduction of incoming water in upstream rivers and the limitation of the total amount of groundwater extraction, a large number of water sources such as South-to-North Water Diversion, Yellow River Water Diversion, and Weihe River Water Diversion are used to replace domestic and industrial water. In support of Handan’s dynamic supply and demand of water resources, the transported water was generalized as a virtual reservoir and introduced into the GWAS model. The allocation results show that the total water shortage volume and rate of Handan was 527.60 × 106 m3 and 17.92% in 2025 at a P = 50%, respectively. Water shortage was concentrated in the primary industry. The allocation results align with actual water use conditions. The allocation of transported water is more reasonable than the conventional allocation scheme, and the domestic water is completely replaced by the South-to-North Water Diversion in the eastern plain of Handan. These research results can provide a technical reference for water resource allocation in Handan.
... The numerous conveyance channels in the north of China play an important role in improving the regulation level of water resources and the water supply (Lu and Chen, 2015;Wang et al., 2008) in the frozen soil region. However, the conveyance channels are located in the seasonally frozen soil region; because of the long freezing period and cold temperature in winter, the freeze-thaw cycle of the foundation soil often leads to frost-heaving damage of the lining structure, reducing the service life and increasing maintenance costs of water diversion projects (Liu et al., 2011). ...
... Due to its large population and rapid economic development, China is facing a severe water shortage problem. The country's per capita water resource is only one-fourth of the world average level [4]. Therefore, an accurate estimation of ET 0 in this region would provide a scientific basis for rationally allocating water resources and minimizing the imbalance between water supply and demand [5]. ...
Reference Crop evapotranspiration (ET0) datasets based on reanalysis products can make up for the time discontinuity and the spatial insufficiency of surface meteorological platform data, which is of great significance for water resources planning and irrigation system formulation. However, a rigorous evaluation must be conducted to verify if reanalysis products have application values. This study first evaluated the ability of the second-generation China Meteorological Administration Land Data Assimilation System (CLDAS) dataset for officially estimating ET0 (the local meteorological station data is used as the reference dataset). The results suggest that the temperature data of CLDAS have high accuracy in all regions except the Qinghai Tibet Plateau (QTP) region. In contrast, the global solar radiation data accuracy is fair, and the relative humidity and wind speed data quality are poor. The overall accuracy of ET0 is acceptable other than QTP, but there are also less than 15% (103) of stations with significant errors. In terms of seasons, the error is largest in summer and smallest in winter. Additionally, there are inter-annual differences in the ET0 of this data set. Overall, the CLDAS dataset is expected to have good applicability in the Inner Mongolia Grassland area for estimating ET0, Northeast Taiwan, the Semi Northern Temperate zone, the Humid and Semi Humid warm Temperate zone, and the subtropical region. However, there are certain risks in other regions. In addition, of all seasons, summer and spring have the slightest bias, followed by autumn and winter. From 2017 to 2020, bias in 2019 and 2020 are the smallest, and the areas with large deviation are south of climate zone 3, the coastal area of climate zone 6, and the boundary area of climate zone 7.
... China has been facing severe water scarcity with per capita water resources of only about one-fourth of the world average and extensive flood damages, with almost 10% of global flood damage in the period 1990-2017 (Wang et al., 2008, Kundzewicz et al., 2019. To address these problems, a considerable number of water conservancy projects have been adopted, accounting for almost half the number of global dams, 20% of global hydropower generation, and 21% of the global irrigated area (Liu et al., 2013). ...
Water National Parks (WNPs) have been launched by the Ministry of Water Resources of China (MWR) to develop tourism functions for water conservancy projects since 2001. Although WNPs can provide socioeconomic benefits, their tourism activities may overload environmental carrying capacity. This study developed a sustainability analysis framework to measure the impact of tourism holistically and explore the challenges inherent in the sustainable development of WNPs. The framework, based on the Pressure-State-Response model, consists of four components: characterisation of WNPs; pressure, state, and response assessment; calculation of a sustainability score; and sustainability analysis of WNPs. To demonstrate the usability of the framework, this study first collected data on 778 WNPs from the MWR in order to characterise WNPs in China, followed by selecting 83 WNPs as examples for a detailed sustainability assessment. The results show that the framework enables: (1) the sustainability analysis of WNPs based on temporal trends, spatial distribution, and types of WNP; and (2) sustainable development challenges to be identified such as the tendency to increase waste discharges and energy consumption. The framework provides a strategic approach for the sustainability analysis, assisting WNPs and other water conservancy projects to achieve sustainable development goals.
... With the rapidly development of society and economic, the shortage of water resources is increasingly serious [1] , which become the bottleneck of the sustainable development of economic in China [2] . The norm of water intake for industrial products is one of the main indicators for the assessment of water efficiency and water conservation level of each industry and enterprise [3] . ...
The evaluation on the implementation effect of the standard not only constitutes an important basis for promoting the implementation and the quality of the standard, but also provides an important technical basis for implementing national water conservation actions and achieving the dual control targets for water consumption and intensity. This article analyzes and evaluates the implementation effect of the National Standard GB/T18916.1-2012 Norm of Water Intake-Part 1: Fossil Fired Power Production from three aspects including the Standard’s technical indexes, implementation effect and implementation benefits, and provides a foundation and reference to study and conduct evaluations on the implementation effect of the national standard for the norm of water intake.
