scholarly journals Predicting the Water Rebound Effect in China under the Shared Socioeconomic Pathways

Author(s):  
Aijun Guo ◽  
Rong Zhang ◽  
Xiaoyu Song ◽  
Fanglei Zhong ◽  
Daiwei Jiang ◽  
...  

The rebound effect exists widely in the fields of energy, irrigation, and other resource utilizations. Previous studies have predicted the evolution of different resource utilizations under the shared socioeconomic pathways (SSPs), but it is still unclear whether total water use has a rebound effect. This study uses the SSPs as the basic prediction framework and evaluates the water resources and economic status of the provinces in China using the hydro-economic (HE) classification method. Then, combined with the SSPs scenario setting parameters, the conditional convergence model and the method recommended by the Food and Agriculture Organization of the United Nations (FAO) are used to simulate the changes in water use efficiency of the different provinces in China under different scenarios. Based on the future GDP forecast data of China’s provinces, combined with the forecast of water use efficiency changes, the total water use changes in China’s 31 provinces under different pathways from 2016 to 2030 are calculated. Among them, the future GDP data is predicted based on the Cobb–Douglas production function and SSPs scenario settings. Using a comprehensive evaluation of the evolution of the efficiency and the total amount, this study reveals whether there is a rebound effect. The results showed that with the continuous growth in the water use efficiency, the total water use had a “U” type trend, which indicated that there was a rebound effect in the total water use of China under the different SSPs. Based on this information, this study proposes some suggestions for irrigation water-saving technologies and policies.

2020 ◽  
Vol 12 (3) ◽  
pp. 1246 ◽  
Author(s):  
Wenjie Xu ◽  
Xiaoping Zhang ◽  
Qian Xu ◽  
Huiling Gong ◽  
Qing Li ◽  
...  

In order to achieve the sustainable utilization of water resources and the sustainable development of the economy, an evaluation index system for water-use efficiency and economic development systems was constructed. The entropy weight and the comprehensive evaluation methods were adopted to determine the index weights and conduct a comprehensive evaluation for the two systems. A coupling coordination model was used to calculate the coupling degree, coordination degree, and coupling coordination degree of the two systems. The annual coupling stage and coupling coordination intensity of the two systems were analyzed and determined. The results showed that the comprehensive evaluation values of both the water-use efficiency system and the economic development system in Jinan increased greatly from 2008 to 2017, and showed a changing trend of ups and downs. The two systems were in the antagonistic stage, and were gradually approaching the running-in stage, indicating that they were in the state of common development. The coupling coordination degree of the two systems gradually increased in waves, progressing from moderately to highly coordinated coupling. In the future, if the water control path appropriate to Jinan can be explored actively, the water-saving kinetic energy of economic development can be increased constantly, and the linkage effect between economic development and water resource utilization can be given full play. The two systems will then be in sync, enjoying a benign interaction and a healthy harmonious development.


1990 ◽  
Vol 41 (3) ◽  
pp. 431 ◽  
Author(s):  
KHM Siddique ◽  
D Tennant ◽  
MW Perry ◽  
RK Belford

Water use and water use efficiency of old and modern wheat cultivars and one barley cultivar were measured in a Mediterranean environment at Merredin, W.A. Water use efficiency for grain increased substantially from old to modern cultivars, with little difference among modern cultivars. Water use efficiency for dry matter was similar between cultivars. Barley had the highest water use efficiency of both grain and dry matter. Improved water use efficiency for grain in modern cultivars was associated with faster development, earlier flowering, improved canopy structure and higher harvest index. Modern cultivars used slightly less water than old cultivars. The pattern of water use was also different, with late-maturing old cultivars using more water in the pre- than the post-anthesis period. The ratio of pre- to post-anthesis water use was highest with the late-maturing, old cultivar Purple Straw (5.2:1) and lowest with early-maturing, modern cultivar Gutha (3.0:1). Soil evaporation estimates showed that modern cultivars had lower rates of soil evaporation in the early part of the growing season. This was associated with their faster leaf area development and improved light interception. About 40% of the total water use was lost by soil evaporation with very little difference between wheat cultivars. Barley had 15% less soil evaporation than wheat. Water use efficiency for grain based on transpiration (transpiration efficiency) for the four modern cultivars was 15.8 kg ha-1 mm-1, similar to other studies in comparable environments. Some further improvement in water use efficiency appears possible through improvement in crop biomass and harvest index. However, given the frequent and severe limitations of total water supply at low rainfall sites such as Merredin, there appears to be more scope for improvement in yield and water use efficiency in the medium and high rainfall areas of the wheatbelt.


