LOADING RESPONSE OF STERN TAB MOTION CONTROLS IN SHALLOW WATER

The ride control systems of high-speed vessels frequently use active stern tabs for both motion control and maintenance of correct trim at various speeds and sea conditions. This paper investigates the effect of water depth on the lift force provided by stern mounted trim tabs, of the type fitted to INCAT high speed wave-piercer catamaran vehicle ferries and similar vessels. This investigation was carried out at model scale with the use of a test apparatus in a flume tank in the University of Tasmania hydraulics laboratory. The lift force magnitude and location were measured over a range of tab angles and flow depths. This was used to calculate the lift coefficient of the tab and asses the performance of the tab over the range of flow depths. It was found that the lift force increased and the force location progressed further forward of the hinge as flow depth decreased. The lift curve slope of the stern tab increased by a factor of over 3 relative to the deep water value when the water depth below the hull was approximately equal to the tab chord. The deep water lift curve slope appears to be approached only when the water depth exceeded 4 or more tab chord lengths. The centre of pressure of the lift force was more than two chord lengths ahead of the tab hinge, showing that most of the lift produced by the tab was under the hull rather than on the surface of the tab itself.

Estimating the Impact of Ecological Migrants on the South-to-North Water Diversion in China

The South-to-North Water Diversion (SNWD) provides significant benefits in facilitating water security and improving ecology in northern China. However, few studies have estimated the water value of the SNWD and the corresponding subsequent subsidies of the ecological migrants in Xichuan County displaced by the project. Based on the Google Earth Engine (GEE), this study analyzed the water ecosystem changes in Xichuan County in 2000–2020 and valued the water transfer of the SNWD. We calculated the water cost, the water value of the trunk line project, and the four provinces (Hebei, Henan, Beijing, and Tianjin) of CNY 4.04, 39.64, and 120.93 billion, respectively, and the proportion of the three was 1:10:30 during 2014–2020. The water ecosystem area showed a rapid increase when the SNWD became operational since the end of 2014. The subsequent annual subsidy gap of ecological migrants was CNY 0.84 billion, which only accounted for 4.31% of the gross profit of SNWD. Our results imply that relevant water sectors have sufficient profits to support corresponding subsequent subsidies for ecological migrants. Ecological migrants are a major challenge for water transfer projects. Overall, this study fills a gap of interactions between subsequent policies and ecological migrants and provides a typical case for managing the migration problem caused by sustainable water management worldwide.

Optimal water allocation based on agricultural and environmental water value

Despite the significant role of wetlands in maintaining a healthy ecosystem and providing various ecosystem services, they are under threat due to human activities and agriculture use. The fact that the economic value of ecosystem services is not considered in hydro-economic models and integrated water resources management is a key issue that affects the ecosystem and its degradation. the economic value of ecosystem services provides a quantitative and important basis for the reasonable management of water resources. Given that supplying the agriculture and environmental demands conflict with each other, achieving a balance between these goals is very important. So, in this study, a simulation-optimization (WEAP-PSO) approach is employed for optimal planning at the basin and designing environmental flow based on wetland ecosystem services. The objective function of the problem is considered to be the total economic value of the river, which includes the economic value of the agricultural sector and the economic value of the wetland ecosystem services. The decision variables of the problem are considered as, the cultivation area of agricultural units and environmental flow of Kani Barazan wetland. The results show that considering these two objectives together, in addition to sustainable development, causes the highest economic efficiency in the basin.

What Is Learned in Pavlovian Conditioning in Crickets? Revisiting the S-S and S-R Learning Theories

In Pavlovian conditioning in mammals, two theories have been proposed for associations underlying conditioned responses (CRs). One theory, called S-S theory, assumes an association between a conditioned stimulus (CS) and internal representation of an unconditioned stimulus (US), allowing the animal to adjust the CR depending on the current value of the US. The other theory, called S-R theory, assumes an association or connection between the CS center and the CR center, allowing the CS to elicit the CR. Whether these theories account for Pavlovian conditioning in invertebrates has remained unclear. In this article, results of our studies in the cricket Gryllus bimaculatus are reviewed. We showed that after a standard amount of Pavlovian training, crickets exhibited no response to odor CS when water US was devalued by providing it until satiation, whereas after extended training, they exhibited a CR after US devaluation. An increase of behavioral automaticity by extended training has not been reported in Pavlovian conditioning in any other animals, but it has been documented in instrumental conditioning in mammals. Our pharmacological analysis suggested that octopamine neurons mediate US (water) value signals and control execution of the CR after standard training. The control, however, diminishes with extension of training and hence the CR becomes insensitive to the US value. We also found that the nature of the habitual response after extended Pavlovian training in crickets is not the same as that after extended instrumental training in mammals concerning the context specificity. Adaptive significance and evolutionary implications for our findings are discussed.

Applying a novel framework for the estimation of the full cost of water in a degraded rural watershed

Water Resources Management's modern concerns include solutions on water scarcity, water quality problems and the use of economic and decision-support tools. Especially, the agricultural sector in South Europe under the requirements of the Water Framework Directive 2000/60/EC(WFD) remains a challenge. Most scholars so far doubt and criticize the implementation of the full cost of irrigation water, review papers highlight the limited progress, and fewer cases provide guidance on how to address this case. The present study applies a novel methodological framework for the estimation of the full cost of irrigation water, based on hydro-economic concepts such as: water balance, profits from agriculture, water value, water quality, monetary, opportunity and environmental costs. Originally, the method has been applied only once in a rural watershed with surface and groundwater resources. Here, a degraded Greek watershed using only groundwater resources is the study area, and the results of the two cases are compared. The model was also examined under demand management strategies and recommendations to scrutinize the effects and the applicability of the proposed measures in hydrological and economic terms. The findings give useful insights on the future management of achieving economic objectives with environmental constraints and the harmonization of Greek agriculture to the WFD.

