scholarly journals Dynamic Modeling and Simulation of Urban Domestic Water Supply Inputs Based on VES Production Function

Mathematics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 89
Author(s):  
Kebai Li ◽  
Zhilei Ding
Keyword(s):  
Water Supply ◽  
Production Function ◽  
Water Demand ◽  
Early Stage ◽  
Supply And Demand ◽  
Labor Input ◽  
Domestic Water ◽  
Straight Line ◽  
Per Capita ◽  
Domestic Water Supply

The Gompertz growth curve is used to describe the urban water population, the linear function is used to represent the per capita disposable income, and the domestic water demand is described combined with the factors of population, income, and the water-saving consciousness. The VES production function is used to describe the production function of the domestic water supply. Combined with system dynamics, the supply and demand management model of urban domestic water in Jiangsu province, China, is developed. The process of water supply investment and labor input in the urban domestic water system is studied with two depreciation methods: the straight-line depreciation method and the sum of years digits method. In the case that the water consumption population is expected to decline, four water demand scenarios composed of different per capita disposable income and the growth rate of water-saving consciousness are investigated. Investment and labor input are taken as control variables to conduct water supply and demand simulations for the four scenarios. The results show that the control schemes in all four scenarios reach a balance between water supply and demand. Moreover, the investment of the sum of years digits method is larger than that of the straight-line depreciation method in 2005–2019 but less than that of the straight-line depreciation method in 2020–2034. The sum of years digits method has the characteristics of more depreciation in the early stage and less depreciation in the later stage, which is conducive to timely compensation for the large loss of fixed assets in the early stage.

scholarly journals Urban Industrial Water Supply and Demand: System Dynamic Model and Simulation Based on Cobb–Douglas Function

2019 ◽  
Vol 11 (21) ◽  
pp. 5893 ◽  
Author(s):  
Li ◽  
Ma ◽  
Wei ◽  
Zhang
Keyword(s):  
Water Supply ◽  
Production Function ◽  
Water Demand ◽  
Supply And Demand ◽  
Industrial Water ◽  
Labor Input ◽  
Control Variables ◽  
Suzhou City ◽  
Water Supply And Demand ◽  
Industrial Water Demand

In order to meet the needs of water-saving society development, the system dynamics method and the Cobb–Douglas (C–D) production function were combined to build a supply and demand model for urban industrial water use. In this model, the industrial water demand function is expressed as the sum of the general industrial water demand and the power industry water demand, the urban water supply function is expressed as the Cobb–Douglas production function, investment and labor input are used as the control variables, and the difference between supply and demand in various situations is simulated by adjusting their values. In addition, the system simulation is conducted for Suzhou City, Jiangsu Province, China, with 16 sets of different, carefully designed investment and labor input combinations for exploring a most suitable combination of industrial water supply and demand in Suzhou. We divide the results of prediction into four categories: supply less than demand, supply equals demand, supply exceeds demand, and supply much larger than demand. The balance between supply and demand is a most suitable setting for Suzhou City to develop, and the next is the type in which the supply exceeds demand. The other two types cannot meet the development requirements. We concluded that it is easier to adjust the investment than to adjust the labor input when adjusting the control variables to change the industrial water supply. While drawing the ideal combination of investment and labor input, a reasonable range of investment and labor input is also provided: the scope of investment adjustment is , and the adjustment range of labor input is .

scholarly journals Optimum Matching Model Using Long-Term Computing on Safer Rural Domestic Water Supply Based on Rainwater Harvesting

2018 ◽  
Vol 15 (12) ◽  
pp. 2864 ◽  
Author(s):  
Yan-Zhao Jin ◽  
Lu-Wen Zhou ◽  
Kwong Lo
Keyword(s):  
Water Supply ◽  
Rural Areas ◽  
Storage Capacity ◽  
Rainwater Harvesting ◽  
Supply And Demand ◽  
Computation Method ◽  
Matching Model ◽  
Domestic Water ◽  
Domestic Water Supply

A safe rural domestic water supply project has been initiated based on different consumption uses. Long-term computation method and the water balance principle are used to analyze the yearly water demand. Water supply and demand balance is achieved through regulated planning of the rainwater collection surface area and water storage capacity. The best combination of collection area and storage capacity is then determined for various rainfall zones in order to satisfy safe domestic water needs. Ultimately, an optimum matching model is developed to utilize rainwater harvesting for providing safe domestic water in rural areas.

scholarly journals Urban stormwater harvesting for domestic water supply: a water evaluation and planning approach

2021 ◽  
Author(s):  
S. S. Pravin ◽  
C. Gajendran ◽  
T. Divya
Keyword(s):  
Surface Water ◽  
Water Supply ◽  
Water Demand ◽  
Supply And Demand ◽  
Stormwater Runoff ◽  
Water Bodies ◽  
Domestic Water ◽  
Domestic Water Demand ◽  
Surface Water Bodies ◽  
Water Evaluation And Planning

