Some Characteristics and Impacts of the Drought and Water Crisis in Southeastern Brazil during 2014 and 2015

Since the austral summer of 2014 southeastern Brazil has been experiencing one of the most severe droughts in decades. This rainfall deficiency has generated water shortages and a water crisis that have affected population and local economies in the metropolitan region of Sao Paulo, the largest megacity in South America. By January 2015, main reservoirs had reached storage levels of only 5% of their 1.3 billion m3 capacity. The meteorological causes of the drought situation were linked to changes in the regional circulation, characterized by a mid-troposphere blocking high that lasted 45 days during the summer of 2014 over southeastern Brazil, something not seen in five decades. The water crisis was aggravated by a combination of lack of rainfall and higher temperatures, the summer of 2014 being the warmest and driest over the Cantareira reservoir system since 1951. Increasing population and water consumption increased vulnerability in the region, and while human-induced warming may not have generated the atmospheric conditions behind the 2014 and 2015 summer droughts in Southeast Brazil, it is more likely that the warm temperatures have affected the severity of the drought and exacerbated the impacts on the population.

Crisis of Water Resources on the Ulan Buh Desert Oases, Inner Mongolia, China-A Case Study of Dengkou County

Hetao Plain, composed of hundreds of oases, is one of the most important grain-producing areas in China. Most crops, especially wheat and corn, depend on irrigation, thus water availability is a key issue for grain productivity on this land. The Yellow River is the main water source for irrigation and a crisis of water resources for agricultural use occurs because of increasingly reduced river flows and water-using competition with industry and human residential use. In order to understand the current situation and distribution of water resources on these oases, we collected 20-yr＇s data of river runoff, irrigation volumes, infiltration and precipitation to examine the relationships between water resources distribution and its agricultural use. We found that the oasis in Dengkou county was short of water resources with a water deficit rate of 5.14% in 2010. Based on the trend of the data, water deficit will continue to increase as the population grows in the future. Water resource is a limiting factor to agricultural development in this region and proper management of water use and strategies for water resource conservation are urgently needed. Especially, based on our results we suggest that current irrigation methods need to be greatly improved to save the water that was lost from evaporation.

Implications of the New Operational Rules for Cantareira Water System: Re-Reading the 2014-2016 Water Crisis

During the 2014-2016 water shortage crisis, the Metropolitan Area of Sao Paulo (MASP) water supply system extracted pumping volume from the Cantareira System. Before the crisis, between 1984 and 2013, the reservoir’s average water extraction flow was 29.6 m3·s-1. During the period of pumping volume usage, the average extraction flow was 16.2 m3·s-1. Following the crisis, two new mitigation policies were implemented: a water extraction Resolution (in 2017) and a Resolution for water reallocation from another basin (in 2018). This study provides a novel investigation of the Cantareira System water crisis by assessing the mitigation policies impacts on storage level dynamics. The system storage level was evaluated using the reservoir simulation module of PDM-Cemaden hydrological model, assuming that the new policies had already been implemented prior to the crisis. A control simulation was run with observed in- and out-flow and operationally-practiced extraction flow. The storage level dynamics impacts were evaluated under 4 water mitigation policies scenarios varying the policies implementation starting date, the extraction flow range and including the water reallocation variable. Results showed that pumping volume would only need extraction during a short period (Scenarios I, III and IV), and considering the water reallocation, pumping volume extraction would not have been necessary (Scenario II). Although the pumping volume would still have been extracted during a short period, water shortage impact would have been lessened, had the policies been already implemented before the crisis. The water mitigation policies implementation supports the reservoirs storage management but does not guarantee that MASP water demand is fully met. Therefore, in order to effectively improve water security, further policies and practices to reduce water demand and enhance supply should be considered.

Water-Level Fluctuations of Urmia Lake: Relationship with the Long-Term Changes of Meteorological Variables (Solutions for Water-Crisis Management in Urmia Lake Basin)

Urmia Lake in northwest of Iran, through the recent years has been extremely faced with the water crisis. Climate variations and anthropogenic impacts could be two main affiliated factors in this regard. We considered the long term data series of precipitation, temperature and evaporation in monthly and yearly scales in order to compare to water-level values of Urmia Lake. The statistics approaches such as: standard deviation, trend analysis, T test, Pearson and Spearman correlations, liner regression are used to analyze all variables. The results released that the water-level of Urmia Lake along with the precipitation and temperature of the lake’s basin have experienced the periodic changes through 1961 to 2010, as there are some gradual dryness trends on the study area according to precipitation and temperature variations. Urmia Lake periodic water-level fluctuations show more significant correlation to temperature than the precipitation. Whiles, the water-level’s decreasing behavior especially through 1998 to 2010 is more harsh and different than the rate that is considered for precipitation’s decrease and temperature’s increase. Thus, there could be some anthropogenic factors in the basin which produced some supplementary causes to shrink Urmia Lake. Extracting the double precipitation over the basin through introducing and categorizing of atmospheric synoptic systems in order to cloud seeding operation could be one of urgent and innovative solutions to mitigate water crisis in the basin.

