scholarly journals Blue water footprint caps per sub-catchment to mitigate water scarcity in a large river basin: the case of the Yellow River in China

2021 ◽  
pp. 126992
Author(s):  
Luc T. Albers ◽  
Joep F. Schyns ◽  
Martijn J. Booij ◽  
La Zhuo
2014 ◽  
Vol 11 (1) ◽  
pp. 135-167 ◽  
Author(s):  
L. Zhuo ◽  
M. M. Mekonnen ◽  
A. Y. Hoekstra

Abstract. Water Footprint Assessment is a quickly growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of water footprint estimates to changes in important input variables and quantifies the size of uncertainty in water footprint estimates. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat in the Yellow River Basin in the period 1996–2005. A grid-based daily water balance model at a 5 by 5 arcmin resolution was applied to compute green and blue water footprints of the four crops in the Yellow River Basin in the period considered. The sensitivity and uncertainty analysis focused on the effects on water footprint estimates at basin level (in m3 t−1) of four key input variables: precipitation (PR), reference evapotranspiration (ET0), crop coefficient (Kc), and crop calendar. The one-at-a-time method was carried out to analyse the sensitivity of the water footprint of crops to fractional changes of individual input variables. Uncertainties in crop water footprint estimates were quantified through Monte Carlo simulations. The results show that the water footprint of crops is most sensitive to ET0 and Kc, followed by crop calendar and PR. Blue water footprints were more sensitive to input variability than green water footprints. The smaller the annual blue water footprint, the higher its sensitivity to changes in PR, ET0, and Kc. The uncertainties in the total water footprint of a crop due to combined uncertainties in climatic inputs (PR and ET0) were about ±20% (at 95% confidence interval). The effect of uncertainties in ET0 was dominant compared to that of precipitation. The uncertainties in the total water footprint of a crop as a result of combined key input uncertainties were on average ±26% (at 95% confidence level). The sensitivities and uncertainties differ across crop types, with highest sensitivities and uncertainties for soybean.


2020 ◽  
Author(s):  
Pengxuan Xie ◽  
La Zhuo ◽  
Pute Wu

<p>Blue water (surface and ground water) and green water (water stored in unsaturated soil layer and canopy evapotranspiration from rainfall) are the two sources of water generated from precipitation and communicating vessels that define the limits of water resources for both human activities and ecosystems. However, the blue and green water evapotranspiration in irrigated fields and their contribution to blue and green water flows have not been identified in studies conducted on blue and green water resources. In addition, information on intra-annual variations in blue and green water footprints (WFs) is limited. In particular, there is a lack of information on water consumption obtained from hydrological model-based blue and green water assessments at the basin scales. In this study, the Yellow River Basin (YRB) over 2010-2018 was considered as the study case, and the inter- and intra-annual variations in blue and green water resources, WFs and water scarcities were quantified at sub-basin levels. Water resources and WFs were simulated using the Soil and Water Assessment Tool (SWAT) model. The results revealed that the annual average blue and green water resources of the YRB were 119.33 × 10<sup>9</sup> m<sup>3</sup> yr<sup>-1</sup> and 296.94 × 10<sup>9</sup> m<sup>3</sup> yr<sup>-1</sup>, respectively, over the study period. The total amount of green water flow was larger than the total amount of blue water flow each year. The blue and green WFs of the crops in the middle reach were significantly larger than those of the crops in the upper and lower reaches. The annual blue and green water scarcity levels under the consideration of the overall YRB were low. However, several areas in the middle reaches were subject to both blue and green water scarcities at least modest level for a minimum of three months a year. The northern region of the YRB was subject to significant and severe blue water scarcity throughout each year.</p>


2014 ◽  
Vol 18 (6) ◽  
pp. 2219-2234 ◽  
Author(s):  
L. Zhuo ◽  
M. M. Mekonnen ◽  
A. Y. Hoekstra

