Programming a spatial water model for improving water efficiency in China

Water Policy ◽  
2009 ◽  
Vol 11 (4) ◽  
pp. 504-523 ◽  
Author(s):  
Lan Fang ◽  
Ernst-August Nuppenau
Keyword(s):  
Programming Model ◽  
Project Managers ◽  
Water Saving ◽  
Water Model ◽  
Irrigated Agriculture ◽  
Transit Systems ◽  
Public Investments ◽  
Product Pricing ◽  
Private And Public ◽  
Irrigation Technologies

This paper deals with heavy pressures to save water in natural resource management due to increased water scarcity. We take the example of a Chinese watershed and investigate the water use efficiency in Chinese irrigated agriculture through a field study as dependent on investments in on-farm water saving technologies and canal water conveyance. The economic and environmental impacts of farmers adopting modern irrigation technologies and public sectors improving water transit systems are studied in particular. A spatial mathematical programming model is employed for optimization. The emphasis is on private and public investments in water saving. Water saving in a canal system enables an extension of the system and provides food and income for more farmers. The model results are of great value for policy makers and project managers, who want to optimize irrigation projects, because scenarios (for instance water and product pricing) are provided. We also provide references for farmers in applying suitable irrigation technologies.

scholarly journals Private and Public Investments in Biomedical Research

2021 ◽  
Author(s):  
Maya Durvasula ◽  
Lisa Larrimore Ouellette ◽  
Heidi Williams
Keyword(s):  
Biomedical Research ◽  
Public Investments ◽  
Private And Public

Parallelization of a Commercial Streamline Simulator and Performance on Practical Models

2010 ◽  
Vol 13 (03) ◽  
pp. 383-390 ◽  
Author(s):  
R.P.. P. Batycky ◽  
M.. Förster ◽  
M.R.. R. Thiele ◽  
K.. Stüben
Keyword(s):  
Large Scale ◽  
Programming Model ◽  
Scaling Law ◽  
Independent Solution ◽  
Parallel Execution ◽  
Water Model ◽  
Test Machine ◽  
Multicore Architectures ◽  
Streamline Simulation ◽  
Run Time

Summary We present the parallelization of a commercial streamline simulator to multicore architectures based on the OpenMP programming model and its performance on various field examples. This work is a continuation of recent work by Gerritsen et al. (2009) in which a research streamline simulator was extended to parallel execution. We identified that the streamline-transport step represents approximately 40-80% of the total run time. It is exactly this step that is straightforward to parallelize owing to the independent solution of each streamline that is at the heart of streamline simulation. Because we are working with an existing large serial code, we used specialty software to quickly and easily identify variables that required particular handling for implementing the parallel extension. Minimal rewrite to existing code was required to extend the streamline-transport step to OpenMP. As part of this work, we also parallelized additional run-time code, including the gravity-line solver and some simple routines required for constructing the pressure matrix. Overall, the run-time fraction of code parallelized ranged from 0.50 to 0.83, depending on the transport physics being considered. We tested our parallel simulator on a variety of large models including SPE 10, Forties-a UK oil/water model, Judy Creek-a Canadian waterflood/water-alternating-gas (WAG) model, and a South American black-oil model. We noted overall speedup factors from 1.8 to 3.3x for eight threads. In terms of real time, this implies that large-scale streamline simulation models as tested here can be simulated in less than 4 hours. We found speedup results to be reasonable when compared with Amdahl's ideal scaling law. Beyond eight threads, we observed minimal speedups because of memory bandwidth limits on our test machine.

scholarly journals Opportunities for saving and reallocating agricultural water to alleviate water scarcity

Water Policy ◽  
2017 ◽  
Vol 19 (5) ◽  
pp. 886-907 ◽  
Author(s):  
Brian D. Richter ◽  
James D. Brown ◽  
Rachel DiBenedetto ◽  
Adrianna Gorsky ◽  
Emily Keenan ◽  
...  
Keyword(s):  
Water Use ◽  
Water Scarcity ◽  
Water Saving ◽  
Internet Survey ◽  
Irrigated Agriculture ◽  
Irrigation Systems ◽  
Water Savings ◽  
Consumptive Water Use ◽  
Water Scarce ◽  
Consumptive Water

