Changing food habits of Macquarie perch, Macquaria australasica Cuvier (Pisces : Percichthyidae), during the initial filling phase of Lake Dartmouth, Victoria

1986 ◽  
Vol 37 (5) ◽  
pp. 647 ◽  
Author(s):  
PL Cadwallader ◽  
J Douglas
Keyword(s):  
Water Level ◽  
Food Supply ◽  
Food Habits ◽  
North Eastern ◽  
Riverine Habitat ◽  
Filling Phase

The composition of the diet of Macquarie perch changed markedly during the various stages of rising and falling water-level during the initial filling phase of Lake Dartmouth, an impoundment formed by the construction of Dartmouth Dam on the Mitta Mitta River in north-eastern Victoria. Macquarie perch fed on typical river-dwelling organisms from inflowing rivers, on terrestrial organisms that became displaced as the water-level rose, and on typical still-water or sluggish-water organisms, which were extremely abundant in the newly created lake. The relative proportions of several of these food types in the diet varied depending on whether the water-level was rising or falling. Macquarie perch appear to have adapted well to the changing food supply in the lake, and have included in their diet several food types that they would not normally have encountered in their natural riverine habitat.

Food habits of the freshwater catfish, Tandanus tandanus Mitchell, in the Gwydir River, Australia, and effects associated with inpoundment of this river by the Copeton Dam

1977 ◽  
Vol 28 (4) ◽  
pp. 455 ◽  
Author(s):  
TLO Davis
Keyword(s):  
Seasonal Variation ◽  
Water Level ◽  
Significant Relationship ◽  
Food Habits ◽  
Food Item ◽  
Aquatic Invertebrates ◽  
Ontogenetic Changes ◽  
Important Food ◽  
Filling Phase ◽  
Important Food Item

The composition of the diet of T. tandanus was investigated in the Gwydir River before and during inundation of the river by the Copeton Dam. Decapods (Macrobrachiurn australiense and Chevax neopunctatus) were the most important component of the diet by weight, followed by chironomids, fish (Hypseleotris klunzingeri) and miscellaneous aquatic invertebrates. Although fish have not previously been recorded in the diet, they were found to be very important in the diet of small catfish (40% by weight). Ontogenetic changes in the diet were pronounced with a general progression: Entomostraca-Diptera-fish-Decapoda. There was a tendency for larger fish to prefer larger prey. A direct and significant relationship was observed between the size of catfish and the size of M. australiense and C. neopunctatus eaten. Investigation of the seasonal variation in the composition of the diet revealed that M. australiense was the most important food item in summer and chironomids were most abundant in winter. During the filling phase of the dam a high proportion of terrestrial organisms (up to 52%) were included in the diet. Successional blooms of species, not observed in the diet previously, accompanied stabilization of the water level; these included pulmonate snails and dipterans associated with a massive build-up of floating hydrophytes.

Development and Testing of a Low-cost Water Level Sensor and a Mobile based Real-time Flood Warning System for the Flash Flood Prone North Eastern part of Bangladesh

2020 ◽  
Vol 10 ◽  
Author(s):  
Nova Ahmed ◽  
Md. Sirajul Islam ◽  
Sifat Kalam ◽  
Farzana Islam ◽  
Nabila Chowdhury ◽  
...  
Keyword(s):  
Water Level ◽  
Real Time ◽  
Flash Flood ◽  
Low Cost ◽  
Warning System ◽  
Outdoor Environment ◽  
Flood Warning ◽  
North Eastern ◽  
Flood Warning System ◽  
North Eastern Part

