PRESSURE OF WATER SHORTAGE ON AGRICULTURE IN ARID REGION OF CHINA

The arid areas in China are mainly located in North China and Northw est China. The North China is the main region for food production. There is 31.1 9%of the total farmland and 26.01%of the total population, but only 6.14%of t he available water resources of China. Groundwater is over pumped (6.53×109m3 e very year) in the regions of Beijing, Tianjin, and Hebei Province, so water supp ly could not meet the water demand there. The distribution of water in Northwest China is uneven, some inland rivers and lakes are dried up, and desertification has expanded since river water in the upper and middle reaches is diverted for irrigation. Up to 2050, population will be up to 1.6×109 in China, and industry will be developed fast, therefore 50%of the water supply will be used by indus try and resident, and water for agriculture will be decreased year by year. In t he coming 50 years, water demand for agriculture will be increased by 5.6×109m3 in the Huanghe (Yellow) River valley, and by 1.7×109m3 in the Northwest China. It will be impossible for the Huanghe River to meet the water demand, because i t always dried up in the cold half year since 1984. To avoid water shortage of a griculture in the arid regions, it is necessary to divert water from the Changji ang (Yangtze) River in the south of China, and to use water efficiently. It is t he best way to use drip irrigation in agriculture, recycle water in industry and resident use, and control water pollution. Otherwise water shortage in the arid regions will restrict the development of agriculture in China.

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.

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.

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.

Sustainable development of Shandong Peninsula urban agglomeration:a scenario analysis based on water shortage and water environment changes

China has experienced a rapid urbanization since late 1970s. The great increase of urban population has resulted in various environmental changes, of which urban water shortage and water environment problems have oc-curred in most cities, especially in the rapidly developing urban agglomerations in the eastern coastal region. This research, taking Shandong Peninsula Urban Agglomeration (SPUA) as a case study area, analyzes the urbanization expansion in the last decades, discusses the water shortage and water environment changes following the rapid eco-nomic development and urbanization such as groundwater sinking in the urban and plain area, sea water and salt-water intrusion in the coastal cities, water pollution overspreading and water ecosystem degradation, and puts for-wards some strategies for sustainability in populous regions with severe water shortage. Some countermeasures for sustainable development of SPUA are put forward, such as constructing modern water resources inter-city networks to regulate water resource between cities, adjusting urbanization policy and urban scale planning to promote the de-velopment of small towns and medium sized cities, optimizing urban industry structure by restricting high water con-sumption enterprises and stimulating the growth of tertiary industry, improving water use eff iciency to reduce fresh water consumption and wastewater discharge, introducing economic means to water pricing and water management system, and restoring ecological conditions to strengthen the natural water-making capacity.

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.

关于中国水达峰几个问题的讨论

用水演变态势与需求峰值事关经济社会发展、生态环境保护大局,直接影响国家水网规划布局和重大水利工程建设。本文在水达峰内涵解析的基础上,总结了水达峰的自然社会特征和内涵,阐明了水达峰与需水、用水、缺水之间的关系,深入分析了中国统计用水量出现拐点的现象以及造成这种现象的6种可能原因,指出目前尚不能得出中国用水需求已达峰的结论。通过与国际上发达国家水达峰时人均GDP、产业结构、城镇化率等主要指标对比分析,认为中国现阶段也不具备水达峰的经济社会基础。最后指出,目前中国水资源保障安全的压力仍然较大,未来用水演变态势存在一定的不确定性,中国用水何时达峰、达峰水量是多少等结论需要进一步深入研究。需要做好国家水网工程的顶层设计,提升不同尺度的水资源优化配置能力,为国家高质量发展提供水资源保障。

缺水胁迫区水系统优化调控理论与模式

开展水系统优化调控是实现缺水胁迫区人-水-生态和谐可持续发展的关键措施之一,对于保障地区经济社会稳定发展和生态健康具有重要意义。本文以京津冀作为典型缺水胁迫区案例,通过解析水系统内涵,总结得出缺水胁迫区水系统存在深度耦合、强烈竞争和系统失衡三大现象,发现水系统呈现非稳态和稳态之间交替演进的模式,并通过构建水系统稳态指数,研判了京津冀地区水系统状态变化发展过程。研究以实现自然社会水系统健康为调控目标,提出缺水胁迫区水系统“高内聚-低耦合”解耦式调控模式,结合京津冀现实状态,在需求侧开展“保障刚需-压缩弹性-抑制奢侈”层次化调控,在供给侧进行“自然水网-人工水网-虚拟水网”适配性优化,提出京津冀“三线七河、四区八源”一体化水网布局,进而实现水系统的整体健康。

