Calculating Price Elasticity of Water Demand Using Gene Expression Programming Based on Economic,Social and Meteorological Variables

Determining the changing rate of water consumption through altering parameters such as water tariffs can help water companies select appropriate water policies. This paper is intended to find the proper relation between the water price elasticity of demand and some social, economic and climatic variables that are released annually by international organizations like the United Nations Development Program and the World Bank. By using genetic algorithm, different combinations of water price elasticity of demand and variables like gross domestic product, per capita gross domestic product, gross national income, precipitation, human development index, average temperature and household size have been analyzed. It was found that the absolute price elasticity of water demand has positive relationships with precipitation and price of water. It has also been found that the gross national income, average percent of consumers who have secondary education and human development index have a negative relation with the absolute price elasticity of water demand.

     

Factors Influencing Per Capita Water Consumption In Urban Areas Of Developing Countries And Their Implications For Management,With Special Reference To The Khartoum Metropolitan Area

ABSRTACT

The fast growing population in Third World countries and the limited physical resources in rural areas have led to the dramatic expansion of the urban areas of these countries. It is now recognized that when planning for the development of these areas, early consideration must be given to the difficulties and cost of providing potable water equitably to all users. Detailed studies are necessary for particular situations so as to provide a basis for better management practices.

Khartoum, a growing urban area in Sudan, has been chosen as a case study. A proposed framework and technique of analysis is shown. Factors influencingper capita consumption are correlated and mathematical models have been generated for the two distinct classifictions of consumers: (1) consumers with piped supply and (2) consumers obtaining water from water vendors or from standpipes (squatter settlements).

The most significant factors affecting the consumption appear in the fitted equations. Of these factors, the number of occupants in the household influences the per capita consumption but at a decreasing rate. Price has a significant impact on demand: price elasticities of about -0.60 and -0.78 are obtained for households with piped connections and squatter areas respectively. Water utility authorities can use price as a tool to ration or discourage water consumption in the piped connection households and to increase the rate of consumption in the squatter areas.     

Domestic Water Consumption under Intermittent and Continuous Modes of Water Supply

Although an extensive literature emphasizes the disadvantages of intermittent water supply, it remains prevalent in rural areas of developing countries. Understanding the effects of water supply time restrictions on domestic water use activities and patterns, especially for hygienic purposes, is important for the elaboration of the water supply. We studied the influence of intermittent and continuous water supply on water consumption and related activities in villages in the central region of the Wei River basin, China. Data were collected from a survey of 225 households in the sampled villages. Compared with a continuous water supply of 24 h d^?1 (hours per day), adopting an intermittent water supply can reduce domestic water consumption. However, it presents risks in terms of hygiene behavior, particularly the frequency of face, hands, and feet washing, as well as water sharing among family members. Outdoor water consumption is more affected than indoor water consumption under slight supply restriction (≥6 and?<?24 h d^?1), whereas indoor water use is most affected under moderate supply restriction (>1.5 and?<?6 h d^?1). Villages with high supply restriction (≤1.5 h d^?1) meet only the minimum basic requirements for domestic use, 33.6–34.7 L c^?1 d^?1 (liters per capita per day). We conclude that the determination of the daily water delivery duration for intermittent water supply in rural communities of developing countries should give greater consideration to differences in water use activities and patterns under the water supply time restrictions.     

Assessing and Modelling the Influence of Household Characteristics on Per Capita Water Consumption

Sustainable urban water supply management requires, ideally, accurate evidence based estimations on per capita consumption and a good understanding of the factors influencing the consumption. The information can then be used to achieve improved water demand forecasts. Water consumption patterns in the developed countries have been extensively investigated. However, very little is known for the developing world. This paper investigates per capita water consumption resulting from water use activities in different types of households typically found in urban areas of the developing world. A data collection programme was executed for 407 households to extract information on household characteristics, water user behaviour and intensity and the nature of indoor and outdoor water use activities. The rigorous statistical analysis of the data shows that per capita water consumption increases with income: 241, 272 and 290 l/capita/day for low, medium and high income households, respectively. Additionally, the results suggest that per capita consumption increases with the number of adult female members in the household and almost one-third of consumption is via taps. The collected data has been used to develop statistical models using two different regression techniques: multiple linear (STEPWISE) and evolutionary polynomial regression (EPR). The inclusion of demographic parameters in the developed models considerably improved the prediction accuracy. Two of the best performing models are used to forecast the water demand for the city, using four future scenarios: market forces, fortress world, policy reform and great transition. The results suggest that the domestic water demand would be highest in the fortress world scenario due to the increase in population and size of built-up area.     