... The degree of heavy metal content in soil is related to the prolonged irrigation as well as the of heavy metal content in effluents, Abou seeda (1975), Abou seeda etal (1997), Liu et al., (2005); Rattan et al., (2005). Wang et al., (2008) found that long-term, sewage water application gradually increased and sometimes exceeded the standards. This is Cu, Pb, Zn, Cd, As, Hg, Cr and other harmful substances seriously exceeded the limits of soil capacity. ...
BSTRACT In arid and semi-arid regions of the world, water has become a limiting factor, particularly for agricultural and industrial development. Water resources planners are continually looking for additional sources of water to supplement the limited resources available to their region. Several countries of the Eastern Mediterranean region, for Example, where precipitation is in the range of 100-200 mm a-1. In such situations, source substitution appears to be the most suitable alternative to satisfy less restrictive uses, thus allowing high quality waters to be used for domestic supply. Consider low quality waters such as wastewater, drainage waters and brackish waters should, whenever possible, as alternative sources for less restrictive uses. Agricultural use of water resources is of great importance due to the high volumes that are necessary. Irrigated agriculture will play a dominant role in the sustainability of crop production in years to come. The use of appropriate technologies for the development of alternative sources of water is, probably, the single most adequate approach for solving the global problem of water shortage, together with improvements in the efficiency of water use and with adequate control to reduce water consumption. The use of wastewater constitutes an important element of a water resources policy and strategy. Many nations, particularly those in the arid and semi-arid regions such as the Middle Eastern countries, have adopted in principle the use of treated wastewater as an important concept in their overall water resources policy and planning. However, accompanied with an extensive implementation of sewage irrigation, some problems with sewage irrigation became gradually obvious in agriculture, especially those related with pollution and destruction of farmlands. In this paper, the effects of sewage irrigation on soil physical (soil bulk density, soil resistance to penetration and field capacity), chemical (pH, soil organic matter, nitrogen, phosphorus, potassium, heavy metal and organic pollutants) and biological characteristics (soil microorganisms and enzyme activities) were systematically reviewed. To ensure long-term sustainability, sufficient attention must be given to the social, institutional and organizational aspects of effluent use in agriculture and aquaculture. The reuse of WW finds increased application in irrigation but the presence of toxic elements and microorganisms limits its use for irrigation purpose. To reduce the contamination of WW for irrigation, drip system is seen as an appropriate choice due to restricted quantity of water application. Emitter clogging is viewed as the main problem associated with drip system for its large-scale use with WW. Physical and chemical characteristics of WW were restricted. Higher EC, pH, Mg, and CO3, higher turbidity, total solids, HCO3, and Ca were observed in the waste water treatments.
... The water consumption per Yuan of GDP in China dropped by 31%, and the water consumption per Yuan of industrial value added decreased by 35%. But China's water resources problem is still serious (Qin et al., 2019;Wang et al., 2008Wang et al., , 2014. China's water consumption per Yuan of industrial value added is about twice the level of developed countries. ...
To help minimize urban industrial water consumption and realize the goal of a water-saving society, this paper develops a method for the dynamic optimization of the input production factors in an urban industrial water supply model. A negative exponential curve describes the urban industrial water consumption per Yuan of urban industrial value added, the latter being described by a Gompertz curve. The product of the two describes the urban industrial water demand. The production function of urban industrial water supply is expressed by the fixed substitution proportional production function. Taking investment and labor input as control variables, the system goal is to balance of industrial water supply and demand. The time-varying model can not only solve the stable state problem for infinite time horizon, but also the transient problem for finite time horizon. Taking Jiangsu province in eastern China as an example, the applicability of the method was investigated under different parameter combinations. The simulation results show its effectiveness in these cases. In the earlier period, meeting balance requirements is easier using the straight-line capital depreciation method. In the later period, the fixed rate on declining balance method allows to meet the requirements more easily. In general, it is easier to achieve the goal by choosing a smaller and feasible weight matrix coefficient of the control variables.
... The alternate source of water supply in the county is Miaoergou spring water and confined water source of the county. As the irreplaceable natural resources, water resource plays an important part in economic development and the improvement of people's living standards [2][3][4][5][6][7]. The analysis and assessment of the confined water quality in this area provide the reference for improving the utilization efficiency of groundwater in this area and plays a significance role in the sustainable development of local economy ...
To understand the quality of confined water in Huan County, Qingyang City and explore whether the water can be directly used as drinking water, this paper carried out the single component evaluation and comprehensive evaluation according to the national standard Sanitary Standard for Drinking Water (GB5749—2006) and Quality Standard for Ground Water (GB/T14848—2017). The result shows that the turbidity, total hardness, total dissolved solids, sulfate, chloride, fluoride and total σ radioactivity of in the single group of the confined water in Huan County, Qingyang City, cannot reach the national standard. In conclusion, based on the water quality analysis report and classification standard of the groundwater quality, the confined water quality of the water source in Huan County is poor, which cannot be directly used as the drinking water.
... However, due to China's large population, per capita water resources account for approximately one-fourth of the world [1] . At the same time, with the spatial and temporal distribution of water resources in China is not compatible with the demand for water in some areas [2] , along with the rapid development of industry, water pollution has become more and more serious, which further exacerbates the scarcity of water resources. In order to solve the crisis of water resources shortage, it is necessary to optimize the allocation of water resources to realize the transfer of water resources from low-value use to high-value use and improve the utilization efficiency of water resource. ...
