scholarly journals A System for Measuring Water Levels in Open-Air Irrigation Canals

2021 ◽  
Vol 248 ◽  
pp. 02011
Author(s):  
Fausto Freire Carrera ◽  
Harry Saltos Sanchez ◽  
Yelitza Garcia-Orellana ◽  
Olga Chadrina

The measurement of the water level in a canal allows us to know its flow. This information is essential for the correct administration of the water resource. Manual quantification can be replaced by micro controlled systems with an internet connection. Thus, the measurement and recording of water levels in open canals in real time is achieved. The chosen micro controlled system was based on ultrasonic instrumentation with GPRS communication. It had a wide cellular network to achieve an effective connectivity in rural areas, a power system combining solar energy with pollutant free batteries and the capacity to store data. The obtained percentage and average errors were lower than the permissible error specified in the requirements. Consequently, the evaluated measurement system is reliable for the evaluation of canals in a real-world setting.

2021 ◽  
pp. 107754632110037
Author(s):  
Sun Jiaojiao ◽  
Xia Lei ◽  
Ying Zuguang ◽  
Huan Ronghua ◽  
Zhu Weiqiu

A closed-loop controlled system usually consists of the main structure, sensors, and actuators. The dynamics of sensors and actuators may influence the motion of the main structure. This article presents an analytical study on the first-passage reliability of a nonlinear stochastic controlled system under the consideration of the dynamics of sensors and actuators. The coupled dynamic equations of the controlled systems with sensors and actuators are first given, which are further integrated into a controlled, randomly excited, dissipated Hamiltonian system. By applying the stochastic averaging method for quasi-Hamiltonian systems, a one-dimensional averaged differential equation for the Hamiltonian function is obtained. The backward Kolmogorov equation associated with the averaged equation is then derived for the first-passage reliability analysis, from which the approximate reliability function and probability density of first-passage time are obtained. The accuracy of the proposed procedure is demonstrated by an example. A comparative analysis of the reliability of the system with/without sensors and actuators is carried out, which indicates that ignoring sensors and actuators will make underestimation of the reliability of the closed-loop system with small time. However, when time increases, there appears the opposite trend. Our findings provide a reference for control strategy design.


2020 ◽  
Author(s):  
◽  
Mpumelelo Dolo

Water is regarded as the most important substance found on earth. There is no substitute for it. The daily running of production businesses, industrial firms and agricultural production that help sustain the economy of countries are largely dependent on the availability of water for them to function. The importance of water cannot be over emphasised. The food which is consumed daily depends on water; it can therefore be safely concluded that without water there would be no food, and without food there would be no life. Despite the importance of water in relation to human life, animals and plants, research studies show that the its availability becoming increasingly deficient around the globe. Water levels of major dams and rivers around the world are dropping, limiting the supply of potable water to those dependent on them. Global warming is one factor that is influencing the dropping of water levels, through evaporation. Other factors include climate change, drought and population growth. In South Africa, the government has been fighting a continuous battle of trying to address the backlog of water infrastructure, particularly in the areas which were disadvantaged by the apartheid government. These areas include rural areas, small towns (semi-urban) and townships. The Eastern Cape province in South Africa is top of the list from a backlog point of view. Rural dwellers migrate to urban areas for various reasons such as better education, better health care, job opportunities and more efficient services. Water supply is one of the services which is more adequately supplied in the cities compared to the rural areas. Even though the supplied water in the urban areas of the Eastern Cape is not the best standard when compared to other cities around the country or the world, it is still at an acceptable standard. Thus, this study was conducted to seek ways of improving the supply of water in the urban and rural areas of the Eastern Cape. The availability and the quality of water differs between the urban and rural areas. The purpose of this study was to seek ways of bridging the gap between these areas while improving the standard of water supply in both rural and urban areas. While working towards improving the lives of the Eastern Cape people, the study also seeks to promote water preservation and awareness to the people of the province. In order to find better alternatives which have been tested in various places around the world, an in-depth literature review was conducted in the study. This functioned as an effective comparison of what is obtained in different places around the world and the context of this study, which is the Eastern Cape. A survey method was used to gather data regarding the problems surrounding water supply and options that could be adopted to remedy those problems. The survey was conducted in the form of a self-observation assessment, questionnaire for households in urban and rural areas and interview sessions with prominent government entities and local technical service providers. The survey covered the whole spectrum of individuals and groups that play a major role in the supply and usage of water. The study was conducted within three municipalities of the Eastern Cape. These municipalities cover approximately two-third of the Eastern Cape considering the size of population in those areas. The municipalities covered by the study were: Amathole District Municipality (ADM), Buffalo City Metropolitan Municipality (BCMM) and OR Tambo District Municipality (ORTDM). The findings from the study showed that indeed the standard of water supply between urban and rural areas was not equal. This relates to the purification methods, the convenience of collecting water by users, the quality of infrastructure being constructed (due to good or poor monitoring during construction) and the quality of the water as well as operation and maintenance response from the various service providers. Moreover, it was found that there was an acceptable level of awareness by citizens when it comes to using water, and precautions to save it were being taken by some. However, some dominant factors such as poor management, poor infrastructure resulting in leaks, climate change, run-offs and population growth were putting a strain on the existing water resources which is not coping with the increasing demand by people. Recommendations made in the study to balance the supply of water in rural areas and urban areas include: improving the purification of water so as to achieve a standard quality within the Eastern Cape; that rural areas be allowed to have an option of having yard or house connections, particularly those who are willing to pay rates at a scale suiting their class or standard; and that water service providers make it their responsibility to extend reticulation networks if there is expansion or development of more houses in rural areas in order to keep the distance minimal to standpipes


