Dynamic forecasting of agricultural water footprint based on Markov Chain-a case study of the Heihe River Basin

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

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.

The state-of-the-art system dynamics application in integrated water resources modeling

In recent years, water resources management has become more complicated and controversial due to the impacts of various factors affecting hydrological systems. System Dynamics (SD) has in turn become increasingly popular due to its advantages as a tool for dealing with such complex systems. However, SD also has some limitations. This review contains a comprehensive survey of the existing literature on SD as a potential method to deal with the complexity of system integrated modeling, with a particular focus on the application of SD to the integrated modeling of water resources systems. It discusses the limitations of SD in these contexts, and highlights a number of studies which have applied a combination of SD and other methods to overcome these limitations. Finally, our study makes a number of recommendations for future modifications in the application of SD methods in order to enhance their performance.

Forecasting the Water Demand in Chongqing, China Using a Grey Prediction Model and Recommendations for the Sustainable Development of Urban Water Consumption

High accuracy in water demand predictions is an important basis for the rational allocation of city water resources and forms the basis for sustainable urban development. The shortage of water resources in Chongqing, the youngest central municipality in Southwest China, has significantly increased with the population growth and rapid economic development. In this paper, a new grey water-forecasting model (GWFM) was built based on the data characteristics of water consumption. The parameter estimation and error checking methods of the GWFM model were investigated. Then, the GWFM model was employed to simulate the water demands of Chongqing from 2009 to 2015 and forecast it in 2016. The simulation and prediction errors of the GWFM model was checked, and the results show the GWFM model exhibits better simulation and prediction precisions than those of the classical Grey Model with one variable and single order equation GM(1,1) for short and the frequently-used Discrete Grey Model with one variable and single order equation, DGM(1,1) for short. Finally, the water demand in Chongqing from 2017 to 2022 was forecasted, and some corresponding control measures and recommendations were provided based on the prediction results to ensure a viable water supply and promote the sustainable development of the Chongqing economy.