基于多智能体的城镇家庭用水量模拟预测分析

提出了基于多智能体的城镇家庭用水量模拟模型(MA-UHWDS),通过构造不同发展情景,对家庭用水量变化趋势及其影响因素进行了分析。以青岛市为实证城市,采用2003—2012年统计资料,计算分析了居民用水边际消费倾向、基本用水需求和不同收入户人均用水量,并对不同情景下2013—2022年各类收入户人均用水量和城镇家庭用水总量进行了定量模拟预测分析。结果表明:2003—2012年中,城镇家庭平均水费支出占总消费支出的比重仅为0.395%,易造成居民节水意识淡薄,最低收入户人均用水量除2008年外均低于基本需水量,而最高收入户平均超过基本需水量14.16 m3,水价改革需综合考虑低收入家庭的支付能力和高收入家庭的过度用水;2022年7类收入户在水价高增长收入低增长情景下的人均用水量与在水价低增长收入高增长情景相比下,分别减少了16.7%、18.4%、18.1%、16.1%、15.0%、17.8%和13.8%,水价和收入会明显影响家庭用水量。MA-UHWDS为区域用水总量调控提供了新的研究思路和工具。     

A Large Scale Study of Drinking Water Requirements in the Po Basin (Italy)

Abstract

A newprocess that consists of showing the dependence of drinking water consumption on the economic, productive, and physical characteristics of municipalities was proposed. Statistical procedures were used in a survey of the territorial distribution of drinking water consumption in the Po Valley (Italy) carried out using the results of the 1987 National census and Ministry of Public Works investigations. The factor analysis proved to be particularly useful, allowing the expression of two components describing the water supply of the municipalities included in the survey, respectively defined as water availability and anthropic activity. The former is explained through variables such as precipitation, air temperature, and the geographical location of the municipality, according to specific climatic peculiarities. The latter is adequately represented by the type ofprevalent activity of the population (i.e., rural or urban), the level of urbanisation of the municipalities, and then the level of public services itprovides and the overall municipal income. The methodology described could prove useful in planning and managing the resources allocated for drinking purposes. Adjustment coefficients for the average per capita consumption of each demographic class are then calculated using suitable multiple regression models based on results of the factor analysis. An estimation of the water losses in the supply systems of some Italian towns is also presented.     

Facing Water Scarcity in Jordan

Abstract

Jordan is extremely water-scarce with just 167 m³ per capita per year to meet domestic, industrial, agricultural, tourism, and environmental demands. The heavy exploitation of water resources has contributed to declines in the levels of aquifers and the Dead Sea. Rapid growth in demand, particularly for higher quality water for domestic, industrial, and tourism uses, is significantly increasing pressure on agricultural and environmental uses of water, both of which must continue to adapt to reduced volumes and lower quality water. The agricultural sector has begun to respond by improving irrigation efficiency and increasing the use of recycled water. Total demand for water still exceeds renewable supplies while inadequate treatment of sewage used for irrigation creates potential environmental and health risks and presents agricultural marketing challenges that undermine the competitiveness of exports. The adaptive capability of the natural environment may already be past sustainable limits with oasis wetlands having been most seriously affected. Development of new water resources is extremely expensive in Jordan with an average investment cost of US$4 to $5 per cubic meter. This paper examines four integrated water resources management (IWRM) approaches of relevance to Jordan: water reuse, demand management, energy-water linkages, and transboundary water management. While progress in Jordan has been made, the Ministry of Water and Irrigation continues to be concerned about the acute water scarcity the country faces as well as the need to continue working with concerned stakeholders to assure future water supplies.     

南水北调受水区生活用水影响因素与节水潜力

为持续推进水资源节约工作,保障南水北调受水区经济社会可持续发展,开展居民用水习惯问卷调查,分析 南水北调东线和中线受水区各省（直辖市）居民家庭用水现状及差异特点,识别生活用水的主要影响因素,设计节 水情景模拟家庭节水潜力。结果表明,受水区居民用水习惯呈现较明显的地域性差异,其中：天津市和河北省居 民整体节水意识较高,河南省和山东省现状人均日用水量比北京市、安徽省和江苏省低 12%;从用水行为上看,家 庭洗浴日均用水量浮动范围达 30%,是造成用水差异的主要环节。节水情景模拟结果显示,通过进一步提高居民 节水意识、替换高等级节水器具、增强家庭内部废水循环利用等措施,受水区居民人均日用水量可下降 12%～29%。根据受水区各省 (直辖市) 针对其生活用水特点,提出了进一步开展节水器具普及工作、完善节水管 理体制机制、提升居民节水意识以及合理利用废水等节水建议,因地制宜持续推进节水工作。     

