Driving Forces of Water Intensity in China’s Industrial Sector: A Global Meta-Frontier Production–Theoretical Decomposition Analysis

The shortage of water resources has prohibited the sustainable growth of China. Identifying the driving forces of water intensity is critical to initiating cost-effective policies and regulations to reduce water consumption across China. We develop a global meta-frontier production decomposition approach, which could simultaneously address the spatial and temporal heterogeneities, to decompose the water intensity of the industrial sector in China at various levels from 2011 to 2015. Results show that the industrial water intensity in all provinces except Shanxi has been declining over the sample period, with little potential for a further reduction. Second, at the national level, the potential water usage factor and the temporal catch-up effect of water usage technology are two significant contributors in reducing the industrial water intensity. Third, we find that some factors have mixed results at the regional and provincial levels, calling for customized policies in these aspects. Our approach provides a more precise decomposition and reveals more details in China’s variations of industrial water intensity, which has manifold implications for regional water management.

Analysis of Virtual Water Trade Flow and Driving Factors in the European Union

The inefficient application of water resources has become an urgent problem restricting the world’s sustainable development. Virtual Water Trade opens a new perspective on improving water resource utilization efficiency. Based on a multi-regional input–output model and the logarithmic mean Divisia index, the virtual water flows between 2000–2014 in 43 countries and regions have been evaluated, and the driving forces of changes in virtual water flows for the European Union were revealed. During the study period, the total amount of virtual water flow continued to increase. The United Kingdom is a net virtual water importer that depends on the European Union significantly. There was a large amount of virtual water flow from the European Union to the United States during 2000–2012. However, China gradually seized the share of virtual water from European Union exports after 2012. Economic effects and virtual water intensity effects are the most significant drivers of virtual water flows. The difference is that the economic effect positively drives virtual water flows, while the virtual water intensity effect negatively influences. The results reveal the nature of the United Kingdom in the virtual water trade and can provide post-Brexit recommendations.

The changes in Mulberry-based fish ponds in the Guangdong-Hong Kong-Macao Greater Bay Area over the past 40 years

<p>Mulberry-based fish ponds are representative traditional eco-agriculture in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). Investigations about the changes in such ponds and their relevant water environment under the background of rapid urbanization can provide a reference for the protection and development of these ponds. Using the Landsat images obtained after 1986, this study employed supervised classification and visual interpretation approaches and water intensity index as well as calculating synthesized index to identify the spatial patterns of changes in Mulberry-based fish ponds in the GBA. The results indicated that the year of 2013 was the inflection point of fish pond changes, which can also be proved by calculating synthesized index. The causes to the changes in fish ponds were further explored from four aspects: land use change, industrial transfer, government guidance and financial motives.</p>

Water and Sediment Supply Requirements for Post-Wildfire Debris Flows in the Western United States

ABSTRACT This work explores two hypotheses related to runoff-related post-wildfire debris flows: 1) their initiation is limited by rainstorm intensity rather than cumulative rainfall depths and 2) they are not sediment supply limited. The first hypothesis suggests that it is common to generate more than enough rainfall to account for the volume of water in the debris flow, but to actually produce a debris flow, the water must be delivered with sufficient intensity. This is demonstrated by data from 44 debris flows from eight burned areas in California, Colorado, and Utah. Assuming a debris flow comprises 30 percent water and 70 percent solids, these events were generated during rainstorms that produced an average of 17 times as much water as necessary to develop a debris flow. Even accounting for infiltration, the rainstorms still generated an overabundance of water. Intensity dependence is also shown by numerous cases in which the exact timing of debris flows can be pinpointed and is contemporaneous with high-intensity bursts of rainfall. The hypothesis is also supported by rainfall intensity-duration thresholds where high-volume storms without high-intensity bursts do not generate debris flows. The second hypothesis of sediment-supply independence for the initiation of debris flows is supported by a significant increase in flow volume occurring directly after wildfire, compared to flows in unburned terrain. Also, repeated flows within short time intervals are only possible with an abundance of channel sediment, dry ravel, and bank failure material that can be mobilized. Field observations confirm these sediment sources, even directly after a debris-flow.

WATER SAVING MEASURES SUBSTANTIATION FOR RICE IRRIGATION SYSTEMS

Purpose: analysis of the rice production water intensity and justification of measures for water saving, allowing to reduce the use of water resources for growing rice and companion crops, to reduce water intensity of production of a production unit while maintaining high yields. Materials and methods. Methods of analysis and synthesis to substantiate the rice and companion crops irrigation regime were used. Results. The analysis of long-term studies of the FSBSE “RSRILIP” showed that the water demand design norms for rice irrigation are exceeded by 1.5–2.0 times. For example, in the low-water year 2020, the rice irrigation rates on the rice systems of Rostov region fluctuated in agricultural enterprises from 27 to 47 thousand cubic m/ha. To save water resources, the main measures should be: maintaining the reclamation network and hydraulic structures in good condition, planned water use and water distribution, improving irrigation equipment and technologies. The first place in terms of influence on the value of the irrigation rate is the evenness of the check surface, since if the height in the check is more than 0.03–0.05 m from the design, the irrigation rate can double due to the need to create a given layer of water over the entire check area. It was found that the irrigation rate value is also influenced by the natural moisture content of the territory, the granulometric composition of the soil, the rate of filtration, the depth of groundwater, the degree of soil salinity and alkalinization. Depending on these factors under the conditions of Rostov region, the irrigation rate for rice can vary from 27 to 36 thousand cubic m/ha and more. Conclusions. To reduce the irrigation norms, irrigation regimes of the shortened type of flooding and obtaining seedlings on natural moisture reserves are recommended. The rice and companion crops cultivation using the ridge technology with periodic sprinkler irrigation or check flooding requires study.

Comment on “The intensification of the water footprint of hydraulic fracturing”

Kondash et al. provide a valuable contribution to our understanding of water consumption and wastewater production from oil and gas production using hydraulic fracturing. Unfortunately, their claim that the water intensity of energy production using hydraulic fracturing has increased in all regions is incorrect. More comprehensive data show that, while the water intensity of production may have increased in regions such as the Permian basin, it has decreased by 74% in the Marcellus and by 19% in the Eagle Ford region. This error likely stems from an improper method for estimating energy production from wells: The authors use the median well to represent regional production, which systematically underestimates aggregate production volumes. Across all regions, aggregate data suggest that the water intensity of oil and natural gas production using hydraulic fracturing has increased by 19%. There also appears to be an error in estimates for water consumption in the Permian basin.