As water scarcity worsens globally, there is growing interest in finding ways to reduce water consumption, and for reallocating water savings to other uses including environmental restoration. Because irrigated agriculture is responsible for more than 90% of all consumptive water use in water-scarce regions, much attention is being focused on opportunities to save water on irrigated farms. At the same time, many recent journal articles have expressed concern that claims of water-saving potential in irrigation systems lack technical credibility, or are at least exaggerated, due to failures to properly account for key elements of water budgets such as return flows. Critics have also asserted that opportunities for reallocating irrigation savings to other uses are limited because any freed-up water is taken up by other farmers. A comprehensive literature and internet survey was undertaken to identify well-documented studies of water-saving strategies in irrigated agriculture, as well as a review of case studies in which water savings have been successfully transferred to other uses. Our findings suggest that there is in fact considerable potential to reduce consumptive water use in irrigation systems when proper consideration is given to water budget accounting, and those savings can be beneficially reallocated to other purposes.

scholarly journals Segregation in Housing and Urban Forms: An Issue of Private and Public Concern

2018 ◽  
Vol 7 (9) ◽  
pp. 145
Author(s):  
Rui Ramos ◽  
Eliseu Gonçalves ◽  
Sergio Dias Silva
Keyword(s):  
The State ◽  
Urban Forms ◽  
Social Fabric ◽  
Housing Design ◽  
Residential Architecture ◽  
Mass Tourism ◽  
Public Investments ◽  
Private And Public ◽  
The University ◽  
Market Pressure

The Mapping Public Housing investigation project (MdH), based at the University of Porto, Faculty of Architecture, Centre for Studies in Architecture and Urbanism, is building a database of State-subsidized residential architecture in Portugal designed between 1910 and 1974. An ongoing survey of laws directly or indirectly influencing housing construction, and of their concretization, allows for a reading of the influence of the State in housing architecture. This paper will focus on two scopes of segregation through housing design in the Portuguese 20th century, both in private initiatives—the “Ilhas”, low rent housing built in the backyards of Porto in the first half of the century—and in public investments—using the example of the “Affordable Houses”, a housing programme created by the Portuguese dictatorial regime in 1933 in which the buyers of the houses were subjected to surveillance by the State. An ongoing context of market pressure caused by speculative real estate investing and mass tourism, suggests an evolution of the original processes of segregation into systems of gentrification, transforming the cultural and social fabric.

scholarly journals Policy reforms to promote efficient and sustainable water use in Swiss agriculture

Water Policy ◽  
2012 ◽  
Vol 14 (5) ◽  
pp. 887-901 ◽  
Author(s):  
Robert Finger ◽  
Niklaus Lehmann
Keyword(s):  
Water Resources ◽  
Water Use ◽  
Sustainable Use ◽  
Water Saving ◽  
Water Withdrawal ◽  
Policy Reforms ◽  
Environmental Laws ◽  
Scarce Water ◽  
Irrigated Crops ◽  
Irrigation Technologies

The more sustainable use of scarce water resources is a policy goal in several countries. In this regard, current discussions on potential policy reforms in Switzerland revolve around the subsidization of water-saving irrigation technologies. Today, the share of drip irrigation systems is low, at 3%. In Switzerland, environmental laws specify levels of water flow that must not be undercut. Variable pricing of water, however, has not yet been used. This paper analyzes whether subsidies on water-saving irrigation techniques would be beneficial in this legislative setting, and shows that such subsidies may have crowding out effects because they could provide incentives to switch from non-irrigated crops (e.g. wheat) to the production of crops (e.g. potatoes) that require irrigation. This may result in even higher water withdrawal rates. Such an increased competition for water resources may also result in adverse conditions for farmers. By contrast, our analysis shows the implementation of water prices could lead to a sustainable increase in the share of water-saving technologies, to a shift from irrigated to non-irrigated crops, and therefore to a reduction of overall water use in agriculture. Thus, the introduction of water prices should have absolute priority if agricultural water policies are reformed in Switzerland.

scholarly journals Park-scape infrastructure

2021 ◽  
Author(s):  
Jordan Emmanuel Breccia
Keyword(s):  
Public Space ◽  
Large Scale ◽  
Mass Transit ◽  
Urban Park ◽  
Transit Systems ◽  
Urban Core ◽  
New Public ◽  
Private And Public ◽  
The Subject ◽  
East West

