Assessing the option water-saving willingness of irrigation areas considering farmers' risk tolerance.

Water option trading could facilitate water conservation in irrigation areas to achieve optimal allocation of agricultural water resources. However, the risk associated with water-saving decisions increases due to the uncertainties of tradeable water and water-saving benefits, which makes farmers in the irrigation area with heterogeneous risk tolerances exhibit varied option water-saving willingness (OWSW) in response to the water option contract. Thus, this article provides a novel framework for prior assessing the OWSW in the irrigated area that considers farmers' heterogeneous risk tolerance and proposes the optimal contractual water demand to stimulate the OWSW. First, a multiobjective optimal allocation model for cropping water is constructed to predict tradeable water, and then risk trust, risk-return perception and reference are integrated into water-saving return analysis for proposing a willingness calculation model involving forecast information. Finally, the influence of heterogeneous risk tolerance on farmers' water-saving path choices and the irrigation area's OWSW is analyzed with three sets of comparative data from 2014 to 2021. Results indicate that the intensity and stability of OWSW in water-scarce irrigation areas increase as farmers' risk tolerance rises, but the enhancement utility exhibits a diminishing marginal trend. When both prediction accuracy and farmers' risk tolerance are low, contracts with relatively adventurous and differentiated water demands are more likely to stimulate OWSW. This study provides insights into activating water options trading and stimulating water conservation in agriculture from a risk management perspective.

Novel annual nitrogen management strategy improves crop yield and reduces greenhouse gas emissions in wheat-maize rotation systems under limited irrigation.

Excessive irrigation and nitrogen application have long seriously undermined agricultural sustainability in the North China Plain (NCP), leading to declining groundwater tables and intensified greenhouse gas (GHG) emissions. Developing low-input management practices that meet the growing food demand while reducing environmental costs is urgently needed. Here, we developed a novel nitrogen management strategy for a typical winter wheat-summer maize rotation system in the NCP under limited irrigation (wheat sowing irrigation only (W0) or sowing and jointing irrigation (W1)) and low nitrogen input (360 kg N ha-1, about 70 % of traditional annual nitrogen input). Novel nitrogen management strategy promoted efficient nitrogen fertilizer uptake and utilization by both crops via optimization of nitrogen fertilizer allocation between the two crops, i.e., increasing nitrogen inputs to wheat (from 180 to 240 kg N ha-1) while reducing nitrogen inputs to maize (from 180 to 120 kg N ha-1). Three-year field study demonstrated that integrated management practices combining novel nitrogen management strategy with limited irrigation increased annual yields and PFPN by 1.9-5.7 %, and reduced TGE by 55-68 kg CO2-eq ha-1 and GHGI by 2.2-10.3 %, without any additional cost. Our results provide agricultural operators and policymakers with practical and easy-to-scalable integrated management strategy, and offer key initiative to promote grain production in the NCP towards agriculture sustainable intensification with high productivity and efficiency, water conservation and emission reduction.

Improvement of Salinity Tolerance in Water-Saving and Drought-Resistance Rice (WDR).

Rice is one of the most economically important staple food crops in the world. Soil salinization and drought seriously restrict sustainable rice production. Drought aggravates the degree of soil salinization, and, at the same time, increased soil salinity also inhibits water absorption, resulting in physiological drought stress. Salt tolerance in rice is a complex quantitative trait controlled by multiple genes. This review presents and discusses the recent research developments on salt stress impact on rice growth, rice salt tolerance mechanisms, the identification and selection of salt-tolerant rice resources, and strategies to improve rice salt tolerance. In recent years, the increased cultivation of water-saving and drought-resistance rice (WDR) has shown great application potential in alleviating the water resource crisis and ensuring food and ecological security. Here, we present an innovative germplasm selection strategy of salt-tolerant WDR, using a population that is developed by recurrent selection based on dominant genic male sterility. We aim to provide a reference for efficient genetic improvement and germplasm innovation of complex traits (drought and salt tolerance) that can be translated into breeding all economically important cereal crops.

Modelling the potential of rainwater harvesting to improve the sustainability of landscape and public garden irrigation.

