Not only large reservoirs, such as the Spanish data set mentioned above (Avenda˜no Salas et al., 1997), can be used for sediment yield estimation, but also smaller reservoirs like check dam reservoirs, irrigation and water supply ponds, etc., can be in a similar way, a source of information. Verstraeten and Poesen (2000) quantify the number of these structures around the world in a few million dams, with small dams being defined as retention structures with a storage capacity of between 50 and 5 × 10 6 m 3 . This large number of small reservoirs in the world is a high potential source of informa- tion for sediment yield assessment and modelling. Some ex- amples of sediment yield studies based on sedimentation vol- umes in small reservoirs include McManus and Duck (1985), Van den Wall Blake (1986), Neil and Mazari (1993), Fos- ter and Walling (1994), White et al. (1996), Romero-D´ıaz et al. (2007), Boix-Fayos et al. (2008), Sougnez et al. (2011) and Bellin et al. (2011). Verstraeten and Poesen (2002) cal- culated the error on sediment yield estimation for 21 catch- ments located in central Belgium using small reservoir de- posits and concluded that this is a suitable methodology for medium-sized catchments (10 1 –10 4 km 2 ) and for mid- term sediment yield estimations (10 0 –10 2 yr). Errors on to- pographical surveys, sediment dry bulk density and reservoir trap efficiency must be taken into account, although the mean accuracy of this information is comparable to other method- ologies used for sediment yield estimation, such as sediment rating curves or suspended sediment sampling.
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Total 62 observation wells, scattered in 22 villages are selected in the entire Machhan River Basin out of which 8 wells well No. 50 to 57 are located in the catchment of Bambela Check dam. Amongst these 8 wells 2 wells are located in village Anwarpura, 2 in Bhanpur and 4 in Dhavadia. Table 2 gives details of these water levels in BGL. Data of water levels are processed by working out Reduced Water Levels and analysis is done by plotting pre and post monsoon Reduced Water Levels (R.W.L.) for the period before check dam construction and after check dam construction. Graphs 1 to 12 illustrate these plots. Post-monsoon water levels were also compared with trend of rainfall variation.
Abstract. There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes within restored gully reaches, despite it be- ing a crucial issue for the design of gully restoration mea- sures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam- filling conditions as well as a method of estimating efficiency in order to provide design guidelines. The model integrates several previous mathematical approaches for assessing the main processes involved (hydraulic jump, impact flow, grad- ually varied flows). Ten main classifications of flow regimes were identified, producing similar results when compared with the IBER model. An interval for optimal energy dis- sipation (ODI) was observed when the steepness factor c was plotted against the design number (DN, ratio between the height and the product of slope and critical depth). The ODI was characterized by maximum energy dissipation and total influence conditions. Our findings support the hypothe- sis of a maximum flow resistance principle valid for a range of spacing rather than for a unique configuration. A value of c = 1 and DN ∼ 100 was found to economically meet the ODI conditions throughout the different sedimentation stages of the structure. When our model was applied using the same parameters to the range typical of step-pool systems, the pre- dicted results fell within a similar region to that observed in field experiments. The conceptual model helps to explain the spacing frequency distribution as well as the often-cited trend to lower c for increasing slopes in step-pool systems. This reinforces the hypothesis of a close link between sta- ble configurations of step-pool units and man-made interven- tions through check dams.
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revealed that great changes had occurred in the stream channel. Some stream channel reaches became covered with a thick layer of sediment. At the same time, the number of erosion-pro- duced side cuts increased, while the number of knickpoints and rock outcrops decreased. De- position is currently the primary process shap- ing the stream channel. The analyzed stream channel was filled in with material released from the sedimentation reservoir of the check dam completely. Moreover, it was addition- ally filled by the material from the right bank, where strong lateral erosion had occurred. Substantial erosion, due to a flood event, in the stream channel section located upstream of the check dam was observed. The material depos- ited up to that time within the dam reservoir and above it became eroded and transported to the channel reach downstream of the dam. Analyzing the changes in the cross-sectional area in years 2013–2016, it can be clearly no- ticed that the cross-sectional areas drastic de- creased over the whole section below the check dam in 2013–2014. In subsequent years, the cross-sectional areas were increased due to the sediment movement, especially in the lower stream course. It is very important to note that the identified erosional and accumulation ten- dencies calculated for 2014 year are the same at corresponding cross sections: the measured values and the values calculated based on the model. This also provides a practical form of model validation.
