Water shortage and wastewater reuse

China is not abandantly supplied with freshwater. Water shortage is a crucial problem in northern China, and affects the development of economy and causes a host of environmental and ecological problems. Water saving, water resource protection, strengthening of management and exploitation of new water resources are some of the major measures for solving the water shortage problem. Wastewater reuse is also a feasible and practical means of alleviating the problem.

Water Shortages in China's Cities

"Water,woater evenyuwhere,and nary a drop to drink!"Poetry becomes reality in China,as experts scramble to find new supplies of the preious liquid to slake the thirst of a growing population and industry.

Some Indicators of the Water Regime in Some Varieties Belonging to the Monarda didyma L. Genus in the Conditions of Tashkent (Uzbekistan)

In this article, the names of 3 varieties of Monarda didyma L., which are considered to be introduced species, some indicators of the water regime in the climatic conditions of Uzbekistan: the amount of water in the leaves, water deficit, water storage capacity were studied in spring and summer, and seasonal changes were determined. According to these indicators of the water regime, the studied varieties belong to the labile water regime, high green mass (centner), seed yield (how many grams), resistance to diseases and pests have been determined, which shows that it is promising for introduction in the conditions of our republic. Therefore, it is recommended to breed these varieties in the foothills and hilly regions of Uzbekistan, where the amount of precipitation is more than 400 - 500 mm.

Effects of Desalination Processes on the Water Circulation and Earth System

Desalination is emerging as a promising alternative among various technologies to resolve water shortage. However, desalination requires a sufficient energy and cooling device and therefore poses limitations for its installation and application. In particular, many countries suffering water deficits are economically underdeveloped and cannot afford the technology. As this technology, which changes seawater into freshwater, has little environmental impact, developed countries will need to assist less developed countries to introduce this technology as a humanitarian effort. This will help reduce the number of countries that have experienced difficulty with development.

An inexact risk management model for agricultural land-use planning under water shortage

Water resources availability has a significant impact on agricultural land-use planning, especially in a water shortage area such as North China. The random nature of available water resources and other uncertainties in an agricultural system present risk for land-use planning and may lead to undesirable decisions or potential economic loss. In this study, an inexact risk management model （IRM） was developed for supporting agricultural land-use planning and risk analysis under water shortage. The IRM model was formulated through incorporating a conditional value-at-risk （CVaR） constraint into an inexact two-stage stochastic programming （ITSP） framework, and could be used to control uncertainties expressed as not only probability distributions but also as discrete intervals. The measure of risk about the second-stage penalty cost was incorporated into the model so that the trade-off between system benefit and extreme expected loss could be analyzed. The developed model was applied to a case study in the Zhangweinan River Basin, a typical agricultural region facing serious water shortage in North China. Solutions of the IRM model showed that the obtained first-stage land-use target values could be used to reflect decision-makers＇ opinions on the long-term devel- opment plan. The confidence level a and maximum acceptable risk loss fl could be used to reflect decision- makers＇ preference towards system benefit and risk control. The results indicated that the IRM model was useful for reflecting the decision-makers＇ attitudes toward risk aversion and could help seek cost-effective agricul- tural land-use planning strategies under complex uncer- tainties.

Optioning Water Rights:A Potential Alternative to the Hanjiang-Weihe River Water Transfer Project,China

China has started shifting from relying on supply management to demand management strategy in addressing its water shortage problems.Water option,a financial derivative for water commodity,has been utilized to manage water demands in the United States and Europe since the 1990 s but is still novel to China.In this study we analyzed the pros and cons of China’s existing system for water rights transfers and proposed an alternative,flexible trading instrument-water options for China.Incorporating the uncertainty to water option pricing,this study first conducted an empirical analysis of the water option in the water-receiving area of the Hanjiang-Weihe River Transfer Project of China,and then evaluated the benefits of the water option applications.Results show that water option trading can bring water cost saving and increase the potential industrially added value for industrial enterprises in the receiving area,and trading of short-and-medium term water options is more favorable than the long-term water options trading.The novel water option trading proposed in this study,once verified through pilot studies,will be helpful in addressing water shortage problems in China.