Investigation of Water Balance and Map Crisis Preparation in the Recent Two Decades of Kalacho Plain,Dehdasht,Iran

Considering the water restrictions,it is important to check the water balance in each area.These restrictions are even more important in arid and semi-arid regions.The purpose of this study was to study the water balance in the Kalacho plain of Kohgiluyeh city.Kalacho plain is about 15 km east of Dehdasht city.In recent years,due to the excessive extraction of lowland wells,the quality of groundwater has also declined steadily.Therefore,hydrogeological assessment and aquifer management seems necessary.Groundwater management requires understanding and functioning of the aquifer under natural conditions(firstly)and then predicting the effects of harvesting or feeding.Undoubtedly,understanding the actual behaviors of a natural system requires some research for each particular area.The average annual temperature and precipitation in the meteorological stations is about 18.1°C and 394 mm,respectively.The water crisis map of this plain has been prepared based on the data of 45 km2 area during the 1991-1992 blue water year.Groundwater Balance Range of the Kalacho Plain is selected based on available statistics and distribution of piezometers,wells and agricultural areas.According to the long-term hydrograph,the plain faces an average loss of 0.15 m and a reservoir deficit of 2.5 million m3.Also during the 20-year period,a total of 24 m of drop and 68 million cubic meters of reservoir deficits were created in the plain.By calculating the effective parameters in the general water balance equation(inputs and outputs),the plain was finally divided into five critical areas.Zones 1,2 and 3 are the most critical lowland areas in the vicinity of the hydraulic connection with the Gachsaran Fm.,and areas 4 and 5 are less critical because of the adjacent Asmari Formation,which feed on this karstic aquifer.Overall,this negative balance indicates an increasing drop in groundwater level and its reservoir deficit.

Preventing a Water Crisis

Water security in Africa has never been as starkly highlighted as the countdown to Day Zero in Cape Town. South Africa, where becauseof an unprecedented drought, the entire city of about 4 million residents could be without water in July. Water restrictions for all residents are already in place and Day Zero has an activation date of July 9 （at the time of writing）. If this catastrophe happens, it would make the famous tourist city that is frequently voted the world＇s most beautiful destination, earn another more dubious title that of the first major city in the world to ever run out of water.

Determining safe yield and mapping water level zoning in groundwater resources of the Neishabour Plain

Groundwater is a crucial sources of water supply,especially in arid and semi-arid areas around the world.With uncontrolled withdrawals and limited availability of these resources,it is essential to determine the safe yield of these valuable resources.The Hill method approach was used in this study to determine the safe yield the Neishabour aquifer in Khorasan Razvi province in Iran.The results showed that the safe yield in the Neishabour aquifer is 60%lower than the current pumping amounts during the study period,indicating that further overdrafts could result in the destruction of this aquifer.This highlights the importance of using the Hill method to estimate the permitted exploitation from other aquifers,thus preventing problems caused by over-extraction and maintaining stability of global groundwater levels.

咸海变迁——危机和现状

咸海曾是世界第4大湖。20世纪60年代开始,由于农业灌溉需求,咸海流域各地区大量从阿姆河和锡尔河调水,从而导致咸海快速缩小、水面降低、水质恶化。到21世纪初,湖面已缩减到原来的1/8,干涸的湖底成为盐碱度很高的盐漠,生物物种大量减少,生态环境恶化造成生态危机。中亚国家独立后,阿姆河与锡尔河上下游地区由于缺水产生了矛盾,进而严重影响了国家之间的关系。虽进行了多次协商,但最终中亚国家未能对咸海水资源危机提出一致的解决方案。随后,哈萨克斯坦独自开展针对咸海的保护措施,挽救了咸海北部的部分水体;乌兹别克斯坦近年来也开始在咸海危机治理方面采取积极态度。目前,学术界主流意见是,咸海危机是人为的,不宜将其与全球气候变化相联系。咸海危机由于治理和地下水的补给有所缓和,虽不会像预测中的那样完全消失,但最终能够恢复到什么程度还有很大的不确定性。本文通过对咸海危机的历史、现状和前景做了较完整的论述,以期为我国西北干旱环境治理提供科学参考。