Author(s):  
Wen-Jie Xu ◽  
Xiao-Ping Zhang ◽  
Qian Xu ◽  
Hui-Ling Gong ◽  
Qing Li ◽  
...  

In order to realize the sustainable utilization of water resources and the sustainable development of economy, the evaluation index system of water use efficiency system and economic development system was constructed. Entropy weight method and comprehensive evaluation method were adopted to determine the index weights and conduct comprehensive evaluation for the two systems. The coupling coordination model was used to calculate the coupling degree, coordination degree and coupling coordination degree of the two systems. The annual coupling stage and coupling coordination intensity of the two systems were analyzed and determined. The results showed that the comprehensive evaluation values of both water use efficiency system and economic development system in Jinan City increased greatly from 2008 to 2017, and showed a changing trend of ups and downs. The two systems were in the antagonistic stage, and were gradually approaching the running-in stage, indicating that they were in the state of common development. The coupling coordination degree of the two systems gradually increased in waves, progressed from the moderately to the highly coordinated coupling. In the future, if the water control path appropriate to Jinan City can be explored actively, the water-saving kinetic energy of economic development can be increased constantly, and the linkage effect between economic development and water resources utilization can be given full play to, the two systems will be in the orbit with the benign interaction and healthy harmonious development.


1986 ◽  
Vol 13 (4) ◽  
pp. 523 ◽  
Author(s):  
JM Morgan ◽  
AG Condon

Genotypic differences in turgor maintenance in wheat were shown to be associated with differences in grain yield in the field at both high and Low water deficits. High water deficits were produced by growing plants in field plots using water stored in the soil at sowing, and excluding rain with a rain cover. At low water deficits plants received rainfall, and irrigation was supplied before and immediately after sowing, at tillering, at jointing, at ear emergence, and during grain filling. Yield differences were analysed in terms of harvest index, water use, and water use efficiency. Water use was calculated from changes in soil water contents. At high water deficits all three factors were associated with differences in turgor maintenance. However, only the variations in water use and harvest index could be logically associated with differences in turgor maintenance. Analysis of the soil water extraction data showed that the differences in water use efficiency were due solely to differences in water use at depth while surface water losses were the same, i.e. the ratio of transpiration to soil evaporation would have been higher in low-osmoregulating genotypes. At low water deficits, no differences were observed in harvest index, though there were non-significant correlations between turgor maintenance and total water use efficiency or total water use. A similar result was obtained when the water use and yield data were related to osmoregulation measurements made in the glasshouse. It is therefore concluded that effects of turgor maintenance or osmoregulation on grain yield were primarily associated with differences in water use which were, in turn, due to differences in water extraction at soil depths between 25 and 150 cm.


1981 ◽  
Vol 17 (1) ◽  
pp. 105-111 ◽  
Author(s):  
S. S. Prihar ◽  
K. S. Sandhu ◽  
K. L. Khera ◽  
B. S. Sandhu

SUMMARYIn a 3-year field study with mustard (Brassica juncea L.) on deep well-drained sandy loam and loamy sand soils, 11 post-sowing irrigation schedules based on pan evaporation and growth stages were compared. One irrigation three weeks after sowing gave maximum grain yield and water use efficiency, increasing yield 40% in 1973–74 and 30% in 1976–77 compared with no irrigation. The total water use in this treatment averaged 31·2 cm, of which 15·8 cm was extracted from the 0–180 cm soil profile. Use of soil water by the crop decreased with the amount of post-sowing irrigation. More than one post-sowing irrigation tended to decrease yield and water use efficiency.