In order to solve the water crisis, it is important to optimize the allocation of water resources. In this paper, the Whale Optimization Algorithm (WOA) is applied to the optimal allocation of water resources in Xingtai with the goal of maximum economic benefit and minimum total water shortage. The results show that the total water demand of different water users in each district is 26.94×108m3, the total allocated water is 19.83×108m3, the total water shortage is 7.11×108m3, and the water shortage rate was 26.39%. The lack of water is mainly concentrated in the primary industry. The result of the solution reflects the principle of water supply order and water use equity, which is in line with the actual development and utilization of water resources in the study area. It also verifies the feasibility of the whale optimization algorithm, such as less parameter adjustment, faster convergence, and better global optimization ability when solving water resources optimization problems.
... However, the per-capita water resource 41 volume is relatively limited, (i.e., 2.3 *10 3 m 3 ), considering the large population of China. It only 42 represents 25 % of the world average level, becoming thus one of the poorest countries of water 43 resources per capita (Fatta-Kassinos et al., 2011;JR, 1991;Wang et al., 2008). Even worse, the regional 44 water resource characteristics and seasonal distribution in China constrain the sustainable development 45 of economic and social development in water shortage areas (Piao et al., 2010). ...
Fresh water is a valuable nonrenewable resource and plays an important role in maintaining economic and social development. Considering its large population and consumption potential, water resources deficit will certainly impede basic industries a sustainable development in China in the near future. Application of sewage irrigation, to some extent, was regarded as an alternative way to solve the problem of agricultural irrigation water shortage in some areas (such as North China). However, accompanied with an extensive implementation of sewage irrigation, some problems on sewage irrigation in agriculture are gradually obvious, especially serious pollution and destruction of farmlands. In this paper, the effects of sewage irrigation on soil physical (soil bulk density, soil resistance to penetration and field capacity), chemical (pH, soil organic matter, nitrogen, phosphrous, patassium, heavy metal and organic pollutants) and biological characteristics (soil microorganism and enzyme activities) of farmlands in China were systematically reviewed on the base of the current utilization status of China’s farmland sewage irrigation. Some feasible suggestions were put forward to the development prospects in the future. This review will be beneficial for promoting a healthy development of sewage irrigation and providing a theoretical support for reclamation and a high efficiency use of effluents in China.
... Based on the selective principle of floating bed plant [6][7][8][9], Purple iris, a thelocal common dominant emergent aquatic plant, was chosen in this study due to its favorable features such as cold-resistant, half overcast environment resistant, ability to survive in shallow-water and certain ornamental value . Packing combined with elastic packing was used as the artificial medium, which was suspended into the mixture of activated sludge and experimental water for 7 days to form biofilm before the experiment. ...
The traditional ecological floating bed combined with micro-aeration system and artificial medium was developed for the removal of contaminants and remediation of surface water. This micro-aeration enhanced ecological floating bed (MAEEFB) consisted of aeration unit, microbial processing unit and aquatic plant unit. Batch experiments were conducted in different operating conditions on the removal of chemical oxygen demand (COD) in the sewage using MAEEFB. The removal rate of COD by MAEEFB, enhanced ecological floating bed (EEFB) and traditional ecological floating bed (TEFB) in the same reaction conditions was 59.2%, 56.9% and 30.6%, respectively, indicating that the combination of micro-aeration system and artificial medium could enhance the removal efficiency of COD in TEFB. In MAEEFB, the aeration intensity should be designed reasonablely considering both treatment efficiency and operation cost. Only increasing the specific surface area of the packing cannot effectively improve the purification efficiency of water. Factors like packing material, ability of intercepting organics and complicated extent of microorganisms attaching on the packing should also be considered.
... Previous water resource management strategies focusing on water conservancy and transfer projects, e.g., irrigation canals and dams, have allowed China to leverage its limited water resources and arable land to feed its large population. Although China's annual average freshwater resources of 2800 billion cubic meters is ranked as the sixth largest in the world, the per capita water resources of the country stands at a mere 2040 m 3 per capita which are only one fourth of the global average (Wang et al. 2008). In addition to the low per capita availability of water resources, there is a mismatch in China between the spatial distribution of water resources and geographic regions with high population densities. ...
Water resources are essential for agricultural production in the grain-producing region of China, and water shortage could significantly affect the production and international trade of agricultural products. China is placing effort in new policies to effectively respond to changes in water resources due to changes in land use/land cover as well as climatic variations. This research investigates the changes in land, water, and the awareness of farmer vis-à-vis the implementation of water-saving policies in Zhangye City, an experimental site for pilot programs of water resources management in China. This research indicates that the water saved through water-saving programs and changes in cropping structure (2.2 × 10⁸ m³ a⁻¹) is perhaps lower than the newly increased water withdrawal through corporate-led land reclamation (3.7 × 10⁸ m³ a⁻¹). Most critically, the groundwater withdrawal has increased. In addition, our survey suggests that local government is facing a dilemma of water conservation and agricultural development. Therefore, the enforcement of the ban on farmland reclamation and irrigation water quotas in our study area is revealed to be relatively loose. In this vein, the engagement of local stakeholders in water governance is essential for the future sustainable management of water resources.
... Naturally, freshwater is unevenly distributed; resulting in potential conflicts in many regions where freshwater is required the most while the availability is comparatively the least (Gleick, 1993). For example, China's total water resource is approximately 2800 billion m 3 , ranking the sixth in the world, but the per capita water resource is only 25% of the global average (The Ministry of Water Resources of the People's Republic of China, 2007;Wang et al., 2008). Moreover, the distribution of water resources is spatially and seasonally uneven in China (Piao et al., 2010). ...