Abstract Renewable groundwater and surface water supplies are insufficient for the existing urban population all over the world as water demand is increasing rapidly. Usage per capita in urban areas transcends 160 liters per day. Climate change is projected to increase water demand even more. Sources of surface water obtained by stormwater runoff can be well used to fulfill this requirement. The main objective of this work is to assess the water supply and demand in the dry condition in the Coimbatore region, Tamil Nadu, India, and to use the Water Evaluation and Planning method to create a model for supply and demand in the future. There are more than three dozen of surface water bodies in and around the metropolitan center. Most sources are heavily encroached upon. By linking stormwater runoff from its respective elevation to the accessible surface water bodies, an additional water supply source can be obtained. By using the Water Evaluation and Planning framework as a guide, models were developed to determine potential needs, compare demand and supply, water usage, lack of water use, and population coverage. The enhanced stormwater drainage system for Coimbatore city was also designed in such a way that the corporation's various roads were connected to the major water bodies. The domestic water demand in the future is predicted to be around 27 Million Cubic Feet(MCFT). Meanwhile, the possible amount of stormwater collection in the selected water bodies is predicted to be 50 Million Cubic Meter (MCM) to 320MCM. Thus, the study concluded that 100% of urban domestic water demand can be met if the urban stormwater is utilized by harvesting and storing in surface water bodies.

scholarly journals Impact of Rapid Tourism Growth on Water Scarcity in Bali, Indonesia

2021 ◽  
Vol 2 (1) ◽  
pp. 1-16
Author(s):  
Eva Mia Siska Yamamoto ◽  
Takahiro Sayama ◽  
Kaoru Takara
Keyword(s):  
Water Supply ◽  
Water Scarcity ◽  
Water Demand ◽  
Supply And Demand ◽  
Scientific Data ◽  
Clean Water ◽  
Domestic Water ◽  
Domestic Water Demand ◽  
Tourism Sector ◽  
The Impact

Despite Bali’s dependency on tourism, concerns over the impact of tourism on water scarcity are increasing. The objective of this study is to analyze the clean water demand related to tourism growth and compare them with the available clean water supply. This study suggested that tourism water demand has increased by 20.8 million m3 (295%) from 1988 to 2013. Sixty-eight percent of the increase was concentrated in Badung Regency, where the tourism water demand ratio has increased from 31% to 46%. The study also suggested that rapid population growth has caused an increase in domestic water demand by 48.3 million m3 (48%). This study also shows that the capacity of clean water supply in Bali has increased significantly to meet these demands and the water supply coverage of domestic water demand has increased significantly from 13% in 1988 to 53% in 2013. The water supply coverage of tourism demand varies from year to year with an average of 28% in the study period. The increasing issues over water scarcity despite the improvement in the coverage of domestic water demand suggest further investigations. Yet, despite the large gap between supply and demand in the tourism sector the industry still can have undisrupted clean water throughout the year. This indicates the use of alternative clean water which can be obtained locally such as groundwater. Wise water management through the sharing of scientific data, including in the tourism sector is imperative in solving water scarcity in Bali.  Keywords: clean water demand, water scarcity, Badung Regency

WATER VENDORS PARTICIPATION IN DOMESTIC WATER SUPPLY IN UNGUWA UKU, TARAUNI LOCAL GOVERNMENT, KANO STATE, NIGERIA

2021 ◽  
Vol 4 (4) ◽  
pp. 252-258
Author(s):  
Nura Isyaku Bello ◽  
Aminu Shehu ◽  
Ahmad S. Abubakar ◽  
Abdulkadir Bello ◽  
Mahmoud Z. Iman
Keyword(s):  
Seasonal Variation ◽  
Water Supply ◽  
Water Demand ◽  
Descriptive Statistics ◽  
Water Supply Systems ◽  
Domestic Water ◽  
Secondary Sources ◽  
Design And Implementation ◽  
Supply Systems ◽  
Domestic Water Supply

Water vending is seen as a signing of a failure in piped-borne water supply systems, it still plays significant role in providing water especially to urban dwellers in many parts of developing countries, Nigeria inclusive. Therefore, this study examined water vendors participation in domestic water supply in Unguwa Uku, Tarauni LGA Kano state. The data used in this research collected from both primary and secondary sources. The data collected was analyzed using descriptive statistics, where simple percentages and tables used. The data analysis revealed that 57.4% of the residents in the study area patronized the services of water vendors.     Patronage of vendor service dominated the frequency with 64.9% of respondent’s patronage of vended water. Seasonal variation in vended water supply patterns exist in the study area, with dry season account for the highest water demand and most supplies occurred during morning and evening hours. Based on the challenges bedevilled water-vending activities, the study recommends that vendors should be recognized as an integral part of the system as this may help in the design and implementation of more comprehensive policies that better serve poor end-users, by ensuring greater accessibility and affordability of water vendor’s service.

scholarly journals Urban Comprehensive Water Consumption: Nonlinear Control of Production Factor Input Based upon the C-D Function

