Water withdrawal for brackish and inland aquaculture, and options to produce more fish in ponds with present water use

Water Policy ◽  
2009 ◽  
Vol 11 (S1) ◽  
pp. 52-68 ◽  
Author(s):  
M. C. J. Verdegem ◽  
R. H. Bosma

This paper reviews freshwater use in inland and coastal pond aquaculture, and focuses on options to increase productivity while reducing water use. Total freshwater use depends on system-associated and feed-associated water losses. System-associated water losses depend on total area, evaporation, infiltration and water replacement. About 8,750,000 ha freshwater and 2,333,000 ha brackish water ponds are in use today. Total water withdrawal in freshwater aquaculture is estimated at 16.9 m3/kg production, representing 429 km3/yr, which is 3.6% of flowing water globally. Infiltration and replacement water recharges aquifers; if these losses are clean, their re-use decreases aquaculture-related water withdrawal by nearly 60%. A further reduction in freshwater use in aquaculture can come from intensification and aquafeed development. The goal should be to feed the pond, not the fish. A tripling of average pond production should be possible, without increasing total freshwater use. Such improvements will also benefit brackish water aquaculture, which could in turn further reduce freshwater use by increasing the productivity of saline systems.

Author(s):  
S.D. Isaeva ◽  
A.L. Buber

В статье проведен анализ состояния оросительных, в том числе рисовых, систем Краснодарского края за 20 лет. Рассмотрены основные способы полива, динамика орошаемой площади, суммарной водоподачи, оросительные нормы, объем коллекторно-дренажного стока и др. Выявлено сокращение поливаемых земель в Краснодарском крае, снижение суммарного водозабора и оросительных норм. Выполнен аналитический прогноз рассмотренных показателей на перспективу до 2030 г. и предложены меры по развитию и повышению эффективности орошения в Краснодарском крае, прежде всего за счет строгого планирования водопользования на основе цифровых технологий и математического моделирования.Сondition of irrigation systems analysis was carried out in the Krasnodar Territory. Irrigation methods, dynamics of irrigated area, total water supply, irrigation norms are considered. Reduction of irrigated land, total water withdrawal and irrigation norms has been established in the Krasnodar Territory. An analytical forecast of the considered indicators for the future until 2030 has been completed. Measures to develop and improve irrigation efficiency are proposed. Above all, this is rigorous water use planning based on digital technology and mathematical modeling.


2018 ◽  
Vol 114 (3/4) ◽  
Author(s):  
Megan J. Cole ◽  
Richard M. Bailey ◽  
James D.S. JCullis ◽  
Mark G. New

Water is fundamental to human well-being and economic growth. Measuring how water contributes to sustainable development is an important aspect of the United Nations Sustainable Development Goal (SDG) 6, ‘Water and sanitation for all’. This importance is especially significant for water-scarce developing countries such as South Africa. Appropriate indicators can support decision-making and highlight key issues on inequality, unemployment and sustainability. In this paper, additional indicators for SDG 6.4 on water-use efficiency are proposed that focus on how individuals and households benefit, both directly and indirectly, from the allocations and use of water resources. The Berg Water Management Area (WMA) in the southwest corner of South Africa is used as a case study to illustrate the results. Residential per capita water use and municipal water losses were determined for all towns in the area. Figures for jobs and income per unit of water use were calculated for the heavily water-dependent industries, namely, agriculture, agriprocessing, freshwater aquaculture, mining and steel processing. This approach to measuring the socio-economic benefits of water use are relevant for other countries seeking to measure the role that water plays in achieving inclusive sustainable development, and could be included in the final SDG 6 indicator suite.


Author(s):  

The article deals with investigation of the Lake Khanka water resources’ use. We have stated that the predominant development of agriculture determines the water resources use on both the Russian part and the Chinese part of the basin. We have assessed the irrigated land areas and water volumes used for this end, as well as economic activities’ impact of the lake water level. On the basis of statistical data, satellite images and published scientific articles we have assessed for the first time the irrigated lands’ dynamics in the Lake Khanka basin over the 1960–2015 period. Analysis of the official information and the expert-restored data on water withdrawal made it possible firstly to estimate the dynamics of water use for irrigation and establish the values of water consumption (irrevocable water losses) during irrigation in the Russian part of the lake basin for the same period. We have established that the source for irrigating rice crops in Russia is the lake itself. The use of Lake Khanka’s waters in China is possible only in low water years. The influence of water use on irrigation in the Russian part of the basin at the lake level for the entire period of rice cultivation was manifested only in its reduction, and to a very small extent. In high water years, the Lake Malaya Khanka acts as a reservoir for the flood waters of the Mulinghe River, which, if discharged into the Lake Khanka, can have an impact on the growth of the Lake Khanka level.