An improved multi-objective optimization model based on goal programming (GP) for supporting reservoir operation was developed under inflow senarios of multiple runoff guarantee rates (i.e., 25%, 75%, perennial mean, and 95%) and ecological goals with the combination of steady- and pulse-state ecological water demands. Under these four scenarios, discharge flows of Danjingkou Reservoir would be 358.40, 369.67, 268.91 and 98.14 × 108 m3/a, and those at Taocha Canal headwork would be 104.61, 86.62, 95.08 and 64.00 × 108 m3/a, respectively. The generated results for stream flows could successfully meet the predetermined operational goals for the project. Comparatively, under the scenario of 95% runoff guarantee rate, the obtained strategies could not satisfy the ecological water demands. The modeling results indicated that the capacity of water diversion and storage for Danjiangkou Reservoir would be enhanced due to the operation of the South-to-North Water Diversion Project. The results showed the risks associated with possible flooding would be comparatively low under those four runoff guarantee rates. This represents the current priority for flood control in Danjiangkou Reservoir needs to be changed into multiple ones including ecological water supply, water transfer, as well as downstream water security maintenance.
... Water shortage has had a serious impact on social economy and people's life, especially on agricultural production [1]. In arid and semiarid areas of north China, shortage of water resources and low utilization of water resources lead to regional drought vulnerability, which seriously hindered the development of agriculture in the area [2]. At the same time, lack of scientific and reasonable planning leads to long-term unreasonable exploitation and utilization of water resources. ...
... China's groundwater is an endangered resource, and water scarcity is an issue of growing concern for China, particularly in the north (Scott, 2014). Across the whole country, 164 major groundwater areas are being exploited unsustainably, causing the depth to the groundwater table to increase by an average of 1.5 m per year in the arid and semiarid regions in the north (Wang et al., 2008b). For example, the groundwater table has dropped by 65 m in Beijing's urban area since 1965 (Li, 2000). ...
... Its total water resource is one of the world's largest, which ranks sixth globally. However, its water resource per capita is only approximately 2,000 m 3 , which is lower than a quarter of the world average value (Wang et al., 2008). With rapid economic development and climate change, China is faced with increasingly serious water problems, including water shortage, low efficiency of water use, excessive exploitation of change their behavior based on the predominant descriptions of the groups to which they belong. ...
Mass media are important sources of information about water issues that significantly influence civil life. This paper presents a content analysis approach to contextualize the water issues reporting of the People's Daily. The intent of our approach is to uncover the reporting pattern of water issues and the relationship between government policies and their news reports. Using the newspaper with the second widest circulation in China, the content analysis approach reveals that the document frequency of water issues had shown a flat trend since the 1970s. Water-related articles were given more significance by providing additional front pages. The results suggest that newspapers have been focusing more on the recreational function and protection of water since the 1980s. The results also show that there was a relative shortage of coverage on certain types of water-related central government documents. Lacking persistence was another feature of policy propaganda. These factors could work against public engagement in water issues and undermine the public's understanding of and confidence in water management measures. We believe these results could help water resource managers to interpret media content of water issues and improve the propaganda of their policies, which would contribute to better administration of water resources.
... Irrigated). Although this water resource is large in the absolute terms, ranking sixth in the world, the per capita water resource is only 25% of the world average (Wang et al. 2008). China is listed as one of the 13 countries in the world with most severe water shortages. ...
China's economy has made great strides since 1949, and especially after China has initiated economic reforms and the open-door policy in the 1980s. The growth in agricultural production has been one of the main national accomplishments. By 1996 China was feeding 22% of the global human population with only 7% of the world's arable land. The use of fertilizers and irrigation has played a crucial role. However, further increases in crop production will be more problematic than has been the case, with availability of water being a major limiting factor in China. Agricultural inputs must be reduced, especially nitrogen and phosphorus fertilizers, whose overuse led to environmental problems such as increased greenhouse gas emissions and severe water pollution in parts of China. We emphasize two pivotal components for increasing crop productivity with efficient use of resources (e.g. nutrients and water): (1) the development of integrated soil-crop systems management (ISSM), which will address key constraints using existing crop varieties, and (2) the production of new crop varieties that offer higher yields but use less water, fertilizer or other inputs.
... At the same time, the shortage of water resources has become a major obstacle to the achievement of sustainable development in China. It is estimated that the population of China will be 1.6 billion in 2030, and the average of water resources per capita is only 1750 m 3 , the total actual use of water resources is about 8.5 Â 10 11 m 3 in China, and the water consumption will be close to the maximum amount of rational use of water resources (Wang et al., 2008b;Zhang et al., 2009). At the same time, extreme hydrological events, such as droughts and floods, occurred more and more frequently, from December 2009 to April 2010; extreme drought happened in five provinces in southwest China, and the return period of that drought was almost beyond 100 years. ...
The statistical properties of annual runoff in major rivers of China are studied based on the theory of stochastic process and technology of time series analysis. These properties include the characteristics of intra‐annual and inter‐annual variations of runoff, trends, abrupt changes and periodicities. The new findings from the intensive calculations and appropriate analysis of data in longer period are as follows: (i) compared with the nonuniformity of intra‐annual runoff before 1980, the nonuniformity of intra‐annual runoff in China generally decreased after 1980, except for Huaihe River and Songhua River; (ii) compared with the annual runoff before 1980, the annual runoff in China generally decreased after 1980 except for WangJiaba station in Huaihe River and Ha‐Erbin station in Songhua River; the frequency of continuous low flow and continuous high flow in Haihe River and the downstream of Yellow River is higher than those in other rivers in China; (iii) annual runoff shows a downward trend in major rivers of China especially in Haihe River, Liao River and the midstream and downstream of Yellow River; (iv) there exist certain abrupt changes of annual runoff in major rivers of China; the abrupt change‐points are different among different river basins; and (v) almost periodicities of annual runoff sequences in major rivers of China are generally 20 years below, that is, 3~7 and 12~20 years. The reasons for these changes are mainly caused by climate change and human activities. Copyright © 2011 John Wiley & Sons, Ltd.