ABSTRACT: Karamana River originates from the southern tip of the Western Ghats at Agastyar Koodam and it is an important water resource to meet the domestic and drinking water needs of the population in Trivandrum city. But it is highly polluted due to various activities. As part of management plan for pollution abatement, a proposal has been made to construct a check dam to prevent salt water intrusion from Poonthura Pozhi and sewage contaminated water from Parvathy Puthanar during high tide. This paper is a report on constructing a check dam at Kalady as a step to control pollution in Karamana River. The proposed location is at downstream of Karamana Bridge, at Dobhy Ghat Kadavu; 350 meters downstream of Karamana NH Road Bridge. The dam prevent up flow of water and sewage contamination to the upstream of check dam and enhances recharge of ground water to surrounding area.
The construction of fully closed check dam (CD) is a conventional flood prevention mechanism implemented on rivers. Fully closed CDs trap large amounts of sediments in rivers to stabilize the river slopes and control erosion. However, fully closed CDs cannot selectively trap sediment and may easily overflow, causing them to losing their ability to mediate and hold sediments. Previous studies proposed the concept of “breathable CDs”. The researcher introduced metal slit dam (SD) that could be assembled and disassembled quickly and conveniently. Once a CD reaches maximum capacity, operators must ensure that the water channels of the dam are free from blockage. More- over, they must inspect the internal accumulation conditions of the dam periodically or imme- diately following heavy typhoon rains. When necessary, either the sediment buildup in the upriver blockage must be cleared, or the transverse structure of the dam must be removed to allow fine particles to be discharged along with a moderate amount of water. These actions can free up the sediment-storing capacity of the dam for the next heavy typhoon rains. In addition, operators should also inspect the damages inflicted on the dam, such as erosion, wear and tear, and defor- mation conditions. Damaged components should be disassembled and repaired if possible, or re- cycled and reused. The present study performed channel tests to simulate closed CDs, SDs, steel pipe dam (SPDs), and steel pipe plus slit dam (SPSDs) for 50-year and 100-year frequency floods. Results were then analyzed to determine the sediment trapping (ST) effects of various CDs, the ef- fects of “adjustable CDs”, and the changes of moderated riverbeds.
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Overview of the check dams covered by the study Based on a previous study , we focused on both timber (all-wood type) and concrete check dams, which can pre- vent the same volume of sediment runoff to ensure the consistency of functional units. The structure of an all-wood timber check dam (Fig. 1) is such that the squared timbers (width: 0.30 m, height: 0.25 m, length: 0.60–3.60 m) are stacked parallel to the length and width of the dam alter- nately. Then, they are connected with one another toward the vertical direction in a staggered arrangement using connectors (0.46 m in length) to establish the dam body. Since the dam body is constructed only with squared tim- bers and connectors, the wood utilization rate in the volume per dam reaches more than 90 %. This type of dam is a forestry civil engineering structure that can contribute to the effective utilization of mature trees producing large-diam- eter logs in Japanese forests. Squared timbers of 60-year-old sugi (Cryptomeria japonica D. Don) are used for the dam in this study. With regard to the connectors, metal fittings called lag screws are used for the areas where the tensile load acts on the dam body, while steel bars are used for the other areas. Furthermore, when an all-wood timber check dam is constructed in Akita Prefecture, a front apron is set up to prevent the scouring of the downstream side of the structure caused by the water flowing from the upstream area.
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investigated in this article. Although the size of the model in our experiments is relatively small, the experimental re- sults can still account for the interaction between the de- bris flows and erodible bed under certain hydraulic structure. When the experimental data are used to predict debris-flow motion and scour feature downriver of a check dam in pro- totype, the effects of physical model scale should be consid- ered. The scaling effect is mainly induced by dissatisfaction of mobility similitude of model sediment in physical model experiments and it leads to discrepancies between the esti- mated and actual scour results. Just like the experimental investigation on the scale effect in pier-scour experiments, the bed-particle mobility similitude (Ettema et al., 1998; Et- tema and Melville, 1999) or the flow-strength similitude (Lee and Sturm, 2009) should be satisfied to weaken or eliminate the scaling effect for debris-flow scour when the experimen- tal results are extrapolated to predict prototype performance. Additionally, the experimental results obtained in large-scale models are undoubtedly closer to the prototype results than those in small-scale models.
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Dam location is lies in the Yagachi River basin and is the only source of water for the area and hence check dam is proposed to construct near by the Bylahally, which located upstream of the railway bridge across the river Yagachi. The river Yagachi originates at Thotadappanagiri in the Western Ghats near the city of Chickmagaluru and riverflows through Belur Taluka of Hassan District, finally it confluences in the back water of Hemavathi reservoir. Yagachi river is the main tributary of the Hemavati River, further it is tributary of Cauvery river which is the one of the major river basin of India.