2012 ◽  
Vol 7 (2) ◽  
Author(s):  
I. Nhapi ◽  
A. J. Nshimiyimana ◽  
U. G. Wali ◽  
F. O. K. Anyemedu ◽  
J. J. Kashaigili

After the genocide of 1994, Rwanda has been struggling to contain urban migration and its pressures on existing facilities. Water supply coverage is low at 76% in urban areas and 68% in rural areas. This implies that huge investments are required to meet the Millennium Development Goals on water supply and sanitation. This study was conducted to assess the existing problems of raw water intake systems at Yanze and Nyabarongo intakes in Kigali; Shyogwe intake in Ruhango District; and Kadahokwa intake in Huye District. The study was in response to high amounts of sediments in raw water which literally clogged the intake systems for a number of days, resulting in erratic water supplies to the residents in the rainy season. The study focused on performance problems of the intake systems, raw water turbidity variations and the assessment of how environmental concerns could be addressed in the design of intake systems in areas of high soil erosion activities. Data was collected through interviews and physical measurements. The study revealed that flooding, intake site selection, erosion, screen clogging, intake protection, high raw water turbidity, inadequacy of raw water supplied to the water treatment plants, and low downstream environmental flows were the main intake problems. The Yanze intake had worst problems with high levels of flooding, erosion, sedimentation, and high raw water turbidity levels. The bank filtration system at Nyabarongo gave the least problems of raw water turbidity. Yanze and Nyabugogo river intakes systems were found to be threatened by decreasing water levels attributed to surrounding upstream landuse activities. It was recommended that proper maintenance of existing structures, landuse management around river intakes, use of well-designed reservoir abstraction systems, increased groundwater abstraction systems (including bank filtration), would greatly improve the performance of intake systems in Rwanda.


2008 ◽  
Vol 54 (No. 3) ◽  
pp. 129-134 ◽  
Author(s):  
J. Vaněk ◽  
J. Jarolímek ◽  
P. Šimek

The paper deals with the current trends in development of communication infrastructure which is, above all, represented by high-speed Internet connection (broadband). It is focused on conditions of the Czech Republic; or more precisely, on its rural areas, including possibilities of further development in the following period in context of trends in the world, in the OECD and the EU countries.


Author(s):  
Amal Ahmed Eltahir ◽  
Rashid A. Saeed

Integration of vehicular ad-hoc network (VANET) and cellular network is a promising architecture for future machine-to-machine applications. This integration helps the vehicles have steady internet connection through cellular network (i.e., LTE), and at same time communicate with other vehicles. However, dead spot areas and unsuccessful handoff processes due to the high speed of vehicles that can disrupt the implementation of this kind of architecture. In this chapter, simplified cluster-based gateway selection (SCGS) scheme for multi-hop relay in VANET network is proposed. The scheme is achieved by utilizing a new routing protocol called an enhanced hybrid wireless mesh protocol (E-HWMP). The simulations results show that SCGS scheme through E-HWMP protocol performed better than ad-hoc on demand distance vector (AODV) routing protocol. Furthermore, SCGS scheme through E-HWMP is compared with other cluster-based gateway selections used in the previous works; the result shows that SCGS scheme through E-HWMP protocol outperforms the other cluster-based gateway selections schemes.