... Nowadays, with the growth of population and development of economies, water crisis is becoming a considerable threat to security and sustainable development all over the world. The total water resource of China ranks the 6th in the world, but the water resource per capita is only 25% of the world average, which results in remarkable vulnerability of China to changes of its water resources (Wang et al., 2008;Piao et al., 2010). Therefore, it is of great significance to investigate the possible impacts of climate change on water resources. ...
Changes in precipitation minus evaporation (P-E) are analyzed to investigate the possible impacts of climate change on water resource conditions in China. Simulations of SRES A1B and 20C3M scenarios from the WCRP CMIP3 GCMs are employed in the study. Time slice analysis shows that there would be more annual mean P-E across China in 2040–2055 and 2080–2099, compared to 1980–1999, with the largest percentage change over Northwest China and the Bohai Rim area. Precipitation and evaporation would also increase over entire China during these two periods. Annual mean P-E, precipitation, and evaporation averaged over the whole China and its eight sub-areas all yield generally upward trends during the 21st century. This indicates that on annual mean scale, the global warming related precipitation dominates the hydroclimate conditions in China. On seasonal mean scale, although precipitation is projected to increase over China, P-E exhibits both decreasing and increasing trends over certain regions of China. This suggests that the variation of global warming related evaporation dominates hydroclimate conditions over some parts of China, especially in northern China. Therefore, in hydroclimate condition projections, considering both evaporation and precipitation changes should be more reasonable than considering only precipitation.
... China's annual average total freshwater resources are about 2800 billion m 3 (MWR, 2011b). Although the absolute freshwater volume is big, ranking as the sixth largest among all countries in the world, the per capita water resources were only 2040 m 3 /cap/ yr in 2008, about one-fourth of the world average ( Wang et al., 2008). Besides the small per capita water resources, the uneven temporal and spatial distribution of water severely worsens the water scarcity problem (Fig. 2). ...
... China's annual average total freshwater resources are about 2800 billion m 3 (MWR, 2011b). Although the absolute freshwater volume is big, ranking as the sixth largest among all countries in the world, the per capita water resources were only 2040 m 3 /cap/ yr in 2008, about one-fourth of the world average (Wang et al., 2008). Besides the small per capita water resources, the uneven temporal and spatial distribution of water severely worsens the water scarcity problem (Fig. 2). ...
China’s water policies in the past decades have relied heavily on the construction of massive water conservancy projects in the form of dams and reservoirs, water transfer projects, and irrigation infrastructure. These facilities have brought tremendous economic and social benefits but also posed many adverse impacts on the eco-environment and society. With the intensification of water scarcity, China’s future water conservancy development is facing tremendous challenge of supporting the continuous economic development while protecting the water resources and the dependent ecosystems. This paper provides an overview of China’s water conservancy development, and illustrates the socioeconomic, environmental and ecological impacts. A narrative of attitude changes of the central government towards water conservancy, as well as key measures since the 1950s is presented. The strategic water resources management plan set by the central government in its Document No. 1 of 2011 is elaborated with focus on the three stringent controlling ‘‘redlines’’ concerning national water use, water use efficiency and water pollution and the huge investments poised to finance their implementation. We emphasize that realizing the goals set in the strategic plan requires paradigm shifts of the water conservancy development towards maximizing economic and natural capitals, prioritizing investment to preserve intact ecosystems and to restore degraded ecosystems, adapting climate change, balancing construction of new water projects and rejuvenation of existing projects, and managing both ‘‘blue’’ (surface/groundwater) and ‘‘green’’ water (soil water).
Medium-heavy alloys (MHAs) were rolled under different temperatures to characterize the microstructural evolution and mechanical properties by using optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, electron back scattered diffraction, tensile testing and microhardness testing. The results show that with an increase in the degree of deformation, the equiaxed grains are elongated along the rolling direction. A large number of slip bands are generated to coordinate intense plastic deformation, which leads to the formation of a fibrous texture. The sharp increase in dislocation density promotes significantly the dislocation interaction, which, in turn, refines the grain size of the MHAs to the nanometer level. Compared with the room-temperature rolling specimens, the cryorolling specimens underwent intense deformation. After 90% cryorolling deformation, the MHA grains were refined to 16.1 nm. The strength and hardness of the cryorolling specimens were significantly higher than those of the room-temperature rolling specimens, though the elongation was slightly lower. The fracture morphology of both specimens changed from ductile fracture (before deformation) to a mixed ductile–brittle fracture (after deformation).