Background: The North-Eastern part of Bangladesh is suffering from flash flood very frequently, causing colossal damage to life and properties, especially the vast croplands. A distributed sensing system can monitor the water level on a continuous basis to warn people near the riverbank beforehand and reduce the damage largely. However, the required communication infrastructure is not available in most of the remote rural areas in a developing country like Bangladesh. Objective: This study intends to develop a low-cost sensor based warning system, customizing to the Bangladesh context. Method: The system utilizes a low-cost ultrasound based sensor device, a lightweight mobile phone based server, low-cost IoT sensing nodes, and a central server for continuous monitoring of river stage data along with the provision of storage and long-term data analytics. Results: A flash flood warning system developed afterward with the sensors, mobile-based server, and appropriate webbased interfaces. The device was tested for some environmental conditions in the lab and deployed it later in the outdoor conditions for short-term periods. Conclusion: Overall, the warning system performed well in the lab as well as the outdoor environment, with the ability to detect water level at reasonable accuracy and transmit data to the server in real time. Some minor shortcomings still noted with the scope for improvements, which are in the way to improve further.

The Use of SISO ARX Models in the Determination of the Damage to Dams

2010 ◽  
Vol 20 (7) ◽  
pp. 979-1001 ◽  
Author(s):  
Engīn Gülal ◽  
Hediye Erdoğan ◽  
Nedim Onur Aykut ◽  
Halil Erkaya
Keyword(s):  
Water Level ◽  
Water Levels ◽  
The Body ◽  
Original Design ◽  
Engineering Structures ◽  
Arx Model ◽  
Filling Stage ◽  
Filling Phase ◽  
Standard Deviations ◽  
The Impact

Modal characteristics of engineering structures can be determined via dynamic observation in scope of system identification and they can be used for a variety of purposes, including model updates, damage assessment, active control, and original design re-evaluation. This paper presents the use of an autoregressive with eXogenous inputs (ARX) model to assess the impact of horizontal displacements in the Oymapinar Dam in Antalya province, Turkey, during the first reservoir filling stage. Besides, displacements in the dam after the filling stage are predicted. There is a high linear correlation between the displacements of the body of the dam and the first filling phase of the reservoir. An ARX model of the dam without damage is created using displacements predicted from a 3D finite element model of the dam and the changes in water level. The displacements in the dam observed in the first filling phase are recalculated using water level changes for damaged or undamaged cases, observed displacements, and the parameters of the undamaged ARX model. The standard deviations of the residuals calculated from the ARX model of the undamaged dam are statistically compared for different confidence intervals using the standard deviations of residuals of the ARX model of the undamaged or damaged dam’s observations, and it was determined that there was no dangerous damage to the dam. In addition, the observed displacement values were extended in different scales and standard deviations of these displacements are calculated using the ARX of the undamaged dam model. These standard deviations and the one calculated from undamaged model of the dam were compared, and it was determined that 55 mm of displacement could be dangerous for the dam. Finally, the displacements in the dam for different water levels in the operation phase (after filling) were predicted using the ARX model and were found to be consistent with the measured displacement values.

scholarly journals Design of an Automatic Irrigation System

2019 ◽  
Vol 4 (3) ◽  
pp. 97-99
Author(s):  
Nkolika O. Nwazor ◽  
Peter E. Odiushovwi ◽  
Lukman Onalaja
Keyword(s):  
Water Level ◽  
Food Supply ◽  
Humidity Sensor ◽  
Irrigation System ◽  
Low Cost ◽  
Research Work ◽  
Irrigation Systems ◽  
Soil Humidity ◽  
Crop Farming ◽  
Peasant Farmers

Over the years, a lot of irrigation systems have been developed to aid crop farming but most of them are manually operated. The few automatic irrigation systems available in the country are very expensive and therefore not easily available to the peasant farmers. The need for improved non-seasonal crop farming gave rise to this research work on a low cost irrigation system made from locally sourced components. The system designed in this work makes use of a locally made soil humidity sensor to check the water level in the soil. If the water level is below the required level, the irrigation system is turned on by sending a signal to the relay connected to the pump which opens the valve to let water out.  Once the required humidity is obtained, it is turned off through a similar mechanism. The control also has six buttons for time-based control of irrigation for crops that demand irrigation at specific times of the day. With a system like this, non-seasonal farming is ensured thus increasing food supply and reducing hunger.