光热膜蒸馏水处理技术与应用研究进展

利用高效的水处理技术对海水、苦咸水脱盐淡化,以及将工业废水循环再利用,是解决水资源短缺及水污染问题的关键。目前应用较多的膜分离技术尚存在高能耗、低热效率、二次污染等问题。因此,新型的膜分离技术受到广泛关注。光热膜蒸馏技术具有热效率高、能耗低、零排放等特点,在海水淡化、水资源再利用等领域的应用已展现出良好前景。文章综述了光热膜蒸馏的基本过程和原理,光热膜材料的研发和光热膜蒸馏系统的设计研究进展,并对光热膜蒸馏的综合实际应用进行详细阐述。另外,还探讨了当前光热膜蒸馏技术的局限性及未来的挑战,以期为光热膜蒸馏系统的进一步发展及应用提供参考。

流域国水资源短缺性组合评价模型及应用

随着全球淡水资源的日益短缺,跨境水资源分配的不公平性已成为引发流域国水资源冲突的主要根源之一。首先,通过考察美、非、亚、欧典型跨境河流,梳理流域国水资源短缺性的影响因素。其次,针对跨境河流的特点,构建流域国水资源短缺性评价的8个评价指标,包括人均水资源量、产水模数等反映水资源自然禀赋和水资源供给能力的指标,总用水量、农业用水量占比等反映水资源需求状况的指标,以及内部可再生淡水资源等反映替代水源的指标。再次,构建流域国水资源短缺性指数测度模型,在通过加性加权法、物元关联法、改进TOPSIS法分别进行评价的基础上,运用基于循环修正的组合评价模型集成评价结果,并通过Kendall协和系数法开展事前一致性检验,通过Spearman法开展事后一致性检验。最后,结合澜湄流域开展应用研究,测算澜湄流域内六个流域国的水资源短缺性状况,验证模型的可行性和实用性。

质子交换膜燃料电池电堆阳极饥饿反极的研究

目前,质子交换膜燃料电池(PEMFC)反极研究主要通过单电池完成,反极过程没有考虑相邻电池的影响,与电堆实际情况并不完全相同.本文通过控制加湿度和过量系数等测试条件分析了5片PEMFC电堆阳极在水淹和缺气情况下的饥饿反极情况.结果表明,在电堆阳极水淹情况下,反极单电池电压表现为缓慢下降到电解水平台然后迅速恢复的循环过程,性能恢复归因于水淹单电池阳极进出口压差上升使其液态水排出而氢气重新进入;在电堆阳极缺气情况下,反极单电池电压表现为迅速降低到碳腐蚀平台然后迅速恢复的循环过程,这是由于缺气单电池的阳极进出口压差下降使电堆内氢气重新分配.缺气反极电池电压会降低到碳腐蚀平台,因此会对电池性能造成不可逆的损害.

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.

基于超参数优化的极限学习机区域水资源短缺风险评价

为科学评价区域水资源短缺风险水平,改进极限学习机(ELM)评价性能,提出晶体结构算法(CryStAl)、鹈鹕优化算法(POA)与ELM组合的水资源短缺风险评价模型,并通过云南省水资源短缺风险评价实例进行验证。首先,简要介绍CryStAl、POA原理,通过4个标准函数对CryStAl、POA进行仿真测试;其次,建立水资源短缺风险评价指标体系和等级标准,采用线性内插和随机选取的方法生成样本,并构建ELM超参数优化适应度函数;最后,采用CryStAl、POA对适应度函数进行寻优,利用寻优获得的最佳ELM超参数建立CryStAl-ELM、POA-ELM模型对实例各年度水资源短缺风险进行评价,结果与模糊综合评价法、CryStAl-SVM、POA-SVM、ELM、SVM模型的评价结果作对比。结果表明:CryStAl、POA具有较好的寻优精度及全局搜索能力;CryStAl-ELM、POA-ELM模型对检验样本评价的平均绝对百分比误差(MAPE)分别为0.077%、0.083%,评价精度较CryStAl-SVM、POA-SVM模型提高57.7%以上,较SELM、SVM模型提高83.5%以上;CryStAl、POA能有效优化ELM超参数,提高ELM的评价性能。CryStAl-ELM、POA-ELM模型评价结果表明,实例2006年~2008年水资源短缺风险为“较高风险”,2009年~2012年为“中风险”,2013年~2019年为“较低风险”,2020年~2025年为“低风险”;近15年来云南省水资源短缺风险水平呈下降趋势,且下降趋势显著。

皖东玄武岩熔岩台地贫水区找水方向研究——以来安半塔林场找水打井为例

来安县半塔林场地处皖东玄武岩台地之上,属江淮分水岭东段地下水贫水区。通过专项地质调查、综合电法工作,发现了断层,结合区域构造变形特征、分布特点以及应力场变化特征等进行初步分析,确定了断层的力学特征和含(透)水性,并施工了SJ01、SJ02水源井验证;经SJ02抽水试验表明:该水源井日出水量可达400 t,水质良好;解决了半塔林场约750人的生活饮用水困难,取得了明显的经济效益和社会效益。

Present Water Crises in Iraq and Its Human and Environmental Implications

Iraq is facing a serious water shortage problem now, which has not been experienced before. This is because of the reduction of flow of the Euphrates and Tigris Rivers which is due to the implementation of hydrological projects within the upstream part of the catchment and climate change. Mismanagement of water resources within Iraq made the problem graver. It is believed that serious discussion with all riparian countries to reach an agreement to share the water of the two rivers and their tributaries is desperately needed. In addition, a prudent scientific strategy should be implemented and put into practice to overcome this problem in Iraq. In addition, the key positions within the Iraqi Ministry of Water Resources should be given to people having real experience in the water resources sector to ensure discreet and prudent management of the problem.