The sea is the key to conducting sustainable scientific research and achieving strategic development of economic and environmental goals. The international community attaches great importance to the coordinated development of marine ecology, environment and socio-economic growth, and Europe has taken the lead in conducting relevant research. In recent years, although China has gradually tried to use quantitative and precise models for spatial planning, it still lacks a scientific logic - from theory to methodology - to address marine spatial planning. Based on the previous study of ecological and environmental quality and socio-economic development, this paper advocates the application logic of marine resources and ecological carrying capacity (MRECC) and marine use suitability (MUS). The Wenzhou City in Zhejiang Province was selected as the research area and MRECC is measured by four dimensions: spatial development of the marine area, fishery resources, environment and ecology. Two types of typical marine use, fishing use and construction use, were selected as the suitability for analysis to determine the optimal spatial arrangement of the sea and to assess the spatial conflict of the sea in Wenzhou. The results show that: (1) the comprehensive carrying capacity index of the marine area varies greatly among the districts and counties of Wenzhou city, and the resources and environment are highly differentiated. Longwan and Dongtou counties are overburdened with fishery resource development; Yueqing city and Longwan county are overburdened with marine environment. (2) There are only a few suitable areas for fisheries, and these are distributed in the nearshore area. The unsuitable areas are concentrated in the Oujiang River, Feiyun River and Aojiang River estuary. The areas that are particularly suitable for marine construction are concentrated in the coastal waters. The water depth in the near-shore area is far from urban settlements, which is not suitable for marine construction and development. (3) The spatial conflict phenomena in Cangnan County and Pingyang County are less - the spatial arrangement of marine planning is more reasonable. Yueqing City, Longwan County and Dongtou County have significant conflicts in the arrangement of marine fishery use and need to be optimised. Overall, the intensive development of the sea affects the carrying capacity and suitability of the sea, and inevitably leads to conflicts in the sea. Marine protection and development urgently require active management measures and sound spatial planning. The implementation of targeted and marine spatial planning with “double assessment” is of great importance for coastal spatial planning and an important means to achieve sustainable development of the marine economy. Therefore, the recommendations are to implement environmental protection of coastal areas, improve the level of marine development and balance the development of marine areas to promote the sustainable development of the region.
Mass media are important sources of information about water issues that significantly influence civil life. This paper presents a content analysis approach to contextualize the water issues reporting of the People's Daily. The intent of our approach is to uncover the reporting pattern of water issues and the relationship between government policies and their news reports. Using the newspaper with the second widest circulation in China, the content analysis approach reveals that the document frequency of water issues had shown a flat trend since the 1970s. Water-related articles were given more significance by providing additional front pages. The results suggest that newspapers have been focusing more on the recreational function and protection of water since the 1980s. The results also show that there was a relative shortage of coverage on certain types of water-related central government documents. Lacking persistence was another feature of policy propaganda. These factors could work against public engagement in water issues and undermine the public's understanding of and confidence in water management measures. We believe these results could help water resource managers to interpret media content of water issues and improve the propaganda of their policies, which would contribute to better administration of water resources.
Securing water supply in the face of increasing water scarcity is one important challenge faced by humanity in sustainable development. Inter-basin water transfer is widely applied to provide water supply security in regions where water demand exceeds water availability. However, the effect of inter-basin water transfer on alleviating water scarcity and its inequality is poorly understood especially at the national scale. Based on a newly compiled database of inter-basin water transfer projects in China, here we report a first national assessment of their effect on securing water supply in different basins. We developed a number of indices to facilitate quantifying the effect of water transfer on water scarcity and its inequality. The capacity of inter-basin transfer projects has been steadily increased, which achieved ∼48.5 billion m³ yr⁻¹ by 2016 (equivalent to ∼8% of the national water use). The results indicate that water transfer has impacted water supply of 43 sub-basins out of a total of 76 sub-basins, but it hardly changes a basin's water scarcity level (e.g., from water scarcity to low water scarcity). Approximately three quarters of people in China are affected by water transfer. More than a half of the national population (705 million) benefit from alleviated water scarcity, leading to the inequality coefficient reduced from 0.64 under natural water availability condition to 0.59 considering water transfer in 2016. However, 357 million people in water transfer source basins are subject to increased water scarcity, in which ∼21% are from water stressed sub-basins. This study reveals for the first time water transfer induced water scarcity and inequality change across sub-basins in China, and highlights the challenges to secure water supply across basins.
Fresh water is valuable nonrenewable resource and plays an important role of maintaining economic and social development. Condisering its large population and consumption potential, water resources deficit will certainly impede basic industries sustainable development of China in the near future. Application of sewage irrigation, to some extent, was regarded as an alternative way to solve the problem of agricultural irrigation water shortage in some areas (such as North China). However, accompanied with extensive implementation of sewage irrigation, some problems on sewage irrigation in agriculture are gradually obvious, especially serious pollution and destruction for farmland. In this paper, the effects of sewage irrigation on soil physical (soil bulk density, soil resistance to penetration and field capacity), chemical (pH, soil organic matter, nitrogen, phosphrous, patassium, heavy metal and organic pollutants) and biological characteristics (soil microorganism and enzyme activities) of farmland in China were systematically reviewed on the base of the current utilization status of China’s farmland sewage irrigation and some feasible suggestions were put forward to the development prospect for the future. This review will be beneficial for promoting healthy development of sewage irrigation and providing theoretical support for reclamation and high efficiency of effluents in China.
Egyptian cities have faced several challenges since the start of this new millennium;
rapid population growth, urban decay at the expense of available shelter, and
services, degradation of infrastructure and land, the downgrade of the environment,
social structure and the economy in general, are all factors that have led to
unsustainable living.