Access to water for irrigating amenity landscape and public gardens is under intense pressure due to the rising competition for water between different sectors, exacerbated by increased drought risk and climate change. Rainwater harvesting (RWH) has the potential to reduce the economic impacts of restrictions on irrigation abstraction in dry years and to build resilience to future water shortages. This study investigated the hydrological viability of RWH for the landscape and public garden sector based on an analysis of five Royal Horticultural Society gardens. A RWH model was developed and combined with on-site observations, key informant interviews and GIS analyses, to estimate irrigation demands and the volumes of harvested rainfall for contrasting agroclimatic years. The results showed that gardens located in wetter regions and with low irrigation water demand to harvestable area ratio had a higher RWH potential and could almost exclusively rely on rainwater to meet irrigation demand, even in dry years. RWH potential is more limited for gardens in drier regions where they would require larger areas to harvest rainwater and for storage. Appropriately designed rainwater harvesting systems offer the potential to remove most of the risk of irrigation abstraction restrictions during dry years and associated impacts on amenity planting quality and visitor experience.

Assessing the impact of food trade centric on land, water, and food security in South Korea.

The observed and predicted changes in climate, as well as the growth in urban population, are creating severe stress on existing water resources in South Korea. By the importation of agricultural products from more water-rich countries through the virtual water concept, a country could save local water resources for other important uses. However, these imports from other countries could lead to certain vulnerabilities in the importing country derived from climate change. Therefore, through the application of the virtual water concept and the climate vulnerability index ((CVI) - measure of a country's vulnerability to indirect climate impacts), this study assessed the implication of virtual water imports and climate change through food trade, on the water, land and food security status of South Korea over the period of 2000-2017. The results showed that significant amounts of national water and land was saved through the importation of major upland crops. Virtual water imports increased significantly over time, rising from 16.2 Bm3 in 2000 to 16.5, 17.4, and 20.7 Bm3 in 2005, 2011, and 2017 respectively, with the USA, China, Australia, Brazil and Canada being the major exporters to South Korea. The study also revealed high CVI values for the oils and grains category of imported food, implying the high vulnerability of South Korea to climate change effects resulting from the import of these crops. The quantitative impacts and structural changes in virtual water trade, as well as the link between climate change, food security, international trade, and domestic water consumption could be evaluated for the sustainable management and allocation of resources. This study successfully identified and quantified the status of food trade and its environmental implications in the study area, providing insight into a better allocation of locally available resources.

Economics of household preferences for water-saving technologies in urban South Africa.

Drought severity is expected to increase in South Africa in the coming years, given the deteriorating effects of climate change on rainfall patterns, global temperature, and evaporation. A common mitigation strategy adopted by households is to promote water demand management initiatives to reduce water consumption volume and complement existing water supply management approaches implemented by suppliers. This study contributes to the discussion on adaptation strategies by investigating household preference heterogeneity for water-saving technologies through empirical evidence from urban Cape Town, South Africa. Using a choice modelling framework, we collected primary survey data from 512 urban households in five of the city's major suburbs and investigated heterogeneity among the households based on their preferences for characteristics embedded in four water-saving technologies. Four preference classes were identified by accounting for taste heterogeneity. Overall, respondents had the highest marginal willingness to pay (MWTP) for the greywater technology alternative at 17,025 ZAR (US$ 1142) while rainwater technology has the least willingness to pay value at 5206 ZAR (US$ 349). In addition, the results show that respondents in classes 1 and 2 have a high interest in technologies that save a large quantity of water, whereas members of classes 3 and 4 rely on inexpensive conservation and behavioral habits as climate adaptation measures. This study has important policy implications for many water-stressed and arid cities within and outside South Africa since like Cape Town, many large cities require long-lasting measures that help reduce the pressure on their strained water systems.

Breeding an early maturing, blast resistance water-saving and drought-resistance rice (WDR) cultivar using marker-assisted selection coupled with rapid generation advance.