水网布局下黄河流域应对极端枯水的关键科学问题

变化环境下极端气象水文事件频发,长江、黄河面临同枯风险。在国家水网建设背景下,为提高长江、黄河同枯的极端不利情景下黄河流域水资源安全保障能力,本文分析了长江、黄河两大流域水资源安全面临的现实问题,识别了变化环境下大型流域枯水遭遇—水危机形成—跨流域调水潜力—多线路成网互济—极端枯水下水资源安全保障中亟需破解的关键科学问题,构建了水网布局下黄河流域应对极端枯水的总体研究框架,提出该领域重点研究方向包括:变化环境下长江、黄河极端枯水遭遇规律与空间变异机制,水危机风险多链路传导与复合影响定量评估,极端枯水下跨流域调水挖潜增供,长江和黄河跨流域联合调配与多线路互济精细化调控、极端枯水下流域水资源韧性提升优化调控等。

Coastal Reservoirs Strategy for Water Resource Development—A Review of Future Trend

Water use and access become a more and more important determinant of environmental equity and human development according to the view held by the UN [1]. Water scarcity is one of the major crises which has overarching implications for other world problems especially poverty, hunger, ecosystem degradation, desertification, climate change, threatening world peace and security [2]. In the decades to come, freshwater consumed by human will get to a tipping point. Many projects and concepts have been proposed and implemented for several years to improve the effectiveness of using water. These research activities can be grouped as: desalination plants;water detention (like rainwater tanks for collection and reuse);wastewater reuse;dams and reservoirs. This paper summarized the characters of these water solutions. But these methods can’t provide enough fresh water due to limitations imposed by these methods as well as following industry and population’s development. To overcome these shortcomings, coastal reservoir strategy is proposed in the paper. This new strategy is technically feasible, environmentally sustainable and cost effective by demonstration and comparison.

Modeling the Impact of Land-Use Change on Water Budget of Gaza Strip

Gaza has a water crisis and faces serious challenges for the future sustainability of its water resources. Land-use change has an expected effect on water budget of the Gaza Strip. Three different land cover scenarios;the and cover of 2007, land cover of 2020, and full urbanization land cover were simulated independently using The Automated Geospatial Watershed Assessment (AGWA) tool which work under the umbrella of GIS. In general, the simulation results indicate that land-cover changes will significantly alter the hydrologic response of Gaza region. Percolation is expected to decrease in all options as urban areas are expanded where as the simulated surface runoff reflected a relative departure from the first scenario comparing with other scenarios. In the baseline scenario (2007), the simulated surface runoff and percolation represent 12% and 41% respectively from the water budget components of the Gaza Strip. In year 2020, these values were expected by the simulation results to be 20% and 27% respectively. A unique linear relationship between the relative change in urban area and the corresponding relative change in surface water has been investigated from the simulation results. The analysis of the three urbanization scenarios can give decision makers better understand for the future situation and assist them to advance towards achieving sustainable development planning for water resources system in the Gaza Strip.

Water Resources and Management under Increasing Urban Demography: A Kenyan Perspective—A Review

The United Nations classifies Kenya as a water-scarce country since it has less than 1000 m3 per capita of renewable freshwater supplies. Numerous factors including global warming, contamination of drinking water, and a lack of investment in water resources have aggravated the water crisis in Kenya. Estimates indicate that only about 56% of its population has access to safe water supply. Like many developing countries, Kenya recognizes the crucial role of water in realizing its development goals. Its economic performance and poverty reduction are critically dependent on clean water availability for agriculture, industrialization, energy production and tourism among others. Similar to most developing countries, Kenya suffers from lack of human, monetary and institutional capabilities to efficiently provide clean and sufficient water to its citizens. The water shortage in the major cities is acute and chronic and has continued to worsen with increasing urbanization, water pollution and encroachment of water catchment areas by humans and invasive plant species. Despite the water challenges facing the urban populations, Kenya possesses sufficient water resources to meet demand if the available resources are properly managed. Several initiatives are being put in place in Kenya to mitigate the water challenges and protect water resources in Kenya. These include enacting of water policies to protect water catchment areas, reduce pollution and enhance access to clean water.