The Burullus region, located in the Northern part of the Egypt delta, is an active
commercial and administrative hub. It is one of the five protectorate lakes of Egypt
which accommodates both a recreational summer resort and a poorer all year
residence. The lake has faced, across time, several changes in respect to the
surrounding cities, which in turn impacted dramatically the shore. The changes that
happened to the land use and land footprint have changed the shoreline, and will,
eventually, lead to many environmental and urban problems as well.
Many actions should be taken when thinking about future extensions of cities that
have natural edges like Lake Burullus and huge agricultural lands, the
aforementioned challenges will face existing communities, as well as, extend with
respect to the surrounding areas leading consequently to the change of the identity of
the area at large.
This paper focuses on the importance of urban development and urban solutions of
the cities surrounding Lake Burullus as well as the shoreline protection and
implementation policies to optimize deterioration of shoreline, taking into
consideration the importance of rural regeneration and its impact on this area. It also
highlights a list of actions for successful lake upgrading steps based on the
experiences reviewed and concludes that the success of the development of shoreline
depends on several factors and that metropolitan planning should cover problems
across urban and peri-urban areas and address multijurisdictional issues.
Jordan suffered from a shortage in low-income housing. Jordan faces a surplus in
other housing stock. Factors of imbalance included funding, land, and
construction process. Despite the diagnosis of this imbalance, the government
could not address the issue. Empowerment of the private sector through
partnership potentially bridges housing needs for the growing segment of low income. Further challenges of the proposed study area included cultural values,
living needs, and necessary services, in addition to provision of livelihood sources.
This study examines the possibility of providing adequate and low-cost housing
for the group of Al-Noaim tribe at Al-Mansoura town. This social group still
inhabits Bayt Asha’ar housing typology so as to match their low income pressures.
The study was based on field survey and interviews with of 27 families and
householders. Outcomes proposed a project to be built in two stages during 15
years, 100 residential units distributed on 27 families. The suggested reduction of
the total cost of the project was based on: (1) Site selection, (2) Identifying areas
and patterns of housing units, and (3) Identification of multiple typologies for
construction of the wall section to be used in construction with the retention of
social meanings and psychological impact on such low income social groups.
Excessive water consumption, associated with regional agriculture and livestock development and rapid urbanization, has caused significant stress to the ecological health and sustainable use of water resources. We used the water footprint theory to quantify the spatiotemporal characteristics and variation in the water footprint of agriculture and livestock (WF-AL) in the Beijing–Tianjin–Hebei region of China (2000–2016). We predicted the spatial distribution and sustainability of regional water resources at different levels of annual precipitation. Results showed that the average county WF-AL rose from 8.03 × 108 m3 in 2000 to 10.89 × 108 m3 in 2016. There was spatial heterogeneity compared to the average city WF-AL. The WF-AL varied between the mountains and the plains. The scale of the WF-AL was one of the main reasons for differences in the consumption and distribution of water resources. The development of regional water resources deteriorated from a stable state to an unstable state from 2000 to 2016. Only 5.8% of the areas maintained a stable state of water resources. Even in the predicted wet years, no improvements were found in the instability of water resources in four areas centered on the counties of Xinji, Daming, Luannan, and Weichang. To achieve a medium and long-term balance between WF-AL development and water resource recovery, the WF-AL should be limited and combined with reservoir and cross-regional water transfer.
The reservoir-related tourism industry has been developed for leisure purposes since the 1970s and has gained popularity worldwide. To promote reservoir-related tourism in China, the Chinese government launched a “top-down” project titled “Water Conservation Scenic Spot” (WCSS) in 2001. However, because of the lack of reasonable planning, innovative ideas, and effective governance, there are some problems with WCSS constraining its development. To deal with those problems, it is necessary to have a holistic understanding of the WCSS situation. This study analyses the origin, status, opportunities, and challenges of WCSS development in China. The results show a trend of periodic increase in the number of WCSSs between 2001 and 2016, and WCSS development is unbalanced regarding regions and types. Moreover, the main issues for the WCSS include the failure to follow WCSS guidelines in practice, weak awareness of the scientific educational function, monotonous planning and construction, a lack of cultural preservation, insufficient funding, weak marketing, damaging of natural resources, destruction of clusters of animals and plants, land surface erosion, and landscape pollution. These adverse effects can be alleviated by strengthening supervision and fostering balanced development, promoting education and protecting cultural resources, distributing funding and enlarging popularity, controlling the amount of tourism, and avoiding overexpansion. Overall, the findings of this study can encourage the development of WCSSs in the future and are of significance in supporting the reservoir-related tourism industry.
As the capital and a major political hub for China, Beijing has undergone a rapid urbanization effect with significant population growth in recent years. At the same time, Beijing has also been suffering from severe water problems such as water scarcity, urban flooding and other issues related to water pollution. These have increasingly generated severe water problems and stymied the pace and scope of sustainable urban development. The critical challenges faced by water resource administrations pertains to the issues of sustainable management of water resources and the relevant actions to be put in place in order to address these water-related problems. In this study, the current water situation of Beijing is described in great detail focusing on water resource amounts, water supply, water consumption and water pollution changes analyzed from historical to recent years. The challenges of Beijing urban water management systems are also analyzed to offer possible solutions in light of the current trends. Finally, a number of useful strategies and action-oriented measures are provided for Beijing’s urban water resource administration to assist them in overcoming the current water management challenges and for them to move towards a more sustainable developmental city.