The japonica water-saving and drought-resistance rice (Oryza sativa L.) (WDR) cultivar Huhan 9 harbors genes for resistance to rice blast (Magnaporthe oryzae), including Pi-ta and Pi-b. The early maturing japonica rice cultivar Suhuxiangjing and the high-yield WDR cultivars Huhan 3 and Huhan 11 were used as the parents to conduct single cross breeding and composite hybridization breeding. Strict drought resistance screening was conducted in the segregating generations, the genotypes of which were determined using functional markers of Pi-ta and Pi-b genes. By combining the rapid generation advance of the industrialized breeding system and multi-site shuttle identification, the new WDR cultivar Huhan 106 with early maturity, blast resistance, high yield, and high quality was bred, and it was certified by the Agricultural Crop Variety Certification Commission of Shanghai in 2020. Molecular marker-assisted selection coupled with rapid generation advance and multi-site shuttle identification is a rapid and efficient breeding method for the value-added improvement of crop varieties. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01319-3.

Alternate Wetting and Drying in the Center of Portugal: Effects on Water and Rice Productivity and Contribution to Development.

Rice irrigation by continuous flooding is highly water demanding in comparison with most methods applied in the irrigation of other crops, due to a significant deep percolation and surface drainage of paddies. The pollution of water resources and methane emissions are other environmental problems of rice agroecosystems, which require effective agronomic changes to safeguard its sustainable production. To contribute to this solution, an experimental study of alternate wetting and drying flooding (AWD) was carried out in the Center of Portugal in farmer's paddies, using the methodology of field irrigation evaluation. The AWD results showed that there is a relevant potential to save about 10% of irrigation water with a reduced yield impact, allowing an additional period of about 10 to 29 days of dry soil. The guidelines to promote the on-farm scale AWD automation were outlined, integrating multiple data sources, to get a safe control of soil water and crop productivity. The conclusions point out the advantages of a significant change in the irrigation procedures, the use of water level sensors to assess the right irrigation scheduling to manage the soil deficit and the mild crop stress during the dry periods, and the development of paddy irrigation supplies, to allow a safe and smart AWD.

Evaluating the water-saving and wastewater-reducing effects of water rights trading pilots: Evidence from a quasi-natural experiment.

Water rights trading is a market mechanism that promotes the conservation, protection and optimal allocation of water resources. This paper takes the water rights trading pilots' policy as a quasi-natural experiment, and then adopts the spatial difference-in-differences model to investigate the water-saving and wastewater-reducing effects of water rights trading pilots by using the panel data of 30 provinces in China from 2006 to 2019. The results indicate that water rights trading has good environmental governance effects on water-saving and wastewater-reducing in the pilot areas. However, water rights transactions are mainly concentrated within provinces, and there is no spatial spillover effect. Besides, the pilot policy has more long-term dynamic effects in reducing sewage discharge than water-saving due to rebound effect possibly. The optimization of the industrial structure and environmental regulation play important roles in the realization of the policy effects of the water rights trading pilots. An important implication is that water rights trading pilots are worthy of promotion throughout China in view of the policy effects, and China should focus on inter-regional market transactions and industrial structure transformation to promote the optimization of the water rights trading mechanism.

Water need and water use efficiency of two plant species in soil-containing and soilless substrates under green roof conditions.

Despite the significance of urban landscapes, there are limiting factors like spaces and water resources to expand them across the world. These limitations necessitate the development of water-conserving strategies in vertical infrastructures such as green roofs. One water-conserving strategy is precise irrigation regimes based on the plant species' water needs. We investigated the water need of Carpobrotus edulis and Aptenia cordifolia under treatments with different soil-containing and soil-less water-absorbing substrate amenders and humic acid applications. The experiment was factorial based on a randomized complete block design with three replications and was conducted from May to September 2020. The first factor was the substrates with different green roof substrate compositions including soil-containing and soilless substrates with varying bentonite percentages. The second factor was humic acid levels (zero, 100, and 200 mg/l), which were applied as fertigation every 15 days during the experiment. Water needs were determined using the lysimetric method. The results showed that despite the soil-containing substrate with bentonite, the soilless substrate alone could not lead to optimal plant growth. The highest water use efficiency and the least evapotranspiration were obtained from the substrate containing 20%Soil +20% leca +20% perlite +20% mineral pumice +20% leaf litter plus 12% w bentonite, combined with A. cordifolia. This plant species showed a better performance compared with C. edulis. During the spring and summer months, the soil-containing substrate with bentonite and A. cordifolia can create a sustainable green roof system by creating better coverage, more water conservation, and a more aesthetic appearance. Based on the results, the application of the highest concentration level of humic acid (200 mg/l) increased the water use efficiency by about 40% after the establishment of the plants. Also, using this level of humic acid reduced the evapotranspiration rate in A. cordifolia up to 10 ml/day and in C. edulis up to 15 ml/day.