Abstract. Water Footprint Assessment is a fast-growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of and uncertainty in crop water footprint (in m3 t−1) estimates related to uncertainties in important input variables. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat at the scale of the Yellow River basin in the period 1996–2005. A grid-based daily water balance model at a 5 by 5 arcmin resolution was applied to compute green and blue water footprints of the four crops in the Yellow River basin in the period considered. The one-at-a-time method was carried out to analyse the sensitivity of the crop water footprint to fractional changes of seven individual input variables and parameters: precipitation (PR), reference evapotranspiration (ET0), crop coefficient (Kc), crop calendar (planting date with constant growing degree days), soil water content at field capacity (Smax), yield response factor (Ky) and maximum yield (Ym). Uncertainties in crop water footprint estimates related to uncertainties in four key input variables: PR, ET0, Kc, and crop calendar were quantified through Monte Carlo simulations. The results show that the sensitivities and uncertainties differ across crop types. In general, the water footprint of crops is most sensitive to ET0 and Kc, followed by the crop calendar. Blue water footprints were more sensitive to input variability than green water footprints. The smaller the annual blue water footprint is, the higher its sensitivity to changes in PR, ET0, and Kc. The uncertainties in the total water footprint of a crop due to combined uncertainties in climatic inputs (PR and ET0) were about ±20% (at 95% confidence interval). The effect of uncertainties in ET0was dominant compared to that of PR. The uncertainties in the total water footprint of a crop as a result of combined key input uncertainties were on average ±30% (at 95% confidence level).


Water Policy ◽  
2016 ◽  
Vol 18 (S1) ◽  
pp. 138-152 ◽  
Author(s):  
Huijuan Wu ◽  
Ching Leong

The concept of sustainability has a key component of balancing developmental needs of the present and the future, what we call the time element (TE). Integrated Water Resources Management (IWRM) has emerged as a paradigm of river governance, balancing different interests and needs. This we call the Interest Element (IE). This paper explores how IWRM incorporates sustainability, leading to stronger river governance, reflecting the balance between timeframes as well as across different interests. We investigate the use of indicators for integrated assessment of two large river basins, the Yellow River basin in China and the Ganges River basin in India. The process analysis method is employed for developing framework. A tailored indicator set is selected and categorized under three domains, environmental performance, social wellbeing, and economic development. This framework provides policy-makers with a holistic review of river sustainability through tailored indicator sets, which can be used for underpinning IWRM policies. This speaks to our argument that an explicit recognition of sustainability indicators, resulting in a composite model makes for both conceptual clarity and better policy directions. This paper concludes with a series of key elements for IWRM through a comparative study of river management regimes in China and India.


2019 ◽  
Vol 11 (21) ◽  
pp. 5958 ◽  
Author(s):  
Yu ◽  
Jia ◽  
Wu ◽  
Wu ◽  
Xu ◽  
...  

The construction of hydropower stations is not without controversy as they have a certain degree of impact on the ecological environment. Moreover, the water footprint and its cumulative effects on the environment (The relationship between the degree of hydropower development and utilization in the basin and the environment) of the development and utilization of cascade hydropower stations are incompletely understood. In this paper, we calculate the evaporated water footprint (EWF, water evaporated from reservoirs) and the product water footprint of hydropower stations (PWF, water consumption per unit of electricity production), and the blue water scarcity (BWS, the ratio of the total blue water footprint to blue water availability) based on data from 19 selected hydropower stations in the Yalong River Basin, China. Results show that: (a) the EWFs in established, ongoing, proposed, and planning phases of 19 hydropower stations are 243, 123, 59, and 42 Mm3, respectively; (b) the PWF of 19 hydropower stations varies between 0.01 and 4.49 m3GJ−1, and the average PWF is 1.20 m3GJ−1. These values are quite small when compared with hydropower stations in other basins in the world, and the difference in PWF among different hydropower stations is mainly derived from energy efficiency factor; (c) all the BWS in the Yalong River Basin are below 100% (low blue water scarcity), in which the total blue water footprint is less than 20% of the natural flow, and environmental flow requirements are met. From the perspective of the water footprint method, the cumulative environmental effects of hydropower development and utilization in the Yalong River Basin will not affect the local environmental flow requirements.


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