Water is the source of all life, and is closely related to human civilization. It had a special significance in China, so the ancient Chinese created the dragon god as a symbol of China, the Chinese and Chinese civilization. It can be said that the unique hydrological conditions on the territory of China created three great historical miracles: China, the Chinese people, and Chinese civilization. The Chinese have dedicated more effort than people in any other countries to water control and water use in order to make effective use of water resources and prevent flooding. It is their unparalleled achievements that have laid the foundation for these three miracles. Today, the Chinese people are facing unprecedented challenges in water control and water use. Exploring the historical Chinese relationship with water offers a good opportunity to understand the important role that water plays in long-term social development.
The influence of quartz on the flotation of fine wolframite using octyl hydroxamic acid (OHA) as the collector was investigated by micro-flotation tests, inductively coupled plasma (ICP) measurements, adsorption experiments, zeta potential, and Fourier transform infrared spectroscopy (FT-IR) analysis. Micro-flotation tests showed that a large difference in floatability existed between fine wolframite and quartz in the pH range of 7.0 to 10.0. However, in a synthetic mixture, the flotation separation of fine wolframite from quartz became more difficult as the particle size of the latter decreased. When a dissolved solution of wolframite was used as the flotation medium, quartz floatability improved significantly. Zeta potentials of quartz particles shifted positively in the dissolved solution of wolframite compared to distilled water, especially at a pH level of 7.0–10.0, which was attributed to the metal ions dissolved from the wolframite being adsorbed onto the quartz surface. The surface activation of quartz led to an increase in the OHA adsorption and made the surface hydrophobic. FT-IR analysis further demonstrated that OHA could adsorb onto the activated quartz surface through a dominantly chemical process.
In order to treat the composite micro-polluted groundwater to conform to the standard of drinking water, the process and operating parameters of contact oxidation were studied in this paper. The manganese sand-ceramic-manganese sand consisted of three-level contact oxidation filtration process method was used to treat the composite micro-polluted groundwater that was built through groundwater added MnSO4·5H2O, FeSO4·7H2O, NH4Cl, humic acid, urea and starch. The total thickness of the filter layer was 1. 5 m and the filtration velocity was 1.0 m/h. It shows that the main effluent indexes conform to the drinking water standard by three-level aeration and three-level filtration. Because the oxidation-reduction potential is low, Fe2+ is easily oxidized, by simple drop-aeration, the average removal rate is 95.36% and meets the requirement. Due to the influent CODMn mass concentration is relatively low, the average removal rate achieves 44.21% by simple drop-aeration. The removal rate can be further improved to 53.69% by increasing the DO content. The mass concentrations of effluent manganese and ammonia nitrogen which treated by simple drop-aeration are higher. After increasing aeration intensity, the effluent mass concentrations can gradually reach the standard of drinking water and average removal rates are 96.50%, 97.22%, respectively. It concludes that through three-level aeration and three-level filtration contact oxidation process treating, good purification efficiency of the composite micro-polluted groundwater can be obtained. Meanwhile, DO has a great impact on the manganese and ammonia nitrogen removal.
Water resources are very important for grain production in China. In this study, we investigate the changes in streamflow and grain production in China from 1956 to 2008. Since the 1980s, the increase of total grain production was mainly contributed by northern China where significantly decreasing precipitation and available water resources were observed. From 1985 to 2008, northern China accounted for 92.9 % of the national total grain production growth. Consequently, the main grain production area has shifted from the south to the north. However, the shift was mismatching the spatial distributions and temporal changes in precipitation and available water resources in China. During 1956 through 2008, precipitation decreased in the main grain production areas of the northern China by 1.23-1.27 mm per year. During the same period, observed streamflows in the five major rivers in northern China decreased by 13.4-92.4 %. Current grain production in northern China is dependent on overexploitation of groundwater. From 1987 to 2000, the average groundwater table declined 10.8 m with a maximum decrease of 34.8 m in North China Plain. Furthermore, the impacts of climate change and projected industrial development exacerbate the uncertainty of grain supply by northern China in the future. This study also indicated the potential of southern China for a more important role in ensuring sustainable food security of China, with increasing precipitation and streamflows observed in the Yangtze River and Pearl River basins.
In order to study the impacts of production wastewater recycle in water purification process, the performance data of production wastewater recycle process were compared at BW drinking water treatment plant. On the basis of flow and material conservation, the pollutants were removed by water purification system and were discharged by the exclusion of mud cake. Through the testing of the water quality indexes, wastewater recycle would not make adverse impact on the water quality of low turbid raw water treatment, and the metals, trihalomethanes, and polyacrylamide would not get enrich. Due to the presence of large numbers of colloidal particles, broken floc and incomplete reaction flocculants, humic acid and other substances in wastewater, coagulation will be enhanced and water quality will be improved after mixing with raw water. The results show that the wastewater recycle process can save water resources, enhance the low turbidity water coagulation effect, and have little effect on the safety of plant effluent water quality. ©, 2015, Beijing University of Technology. All right reserved.
During the past decade, the Chinese government launched a series of programs to enhance the sustainable use of water resources and has made great strides in water-saving strategies. The task of fighting water shortage remains challenging, however, and will be increasingly difficult in the future because of increased irrigation requirements due to climate change and other factors. Various measures must work together to deal with irrigation requirement increases. Improving water resource management infrastructure; repairing old irrigation systems; investing in hydraulic projects; promoting watersaving technologies; adjusting agricultural water structures; increasing harmonization among agriculture, forestry, herding, and fisheries as well as water consumption by grain crops, cash crops, and grazing grass; enhancing agriculture water use efficiency; and planting more water efficient cultivars can all contribute to sustainable future management of water resources.
ResearchGate has not been able to resolve any references for this publication.