scholarly journals The Eemian/Early Vistulian development of the Solniki paleolake (north-eastern Poland) as shown by subfossil Cladocera

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Monika Magdalena Niska
Keyword(s):  
Water Temperature ◽  
Water Level ◽  
Subfossil Cladocera ◽  
Climate Fluctuations ◽  
State Of Water ◽  
North Eastern ◽  
Alona Affinis ◽  
Geological Map ◽  
Abundance And Diversity ◽  
Eemian Interglacial

<p>This work presents results of a paleolimnological study focussed on subfossil Cladocera analysis and on different aspects of the evolution of the Solniki paleolake during the Eemian/Early Vistulian period. The study aimed at the reconstruction of the long-term dynamics of this paleoecosystem and at defining the conditions (<em>e.g</em>., water level, trophic status and water temperature) of the ancient lake. Paleolacustrine deposits of ca. 10 m thickness were discovered at Solniki during cartographic works for the Trześcianka sheet of the Detailed Geological Map of Poland. This archives recorded one full-interglacial sequence (Eemian Interglacial), one interstadial warming (Brørup) and two stadial coolings (Herning and Rederstall) stages, which were confirmed by palynological analyses. The subfossil Cladocera fauna from the Solniki paleolake consisted in 17 species belonging to the families Bosminidae, Chydoridae, Sididae and Daphniidae. Littoral species were dominant (52%), the most frequent of which were <em>Alona affinis</em> and <em>Camptocercus rectirostris</em>. The most abundance pelagic species were <em>Eubosmina coregoni</em> and <em>Bosmina longirostris</em>. The sediment species composition was quite similar to that of contemporary Central European lakes. The early and the late stages of Eemian Interglacial were likely the most favourable periods for the Cladocera development in the paleolake, in relation to higher water level, moderate water temperature and the mesotrophic state of water. A further ecologically favourable period was the Brørup Interstadial. The highest species richness, abundance, and diversity during the whole paleolake existence were recorded during these three periods. Surprisingly, the middle of the Middle Eemian Interglacial climate optimum appeared as an unfavourable period for the Cladocera growth as it was associated with decreasing water level and pronounced climate fluctuations. This sequence was also recorded by other studies of Eemian lakes in Central Europe.</p>

scholarly journals Nagaland as the Home for Existential Dread: A Critical Study on the Select Stories of Temsula Ao

2020 ◽  
Vol 9 (S1-Dec2020) ◽  
pp. 40-45
Author(s):  
T Raam Kumar ◽  
B Padmanabhan
Keyword(s):  
Food Habits ◽  
Critical Study ◽  
Cultural Tradition ◽  
Nation State ◽  
Ordinary People ◽  
Conflict Zones ◽  
The North ◽  
Rebel Groups ◽  
The People ◽  
North Eastern

The North Eastern states of India are known for their myths, cultural tradition, folklores and nature which found their expression in many forms of literature. Though this region is gifted by Mother Nature with abundant resources and unblemished beauty it also witnesses bloodshed, violence, turmoil and conflicts in the names of ethnicity, race and national identity. People of this region suffer from various forms of oppression and they are not in a position to find solutions to the problems they face. Their helplessness and lack of political power or support make them vulnerable to oppression and violence. Temsula Ao, the emerging English writer from the Naga community brings out the sufferings and pain of this region through her writings. Violence, which has become the part of their day to day life, is the primary theme of her works and she portrays the significant impact of violence on the people of Nagaland which deprives peace, harmony and other fundamental requirements of coexistence. People are forced to give up their socio-ethnic practices, food habits and culture. The trauma, humiliation, exclusion and discrimination experienced by the marginalized tribes of this region remain the primary cause for the youth joining the armed rebel groups. People are caught up between the nation state and the rebel groups and suffer because of both the elements. This paper focuses to analyse the affliction, disillusionment and trauma experienced by the ordinary people in the conflict zones of Nagaland through the select stories of Temsula Ao.

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