Hydrologic modeling of the Heihe watershed by DLBRM in Northwest China

Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,irrigation,and industrial supplies and even the survival of the ecosystems in Northwest China.This paper describes the preliminary work of adapting the Distributed Large Basin Runoff Model(DLBRM) to the Heihe watershed(the second largest inland river in arid Northwestern China,with a drainage area of 128,000 km2) for understanding distribution of glacial-snow melt,groundwater,surface runoff,and evapotranspi-ration,and for assessing hydrological impacts of climate change and glacial recession on water supply in the middle and lower reaches of the watershed.Preliminary simulation results show that the Qilian Mountain in the upper reach area produces most runoff in the Heihe watershed.The simulated daily river flows during the period of 1990-2000 indicate that the Heihe River dis-charges about 1×109 m3 of water from the middle reach(at Zhengyixia Station) to lower reach,with surface runoff and interflow contributing 51 and 49 percent respectively.The sandy lower soil zone in the middle reach has the highest evapotranspiration rate and also contributes nearly half of the river flow.Work underway focuses on the DLBRM model improvement and incorporation of the climate change and management scenarios to the hydrological simulations in the watershed.

Correctly Evaluating the Effect of Agricultural Water Saving

Water conservation has become the consensus of the whole society and is the general direction of social development. But there is a misunderstanding about the ultimate effect of water saving in agriculture. In the process of comparison,it is easy to draw the conclusion that water saving is better than development of water resources. The difference between water saving and inter-basin water diversion should be correctly understood to avoid misleading decisions. In this paper,the effects of water saving and water transfer in typical irrigation areas were calculated and compared.

Urban Rejected Water Reuse in Agriculture for Irrigation in Major Cities of India:A Synoptic Review

Indiscriminate and rapid urbanization without sufficient infrastructure to manage huge domestic sewage(urban rejected water)generated by urban centers posing serious threats to different ecosystems in many places across the world.On the other hand,the downstream of urban centers facing an acute shortage of water for irrigation.In recent years reuse of urban waste water is being increased in many countries including India irrespective of adverse impacts on other ecosystems.The present study has provided a synoptic review on urban rejected water reuse for irrigation in the major cities of India with a special focus on banks of the Musi river basin in South India where huge wastewater irrigation is being practiced in the world in comparison with global waste water irrigation practices.In all the cases major contaminants namely fecal coliform,nitrates,Biological Oxygen Demand(BOD),Chemical Oxygen Demand(COD)and Dissolved Oxygen(DO)are found in water and with increased soil and groundwater salinity on long term use.The review indicated that there a large scope to intensify the irrigation with proper treatment of wastewater.The study also suggested to understand the impacts of rejected water reuse impact on soil-water-food chain and also emphasizes the need for the establishment of sufficient ETPs to minimize the adverse impacts and also to protect hydro-agro ecosystems.

High Throughput Sequencing of circRNAs in Tomato Leaves Responding to Multiple Stresses of Drought and Heat

Our aim is to study the roles of a new emerging group of non-coding RNAs, circRNAs, in tomato(Solanum lycopersicum L.) plants grown at the combination of drought and heat, two of the most usual stress conditions known to frequently happen in field. Tomato seedlings from cultivar‘Jinling Meiyu’ were treated without stresses(control), at water shortage, high temperature and subjected the multiple stresses. In total, 467 circRNAs were identified with 87.82% from exon using high throughput sequencing technology. Among the circRNAs, 70 were from chr1 with the range from 23 to 49 from the other chromosomes. In detail, 156 circRNAs were shared in the four libraries, while 21, 17 and 36 circRNAs were only shown in drought, heat and multiple stresses libraries, respectively. Through a differential expression analysis, four, seven and nine circRNAs were differentially regulated in tomato at drought, heat and multiple stresses as compared with control. These circRNAs played roles on photosynthesis, starch and sucrose metabolism, RNA transport, RNA degradation, spliceosome, ribosome, etc. Our study underlined the potential role of circRNAs involved in the abiotic stress response in tomato, which might pave the way for studying biological roles of circRNAs responding to multiple stresses in plants.