Exploration of water-nitrogen coupling effects in paddy field based on ORYZA (v3) model.

BACKGROUND: Nitrogen and water are two major factors in rice production. Due to the lack of ample evidence and much uncertainty in field experiments, the coupling effects of water and nitrogen in paddy fields have remained debatable over recent years. RESULTS: A fine-calibrated ORYZA (v3) model was applied to simulate rice growth and development under different nitrogen (N) rates and irrigation regimes for a double rice-cropping system in South China. We designed a numerical experiment of 504 treatments, consisting of seven nitrogen rates (0-300 kg ha-1 ), eight irrigation thresholds (30-100%, presented as the percentage of saturated soil water content) and nine irrigation quotas (20-100 mm), and each treatment was simulated for 30 years. Yield varied greatly with different water-nitrogen conditions, particularly in the scenario of frequently alternate wetting and drying irrigation and low-N rates. The coupling effects had a negligible influence on water input and water loss, which were found to be sensitive only to the irrigation regime and rainfall distribution. Based on the results, the N fertilizer for early rice growing in the wet season is suggested as 150-200 kg ha-1 , and 200-250 kg ha-1 for late rice growing in the dry season. The irrigating threshold and irrigation quota for early rice are suggested as lower than 70% and 30-40 mm, respectively, and, for late rice, 70-80% and 40-60 mm. CONCLUSION: Remarkable water-nitrogen coupling effects were found in the paddy field, and integrative water-nitrogen management strategies were suggested for both early rice and late rice in South China. © 2021 Society of Chemical Industry.

Can cropland management practices lower net greenhouse emissions without compromising yield?

Smart cropland management practices can mitigate greenhouse gas (GHG) emissions while safeguarding food security. However, the integrated effects on net greenhouse gas budget (NGHGB) and grain yield from different management practices remain poorly defined and vary with environmental and application conditions. Here, we conducted a global meta-analysis on 347 observation sets of non-CO2 GHG (CH4 and N2 O) emissions and grain yield, and 412 observations of soil organic carbon sequestration rate (SOCSR). Our results show that for paddy rice, replacing synthetic nitrogen at the rate of 30%-59% with organic fertilizer significantly decreased net GHG emissions (NGHGB: -15.3 ± 3.4 [standard error], SOCSR: -15.8 ± 3.8, non-CO2 GHGs: 0.6 ± 0.1 in Mg CO2 eq ha-1  year-1 ) and improved rice yield (0.4 ± 0.1 in Mg ha-1  year-1 ). In contrast, intermittent irrigation significantly increased net GHG emissions by 11.2 ± 3.1 and decreased rice yield by 0.4 ± 0.1. The reduction in SOC sequestration by intermittent irrigation (15.5 ± 3.3), which was most severe (>20) in alkaline soils (pH > 7.5), completely offset the mitigation in CH4 emissions. Straw return for paddy rice also led to a net increase in GHG emissions (NGHGB: 4.8 ± 1.4) in silt-loam soils, where CH4 emissions (6.3 ± 1.3) were greatly stimulated. For upland cropping systems, mostly by enhancing SOC sequestration, straw return (NGHGB: -3.4 ± 0.8, yield: -0.5 ± 0.6) and no-tillage (NGHGB: -2.9 ± 0.7, yield: -0.1 ± 0.3) were more effective in warm climates. This study highlights the importance of carefully managing croplands to sequester SOC without sacrifice in yield while limiting CH4 emissions from rice paddies.

Water saving practices conditioned by socioeconomic factors: A case study of Ecuadorian households.