Nilai Ekonomi Nilai Ekonomi Penggunaan Air Permukaan Di Sub DAS Cihideung, DAS Cisadane

Surface water is part of the rainfall flowing above the ground to rivers, lakes, or oceans. One of the surface water resources in West Java is the river water from Cihideung sub watershed. People living in the Cihideung river have traditionally benefited water value as environmental services of the river. They use the water for their livelihood, mainly for agriculture, fisheries, and livestock with their level of income up to Rp.512.250.999,00 per year and expenditure of up to Rp.172.079.999,00 per year. Most of them work as farmers with an average age of 47-53 years and the education level is only elementary school level. They put value of water services about Rp. 237.642.578.707,00 for all house hold in Cihideung Sub Watershed for economic value of water utilization. The quality of water tends to be degrading with existing condition is mild to moderate polluted. The water condition have been decreasing people income and need to be restored among other by upland forest conservation using Payment for Environmental Service schema. The value of water could be managed as a source of fund for the conservation program.

Eficácia da Cobrança pelo Uso de Recursos Hídricos condicionada ao Índice de Qualidade da Água: Estudo de Caso, Minas Gerais, Brasil

Em vários países o preço da água pode e melhorou quantitativa e qualitativamente a distribuição deste recurso. O preço adequado e bem utilizado levou a uma melhor sustentabilidade e conservação da água por meio de regulamentos prescritivos, incluindo até o racionamento de água. O uso de preços para gerenciar a demanda de água é mais econômico do que a implementação de programas de conservação sem preços. No Brasil, através de instrumentos legais, é prevista a cobrança pelo uso dos recursos hídricos, sinalizando pela necessidade do reconhecimento do valor econômico da água associado ao seu uso, ao desenvolvimento sustentável mediante aos desafios da escassez hídrica futura. Para que a cobrança pelo uso da água não se torne um mero mecanismo de arrecadação pública, e devido também, a inexistência de estudos que investiguem e expressem de forma clara os objetivos e finalidades da cobrança em Minas Gerais, esta pesquisa se fez necessária. Desta forma, este trabalho objetivou investigar e avaliar a cobrança pelo uso da água e sua eficácia na melhoria do Índice de Qualidade da Água (IQA) estabelecida pelo órgão gestor. Em Minas Gerais, de 91,67% das Unidades de Planejamento e Gestão de Recursos Hídricos (UPGRHs), onde existe a cobrança instituída, não se constatou uma tendência na melhoria do IQA. Apenas 36,36% das bacias estaduais que cobram pelo uso da água melhoraram os níveis de IQA, enquanto 63,63% pioraram ou não tiveram variação significativa. Charging Effectiveness for the Use of Water Resources conditioned to the Water Quality Index: Case Study, Minas Gerais, Brazil A B S T R A C TIn several countries the price of water can and has improved quantitatively and qualitatively the distribution of the resource. The appropriate and well-used price has led to better sustainability and conservation of water through prescriptive regulations, including even water rationing. Using prices to manage water demand is more economical than implementing price-free conservation programs. In Brazil, through legal instruments, charging for the use of water resources is foreseen, signaling mainly the need to recognize the economic value of water associated with its use, sustainable development through the challenges of future water scarcity. So that, charging for the use of water does not become a mere mechanism for public collection, and also due to the lack of studies that investigate and clearly express the objectives and purposes of charging in Minas Gerais state, this research was necessary. Thus, this study aimed to investigate and evaluate the charge for water use and its effectiveness in improving the Water Quality Index (WQI) established by the managing body. In Minas Gerais, of 91.67% of the Water Resources Planning and Management Units (UPGRHs), where the collection is in place, there was no trend in improving the IQA. Only 36.36% of the state basins that charge for the use of water improved the levels of IQA, while 63.63% worsened or had no significant variation.Keywords: Water scarcity. Water availability. Water Value.

Evaluation and spatial aggregation of ecological water use in each region of the Yellow River Basin

Ecological water is the basic condition to maintain river health in a water-deficient basin. The evaluation and spatial distribution of ecological water are significance to the allocation of water resources under the concept of ecological civilization. In this paper, the connotation and composition of value of ecological water are defined from the perspective of ecosystem material circulation. Based on the emergy theory, the quantitative methods of different types of ecological water value are proposed. Combined with the spatial autocorrelation analysis method, the analysis method of spatial distribution and aggregation characteristics of watershed ecological water value is established. We took the Yellow River Basin as an example, and estimated and analysed its ecological water value and the spatial distribution characteristics according to the 9 regions of basin. The results showed that: In the Yellow River Basin, the single water value of the ecological water in the river channel is 17.45-24.36 yuan, the single water value of the sediment transport water is 2.42-7.28 yuan, and the single water value of the ecological water outside the river channel is 10.87-16.61 yuan. Ecological water value presents obvious difference in the space. Both outside and inside the river course, the high concentration areas of ecological water value are in the middle and lower reaches, while the low concentration areas are in the lower reaches, which indicates that we should consolidate the ecological water value in the middle and lower reaches and enhance the water value in the upper reaches. The research results have guiding significance for the allocation of ecological water in each province and region.