An object based household water cycle model: concept and construction

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
S. Liu ◽  
C. Makropoulos ◽  
D. Butler ◽  
F. A. Memon

An object based household water cycle model has been developed using Matlab (Simulink) in the WaND (Water Cycle Management for New Developments) project to facilitate the development of an optioneering tool. The aim of the tool is to allow the assessment of options for conventional and innovative water management over the long term. Benefits of this approach include flexibility, easy expansion and transferability. An object is defined as a generic abstraction of micro-components which have similar functionalities in a household water use context. Following this concept, four kinds of objects are employed - water source, water use, treatment and sink. Each object has a generic interface which indicates its main attributes and functionality. Micro-components which belong to the same object share the same generic interface. An object can be easily implemented by specifying the associated property table and Matlab file. This forms a system - objects - micro-components - database hierarchical architecture. This paper describes the model development so far and includes initial model runs to demonstrate the power and performance of the approach.

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3306
Author(s):  
Dawei Liao ◽  
Zhonghe Pang ◽  
Weiyang Xiao ◽  
Yinlei Hao ◽  
Jie Du ◽  
...  

Understanding the connectivity between surface water and groundwater is key to sound geo-hazard prevention and mitigation in a waterscape such as the Jiuzhaigou Natural World Heritage Site in the southeast Tibetan Plateau, China. In this study, we used environmental isotope tracers (2H, 18O 3H, and 222Rn) to constrain a water cycle model including confirming hydrological pathways, connectivity, and water source identification in the Jiuzhaigou catchments. We established the local meteoric water line (LMWL) based on the weekly precipitation isotope sampling of a precipitation station. We systematically collected water samples from various water bodies in the study area to design the local water cycle model. The regional water level and discharge changes at one month after the earthquake indicated that there was a hydraulic connection underground across the local water divide between the Rize (RZ) river in the west and Zechawa (ZCW) lake in the east by the δ18O and δ2H measurements. We employed an end-member mixing model to identify and quantify Jiuzhaigou runoff-generating sources and their contributions, and we found that the average contributions of precipitation and groundwater to the surface runoff in the catchments are about 30% and 70%, respectively. The two branches of the Shuzheng (SZ) trunk were recharged by 62 ± 19% from the ZCW lake and 38 ± 19% from the RZ river, which was consistent with the fractions calculated by the actual discharge volume. 222Rn mass balance analyses were employed to estimate the water exchange between groundwater and river, which further confirmed this estimate. 222Rn concentrations and 3H contents showed that the groundwater had a short residence time and it was moderate precipitation, thought the contribution of groundwater to the river was 70%, according to the different tracers. A three-dimensional conceptual model of the water cycle that integrated the regional hydrological and geological conditions was established for the catchments.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2312
Author(s):  
Yang Zhou ◽  
Bilal Muhammad Khan ◽  
Jin Yong Choi ◽  
Yoram Cohen

Water use patterns were explored for three small communities that are located in proximity to agricultural fields and rely on their local wells for potable water supply. High-resolution water use data, collected over a four-year period, revealed significant temporal variability. Monthly, daily, and hourly water use patterns were well described by autoregressive moving average (ARMA) models. Model development was supported by unsupervised clustering analysis via self-organizing maps (SOMs) that revealed similarities of water use patterns and confirmed the time-series water use model attributes. The inclusion of ambient temperature and rainfall as model attributes improved ARMA model performance for daily and hourly water use from R2 ~0.86–0.87 to 0.94–0.97 and from R2 ~0.85–0.89 to 0.92–0.98, respectively. Water use predictions for an entire year forward in time was feasible demonstrating ARMA models’ performance of (i) R2 ~0.90–0.94 and average absolute relative error (AARE) of ~2.9–4.9% for daily water use, and (ii) R2 ~0.81–0.95 and AARE ~1.9–3.8% for hourly water use. The study suggests that ARMA modeling should be useful for analysis of temporally variable water use in support of water source management, as well as assessing capacity building for small water systems including water treatment needs and wastewater handling.


2010 ◽  
Vol 14 (10) ◽  
pp. 1863-1880 ◽  
Author(s):  
S. Siebert ◽  
J. Burke ◽  
J. M. Faures ◽  
K. Frenken ◽  
J. Hoogeveen ◽  
...  

Abstract. Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha), China (19 million ha) and the USA (17 million ha). Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.


2021 ◽  
Author(s):  
Camelia-Eliza Telteu ◽  
Hannes Müller Schmied ◽  
Wim Thiery ◽  
Guoyong Leng ◽  
Peter Burek ◽  
...  

Abstract. Global water models (GWMs) simulate the terrestrial water cycle, on the global scale, and are used to assess the impacts of climate change on freshwater systems. GWMs are developed within different modeling frameworks and consider different underlying hydrological processes, leading to varied model structures. Furthermore, the equations used to describe various processes take different forms and are generally accessible only from within the individual model codes. These factors have hindered a holistic and detailed understanding of how different models operate, yet such an understanding is crucial for explaining the results of model evaluation studies, understanding inter-model differences in their simulations, and identifying areas for future model development. This study provides a comprehensive overview of how state-of-the-art GWMs are designed. We analyze water storage compartments, water flows, and human water use sectors included in 16 GWMs that provide simulations for the Inter-Sectoral Impact Model Intercomparison Project phase 2b (ISIMIP2b). We develop a standard writing style for the model equations to further enhance model improvement, intercomparison, and communication. In this study, WaterGAP2 used the highest number of water storage compartments, 11, and CWatM used 10 compartments. Seven models used six compartments, while three models (JULES-W1, Mac-PDM.20, and VIC) used the lowest number, three compartments. WaterGAP2 simulates five human water use sectors, while four models (CLM4.5, CLM5.0, LPJmL, and MPI-HM) simulate only water used by humans for the irrigation sector. We conclude that even though hydrologic processes are often based on similar equations, in the end, these equations have been adjusted or have used different values for specific parameters or specific variables. Our results highlight that the predictive uncertainty of GWMs can be reduced through improvements of the existing hydrologic processes, implementation of new processes in the models, and high-quality input data.