纳米纤维复合水凝胶的制备及其大气集水性能

针对大气集水领域的水凝胶具有力学性能较差和水输送缓慢等缺点,以亲水纤维素纳米纤维(cellulose nanofibers,CNF)作为骨架增强聚N-异丙基丙烯酰胺(poly(N-isopropylacrylamide),PNIPAM)水凝胶的力学性能,并通过浸渍的方法引入氯化锂(LiCl)吸湿剂,制备PNIPAM/CNF@LiCl复合水凝胶。然后,通过静电纺丝将炭黑(carbon black,CB)纳米颗粒均匀嵌入聚丙烯腈(polyacrylonitrile,PAN)纳米纤维中,并将制备的PAN/CB纳米纤维膜作为PNIPAM/CNF@LiCl复合水凝胶的光热层,进一步构筑一体化水凝胶PNIPAM/CNF@LiCl-PAN/CB,利用PAN/CB纳米纤维膜优异的光热性能实现PNIPAM/CNF@LiCl-PAN/CB水凝胶的水汽脱附,从而完成大气水的收集。在温度为25℃、相对湿度为90%条件下,具有分级多孔结构和亲水纤维素纳米纤维的PNIPAM/CNF@LiCl-PAN/CB水凝胶的吸水率为0.71 g/g。制备的双层纳米纤维复合水凝胶力学性能优异,其水传输及大气水收集效率高,研究结果为从大气中收集清洁水提供了新思路。

深圳市再生水利用策略探讨与研究

水资源短缺已成为制约城市高速发展的瓶颈问题,再生水高效利用是贯彻循环经济、节能减排科学理念的主要途径之一,也是城市解决水资源不足、保障城市发展的1项重要举措。针对深圳市再生水综合利用情况复杂的问题,研究通过优化空间布局、梳理重点对象、提升系统、完善管理机制等各环节,提升利用率;并以光明区为试点进行探索,针对各类再生水用户采用不同策略,以实现社会、经济和环境等各方面效益最大化。通过深入挖掘深圳市再生水的高效利用途径,为解决城市水资源不足提供有力的支撑和保障,推进城市可持续高质量发展。

高校用水现状与节水潜力分析

为了适应北京市水资源日趋减少,而需水量又逐渐增加的局面,作为北京市高校,需要进一步分析开发大学校园的节水潜力,加强节水设施建设并培养学生的节水意识。根据北京市有关节水用水要求,高校应高度重视节水工作的重要性,开创高校节水工作的新局面,同时从技术、管理和教育3方面大力节水,从而为北京市建设节水型社会提供宝贵经验．

华北水资源利用现状及其宏观调控对策研究

本文在对全国和华北地区水资源开发利用的现状进行分析比较的基础上 ,总结华北地区水资源利用的特点 ,分析了华北地区水资源开发存在的主要问题 ,然后剖析了该地区资源危机的主要原因 ,最后提供了该地区水资源可持续利用的对策。结果表明 :( 1 )华北地区水资源存在危机 ,且该危机已经相当严重 ;( 2 )人为因素是水资源危机的根本原因 ;( 3)适当的发挥政府的职能 ,通过增加水源、提高水资源的利用率等措施 ,可以缓解华北地区水资源危机。

中国农业可持续发展中的水危机及其对策

水危机是当今世界面临的一个热点问题。它不仅制约着当代的经济增长、社会发展和人类生存,而且关系着未来社会的发展和进步。本文在简要介绍我国水资源危机现状的基础上,着重分析了我国农业用水的形势及存在的主要问题,并从农业可持续发展的高度,论述了农业水资源保护与持续利用的基本策略及其主要途径。

基于微藻细胞培养的水质深度净化与高价值生物质生产耦合技术

水资源和能源危机是21世纪人类面临的重大挑战。开发高效的氮磷控制技术以及寻找可持续再生、环境友好的新型能源是解决这些挑战的有效手段。微藻培养技术的出现,为水质深度净化、氮磷高效去除和生物能源生产提供了可能。总结了微藻培养技术在污水处理中作为三级处理单元深度净化水质、去除氮磷的应用,并分析了大规模培养微藻以获得生物能源的研究现状。在此基础上,提出了将污水处理工艺和生产工艺耦合的理念,以污水为资源,实现污水处理系统从"处理工艺"向"生产工艺"的转化,在深度净化污水的同时,以污水为原料获取"新"资源和"新"能源,为缓解当前资源匮乏、能源紧缺的形势提供可能的解决途径。在未来资源和能源愈加紧张的严峻形势下,基于微藻细胞培养的水质深度净化与高价值生物质生产耦合技术具有广阔的发展前景。

我国农业可持续发展的水危机及广泛开展节水农业前景初探

通过对我国水资源状况及利用特征、水资源利用中存在问题的分析 ,结合国内外专家学者的意见 ,探讨了为实现我国农业可持续发展 。