Quality of rainwater harvesting for rural communities of Delta State,Nigeria

This paper assess the level of potability of rainwater samples harvested from catchments roofs in 6 rural communities of Delta State, Nigeria to achieve this goal a stratified sampling technique was adopted in the establishment of 90 sterilized cans into the 3 senatorial districts of Delta; on the basis of one can for thatch, aluminium, asbestos and corrugated iron sheets, and open surfaces. Six rural communities each were chosen from the three senatorial districts, making a total of 18 rural communities that were chosen for the study. The harvested rainwater samples were analysed with the most appropriate equipment and analytical techniques as recommended by World Health Organisation (WHO) and federal ministry of environment in Nigeria. Kruskal—wallis H’test statistical techniques was employed to ascertain whether differences exist amongst the rainwater samples collected from thatch, aluminium, asbestos and corrugated iron roofing sheets, and open surfaces. The result revealed that most of physiochemical and biological characteristics of rainwater samples were generally below the WHO threshold, as such the rainwater characteristics showed satisfactory concentration in these rural communities. Thus, the rainwater from these rural communities should be harvested, stored for human consumption and for other uses by the inhabitants. But treatment is needed in terms of their pH, TSS, Fe and colour. Similarly, significant differences exist amongst the rainwater samples collected from the 5 roofing types, most especially low quality of rainwater were observed in thatch and asbestos roofing sheets. Thus, rainwater from these sources should be purified before consumption.     

Economic and environmental analysis of standard, high efficiency, rainwater flushed, and composting toilets

The current sanitation technology in developed countries is based on diluting human excreta with large volumes of centrally provided potable water. This approach is a poor use of water resources and is also inefficient, expensive, and energy intensive. The goal of this study was to compare the standard sanitation technology (Scenario 1) with alternative technologies that require less or no potable water use in toilets. The alternative technologies considered were high efficiency toilets flushed with potable water (Scenario 2), standard toilets flushed with rainwater (Scenario 3), high efficiency toilets flushed with rainwater (Scenario 4), and composting toilets (Scenario 5). Cost, energy, and carbon implications of these five design scenarios were studied using two existing University of Toledo buildings. The results showed that alternative systems modeled in Scenarios 2, 4, and 5 were viable options both from an investment and an environmental performance perspective. High efficiency fixtures that use potable water (Scenario 2) is often the most preferred method in high efficiency buildings due to reduced water use and associated reductions in annual water and wastewater costs. However, the cost, energy, and CO(2)EE analyses all showed that Scenarios 4 and 5 were preferable over Scenario 2. Cost payback periods of scenarios 2, 4 and 5 were less than 10 years; in the future, increase in water and wastewater services would further decrease the payback periods. The centralized water and wastewater services have high carbon footprints; therefore if carbon footprint reduction is a primary goal of a building complex, alternative technologies that require less potable water and generate less wastewater can largely reduce the carbon footprint. High efficiency fixtures flushed with rainwater (Scenario 4) and composting toilets (Scenario 5) required considerably less energy than direct energy demands of buildings. However, the annual carbon footprint of these technologies was comparable to the annual carbon footprint from space heating. Similarly, the carbon savings that could be achieved from Scenario 4 or 5 were comparable to a recycling program that can be implemented in buildings.     

Harvesting of rainwater and brooklets water to increase mountain agricultural productivity: A case study from a dry valley of southwestern China

In semi-arid valleys of southwestern China, seasonal shortage of water is the major contributing factor to low and unstable crop yield. Harvesting of both rainwater and brooklets water in the semi-arid valleys of Ningnan county of Sichuan Province has brought about considerable economic and environmental change. Brooklet water is collected throughout the year but mainly during the rainy season in a series of ponds while rainwater is harvested in underground tanks constructed on road side or land boundaries with only a small opening above ground to save limited cropland. Increased water availability has promoted cultivation of sugarcane, tobacco, and mulberry, and increased per unit area yield of food crops. Sericulture, sugarcane and tobacco have become three important sources of farmers' income. The water harvesting has contributed considerably to increased rural income, poverty reduction, reduced soil erosion and improvement in overall environment. Government has played a key role in planning and implementation of water harvesting programmes. Financial support of government and clear ownership of water harvesting facilities are critical for the success of the programme. Application of similar water harvesting techniques in other areas with similar biophysical conditions would contribute to enhancing the rural economy and alleviating poverty.     