Impact of Global Warming on Water Resource in Arid Area of Northwest China

As the unprecedented global warming is under way, the glacier retreat is getting more and more serious. In the inland arid area of Northwest China, due to very scarce precipitation, where there is water, there are oases. And the glacier melt water amounts to 22 % of the total direct supply of the inland river water and is of crucial importance to the survival and development of the oases. In this paper, using both the observed data and the previous research achievements of the glaciers in the inland valley of Northwest China where the oasis depending on the glacier is the only location suitable for human living, the authors describe the glacier retreat trend over the past half century, focusing on discussing the possible impact of the glacier retreat on the melt water runoff that is almost the only water resource efficient to nourish the oases. The authors find that even with increasing amount of water from the glacier with global warming, the water shortage is getting more and more serious and the environment is under a degrading way due to the accelerating economical development. The water shortage is bound to be more serious if the glacier retreat keeps on, especially after the glacier melt water is over its top for the degradedglacier scale. So suggestions are stressed in the end that a new water-saving pattern should be adopted in the area for a sustainable development due to the warming-up induced continuous glacier retreat.

Determinants of agricultural water saving technology adoption:an empirical study of 10 provinces of China

In recent years,China has been faced by an increasingly severe water shortage due to the continual growth of demand on water resources.Although the Chinese government has been actively promoting the agricul-tural water-saving technology adoption,it is ill-informed of the adoption degree of the current agricultural water-saving technologies as well as the function of the governmental policies.Therefore,this paper analyzes the aforesaid problems based on investigative data of 10 provinces in China.The results demonstrate that although there is a rapid increase of adopted agricultural water-saving technologies,the actual adoption area is rather limited.Moreover,the governmental policies and scarcity of water resources are the determinants of agricultural water-saving technology adoption.Ultimately,the paper proposes some policy suggestions.

Solving Water Problems of a Metropolis

The metropolis of Istanbul has faced water supply challenges throughout history;however the situation escalated in the past decade with rapid population growth. Water demand of an ever-growing city could only be solved by transporting water from surrounding water basins as far as 190 km away from the city border. Moreover, imbalanced distribution of water resources and imbalanced water demand on the European and Asian side of the city was resolved by transporting water from Asian side to the European side, by laying water transmission pipes under the Bosphorus Strait and by constructing a tunnel passing 130 m under the Strait. Another difficulty that required challenging solutions was the protection of water reservoirs of the city, hence illegal settlements arose in the reservoir watershed zones due to fast urban growth and migration from rural areas. Discharge of wastewater from illegal settlements caused not only algae growth in water treatment plant (WTP) of one of the largest reservoirs of Istanbul, but also eventual death of algae was a major setback due to anaerobic conditions created in the reservoir. The problem was solved by tertiary treatment of the wastewater and by diverting the effluent through a tunnel away from the reservoir. The aim of this paper is to provide an insight into setbacks faced in a metropolis of 14 million and technical solutions provided against the pollution of reservoirs.

Support of Space Techniques for Groundwater Exploration in Lebanon

Lebanon is known by the availability in water resources whether on surface or among the existing rock for-mations. However, the status-quo does not reflect this availability due to a number of physical factors, as well as the mismanagement of these resources. Hence, the per capita has been reduced by about 50% in the last three decades. There are sixteen exposed rock formations in Lebanon, two of them are major aquifers and they are characterized by highly fractured and karstified carbonate rocks. Recently, challenges for groundwater in Lebanon have been developed. These are the: overexploitation, climate change and the acute geologic setting, which led to decline in rainfall rate, and thus exacerbated water demand. The existing chal-lenges resulted with a number of problems in ground water resources management, namely: quality deterio-ration, impact on springs and groundwater behavior, loss of groundwater o the sea, saltwater intrusion and exacerbated by the lack of data and mismanagement in water sector. In this respect, new technologies can be utilized as a helpful instrument in managing groundwater resources to treat the unfavorable situation. Space techniques and GIS have been recently raised in several topics on water resources management, including, mainly exploration and monitoring. They proved to be capable to extract hydrogeologic information and thus to manipulate this information in creditable approaches of analysis. This study introduced the present status on the Lebanese groundwater resources and the existing challenges and problems. Thus, it extends an appli-cation from Lebanon on the used new approaches for exploring groundwater.

Analysis on the relationship between water resources and environmental change in Northern Thailand

How do people perceive environmental change when coping with scarcity? Previous studies on scarcity tend to overlook the aspect of perception. By analyzing repeated water conflicts in northern Thailand, this study sheds light on this aspect and solves the puzzle posed by repeated water conflicts in a small watershed.