广东省用水效率时空变化分析

用水效率的提高是在用水总量一定的前提下,保障和行业用水需求和经济社会良性发展的重要手段。通过对广东省1980-2011年用水效率指标在年度和地市空间上的变化趋势和变化规律进行分析,结果表明,总用水量年均增长率为1.08％,人均水资源量年均递减率为2.90％,人均用水量年均递减率为1.16％,人均综合用水量年均递减率为1.75％,都与总用水量呈反向变化的特征,而耗水量和农田灌溉亩均用水指标年均变化率分别为0.76％和-0.21％,变化幅度相对较小,说明用水效率整体提高并不明显。并分析了各市不同用水阶段单位农业增加值用水量变化,以2005-2010年最快,年均变化率为-8.52％,同时表现出区域和年际变化差异较大,年灌溉用水效率较低的特点。     

人均生活用水量预测的区间S型模型

本文在大量分析国内外不同时期、不同地区均生活用水量变化规律的基础上,总结了影响人均生活用水量大小的主要因素,认为人均生活用水量与当地社会经济发展水平有一定联系,呈现S型曲线关系,并在一定区间范围内变化.根据这一认识,本文建立了具有普遍意义的人均生活用水量预测的区间s型模型,并介绍了应用原始数据通过最优拟合的方法选择的预测方程.该模型既能给出人均生活用水量变化区间,又能预测其大小.文末以一个实例说明这一模型在预测规划水平年人均生活用水量的应用过程.     

An Evaluation of Demand for and Supply of Potable Water in an Urban Centre of Abeokuta and Environs, Southwestern Nigeria

The current and future demand for potable water supply to Abeokuta city and environs in southwestern Nigeria were estimated in this study. The estimated water demands, up to the year 2030, were based on population growth and per capita water consumption. The study also investigated whether the present source of public water supply to the city and environs could meet the estimated demand. The consumption standards of 120 and 60 l per capita per day for urban and semi-urban water supplies respectively, recommended in the Nigerian Water Supply and Sanitation Policy, were used for domestic demand estimates. The institutional, industrial, fire service, horticulture and animal husbandry water requirements were based on reasonable percentages of the total domestic demand. The flow of Ogun River, which is the source of raw water for the Abeokuta Water Supply scheme serving Abeokuta city and environs, was assessed and found sufficient to meet the estimated future potable water requirements of the study area. The study indicated that the estimated current annual potable water demand of Abeokuta city and environs (in 2011) is 5.52 × 10⁷ m³ (1.51 × 10⁵ m³/day) and the projected annual potable water demand for the year 2030 is 7.67 × 10⁷ m³ (2.10 × 10⁵ m³/day). At a design capacity of 1.62 × 10⁵ m³/day, the total water supply from the Abeokuta Water Supply Scheme at full capacity will just be about the total required in 2014. By 2015, the scheme will no longer be adequate to meet the total water required, even if it is run at full capacity. It is therefore imperative that the current scheme is expanded within the next 4 years in order to meet the potable water demand of the intended population.     

Water Resources Management under Competitive Sectoral Demand A Case Study from Jordan

Abstract

Jordan is a country plagued with water scarcity. The annual per capita share of water is currently estimated at 170 m³ and the figure is expected to drop to 90 m³ in the year 2020 as a result of the disproportional increase in population relative to water resources development. Moreover, about 70 percent of the country's water resources are consumed in irrigated agriculture. For most crops growing in all areas and seasons and managed with different production technologies, analysis of net return from unit volume of irrigation water showed, with few exceptions, low values pertaining to production under protected agriculture. Such a result indicated unjustified waste of water in the agricultural sector at the expense of the domestic sector. This paper reviews current challenges facing water management in the country and proposes short- and long-term alternative solutions.     

ARIMA模型在人均生活用水量预测中的应用

随着生活用水量需求的日益增加,对于人均生活用水量的合理预测成为城市给水规划的关键。以上海市1949-2003年的人均生活用水量统计资料为依据,利用SPSS11．5软件的ARIMA模型功能对上海市短期人均生活用水量进行预测。该模型的缺点是只能对人均生活用水量数据做短期预测,对于长期预测,由于不确定性的增加,结果的偏差将有所增加。     

Preliminary Assessment of Rainwater Harvesting Potential in Nigeria: Focus on Flood Mitigation and Domestic Water Supply

This study was accomplished using 26 locations in the major ecological zones of Nigeria as well as different classes of residential buildings and different levels of water consumption. For each location, house dwelling class and level of water consumption, a water balance approach was used to assess the proportion of water demand that can be met by rainwater. Results obtained indicate that for all the locations in the rainforest zone and some parts in the guinea savanna zone, over eighty percent (80 %) of water demand of those living in bungalows can be met by rainwater. Rainwater harvesting potential was found to be a power function of rainfall coefficient of variation, with coefficient α and exponent β. High correlation coefficients (0.881?≤?R ² ?≤?1) were obtained between coefficient α and roof area per capita. Also, high correlation coefficients (0.847?≤?R ² ?≤?0.992) were obtained between exponent β and roof area per capita.     