2019 ◽  
Vol 11 (4) ◽  
pp. 1125 ◽  
Author(s):  
Kebai Li ◽  
Tianyi Ma ◽  
Tom Dooling ◽  
Guo Wei
Keyword(s):  
Water Supply ◽  
Production Function ◽  
Water Consumption ◽  
Water Demand ◽  
Demand Function ◽  
Production Factor ◽  
Urban Water ◽  
Urban Water Supply ◽  
Labor Input ◽  
Urban Water Demand

Utilizing the urban water demand function and the Cobb-Douglas (C-D) production function, an economic control model for the multi-input-multi-output (MIMO) nonlinear system was designed and implemented to describe urban comprehensive water consumption, where the urban water demand function was expressed as the product of the number of water users and per capita comprehensive water consumption, and the urban water supply function was expressed as a C-D production function. The control variables included capital investment and labor input for the urban water supply. In contrast to the Solow model, Shell model and aggregate model with renewable labor resources, the proposed model eliminated value constraints on investment and labor input in the state equations and hence avoided the difficulty in applying these models to urban water supply institutions. Furthermore, the feedback linearization control design (FLCD) method was employed to accomplish stability of the system. In contrast to the optimal control method, the FLCD method possesses an explicit solution of the control law and does not require the solution of a two-point boundary value problem of an ordinary differential equation, making the method more convenient for application. Moreover, two different scenarios of urban water consumption, one for the growth period and the other for the decline period, were simulated to demonstrate the effectiveness of the proposed control scheme.

scholarly journals Multiple Urban Domestic Water Systems: Method for Simultaneously Stabilized Robust Control Decision

2018 ◽  
Vol 10 (11) ◽  
pp. 4092 ◽  
Author(s):  
Kebai Li ◽  
Tianyi Ma ◽  
Guo Wei
Keyword(s):  
Decision Making ◽  
Robust Control ◽  
Water Supply ◽  
Supply And Demand ◽  
Water Systems ◽  
Demand Systems ◽  
Domestic Water ◽  
Control Scheme ◽  
Domestic Water Consumption ◽  
Domestic Water Supply

The distribution of water resources and the degree of economic development in different cities will result in different parameters for the supply and demand of domestic water in each city. In this paper, a simultaneous stabilization and robust control method is proposed for decision-making regarding multiple urban domestic water systems. The urban water demand is expressed as the product of the urban domestic water consumption population and per capita domestic water consumption. The fixed capital investment and labor input of the urban domestic water supply industry are used as control variables. Based on the Lyapunov stability theory and the linear matrix inequality method, multiple urban domestic water supply and demand systems can accomplish asymptotical stability through the coordinated input of investment and labor. For an empirical analysis, we take six cities—Nanjing, Wuxi, Nantong, Yangzhou, Xuzhou, and Lianyungang—in Jiangsu Province, China, to study the simultaneously stabilized coordinated control scheme. The simulation results show that the same control scheme simultaneously achieves the asymptotic stability of these urban domestic water supply and demand systems, and is robust when it comes to the variation of system parameters. This method is particularly suitable for a water resources administrative agency to make a unified decision-making arrangement for water supply input in different areas. It will help synchronize multiple urban domestic water managements and reduce the difficulty of control.

scholarly journals Assessing Future Water Demand and Associated Energy Input with Plausible Scenarios for Water Service Providers (WSPs) in Sub-Saharan Africa

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2169
Author(s):  
Pauline Macharia ◽  
Nzula Kitaka ◽  
Paul Yillia ◽  
Norbert Kreuzinger
Keyword(s):  
Water Supply ◽  
Water Demand ◽  
Energy Input ◽  
Service Providers ◽  
Sub Saharan Africa ◽  
Water Losses ◽  
Water Service ◽  
Current State ◽  
Per Capita ◽  
Sub Saharan

This study examined the current state of water demand and associated energy input for water supply against a projected increase in water demand in sub-Saharan Africa. Three plausible scenarios, namely, Current State Extends (CSE), Current State Improves (CSI) and Current State Deteriorates (CSD) were developed and applied using nine quantifiable indicators for water demand projections and the associated impact on energy input for water supply for five Water Service Providers (WSPs) in Kenya to demonstrate the feasibility of the approach based on real data in sub-Saharan Africa. Currently, the daily per capita water-use in the service area of four of the five WSPs was below minimum daily requirement of 50 L/p/d. Further, non-revenue water losses were up to three times higher than the regulated benchmark (range 26–63%). Calculations showed a leakage reduction potential of up to 70% and energy savings of up to 12 MWh/a. The projected water demand is expected to increase by at least twelve times the current demand to achieve universal coverage and an average daily per capita consumption of 120 L/p/d for the urban population by 2030. Consequently, the energy input could increase almost twelve-folds with the CSI scenario or up to fifty-folds with the CSE scenario for WSPs where desalination or additional groundwater abstraction is proposed. The approach used can be applied for other WSPs which are experiencing a similar evolution of their water supply and demand drivers in sub-Saharan Africa. WSPs in the sub-region should explore aggressive strategies to jointly address persistent water losses and associated energy input. This would reduce the current water supply-demand gap and minimize the energy input that will be associated with exploring additional water sources that are typically energy intensive.

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