Assessment of Blue and Green Virtual Water Trade: A Case Study of India

Declining water resources and increasing demand of water for agricultural, industrial, and domestic sector and potential climate change has posed a major challenge to maintain water sustainability of a nation. There is a need to adopt long-term perspective for assessment and policy design for sustainability of primary resources like water. It is also argued that virtual water trade has raised issues of water sustainability as even small but continuous net virtual water trade may influence the water sustainability through irreversible losses. With the constraints for water sustainability, virtual water trade has received much attention in the recent years. While the impact of virtual water trade on water sustainability of virtual water exporter country is less explored and assessed. India is a major water exporting country resulted tremendous pressure on water resources that has serious threat to food security and the negative impact on development of economy and other sectors.

Water-Saving Efficiency and Inequality of Virtual Water Trade in China

Virtual water trade is widely considered as a potential method to solve local water shortage and unequal distribution. However, limited research investigated water-saving efficiency and water inequality of inter-provincial virtual water trade. In this study, we sought to explore this issue within China based on the 2015 input-output data. A multi-regional input-output model and a modified input-output model were used to estimate the virtual water trade and its impact on water-saving and water inequality. Our results suggest that: (1) The total virtual water flow across the country is 200.03 × 109 m3, which accounts for 32.77% of water withdrawal. The agriculture sector contributes the highest proportion (73.99%) to virtual water flow. (2) Virtual water trade could decrease water withdrawal by 446.08 × 109 m3 compared with withdrawal under no-trade situation at a national level, and 22 provinces could gain benefits through inter-provincial trade with a positive water-saving efficiency index. (3) Virtual water trade also causes water inequality, which exacerbates water scarcity of exported provinces, especially in northwest provinces. (4) There is a conflict between water conservation and water inequality, but different provinces show significant heterogeneity.

Quantitative analyzes of virtual water net exports under the impacts of natural changes and human activities in the last 20 years in Shandong Province, China

Virtual water trade in a region is affected by both nature and humans. To study the contributions of human activities to virtual water trade quantitatively, an innovative method of quantitative comparison and analysis is put forward. At first, the climates are adjusted into a unified standard. Then the impacts of increment and reduction of foreign water are studied. Additionally, the impacts of water management policy are studied according to the comparable water quotas. Results show that with the development of economy, an N-shaped trend and inverted U-shaped trend exist with regard to the net exports of agricultural and industrial virtual water, respectively. The net imports of virtual water have beneficial effects to the water environments of water deficient areas, while the net exports have negative effects. In 1997, the net exports of agricultural and industrial virtual water reduced by 20.13% and 49.67% respectively due to the cut-off of Yellow River channel compared with that under the average Yellow River water diversion. In 2017, they increased by 1.32% and 41.99% respectively because of the South-to-North Water Transfer project and reduced by 10.01% and 20.39% respectively under the effects of the most stringent water management policy.

Virtual water trade and its implications on water sustainability

Limited and declining water resources, increasing demand of water resources from different sectors has posed a major challenge for maintaining water sustainability and thus overall sustainability for a populous and water scarce country like India. Over extraction and changing climate have put additional pressure to maintain water sustainability. Therefore, there is a need of proper planning of utilization and management of water resource. Recently, virtual water trade has received much attention and become important tool for balancing the water budget. On the other hand, virtual water trade may also adversely effects on water balance of exporter's country as well as economy. Analysis of virtual water trade with its implications on water resources are missing, hence, there is a need of such analysis that will help in management of water resources. In this study an attempt is made to present a quantitative analysis of virtual water trade and its implications on water sustainability. For this study rice crop is considered only due to its characteristics as rice is major water consumer crop and water exporter crop from India.

Future virtual water flows under climate and population change scenarios: focusing on its determinants

Water resources are under increasing pressure from population growth, socio-economic development, and climate change. The main user of freshwater is the agriculture sector, accounting for 70–80% of global water use. Consequently, increasing water productivity and reducing water use in this sector are vital for alleviating water scarcity. It has been alleged that domestic or international trade of water-consumed products from wet-provinces or countries to arid and semi-arid provinces or countries is one possible path to mitigate water shortage. In this regard, virtual water flows and their determinants in Iran are investigated in this paper. This study examines the main determinants of bilateral virtual water flows associated with international trade in agricultural goods among Iran and other countries using a gravity model of trade. The impacts of climate change and socio-economic change scenarios on the virtual water trade are simulated. The result of the gravity model indicated that bilateral virtual water trade flows are influenced by the classical determinants and all the mass-related variables (gross domestic product and population) are significant with expected signs. Finally, the result obtained from the simulation of climate and socio-economic change scenarios showed that under the pessimistic scenario of climate change and population growth rate of 0.98 and 0.44%, VW trade between Iran and other countries would increase by 41 and 66% in the periods of 2016–2045 and 2070–2099, respectively. As a consequence, identifying the appropriate countries for business interactions and adopting effective trade policies are very important and need attention soon.