Effects of climate variability and land use/land cover change on the Daihai wetland of central Inner Mongolia over the past decades

The wetland ecosystem and its driving mechanism are significance impact on the ecological environment and the sustainable development of semi-arid regional economy.Agricultural and industrial land use/land cover change(LUCC) is also important for wetland system.The Daihai wetland(DW)in Inner Mongolia has been suffering from severe environmental problems such as water resource shortages and wetland areas decrease.We analyzed spatiotemporal LUCC at the catchment scale of Daihai Lake,which has recently exhibited a dramatic loss of water area,and investigated the potential role of climatic changes and human activities in the wetland loss.From 1976 to 2015,the arable land and construction land increased by 71.72 and 15.81 km2,with ranges of 18.72% and 39.61%,respectively.Meanwhile,the wetland area decreased by 84.47 km2,accounting for 29.07% of the area in1976.From 1960 to 2015,the area of Daihai Lake decreased by 100.73 km^2,diminishing to 37.09% of the area in 1960,and the lake storage accordingly shrank from 12.9×10~8 to approximately 3.9×10~8 m^3.The lake level also rapidly declined.From 1962 to2014,the lake water mineralization,total nitrogen(TN),and total phosphorus(TP) increased by 2410,7.86,and 0.182 mg L-1,respectively.The pollution sources included not only mineral fertilizers and pesticides,but also livestock,poultry breeding,aquaculture,and rural household waste.The lake area decreased with increasing agricultural development,Daihai power plant(DHPP) water consumption,and catchment climatic dryness.Thus,the urgent implementation of effective restoration and mitigation measures are needed.

A method to estimate aquifer artificial recharge from a hill dam in Tunisia

in arid and semi-arid areas, artificial recharge is a key technology in groundwater resources management, and a reliable estimate of artificial recharge is necessary to its sustainable development. Several methods are available to estimate the artificial recharge; however, most of them require field data or model parameters, thus limiting their applications. To overcome this limitation, we presented an analytical method to estimate the artificial recharge through monitoring the water release by piezometer and analysing the controlling factors of the artificial recharge from a hill dam in Tunisia. A total of 97 measurements of water flow in the streambed recorded from 4 gauging stations were analysed. Results indicated that the average infiltration velocity ranged from 0.043 to 0.127 m/d and the infiltration index varied from 7.6 to 11.8 L/（s.km）. Pearson＇s correlation coefficient analysis shows that the infiltration index, the stream gradient, the thickness of unsaturated zone, the number of infiltration pond, the stream geometry, and the water flow rate were found to be the main factors in determining the infiltration. The high correlation coefficients （0.908 for the number of infiltration pond and 0.999 for the stream geometry） mean that the number of infiltration pond and the stream geometry are the most influential factors. Time variations of groundwater level were used to analyze the recharge effects on the piezometry of aquifer. The analysis showed that during the artificial recharge, the water table increased at a rate of 5 mm/d and that the increase was limited to the area surrounding the recharge site. Based on the results of the study, building infiltration ponds along streambed and improving the potential of rainwater harvesting over the study area are recommended.

How to Purify a Polluted Lake Quickly—A Case Study from Shanghai, China

Water pollution has become a serious worldwide problem, especially for lakes with a large stagnant water body. Is it possible to develop high quality water from a heavily polluted river system quickly? This paper introduces an innovative technology termed SPP (separation, prevention and protection) for this purpose. Its feasibility is preliminarily examined using Dianshan Lake in Shang- hai as an example. Due to its very high population density and intensive industrial activities, almost all waterways in Shanghai are heavily polluted, including the lake. However, the data analysis shows that clean water always appears after heavy rains, especially in its suburban areas. Once the 1st flush water is discharged to downstream, high-quality water can be developed from its Dianshan Lake by using the SPP strategy. The Vollenweider model is used to analyze SPP’s feasibility. The results show that the water quality of the Dianshan Lake can be remediated as a drinking water source within 120 days if the SPP strategy is applied. It is suggested that Jinze reservoir’s water should come from the Dianshan lake, not Taipu River to improve the quality of water supply. It is highly recommended for other cities in the world to consider the SPP technology if needed.