Modelling blue and green water resources availability in Iran

2009 ◽  
Vol 23 (3) ◽  
pp. 486-501 ◽  
Author(s):  
Monireh Faramarzi ◽  
Karim C. Abbaspour ◽  
Rainer Schulin ◽  
Hong Yang
2014 ◽  
Vol 29 (8) ◽  
pp. 1942-1955 ◽  
Author(s):  
Depeng Zuo ◽  
Zongxue Xu ◽  
Dingzhi Peng ◽  
Jinxi Song ◽  
Lei Cheng ◽  
...  

Author(s):  
Gholamabbas Sayyad ◽  
◽  
Lida Vasel ◽  
Ali Asghar Besalatpour ◽  
Bahram Gharabaghi ◽  
...  

2021 ◽  
Author(s):  
Elena De Petrillo ◽  
Marta Tuninetti ◽  
Francesco Laio

<p>Through the international trade of agricultural goods, water resources that are physically used in the country of production are virtually transferred to the country of consumption. Food trade leads to a global redistribution of freshwater resources, thus shaping distant interdependencies among countries. Recent studies have shown how agricultural trade drives an outsourcing of environmental impacts pertaining to depletion and pollution of freshwater resources, and eutrophication of river bodies in distant producer countries. What is less clear is how the final consumer – being an individual, a company, or a community- impacts the water resources of producer countries at a subnational scale. Indeed, the variability of sub-national water footprint (WF in m<sup>3</sup>/tonne) due to climate, soil properties, irrigation practices, and fertilizer inputs is generally lost in trade analyses, as most trade data are only available at the country scale. The latest version of the Spatially Explicit Information on Production to Consumption Systems model  (SEI-PCS) by Trase provides detailed data on single trade flows (in tonne) along the crop supply chain: from local municipalities- to exporter companies- to importer companies – to the final consumer countries. These data allow us to capitalize on the high-resolution data of agricultural WF available in the literature, in order to quantify the sub-national virtual water flows behind food trade. As a first step, we assess the detailed soybean trade between Brazil and Italy. This assessment is relevant for water management because the global soybean flow reaching Italy may be traced back to 374 municipalities with heterogeneous agricultural practises and water use efficiency. Results show that the largest flow of virtual water from a Brazilian municipality to Italy -3.52e+07 m<sup>3</sup> (3% of the total export flow)- comes from Sorriso in the State of Mato Grosso. Conversely, the highest flow of blue water -1.56e+05 m<sup>3</sup>- comes from Jaguarão, in the State of Rio Grande do Sul, located in the Brazilian Pampa. Further, the analysis at the company scale reveals that as many as 37 exporting companies can be identified exchanging to Italy;  Bianchini S.A is the largest virtual water trader (1.88 e+08 m<sup>3</sup> of green water and 3,92 e+06 m<sup>3</sup> of blue water), followed by COFCO (1,06 e+08 m<sup>3</sup> of green water and 6.62 m<sup>3</sup> of blue water)  and Cargill ( 6.96 e+07 m<sup>3</sup> of green water and 2.80 e+02 m<sup>3</sup> of blue water). By building the bipartite network of importing companies and municipalities originating the fluxes we are able to efficiently disaggregate the supply chains , providing novel tools to build sustainable water management strategies.</p>


2006 ◽  
Vol 10 (3) ◽  
pp. 455-468 ◽  
Author(s):  
A. K. Chapagain ◽  
A. Y. Hoekstra ◽  
H. H. G. Savenije

Abstract. Many nations save domestic water resources by importing water-intensive products and exporting commodities that are less water intensive. National water saving through the import of a product can imply saving water at a global level if the flow is from sites with high to sites with low water productivity. The paper analyses the consequences of international virtual water flows on the global and national water budgets. The assessment shows that the total amount of water that would have been required in the importing countries if all imported agricultural products would have been produced domestically is 1605 Gm3/yr. These products are however being produced with only 1253 Gm3/yr in the exporting countries, saving global water resources by 352 Gm3/yr. This saving is 28 per cent of the international virtual water flows related to the trade of agricultural products and 6 per cent of the global water use in agriculture. National policy makers are however not interested in global water savings but in the status of national water resources. Egypt imports wheat and in doing so saves 3.6 Gm3/yr of its national water resources. Water use for producing export commodities can be beneficial, as for instance in Cote d'Ivoire, Ghana and Brazil, where the use of green water resources (mainly through rain-fed agriculture) for the production of stimulant crops for export has a positive economic impact on the national economy. However, export of 28 Gm3/yr of national water from Thailand related to rice export is at the cost of additional pressure on its blue water resources. Importing a product which has a relatively high ratio of green to blue virtual water content saves global blue water resources that generally have a higher opportunity cost than green water.