Farm-level irrigation and the marginal cost of water use: evidence from Georgia

We create a proxy for the cost of irrigation water in Georgia from a sample of Georgia irrigators by investigating the marginal cost of pumping groundwater. We then combine this proxy with agronomic and climatic variables to estimate the response of agricultural water use to differences in the marginal cost of irrigation. The results show that pumping costs are a significant determinant of water use, and imply that agricultural water use would be moderately affected by institutional changes that would explicitly price water.     

Irrigation pricing policies and its impact on agricultural inputs demand in Tunisia: a DEA-based methodology

This paper estimates farmers' individual irrigation water demand functions employing the information hidden in individual farmers' technical efficiency. This information is extracted through the development of a new deductive methodology based on inverse Data Envelopment Analysis (DEA) models. The empirical results for Tunisia show that farmers who are more technically efficient have less elastic irrigation water demand functions; these farmers would adjust demand only to a limited extent and they can afford the water price. In contrast, water pricing significantly affects those that are less efficient. These farmers shift towards a different cropping pattern using significantly less water and more land when the price of water increases. Thus, higher water prices would threaten this category's livelihood if their efficiency is not improved. However, if the technical efficiency of these farmers were to improve, then it would be more difficult to reach water saving objectives since their demand will also become highly inelastic. The findings have important implications in view of the objectives of Tunisia water policy which include:full cost recovery, continuity of the irrigation activity, and water saving at the national level.     

Economic and financial analysis of harvesting and utilization of river reed in the Okavango Delta, Botswana

The Okavango Delta, the largest Ramsar wetland site, is one of the most resource-rich ecosystems in Botswana. A range of resources, including reeds, contribute in various ways to the well-being of many of the communities through subsistence and income generation. The economic value of reeds and other resources found in wetlands has been poorly understood, leading to the perception that wetlands are wastelands, and have little or no economic values. Such resources are therefore likely to receive lower priority in conservation when evaluated against other alternative activities. The aim of this research was to determine the benefit and financial and economic viability of harvesting river reed in the Okavango Delta. Primary data were collected through a structured questionnaire administered at three villages in the Okavango Delta. Secondary data were collected from existing literature. Financial and economic analysis was undertaken using static and financial models. Market prices were used to calculate the net income generated from the sale of harvested reed. The measurement criteria for static models were the annual net cash income, net annual economic benefit, and return on investment (ROI), while those under the dynamic models were the net present value (NPV), benefit cost ratio (BCR), and the net benefit investment (N/K) ratio. It was more financially profitable and economically viable to harvest and sell reeds at Shorobe village (a village relatively close to the District economic centre, Maun), than Shakawe or Etsha-13.     

Particulates pollution management and economic analysis of small rural enterprises in mountain areas: A case study of Wenquan town in China

At present, many rural enterprises in China's mountainous areas are developing rapidly, and due to poor planning and improper management, in an uncontrolled manner. These small enterprises are making atmospheric pollution far more serious and more difficult to control than before. Thus, as is the case with most developing countries, China is facing the challenge of managing the increased environmental pollution that is accompanying its economic development. This paper examines the case of cement dust pollution in the town of Wenquan in Sichuan province in order to determine how to adjust the relationship between development of rural enterprises and atmospheric environmental pollution in mountainous areas. Using the single objective linear programming method, and based on the principle of overall optimization, an optimal control plan for different pollution sources was worked out and an economic assessment on reclamation of cement dust was completed. According to our analysis, after implementation of this plan for four years, two months, the concentrations of suspended particles in Wenquan will achieve the requirement of the national third-order ambient air quality standard; the current serious dust pollution will be completely controlled; and the reclamation of cement dust will totally compensate for the cost of dust control and will result in 92,000 yuan of pure profit per year. At that time, the economy and environment will be in harmony.     