Abstract—The project was set the objective as following 1) Screening for advantage and disadvantage of ten former check dam in Thailand. 2) Making the proper check dam for portable type. 3) Collected the concerned data on preserving water from rainy season up to dry Season. The procedure was done by the three groups of researchers from Rambhai Barni Rajabhat University, Local administrator and local farmer to come together in the field and make a final conclusions among the groups in each step by step at Tambol Huay-Rang, Amphoe Maung, Trad province. For making pilot model was divided into 6 step as following 1) Take a consideration to former check dam in Thailand 2) Making inforcement structure by comparative studies for 5 kinds of local materials 3) Making reinforcement structure by comparative studies for 4 kinds of local materials 4) Sealing for the water control both of sealing and level of water by comparative studies for 4 kinds of local materials 5) Making proper reservoir. 6) The completed portable small check dams for water preservation from rainy season up to dry season in Trad Province getting the achievement. The researchers can get achievement with 5 Portable Small Check Dams.
Although numerous check dams have been constructed in many countries, and its effect on physical factors were well documented, only a few reports were available on its effect on biotic component in adjacent area. This research aims to address effects of the check dam on reptile assemblage in an ephemeral stream based on an assumption that reptile live in the stream and adjacent area may be susceptible to prolonged hydroperiod after check dam construction. Ten stream transects and 40 terrestrial strip transects, including 5, 10, 25, and 50 m from the stream, were used to monitor reptile diversity and composition in a deciduous forest of northern Thailand during April 2009 to February 2011. Physical fac- tors related to water pattern in the stream and the terrestrial habitats were also collected. Results on physical factors indicated that the water pattern and soil moisture in the stream, as well as leaf litter moisture in the terrestrial habitat were increased as a result of the check dam. However, rarefaction curve indicated that reptile diversity was not signifi- cantly different between pre- and post-check dam periods in every transect. Moreover, Morisita’s index of similarity indicated that reptile composition between pre- and post-check dam periods was approximately the same (86% - 100%). These results indicated that reptile assemblage was not affected by the check dam. It can be concluded based on data of one year after the check dam construction that check dam can effectively prolong water and moisture to the habitat with minimal effect on reptile assemblage in the area.
In order to collect the required information, a survey of the streams and selected check dams was done. Long profiles of streams were prepared using Autocad software based on the surveyed data. Using the provided long profiles, slope of stream bed, balance slope of sediments (by dividing the height difference by the sediment length behind check dams), width of stream behind check dams as well as check dam heights were calculated. Samples of the deposited sediments behind the check dams, with depth increments of 15 cm, were collected in spaces at one fourth of the length of deposition behind check dams, in relation to crest spillway, (as an average sample of deposits) for particle size analysis.
Barkachha, a part of central Vindhyan plateau is rocky and undulating land having many small rivulets and channels which quickly drain away the bounties of rainwater along with the fine crust of the top fertile soil. To overcome this situation, two check dam were constructed by the Uttar Pradesh Irrigation Department, during 2001. The present study was under taken to evaluate the rainwater harvesting capacity of these reservoirs for supplementary irrigation of the cultivated crops, viz cereal, pulses and oil seeds. The runoff water accumulated from July and remains up to February/March. Maximum volume of the harvested rainwater in both the reservoirs was during September with a capacity 22550 m 3 and 121170 m 3 in reservoir No. 1 and reservoir No. 2,
(Organic carbon) were analyzed. Topsoil was collected at 5-10 cm depth from the 3 different places of each check dam. The soil samples were dried through dry oven and from the each site 100g samples were mechanically sieved in the laboratory to sort the sediment into different size groups. The soil texture was determined by the hydrometry method (Gee and Bauder 1979) and the grain size distribution was determined by dry sieve analysis (Geo-chemical Lab, GSI, Eastern Region, Kolkata, and Panskura Agricultural Lab). The performance of the check dams and the effect of their location along the streams in retention of fine sediments were plotted in line diagram. Soil color was analyzed using Munsen color Chart and pH and EC of soil was measured using the digital pH meter and digital EC meter (shit et al., 2010). Soil fertility was also analyzed by NPK and OC using Kjeldahl distrilation for Nitrogen (N); Flame photometer for Potassium (K 2 O) and UV-VIS Spectrophotometer for Phosphorous
Plane of nutrition of the ewe during pregnancy can affect maternal behaviours (Nowak, 1996; Everett-Hincks et al. 2005). For example, Dwyer et al. (2003) reported that ewes fed 65% of a pregnancy maintenance diet from 4 weeks of pregnancy until birth spent less time grooming their lambs in the first 30min after birth than ewe on the pregnancy maintenance. Lamb behaviours can also be affected by the ewes plane of nutrition during pregnancy (Muñoz et al. 2009). For example, Everett-Hincks et al. (2005) reported that the proportion of lambs that followed their dam after tagging increased as pasture allowance, from day 64 of pregnancy until birth, increased from 2cm (~800 kg DM/ha) to 8cm (~2000 kg DM/ha). With the exception of the study by Everett-Hincks et al. (2005), studies examining the impact of ewe nutrition on ewe and lamb behaviour have concentrated on the probable consequences of undernutrition. There is a lack of information on the possible advantages, or otherwise, of ad libitum feeding on ewe and lamb behaviour.