2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Trey Dronyk-Trosper ◽  
Brandli Stitzel

AbstractAs water rights and water usage become an ever more important part of municipalities’ and states’ way of life, it becomes important to understand what policies can be effective for encouraging conservation of water. One method that has been employed at various times and throughout numerous communities is to limit outdoor watering days. We use a dataset with over 3 million property-month observations during the 2007–2015 period in Norman, Oklahoma, to identify whether the periodic implementation of mandatory water restrictions reduces water usage. Our data allow us to exploit variance in the timing of these water restriction programs. Our findings indicate that this policy reduces water consumption by 0.7 % of total water consumption. Additionally, we use home assessment prices to identify heterogeneity in this response, finding that high priced homes are more responsive to water use restrictions.


1977 ◽  
Vol 42 (6) ◽  
pp. 909-914 ◽  
Author(s):  
M. B. Maron ◽  
J. A. Wagner ◽  
S. M. Horvath

To assess thermoregulatory responses occuring under actual marathon racing conditions, rectal (Tre) and five skin temperatures were measured in two runners approximately every 9 min of a competitive marathon run under cool conditions. Race times and total water losses were: runner 1 = 162.7 min, 3.02 kg; runner 2 = 164.6 min, 2.43 kg. Mean skin temperature was similar throughout the race in the two runners, although they exhibited a marked disparity in temperature at individual skin sites. Tre plateaued after 35--45 min (runner 1 = 40.0--40.1, runner 2 = 38.9--39.2 degrees C). While runner 2 maintained a relatively constant level for the remainder of the race, runner 1 exhibited a secondary increase in Tre. Between 113 and 119 min there was a precipitous rise in Tre from 40.9 to 41.9 degrees C. Partitional calorimetric calculations suggested that a decrease in sweating was responsible for this increment. However, runner 1's ability to maintain his high Tre and running pace for the remaining 44 min of the race and exhibit no signs of heat illness indicated thermoregulation was intact.


2021 ◽  
Vol 13 (2) ◽  
pp. 807
Author(s):  
Wanrui Zhu ◽  
Wenhua Li ◽  
Peili Shi ◽  
Jiansheng Cao ◽  
Ning Zong ◽  
...  

Understanding how soil water source is used spatiotemporally by tree species and if native species can successfully coexist with introduced species is crucial for selecting species for afforestation. In the rocky mountainous areas of the Taihang Mountains, alien Robinia pseudoacacia L. has been widely afforested into the native shrublands dominated by Ziziphus jujuba Mill var. spinosa and Vitex negundo L. var. heterophylla to improve forest coverage and soil nutrients. However, little is known about the water relation among species, especially seasonal water use sources in different microsites. We selected the soil and plant xylem samples of two opposite microtopographic sites (ridge and valley) monthly in the growth season to analyze isotope composition. The proportions of water sources were quantified by the MixSIAR model and compared pairwise between species, microsites and seasons. We found that deep subsoil water at a depth of 40–50 cm contributed up to 50% of the total water uptake for R. pseudoacacia and Z. jujuba in the growing season, indicating that they stably used deeper soil water and had intense water competition. However, V. negundo had a more flexible water use strategy, which derived more than 50% of the total water uptake from the soil layer of 0–10 cm in the rainy season, but majorly captured soil water at a depth of 30–50 cm in the dry season. Therefore, high niche overlaps were shown in V. negundo with the other two species in the dry season, but niche segregation was seen in the rainy season. The microtopographic sites did not shift the seasonal dynamic of the water source use patterns of the three studied species, but the water use niche overlap was higher in the valley than in the ridge. Taken together, the introduced species R. pseudoacacia intensified water competition with the native semi-arbor species Z. jujuba, but it could commonly coexist with the native shrub species V. negundo. Therefore, our study on seasonal water use sources in different microsites provides insight into species interaction and site selection for R. pseudoacacia afforestation in the native shrub community in rocky mountainous areas. It is better to plant R. pseudoacacia in the shrubland in the valley so as to avoid intense water competition and control soil erosion.