Human Freshwater Demand for Economic Activity and Ecosystems in Taiwan

Freshwater is necessary to economic activity, and humans depend on goods and services generated by water-dependent ecosystems. However, national freshwater management usually focuses on direct use of domestic freshwater. With an increasing scarcity of freshwater, attention has turned to two indirect uses of freshwater by humans. The first indirect use is freshwater used by foreign countries when producing products for export. The second use is freshwater required by local ecosystems: human survival and development depend on goods and services generated in these ecosystems. This work adopted Taiwan as a case study. In addition to two widely recognized ecosystem freshwater demands, evapotranspiration and reversed river flow, this study suggests that freshwater is a constituent of some abiotic components, such as groundwater in aquifers, because excessive withdrawal has already caused significant land subsidence in Taiwan. Moreover, the estimated results show that Taiwan’s net imports of freshwater through trade amounts to approximately 25% of its total freshwater use for economic production. Integrating industrial policy, trade policy, and national freshwater management is a useful approach for developing strategies to limit the growing use of freshwater in Taiwan. Policy implications are then developed by further analyzing withdrawal sources of freshwater (domestic and foreign) for supporting economic production in Taiwan and identifying the factors (domestic final demand and export) driving freshwater-intensive products.     

Evaluation of the impact of forest reserves on harvesting costs and provincial revenues in ontario

The establishment of forest reserves for the benefit of other resources and other land uses in areas where timber harvesting is taking place constitutes a significant withdrawal of wood fiber annually in Ontario.This article reports on a case study carried out on a representative forest area in northern Ontario where the primary land use is timber extraction. The results projected to the whole province show that the direct cost to the provincial economy of removing these forest lands from timber production is of the order of $2.5 million annually.     

Using the guild concept in the assessment of tree harvesting effects on understory herbs: A cautionary note

To help determine whether plants should be grouped into guilds for environmental impact assessment, the responses of six members of a guild of deciduous forest herbs to selective tree harvesting were compared. Harvesting operations themselves (tree cutting and skidding) had little effect on five of the six species but the sixth species decreased more in cut plots than in uncut plots. Subsequent microclimatic changes, resulting from tree cutting, also affected guild members differently. In the first year after cutting, two species increased more in cut plots than in uncut plots, while three other species did not change in frequency of occurrence and the sixth species decreased more in cut plots than in uncut plots. This inconsistent response of guild members to tree harvesting suggests that caution should be exercised in using guilds to assess plant response to environmental change.     

Economic and policy instrument analyses in support of the scrap tire recycling program in Taiwan

Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for scrap tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a scrap tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of scrap tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major tire recycling firms and 10 major tire manufacturers at that time. With estimates of scrap tire generation and possible scale of subsidy with respect to differing tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for scrap tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of scrap tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of scrap tires recycling industry, helping to reduce the required levels of product tax and subsidy. With such initial breakthroughs at hand to handle the complexity of scrap tire recycling technologies, there remains unique management and policy avenues left to explore if a multi-dimensional solution is to be successful in the long run.     