As stated before, study of dam has covered a vast area of research in the field of civil engineering. The design of dam, the failure modes of dam, the seismic effect on dam, the effect of uplift pressure on dam, have been a matter of concern for researchers. An experimental study was conducted by Pina et.al for the study of failure of a gravity dam on a jointed rock foundation to compare the experimental results with the analytical or theoritical ones.
Idukki reservoir consist of three dams. They are Idukki dam, Kulamavu dam, and Cheruthoni dam. The water impounded by these three dams of Idukki, Cheruthoni & Kulamavu has formed a single reservoir spread over 60 km on a height of 2300 ft above Mean Sea Level.The Idukki Dam is a double curvature arch dam constructed across Periyar River in a narrow gorge between two granite hills. Cheruthoni Dam is located 1 km west of Idukki dam. The spill way of the Idukki Reservoir is in the Cheruthony dam. Kulamavu Dam was constructed to prevent the water escape through a rivulet called Kalivally, 30 km west to Idukki Arch Dam. It is a 100 metres tall Masonry gravity dam. Construction of this Cheruthoni Dam, Idukki Arch Dam and Kulamavu Dam created an artificial lake of 60 km2 and the water stored, is used for production of electricity at the Moolamattom Power house. The power house at Moolamattom is the biggest underground power station in India and the pressure shaft is the largest in the country. Cheruthony is the largest and highest gravity dam in Kerala. Storage of water in Idukki Reservoir started in February, 1973. Moolamattom Power Station was
includes a similar move from the teacher as a researcher of her own teaching towards the learners becoming researchers of their own learning (the arrow at the top of the figure). Furthermore, the interdependence and cooperation between the teachers’ decisions and initiatives and her learners’ reactions and responses in the process of action research in the autonomy classroom is the same in both cases. In the research cycle in Figure 2, ‘evaluation’ – the pivot of learner autonomy (Dam, 1995) is implied in reflection. This is taken into account in the steps included in the work cycle / research cycle in Figure 3.
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Since immortal, it has been operates, endeavor to creates the inexhaustible storage of water for irrigation purpose. And dam is the ultimate solution to it. This need was created to construct the dam. Since then up until now, number of different types of dams is constructed. And one of such dam is rubber dam. a French engineer, Mr. Mesnager in 1947, invented the board worked on the project in the fitness In 1959, the first inflatable rubber dam was installed in the USA as a part of water supply project for the city of los angles. The American engineer responsible for the first and subsequent installation was Mr.imberston. In 1960, the first electricity board ordered its first rubber dam in aubas on the Vezere River. In the following decade, ten inflatable rubber dams were installed in france of which four were for French electricity board. Half of these dams still operating and working efficiently.In addition, after this period up until was about 2000 rubber dams were installed in USA and 1500 rubber dams were installed in japan. However, today unfortunately India does not have any rubber dam. The nearest dam site to India is Bangladesh. In Bangladesh, a city called coxbazar has this type of dam.
Since 1993, the Lake of Dahuk dam is one of the main sources of drinking for Dahuk city, in addition to Mosul’s dam lake, where water was pumped to Dahuk city. While Turkey started to build numerous dams in Tigris River that flew from Taurus Mountains (Turkey) to Iraq and reaches the Mosul dam (Ohara et al., 2011), as shown in Figure 1.1, the crisis began between the two countries, as a consequence the government understood that it cannot depend on Mosul Lake to reach exigency water to Dahuk city in the future, and it has to think of another solution.
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