Author(s):  
Henrique Raduenz ◽  
Liselott Ericson ◽  
Kim Heybroek ◽  
Victor J. De. Negri ◽  
Petter Krus

This paper outlines an extended analysis on how multi-chamber actuators can improve the efficiency of valve-controlled systems. Resistive control is a major source of energy losses in valve-controlled systems that share the same pump to drive multiple loads. By combining different chambers, the load on multi-chamber actuators can be transformed into different pressure and flow rate levels. This allows the adaptation of its load to the loads on other actuators. This can lead to a reduction of resistive control energy losses that occur between pump and actuators when driven simultaneously. As a case study to highlight how the system efficiency can be improved, a load sensing system with a conventional and a multi-chamber actuator is analysed. The equations that describe the system steady state behaviour are presented to evaluate the effect of the load transformations on the system efficiency. A disadvantage of such architecture is the fact that load transformations result in different actuator speeds. To reduce this effect, a compensation factor for the command signal to the proportional valve is presented. The highlight from this paper is the potential for efficiency improvement enabled by the adoption of multi-chamber actuators in a valve-controlled architecture. Further research is required for the selection of number of chambers and their areas since they directly affect the system efficiency.


2014 ◽  
Vol 16 (02) ◽  
pp. 1440013
Author(s):  
V. N. USHAKOV ◽  
S. A. BRYKALOV ◽  
A. R. MATVIYCHUK ◽  
A. V. USHAKOV

We consider controlled systems and differential inclusions on a bounded time interval. The investigated problem brings the controlled system to a fixed compact target set in the phase space at a finite time moment. It is known that integral funnels of controlled systems and differential inclusions satisfy the invariance property. We discuss application of the invariance property to constructing approximations to integral funnels. Examples of nonlinear controlled systems are considered in which the proposed algorithm is realized.


Author(s):  
Longke Wang ◽  
Wayne J. Book

Pump controlled hydraulic actuators offer higher energy efficiency than valve controlled actuators. However, there exists mode switching in pump controlled systems and instability may arise when a single rod cylinder is implemented. This paper examines the problem of system stability in a pump controlled system with single rod cylinders. It is shown that the system dynamics have a stable tendency or an instable tendency corresponding to different cylinder movements. The paper shows system instability can be avoided by controlling fluid leakage, and two applicable methods are presented: physical leakage compensation and virtual leakage compensation, which can be applied depending on applications. Experiments and numerical simulations are presented. Results show that the proposed solutions can maintain circuit stability: physical leakage compensation can be a general approach while virtual leakage compensation offers higher energy efficiency and lower cost, but its applications are limited by some factors.


1979 ◽  
Vol 10 (5) ◽  
pp. 287-308 ◽  
Author(s):  
Vincent W. Uhl ◽  
K. Nagabhushanam ◽  
John Olaf Johansson

Two-thirds of India is underlain by consolidated rocks and approximately one-half of this hard rock area is composed of Precambrian crystalline rocks. Many rural areas in India are dependent on ground water for drinking and irrigation water supply. Population growth and increasing demands for food and water have resulted in increased withdrawals of ground water in some areas and a decline in water levels. In contrast, the lack of technical expertise and seed money has inhibited the development of ground-water resources in other areas. In this paper, the ground-water resources of two crystalline rock areas are described. The recent drilling of over 600 wells in these areas by the Evangelical Lutheran Church (E.L.C.) Water Development Project provided the data base. The geology, occurrence of ground water, and types of ground-water flow systems in these areas are discussed. Well data such as yield, depth and thickness of overburden, aquifer depth, and well depth were analyzed statistically for both areas. The results helped to quantify the occurrence of ground water with depth and the distribution of well yields and expected well yields in different rock types and topographic settings. Both step-drawdown and constant-rate pumping tests were conducted on 150 production wells. Aquifer transmissivity ranges from approximately 1 to 400 m2/day (meters squared per day) in both areas. Specific capacity results are also presented.


The objectives of this research were to design and develop an automatic water level warning system for communities living along Khlong Lad Phrao (Lad Phrao Canal) in Bangkok. The development of the system was divided into the following four main parts: 1) a water level measurement system; 2) a precipitation measurement system; 3) a water quality testing system covering dissolved oxygen, pH, turbidity and electrical conductivity and 4) an internet alert system utilizing the LINE application and web-based application information display. The first three parts were to be solar-powered. The design and development effort showed that the system successfully measured water levels along with water quality with speed and precision. Moreover, the system was easy to measure results and was able to alert through the LINE application when water in Khlong Lad Phrao approached critical levels, thereby reducing damage from water levels. Precision testing of the developed water level and quality measurement systems found that precision was in the range of 99.74-99.77%.


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