Institutional reform in the Andean irrigation sector: Enabling policies for strengthening local rights and water management

For centuries, local and indigenous water rights and rules in the Andean region have been largely neglected and discriminated against. The process of undermining local communities’ water access and control rights continues up to today and not only is it headed by powerful local, national and international water‐use actors encroaching local rights — it is also a direct consequence of vertical State law and intervention practices, and the latest privatization policies. Recognition of and security for the diverse and dynamic local rights and management frameworks is crucial for improving rural livelihoods and even national food security in Andean countries. At the request of the Government of Ecuador — in which at that time the indigenous movement had its political participation — a research mission was organized to formulate a proposal for institutional reform, aiming at the strengthening of the national irrigation sector. In this article, some basic mission results are outlined and analyzed within the scope of four concepts (institutional viability, political democracy, equity, and water rights security), and practical elements for institutional reform are suggested, not only for the Ecuadorian irrigation sector but also other settings. The complementary roles of central Government, local governments and water user organizations in water resources management are emphasized as is the need to strengthen enabling legal and policy frameworks. The importance of translating constitutional recognition of local and indigenous rights and common property systems into practical procedures and institutional structures is also stressed.     

长江经济带经济高质量发展差异性机理及对策分析

基于驱动力—压力—状态—影响—响应(DPSIR)模型,建立经济高质量发展系统作用机理分析框架和概念模型,运用结构方程模型对长江经济带上、中、下游三大区域经济高质量发展路径和关键因素进行探索。结果表明:①长江经济带下游地区作用机理为驱动力—压力—状态—影响—响应单向链式作用路径,资源消耗强度、贫困差异和生态环境质量为最关键因素。②长江经济带中游地区为驱动力—压力—状态和影响—响应跳跃式作用路径,产业结构为最关键因素。③长江经济带上游地区为状态—影响—响应的中断式作用路径,生态资源、科技创新和城市化为最关键因素。     

Impact of groundwater markets in India on water use efficiency: a data envelopment analysis approach

In the hard rock areas of India, overdraft of groundwater has led to negative externalities. It increased costs of groundwater irrigation and caused welfare losses. At the same time informal groundwater markets are slowly emerging and are believed to improve water distribution and to increase water use efficiency in the irrigation sector. These claims are evaluated in this study. For this purpose data was collected from a sample containing three different groups of water users: water sellers, water buyers and a control group of non-traders. First the socio-economic characteristics of these groups are compared. Then the efficiency of water use of the three groups is studied using Data Envelopment Analysis. The results indicate that groundwater markets provide resource poor farmers access to irrigation water, giving them the opportunity to raise their productivity. Water buyers are furthermore shown to be most efficient in their water use, while water sellers are also shown to be more efficient than the control group. The differences in efficiency between the groups are statistically significant. The demonstrated potential of groundwater markets to improve the efficiency of water use and to increase equity in resource access should be taken into account by the Indian government when deciding on their attitude towards the emerging groundwater markets.     

Investments in agricultural water management for poverty reduction in Africa: Case studies of Limpopo,Nile, and Volta river basins

Much of Sub‐Saharan Africa is burdened with water scarcity and poverty. Continentally, less than four percent of Africa's renewable water resources are withdrawn for agriculture and other uses. Investments in agricultural water management can contribute in several ways to achieving the Millennium Development Goals of eradicating extreme poverty and hunger and ensuring environmental sustainability. Increased yield and cropping area and shifts to higher valued crops could help boost the income of rural households, generate more employment, and lower consumer food prices. These investments can also stabilize output, income and employment, and have favourable impacts on education, nutrition and health, and social equity. Investments in agricultural water management can cut poverty by uplifting the entitlements and transforming the opportunity structure for the poor. The overall role of investments in agricultural water management in eradicating hunger and poverty is analyzed. This paper contributes to the present debate and efforts to identify strategies and interventions that can effectively contribute to poverty reduction in Africa. It provides an overview of population growth, malnutrition, income distribution and poverty for countries in three case study river basins — Limpopo, Nile, and Volta. With discussions on the contribution of agriculture to national income and employment generation, the paper explores the linkages among water resources investments, agricultural growth, employment, and poverty alleviation. It examines the potential for expansion in irrigation for vertical and horizontal growth in agricultural productivity, via gains in yield and cropping area to boost the agricultural output. Factors constraining such potential, in terms of scarcity and degradation of land and water resources, and poor governance and weak institutions, are also outlined. The paper argues that increased investments in land and water resources and related rural infrastructure are a key pathway to enhance agricultural productivity and to catalyze agricultural and economic growth for effective poverty alleviation.     