2021 ◽  
Vol 14 (6) ◽  
pp. 3843-3878
Author(s):  
Camelia-Eliza Telteu ◽  
Hannes Müller Schmied ◽  
Wim Thiery ◽  
Guoyong Leng ◽  
Peter Burek ◽  
...  

Abstract. Global water models (GWMs) simulate the terrestrial water cycle on the global scale and are used to assess the impacts of climate change on freshwater systems. GWMs are developed within different modelling frameworks and consider different underlying hydrological processes, leading to varied model structures. Furthermore, the equations used to describe various processes take different forms and are generally accessible only from within the individual model codes. These factors have hindered a holistic and detailed understanding of how different models operate, yet such an understanding is crucial for explaining the results of model evaluation studies, understanding inter-model differences in their simulations, and identifying areas for future model development. This study provides a comprehensive overview of how 16 state-of-the-art GWMs are designed. We analyse water storage compartments, water flows, and human water use sectors included in models that provide simulations for the Inter-Sectoral Impact Model Intercomparison Project phase 2b (ISIMIP2b). We develop a standard writing style for the model equations to enhance model intercomparison, improvement, and communication. In this study, WaterGAP2 used the highest number of water storage compartments, 11, and CWatM used 10 compartments. Six models used six compartments, while four models (DBH, JULES-W1, Mac-PDM.20, and VIC) used the lowest number, three compartments. WaterGAP2 simulates five human water use sectors, while four models (CLM4.5, CLM5.0, LPJmL, and MPI-HM) simulate only water for the irrigation sector. We conclude that, even though hydrological processes are often based on similar equations for various processes, in the end these equations have been adjusted or models have used different values for specific parameters or specific variables. The similarities and differences found among the models analysed in this study are expected to enable us to reduce the uncertainty in multi-model ensembles, improve existing hydrological processes, and integrate new processes.


2020 ◽  
pp. 102-109
Author(s):  
D.KH. DOMULLODZHANOV ◽  
◽  
R. RAHMATILLOEV

The article presents the results of the field studies and observations that carried out on the territory of the hilly, low-mountain and foothill agro landscapes of the Kyzylsu-yuzhnaya (Kyzylsu-Southern) River Basin of Tajikistan. Taking into account the high-altitude location of households and the amount of precipitation in the river basin, the annual volumes of water accumulated with the use of low-cost systems of collection and storage of precipitation have been clarified. The amount of water accumulated in the precipitation collection and storage systems has been established, the volume of water used for communal and domestic needs,the watering of livestock and the amount of water that can be used to irrigate crops in the have been determined. Possible areas of irrigation of household plots depending on the different availability of precipitation have been determined. It has been established that in wet years (with precipitation of about 10%) the amount of water collected using drip irrigation will be sufficient for irrigation of 0.13 hectares, and in dry years (with 90% of precipitation) it will be possible to irrigate only 0.03 ha of the household plot. On the basis of the basin, the total area of irrigation in wet years can be 4497 ha, and in dry years only 1087 ha. Taking into account the forecasts of population growth by 2030 and an increase in the number of households, the total area of irrigation of farmlands in wet years may reach 5703 hectares,and in dry years – 1379 hectares. Growing crops on household plots under irrigation contributes to a significant increase in land productivity and increases the efficiency of water use of the Kyzylsu-yuzhnaya basin.


2003 ◽  
Vol 3 (1-2) ◽  
pp. 135-141 ◽  
Author(s):  
Z. Pilipovic ◽  
R. Taylor

In 1996, as part of Waitakere Council’s Water Cycle Strategy, a pressure standardisation programme to permanently lower the average supply pressure citywide was implemented with the aim of reducing water loss and water use. The experience gained during the 1994/95 Auckland water shortage had confirmed that there was considerable scope to reduce pressures in many areas. Since 1996 water pressures have been reduced in over 60% of the reticulated area of the city, with the average pressure reduced from 710 kPa to 540 kPa. As a result of this programme water loss from the network has been reduced, there has been a reduction in the frequency of mains breaks and it is likely that the life of water pipeline assets has been extended. Furthermore both pressure and demand management initiatives have reduced per capita water use in the city by more than 10%. A network computer model was used as a design tool to check the network under various pressure regimes and cost benefit analyses were carried out for various design scenarios. Fire sprinkler systems were checked as part of the design process. Minimum service standards were not reduced and in some cases pressures were actually increased. This paper covers the various aspects of the design, the implementation and the results of the pressure standardisation programme.


2005 ◽  
Vol 5 (3-4) ◽  
pp. 295-301
Author(s):  
J.S. Buckle

This article describes a successful awareness and education project undertaken in an East Rand township by the Water Cycle Management Section of Rand Water. The Project's focus was to create awareness in the community of the broad concept of water cycle management within an environment and to transfer skills to community members (facilitators) who could then assist in ensuring effective and efficient water use.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2791
Author(s):  
Pengyan Su ◽  
Mingjun Zhang ◽  
Deye Qu ◽  
Jiaxin Wang ◽  
Yu Zhang ◽  
...  

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.


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