One of the essential environmental goods is water, thus, some governments have implemented policies that allow regulating and protecting this valuable resource. Additionally, it is necessary to understand the behaviour of people to its consumption. The objective of this paper is to determine which socioeconomic factors have a greater influence on water-saving practices in households in Ecuador and thus be able to recommend policy formulations that help to conserve it. The database for the Monitoring Survey for the National Development Plan applied by the National Institute of Statistics and Censuses [INEC] (December 2019) was used. The sections of the survey that were used to obtain the variables were: education, environmental information, housing, and household data. Furthermore, the econometric logit model was used to identify the factors that influence water-saving practices in the home and five main dependent variables were taken into account: closing the taps while soaping the dishes or doing other activities, showering for less than 10 min, using a bucket and not a hose for certain activities, checking pipes regularly and water reuse while the independent variables were grouped into two groups: socio-economic and environmental awareness and responsibility. The results show that the most significant determinant variables of water-saving practices for households in Ecuador are gender, marital status, homeownership, and the main finding is the variable of perception of environmental problems, which is significant in most of the proposed models. Finally, as a policy implication, in addition to the tax burden on water consumption, governments can implement campaigns that promote awareness, saving, and the proper use of this resource; laws can also be established that sanction the misuse of water.

Impacts of rainfall change on stormwater control and water saving performance of rainwater harvesting systems.

Rainwater harvesting is widely implemented to deal with urban water scarcity and stormwater control issues. In the context of climate change, however, the impacts of rainfall change on rainwater harvesting systems (RHS) are still unknown in many regions. In this study, effects of rainfall change on both water saving and stormwater control performance of RHS across six cities in different climatic zones of Pakistan were investigated and location-specific and adaptive measures to mitigate the negative impacts of rainfall change on RHS were proposed. The commonly defined "dry gets drier, wet gets wetter" rainfall change pattern is not retained in the cities. Water saving performance of RHS is positively affected by increasing trend of rainfall at Khanpur and Peshawar, whereas negatively affected by rainfall decreases at Zhob and Murree. Conversely, increasing trend of rainfall is non-beneficial for stormwater control at Khanpur and Peshawar but rainfall decreases are beneficial at Zhob and Murree. Islamabad and Lahore do not have notable changes in performance of RHS due to the non-significant changing trends in rainfall. The impacts of rainfall change on performance of RHS are dependent on not only the trends and extents of local rainfall change, but also tank sizes and water demands. At Khanpur and Murree, the negative impacts of rainfall change on performance of RHS can be resolved by enlarging tank sizes. At Zhob and Peshawar, however, adjusting contributing areas or water demands should also be considered. Therefore, location-specific and adaptive measures should be adopted for RHS to accommodate rainfall change.

What factors affect the water saving behaviors of farmers in the Loess Hilly Region of China?

Water shortage has become one of the most serious challenges faced by humans. Thus, improving water use behaviors and saving water are critical. In this paper, based on the extended Value-Belief-Norm (VBN) theory, we used the structural equation model and the survey data of 558 households in the Loess Hilly Region to analyze the key factors affecting water saving behaviors of farmers. The domestic water consumption of farmers in Loess Hilly Region is mainly for diet and personal hygiene. The water-saving behaviors of farmers are significantly affected by their willingness, knowledge and age. Personal habits, policy incentives, egocentric values and biospheric values indirectly affect the willingness to save water by acting on personal water-saving norms. Gender and annual household income also have a significant impact on water-saving willingness of farmers. The estimation results of multi-group structural equation model and full-sample structural equation model are generally consistent, and there are significant differences in the influence of gender and water source adjustment variables on water-saving behaviors among different hypothetical paths. Among them, female, cellar water and well water groups have the greater impact on water-saving behaviors. These results provide references for policy makers to formulate effective rural water-saving strategies. Policymakers should strengthen the propagandize of water-saving knowledge and skills, popularize knowledge about water resources and ecological environment changes, encourage farmers to develop good water use habits, and actively promote the subsidy system for water-saving appliances. Then they should establish a supervision and management mechanism of water resources to stimulate farmers to save water, which realize the sustainable use of local water resources.

Evaluating the effectiveness of the water-saving society construction in China: A quasi-natural experiment.

The conservation and efficient use of water resources are directly related to the sustainable and high-quality development in China. This paper regards the pilot policy of water-saving society construction as a quasi-natural experiment, and employs a differences-in-differences approach to evaluate the effectiveness of urban water-saving policies and exploit its drive mechanism by using the panel data of 263 cities in China from 2001 to 2016. Findings show that the pilot policy of water-saving society construction can achieve better water-saving effects, which can not only promote the reduction of urban water consumption in intensity and total amount, but also improve the efficiency of water resources utilization. And this policy has brought long-term dynamic effects on the urban water resources conservation. Heterogeneous effects exist in different types of cities, that is, the water-saving performance is more significant in cities with sufficient water resources and in central China. Besides, this paper finds that the impact of this water-saving policy on urban water resource conservation is mainly through two channels such as water resources infrastructure investment and water resources pricing. These findings provide useful inspirations for local governments to take effective economic measures to manage water resources.