Energy for freshwater supply,use and disposal in the Netherlands: a case study of Dutch households

Abstract

This study presents energy requirements for Dutch household water: 10.2 GJ per capita per year, which includes 9.3 GJ (92%) for heating water, 0.6 GJ (6%) for water supply, and 0.2 GJ for wastewater treatment (2%). The top three energy consumers include shower water (58%), dishwasher water (9%) and washing machine water (8%). The Netherlands, a water-abundant country, expends far more energy to heat water for households than to supply municipal water, or to treat and dispose of wastewater. Policies to make water chains more sustainable should focus on use, rather than supply and disposal.     

Urban Household Water Demand in Beijing by 2020: An Agent-Based Model

Beijing is faced with severe water scarcity due to rapid socio-economic development and population expansion, and a guideline for water regulation has been released to control the volume of national water use. To cope with water shortage and meet regulation goal, it has great significance to study the variations of water demand. In this paper, an agent-based model named HWDP is developed for the prediction of urban household water demand in Beijing. The model involves stochastic behaviors and feedbacks caused by two agent roles which are government agent and household agent. The government agent adopts economic and propagandist means to make household agent optimize its water consumption. Additionally, the consumption is also affected by the basic water demand deduced from extended linear expenditure system. The results indicate that the total water demand of urban households in Beijing will increase to 317.5 million cubic meters by 2020, while the water price keeps growing at a low level. However, it would drop to 294.9 million cubic meters with high growth of water price and low increment in per capita disposable income. Finally, some policy recommendations on water regulation are made.     

Water resources development in India

Abstract

India, an ancient rural and agricultural society that is rapidly modernizing, receives a fair share of its yearly precipitation in only a few days of the monsoon, with high inter-annual variability. In most of its regions, therefore, India needs to store a large proportion of its annual runoff in reservoirs for use in non-monsoon months. In spite of this strategy being in operation for the last 60 years, India’s per capita reservoir storage is relatively small, and water-use efficiency also remains low. Though the overall performance of the water sector in terms of matching of supply and demand has improved, the country remains challenged by deficiencies in laws, regulation policies and institutions, and weakened by a suboptimal work culture in politics, legislature, technocracy and non-governmental organizations (NGOs).     

Comparing 20th Century Trends in U.S. and Global Agricultural Water and Land Use

Abstract

Globally and in the United States, agriculture is the major user not only of water but also of land. This paper compares trends in aggregate and per capita water and land use by the agricultural sector in the United States and the world during the 20^th century. It finds that although cropland use per capita has been declining in both areas since the early 1900s, agricultural water use per capita only began declining in the latter half of that century. That the increases in efficiencies of agricultural water use lagged behind the increases in the efficiency of cropland use is consistent with the fact that farmers (and farming communities) have traditionally had stronger property rights to their land than to their water. As a result, through much of the 20^th century, farmers had a greater incentive to improve the efficiency of land use than that of water use and to substitute water for land (or irrigated land for dryland) in producing crops.     

The Perception of Water Quality Among Rural Communities in South-Western Nigeria: Lesson for Planners

ABSTRACT

“Clean water for all” is one of the goals of the UN International Drinking Supply and Sanitation Decade 1981–90. This goal to be accomplished, requires a level of governmental investment which is difficult to reach in many developing countries. This is particularly so of Nigeria where a vast majority of rural people is yet to benefit from improved water supply and where the level of priority accorded domestic water supply is dismally low, with some states devoting just about 1% of their total capital expenditure to water supply provision.

At the same time, there is evidence that the rural people in many places, aware of the advantages of good water sources and the disadvantages of bad ones, show preferences for and undertake development programmes connected with good quality water supply: this is here exemplified by three rural communities in southwestern Nigeria. Not only are these people knowledgeable about water quality and its relationship with health, they are also eager to seize any feasible opportunities to improve their water supply situation.

It is argued that rather than rely on gigantic time-consuming, capital intensive and difficult to maintain schemes, as we have presently with government projects, more modest ones within the competence of the rural communities should be encouraged.     

基于洛伦兹曲线的甘肃省用水结构分析

辨析区域用水结构特征,对于优化区域水资源配置、社会经济与生态环境协同发展具有重要意义.利用洛伦兹曲线、基尼系数、洛伦兹不对称系数等方法,对甘肃省各区域近10 a来用水结构时空分布特征、均衡差异性、主要用水指标(万元GDP用水量、万元工业增加值用水量、人均综合用水量和净灌溉用水量)进行研究,并对研究结果进行定量分析.结果...