2021 ◽  
Author(s):  
Ronan Abhervé ◽  
Clément Roques ◽  
Laurent Longuevergne ◽  
Stéphane Louaisil ◽  
Jean-Raynald de Dreuzy ◽  
...  

<p>While it is well understood and accepted that climate change and growing water needs affect the availability of water resources, the identification of the main physical processes involved remains challenging. It notably requires to filter interannual to interdecadal fluctuations and extreme events to isolate the underlying trends. Metropolitan areas are specifically subject to growing pressures because of the significant and increasing demand, combined with the strong anthropization of land uses.</p><p>The Meu-Chèze-Canut catchment supplies the city of Rennes with drinking water (680 km² - 500 000 users, Brittany, France). In this field laboratory, we explore the dynamics of the water cycle and water resources availability. In this context, water supply is mostly coming from reservoir storage for which levels shows a medium-term vulnerability in response to frequent relatively dry years. Based on retrospective data analysis, we describe the relationship between climatic forcing (precipitation, temperature) and water availability (aquifer storage, river discharge and reservoir storage) in different parts of the catchment that are characterized by distinct lithological and topographical settings. We then evaluate the resilience of both surface and groundwater resources, their past evolution and their resilience to climate change and increasing societal needs.</p><p>Water resources availability in these catchments relies on two geological formations with distinct hydrodynamics properties: the Armorican sandstone and Brioverian schist. To assess the resilience of the system, we specifically analyzed the relationships between monthly effective precipitation and stream discharge within nine sub-catchments over the past 30 years. We observe annual hysteresis relationships - that is, a time lag between precipitation and discharge highlighting the capacity of the landscape to temporarily store water - with significant variability in shapes across the catchments. We argue that topographic and lithological factors play key roles in controlling this variability through their impacts on subsurface storage capacity and characteristic drainage timescales. We propose perspectives based on the complementary use of calibrated groundwater models to leverage these results and provide adaptive water management strategies.</p>


2021 ◽  
Author(s):  
fawen li ◽  
Wenhui Yan ◽  
Yong Zhao ◽  
Rengui Jiang

Abstract Because of the shortage of water resources, the phenomenon of groundwater over-extraction is widespread in many parts of the world, which has become a hot issue to be solved. The traditional idea of water resources management only considering blue water (stream flow) can't meet the demand of sustainable utilization of water resources. Blue water accounts for less than 40% of total rainfall, while green water (evapotranspiration) accounts for more than 60% of total rainfall. In the natural environment, vegetation growth mainly depends on green water, which is often neglected. Obviously, the traditional water resources management without considering green water has obvious deficiencies, which can't really reflect the regional water consumption situation in the water resources management. And only by limiting water consumption can achieve the real water saving. In addition, the mode of water resources development and utilization has changed from "supply according to demand" to "demand according to supply". In this background, for many regions with limited water resources, it is impossible to rely on excessive water intake for development, and sustainable development of regional can only be realized by truly controlling water demand. This paper chooses Shijin Irrigation District in the North China Plain as the research area, where agricultural water consumption is high and groundwater over-extraction is serious, and ecological environment is bad. In order to alleviate this situation, comprehensive regulation of water resources based ET is necessary. Therefore, this paper focuses on the concept of ET water resources management and includes green water into water resources assessment. Based on the principle of water balance, the target ET value of crops in the study area is calculated, and the ET value is taken as the target of water resources regulation. The actual water consumption is calculated by Penman-Monteith formula, and reduction of crop water consumption is obtained according to the difference between actual ET and target ET. The reduction in crop water consumption leads to a reduction in demand for water supply, which reduces groundwater extraction. The results of this study can provide necessary technical support for solving the problem of groundwater over-extraction and realizing real water saving.


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