Optimal storage sizing for indoor arena rainwater harvesting: Hydraulic simulation and economic assessment.

This study demonstrates a large roof (30,000 m2) rainwater harvesting (RWH) system in an indoor arena by considering three water demand scenarios (toilet flushing, irrigation and combined demand) via hydraulic and economic assessments. The water saving efficiency (WSE) of the RWH system for each scenario was estimated by a simulation model using historical daily rainfall data (1968-2018). Depending on the water demand, the WSE was found to be independent of tank size when the tank size exceeded 1000 m3. The results suggest that the WSE of the RWH system is highly influenced by water demand scenarios, and a storage capacity of 400-1000 m3 would be enough for the applications considered in this study. The economic analysis results further showed that depending on the water demand, the RWH system with a rainwater storage capacity of between 100 and 600 m3 was more economically beneficial due to its positive cost saving values. The results also showed that depending on the water scenarios, the unit water cost between 0.37 and 0.40 £/m3 was lower than the mains water cost (0.40 £/m3). As a result, the use of the RWH system with a tank between 400 and 600 m3 can be the most favourable range under the conditions considered in this study. Given the variations in water price, rainfall patterns and discount rates, the sensitivity analysis showed that water tariffs and discount rates play a significant role in reducing the unit water cost of the system, maintaining it lower than the mains water cost. A payback period analysis of the RWH system with a 600 m3 tank revealed that a 5% discount rate and a water price of 3 £/m3 would be enough to make the RWH system cost effective and that the capital cost could be returned within 10-11 years. This study highlights the need for preliminary sizing of a rainwater tank and an economic analysis of a large rooftop RWH system to maximise the benefits.

Provincial Veterinary Services respond to drought in South Africa.

In 2018, Cape Town, South Africa, nearly ran out of water. That this has not yet happened is in large part due to the water-saving efforts of its citizens. It is highly likely that this situation will be repeated in Cape Town and that similar situations will be experienced by major cities in other parts of the world. Efforts to save water should thus continue and the lessons learned in Cape Town should be shared. The functioning of Veterinary Services during a drought is affected in the same way as any business, in terms of running an office, but veterinary professionals face an increased risk of exposure to pathogens, compared to that of many occupations, and of veterinary officials becoming disease vectors. One component of Veterinary Services is veterinary laboratory services. Laboratory procedures rely heavily on water and, without advance planning, a laboratory's function can be severely limited by a restricted water supply. In many cases, innovative water-saving techniques can be used to reduce water use substantially without compromising the quality of the services offered. Here, the authors share their experiences and some lessons learned while working in Veterinary Services in the Western Cape province of South Africa.

En 2018, la ville du Cap en Afrique du Sud a failli manquer d'eau. Si la pénurie totale a pu être évitée, ce fut en grande partie grâce aux efforts déployés par les habitants pour économiser l'eau. Or, il est très probable que cette situation se reproduise au Cap et que des situations analogues surviennent dans nombre de grandes métropoles d'autres régions du monde. C'est pourquoi il convient de poursuivre les efforts d'économie d'eau et de partager avec d'autres les enseignements tirés dans la ville du Cap. L'impact de la sécheresse sur le fonctionnement des Services vétérinaires est similaire à celui de toute organisation en termes de gestion administrative ; en revanche, par rapport à d'autres professionnels, les vétérinaires de terrain sont davantage exposés à des agents pathogènes et au risque de devenir eux-mêmes vecteurs de maladies. Les laboratoires vétérinaires sont l'une des composantes des Services vétérinaires. Les procédures de laboratoire sont amplement tributaires de l'eau ; or, en l'absence d'une planification préalable, les activités d'un laboratoire pourraient être gravement mises à mal par des restrictions de l'approvisionnement en eau. Dans bien des cas, il est possible d'utiliser des techniques innovantes pour économiser l'eau afin d'en diminuer la consommation sans pour autant compromettre la qualité des services rendus. Les auteurs font part de leur expérience et de certains enseignements tirés lorsqu'ils travaillaient dans les Services vétérinaires de la province du Cap-Occidental en Afrique du Sud.