2021 ◽  
Vol 25 (02) ◽  
pp. 427-435
Author(s):  
Jingyu Zhang

This study was conducted with an objective to determine the optimal negative pressure irrigation suitable for growth and development of eggplant. The total water consumption, yield, growth and development, physiological activity, and quality of eggplant were tested using a pot experiment in a greenhouse with four treatments, namely -3, -8, -15 kPa and normal irrigation (C). The negative pressure was maintained using a stable negative pressure irrigation device. The total water consumption of eggplant was decreased by 20.51–70.00%, the total water consumption intensity was decreased by 22.18–70.27%, and the water use efficiency was increased by up to 7.45–41.48% under negative pressure irrigation compared with control (C). When the irrigation pressure was controlled at -3 kPa, the nitrate reductase activity, root activity, and chlorophyll content were increased by 6.14–15.5%, 11.11–33.33% and 20.04–51.58%, respectively. The yield of eggplant was also increased by 12.43% compared with control. The soluble sugars, soluble protein, and vitamin C contents of eggplant fruits at different maturation stages were increased by 14.47–47.22%, 16.33–58.78%, and 19.64–43.42% at -3 kPa, respectively, compared with the control. Taken together, it was observed that stable negative pressure irrigation in the range of -3 to -15 kPa obviously reduced water consumption of eggplant, and had a water saving effect. Negative pressure irrigation (-3 kPa) improved the water use efficiency, physiological activity, growth and development, and yield and quality of eggplant. © 2021 Friends Science Publishers


Author(s):  
Paulo J. O. P. Souza ◽  
Thaynara F. Ramos ◽  
Lucilene de C. S. Fiel ◽  
Vivian D. da S. Farias ◽  
Denis de P. Sousa ◽  
...  

ABSTRACT The state of Pará is the main regional producer of cowpea, but its yield is still low compared to other states of the Northern region such as Amazonas and Tocantins, due to the management adopted and the water regime during the cycle, since its cultivation is conducted on a rainfed basis. The objective of this study was to evaluate how water deficit imposed during reproductive stage interferes in the yield of cowpea and in its water use efficiency under the climatic conditions of Castanhal, Pará, Brazil, for agricultural planning purposes. The experiment was carried out in Castanhal, northeastern region of the Pará state during the dry season of 2014, 2015 and 2016. The experimental design was randomized blocks with six blocks and four treatments, corresponding to different irrigation depths in the reproductive stage, defined as 100, 50, 25 and 0% of the crop evapotranspiration. Water use efficiency (WUE) was determined by the ratio between total grain yield and total water used in each treatment. Maximum water availability led to an average increase in yield of 58% compared to the treatment without irrigation. Water depths below 260 mm limited yield to values lower than 1,000 kg ha-1. The cultivar adopted had WUE of 4.63 kg ha-1 mm-1, in response to the higher levels of water supply, but showed WUE of 4.31 kg ha-1 mm-1 under water depth of 50% of water demand.


Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 301
Author(s):  
Yuyan Luo ◽  
Lu Yin ◽  
Yong Qin ◽  
Zhong Wang ◽  
Yanfeng Gong

This paper evaluated the water use efficiency in 12 Chinese western provinces from 2005 to 2015. Based on data availability and the index selection rationality and the slacks-based measure (SBM)-undesirable Window analysis model and the Malmquist productivity index, the water resource inputs and outputs were measured to analyze water use efficiency. Total investment in fixed assets for the whole society and total water, made up of total agricultural water, total industrial water, and total domestic water, were used as the input indexes, and regional GDP and waste water discharge were the output indexes, with the waste water discharge being regarded as an undesirable output. The data from different years and different provinces in the same period, and data from the same year and the same provinces in different periods were compared in order to derive the water resource efficiency and technical changes over time and space. It was found that the total water resource factor productivity in the 12 provinces grew slowly in the study period, that water resource technical progress positively affected water use efficiency, and that a lack of technical efficiency restricted water use efficiency growth. Several suggestions are given to optimize water use efficiency in the 12 provinces. The research findings and suggestions provide valuable reference for studies in related fields.


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