北京市大气污染物排放现状分析及治理对策研究

通过对北京市2000—2004年间大气污染物排放情况的考察和研究,着重分析了二氧化硫等大气污染物的排放现状以及大气污染物排放强度指标变化的原因并与国内主要城市及美国大气污染物排放指标进行了对比。结果表明,北京市大气污染物强度在国内处于较低水平,但与发达国家相比,仍有相当的差距,并提出了治理大气污染的对策。     

Emergy evaluation and economic analysis of three wetland fish farming systems in Nansi Lake area,China

Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer’s decisions, the accessibility of land for the required use and investment ability determine the farmer’s choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making.     

广西地下水污染现状与防治对策研究

基于广西地下水基本现状,分析广西地下水污染成因及地下水污染防治中存在的不足,提出建立健全地下水污染防治法律法规;完善地下水监测站网规划,建立地下水监测信息系统;加大宣传力度,提高公众环境保护意识;从整体规划广西地下水的使用与治理;加大资金投入,重视地下水科学研究5点污染防治建议,为今后广西地下水开发利用及污染防治研究提...     

Environmental and economic analysis of switchgrass production for water quality improvement in northeast Kansas

The primary objectives of this research were to determine SWAT model predicted reductions in four water quality indicators (sediment yield, surface runoff, nitrate nitrogen (NO(3)-N) in surface runoff, and edge-of-field erosion) associated with producing switchgrass (Panicum virgatum) on cropland in the Delaware basin in northeast Kansas, and evaluate switchgrass break-even prices. The magnitude of potential switchgrass water quality payments based on using switchgrass as an alternative energy source was also estimated. SWAT model simulations showed that between 527,000 and 1.27 million metric tons (Mg) of switchgrass could be produced annually across the basin depending upon nitrogen (N) fertilizer application levels (0-224 kg N ha(-1)). The predicted reductions in sediment yield, surface runoff, NO(3)-N in surface runoff, and edge-of-field erosion as a result of switchgrass plantings were 99, 55, 34, and 98%, respectively. The average annual cost per hectare for switchgrass ranged from about 190 US dollars with no N applied to around 345 US dollars at 224 kg N ha(-1) applied. Edge-of-field break-even price per Mg ranged from around 41 US dollars with no N applied to slightly less than 25 US dollars at 224 kg N ha(-1) applied. A majority of the switchgrass produced had an edge-of-field break-even price of 30 Mg(-1) US dollars or less. Savings of at least 50% in each of the four water quality indicators could be attained for an edge-of-field break-even price of 22-27.49 US dollars Mg(-1).     

Prospective changes in irrigation water requirements caused by agricultural expansion and climate changes in the eastern arc mountains of Kenya

Water resources and land use are closely linked with each other and with regional climate, assembling a very complex system. The understanding of the interconnecting relations involved in this system is an essential step for elaborating public policies that can effectively lead to the sustainable use of water resources. In this study, an integrated modelling framework was assembled in order to investigate potential impacts of agricultural expansion and climate changes on Irrigation Water Requirements (IWR) in the Taita Hills, Kenya. The framework comprised a land use change simulation model, a reference evapotranspiration model and synthetic precipitation datasets generated through a Monte Carlo simulation. In order to generate plausible climate change scenarios, outputs from General Climate Models were used as reference to perturbing the Monte Carlo simulations. The results indicate that throughout the next 20 years the low availability of arable lands in the hills will drive agricultural expansion to areas with higher IWR in the foothills. If current trends persist, agricultural areas will occupy roughly 60% of the study area by 2030. This expansion will increase by approximately 40% the annual water volume necessary for irrigation. Climate change may slightly decrease crops' IWR in April and November by 2030, while in May a small increase will likely be observed. The integrated assessment of these environmental changes allowed a clear identification of priority regions for land use allocation policies and water resources management.