En 2018 faltó poco para que Ciudad del Cabo (Sudáfrica) se quedara sin agua. Si las cosas aún no han llegado a este extremo es, en gran parte, gracias a los esfuerzos de los habitantes por economizar agua. Es muy probable que en el futuro Ciudad del Cabo vuelva a sufrir esta situación y que grandes metrópolis de otras partes del mundo conozcan dificultades parecidas. Por ello hay que perseverar en los esfuerzos de ahorro de agua y se deben compartir las enseñanzas extraídas en Ciudad del Cabo. Durante una sequía, el funcionamiento de los Servicios Veterinarios se ve afectado del mismo modo que cualquier otra actividad, por lo que respecta al trabajo de oficina, pero además los profesionales del ramo, en comparación con los de otros muchos sectores, corren mayor peligro de exposición a patógenos, lo que a su vez entraña el riesgo de que los propios veterinarios ejerzan de vectores de la enfermedad. Uno de los puntales de los Servicios Veterinarios son los laboratorios veterinarios, cuyo quehacer depende en gran medida del uso de agua. Por ello, cuando no se ha planificado con antelación la eventualidad de una penuria de agua, esta puede imponer graves cortapisas a las funciones de laboratorio. En muchos casos es posible emplear innovadoras técnicas de ahorro de agua para reducir sustancialmente las cantidades utilizadas sin menoscabo de la calidad de los servicios dispensados. Los autores comparten su experiencia y algunas de las lecciones que extrajeron de su trabajo en los Servicios Veterinarios de la provincia sudafricana del Cabo Occidental.

Variation of representative rainfall time series length for rainwater harvesting modelling in different climatic zones.

Rainwater harvesting systems (RHS) have been increasingly used to mitigate urban water scarcity and flooding problems. Rainfall data with various lengths have been used for RHS modelling. However, short-term rainfall data with inadequate lengths used for the modelling of RHS may lead to considerable errors. In this study, a method that can be used to identify representative length of short-term rainfall data for RHS modelling was proposed and tested in 12 cities located in different climatic zones. The influences of local rainfall characteristics on the variation of representative time series lengths (RTSL) were revealed using linear regression and partial correlation analyses. The results show that RHS with larger storage capacity and located in more humid cities can provide higher water saving efficiency and reliability. Rainfall time series length has significant influence on the modelling results of RHS. The RTSL for the 12 cities vary from 6 to 21 years. The RTSL for the 12 cities are non-significantly correlated with mean annual rainfall (R2 = 0.32, n = 12, p > 0.05) and seasonality index (R2 = 0.28, n = 12, p > 0.05), but significantly correlated with variation coefficients of annual rainfall (R2 = 0.76, n = 12, p < 0.05). The partial correlation coefficient between RTSL and the variation coefficients of annual rainfall is 0.878, while the partial correlation coefficients between RTSL and the mean annual rainfall and seasonality index are -0.569 and -0.522, respectively. The results demonstrate the feasibility of using short-term rainfall data with adequate length instead of long-term rainfall data for RHS modelling and also provide insights into the variation of RTSL in different climatic zones.

Developing a strategic framework for adopting water-saving measures in construction projects.

The construction industry consumes substantial water resources. Thus, there is a necessity to adopt effective water-saving measures to reduce water consumption in construction projects. The aim of this paper is providing a strategic framework of water-saving measures for different phases of a construction project. To start with, the prevailing green building rating tools were investigated to explore the alternative water-saving measures. Then, a comparative analysis utilizing relative significance indexing was conducted to identify the foci of water-saving measures in various green building rating tools. Based on the derived results, ten water-saving measures, namely rainwater harvesting, usage of recycled water, NEWater, water-saving technologies, water-saving devices, water-saving efficiency, water monitoring system, monitoring of major water uses, leak detection, and continuous water monitoring, were identified. These measures were further categorized into three strategic aspects, such as water sources substitution, water consumption reduction, and water use monitoring. Based on the results, a strategic framework was developed for reducing water consumption and improving water use efficiency. The developed framework can serve as a systematic guideline for formulating water-saving schemes in different stages of construction projects.