This thesis is predicated on the objectives of Toronto's Official Plan: the cessation of outward suburban development, increased growth in the urban core, increased public amenity space to support this greater density, reduced presence of the car, and the support of public transit, walking and cycling. Recognition of the serious lack of available public domain within Toronto's core to provide the appropriate scale of public space required to support this new level of density, is the subject of this thesis proposal. This thesis proposed a new large scale, north to south linear park for Toronto that integrates a system of bicycle, jogging, and pedestrian paths that connect it into existing mass transit systems, the urban core, and the existing east west park system, the Martin Goodman Trail. It creates this new public space by re-appropriating several vehicular lanes of Jarvis Street, and proposing the integration of new building development, park, sidewalk and street to amalgamate the space needed to accomplish this. Building and landscape, private and public space overlap and interconnect, to complete this new seamless urban park.

scholarly journals Soil Salinity and Sodicity in Drylands: A Review of Causes, Effects, Monitoring, and Restoration Measures

2021 ◽  
Vol 9 ◽  
Author(s):  
Ilan Stavi ◽  
Niels Thevs ◽  
Simone Priori
Keyword(s):  
Soil Salinity ◽  
Agricultural Land ◽  
Anthropogenic Activities ◽  
Soil Salinization ◽  
Management Tool ◽  
Irrigated Agriculture ◽  
Saline Soils ◽  
Chemical Restoration ◽  
Irrigation Technologies ◽  
Over Time

Soil salinization and sodification are common processes that particularly characterize drylands. These processes can be attributed either to natural conditions or anthropogenic activities. While natural causes include factors such as climate, lithology, topography, and pedology, human causes are mostly related to agricultural land-use, and specifically, to irrigated agriculture. The objective of this study was to thoroughly review this topic, while highlighting the major challenges and related opportunities. Over time, the extent of saline, sodic, and saline-sodic croplands has increased, resulting in accelerated land degradation and desertification, decreased agricultural productivity, and consequently jeopardizing environmental and food security. Mapping and monitoring saline soils is an important management tool, aimed at determining the extent and severity of salinization processes. Recent developments in advanced remote sensing methods have improved the efficacy of mapping and monitoring saline soils. Knowledge on prevention, mitigation, and recovery of soil salinity and sodicity has substantially grown over time. This knowledge includes advanced measures for salt flushing and leaching, water-saving irrigation technologies, precision fertilizer systems, chemical restoration, organic and microbial remediation, and phytoremediation of affected lands. Of a particular interest is the development of forestry-related means, with afforestation, reforestation, agroforestry, and silvopasture practices for the recovery of salt-affected soils. The forecasted expansion of drylands and aggravated drying of existing drylands due to climatic change emphasize the importance of this topic.

scholarly journals Land reclamation, farm mechanisation, rural repopulation: the shifting landscape of the Gharb Valley in Morocco, 1912–1956

2019 ◽  
Vol 63 ◽  
pp. 06001
Author(s):  
Michele Tenzon
Keyword(s):  
Spatial Configuration ◽  
Land Reclamation ◽  
Rural Landscape ◽  
Water Drainage ◽  
Urban Planner ◽  
Public Investments ◽  
Demographic Dynamics ◽  
Private And Public ◽  
French Colonial ◽  
Rural Exodus

This article investigates rural resettlement schemes implemented by the French colonial administration in the light of the relationship between major economic, social and demographic dynamics in the Protectorate of Morocco. It explores the ways in which the French colonisers transformed the rural landscape of the Gharb valley in Morocco’s Rabat region. I depict the spatial configuration of the several stages by which rural colonisation and agricultural modernisation took place in the region, in relation to the patterns of human settlement they produced. The initial spatial configuration of the Gharb, determined by French colonial policies through the official colonisation programme and its orientation toward extensive agriculture, was subverted by the massive introduction of water drainage and irrigation infrastructure. The construction of reservoir dams and the establishment of drainage and irrigation perimeters across the valley induced a concentration of private and public investments that led to rural modernisation in certain, delimited areas. To compensate for a rural exodus that was overcrowding the outskirts of major Moroccan urban centres and for the lack of a local workforce available for employment on colonists’ farms, the French architect and urban planner Michel Écochard and his collaborators at the Service de l’Urbanisme conceived an ambitious programme of rural resettlements in the Gharb valley.

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