2011 ◽  
Vol 73 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Harvey J. Pine ◽  
Claude E. Boyd

2022 ◽  
Vol 175 ◽  
pp. 114244
Author(s):  
Kai Wei ◽  
Jihong Zhang ◽  
Quanjiu Wang ◽  
Yi Guo ◽  
Weiyi Mu

HortScience ◽  
2018 ◽  
Vol 53 (12) ◽  
pp. 1891-1896 ◽  
Author(s):  
Nastaran Basiri Jahromi ◽  
Amy Fulcher ◽  
Forbes Walker ◽  
James Altland ◽  
Wesley Wright ◽  
...  

Controlling irrigation using timers or manually operated systems is the most common irrigation scheduling method in outdoor container production systems. Improving irrigation efficiency can be achieved by scheduling irrigation based on plant water needs and the appropriate use of sensors rather than relying on periodically adjusting irrigation volume based on perceived water needs. Substrate amendments such as biochar, a carbon (C)-rich by-product of pyrolysis or gasification, can increase the amount of available water and improve irrigation efficiency and plant growth. Previous work examined two on-demand irrigation schedules in controlled indoor (greenhouse) environments. The goal of this study was to evaluate the impact of these on-demand irrigation schedules and hardwood biochar on water use and biomass gain of container-grown Hydrangea paniculata ‘Silver Dollar’ in a typical outdoor nursery production environment. Eighteen independently controlled irrigation zones were designed to test three irrigation schedules on ‘Silver Dollar’ hydrangea grown in pine bark amended with 0% or 25% hardwood biochar. The three irrigation schedules were conventional irrigation and two on-demand schedules, which were based on substrate physical properties or plant physiology. Conventional irrigation delivered 1.8 cm water in one event each day. The scheduling of substrate-based irrigation was based on the soilless substrate moisture characteristic curve, applying water whenever the substrate water content corresponding to a substrate water potential of –10 kPa was reached. The plant-based irrigation schedule was based on a specific substrate moisture content derived from a previously defined relationship between substrate moisture content and photosynthetic rate, maintaining the volumetric water content (VWC) to support photosynthesis at 90% of the maximum predicted photosynthetic rate. Total water use for the substrate-based irrigation was the same as for the conventional system; the plant-based system used significantly less water. However, plant dry weight was 22% and 15% greater, water use efficiency (WUE) was 40% and 40% greater, and total leachate volume was 25% and 30% less for the substrate-based and plant-based irrigation scheduling systems, respectively, than for conventional irrigation. The 25% biochar amendment rate reduced leachate volume per irrigation event, and leaching fraction, but did not affect total water use or plant dry weight. This research demonstrated that on-demand irrigation scheduling that is plant based or substrate based could be an effective approach to increase WUE for container-grown nursery crops without affecting plant growth negatively.


2013 ◽  
Vol 31 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Arjina Shrestha ◽  
Janet C. Cole

Water use, growth, and leaf necrosis of Burkwood viburnum, Korean spice viburnum, and leatherleaf viburnum were evaluated on plants grown in 0 (full sun), 30, or 60% shade during 2010 and 2011. In both years, total water use of Burkwood viburnum decreased with increased shade intensity. Water use of leatherleaf viburnum was lowest in 0% and highest in 30% shade. Daily water use was lower in 0% than in 30 or 60% shade for leatherleaf viburnum plants in August of both years and September of 2010 due to greater leaf necrosis, leaf abscission, and less growth in height and width. In both years, growth in height and width, and leaf number at harvest generally increased in all three species with increased shade intensity. All species had a larger leaf area, stem dry weight, and root dry weight in 30 and 60% than in 0% shade. Shade intensity did not influence root to shoot (R/S) ratio in Burkwood viburnum in 2010, but in 2011, a curvilinear relationship occurred between R/S ratio and shade intensity. Root to shoot ratio of Korean spice and leatherleaf viburnum decreased linearly in 2010 but curvilinearly in 2011 with increasing shade. Leaf necrosis ratings were lower in shaded plants of all three species in both years. Results indicate that greater plant growth, quality, and water use efficiency occurs when these three viburnum species are grown in shade than when they are grown in full sun.


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