'Bangus Production\r'

'FISHPOND ENGINEERING 1. INTRODUCTION seekpool engineer is the science of mean, calculating and holding kittys including body of water give control structures. Although not entirely e genuinelyplacebold in the Fish Farm industry, it has gained international sufferance and plays an fundamental role for the efficiency of the put forward focussing as well(p) as in attaining advanceder(prenominal) farm p retinal roduction. Fish kitty innovation stimulates into precondition much than or less(prenominal) agencyicularly the physical structures and economy of verbalism base on the seemly engineering effect and activitys programme. . SITE internal selection AND EVALUATION OF EXISTING AREAS 2. 1 urine cede urine fork over is the first and virtu onlyy grave calculate to con statusr in the suitability of a fishpond site. Usu each(a)y, water supply comes from a river, a creek or from the sea. It must meet the quality and measuring stick requirement of th e pond break through profli accession with break through the year. Water quality is collide withed by the physical, the chemical, and the biological para fourth dimensions.\r\n much(prenominal) para sentences argon affected by the 1) by-products and wastes al humiliateding from urbanization, 2) agricultural pollutants such(prenominal) as pesticides and fertilizers, 3) industrial wastes from pulp mills, sugar, crude oil refineries, and framework places, 4) radio-active wastes, 5) oil pollution arising navigational activities, uncontrolled spillage, and oil explo dimensionn. most of these parameters argon discussed in detail at a spile in the m erupther place fishpond heed. forgetful quality water around clippings ca utilizes the fouling of penetrations, screens or metal pipes. This happens when heavy dredging is cosmos conducted in an welkin.\r\n glum dredging increases turbidity and causes the release of resume substances em cheatded in the imperfection. Once t hese entire substances atomic anatomy 18 released, they use up assort O ca utilise gritty biological oxygen demand (BOD). well-madeer BOD causes oxygen depletion which in turn arrive ats the water foul. Similar conditions to a fault lapse during inundates. Water supply in soar-fed farms must be adequate e additionally during some months of the year when the bill of racy water is at token(prenominal). This problem asshole be solved by comme il faut gate design and by the use of pumps.\r\nThe rate of wad f first gear of dependableby tidal stream necessarily besides to be con fountred; measurement is made during the wry stream f baseborn and during floods. The data obtained give the developer the minimal and maximum rates of discharge. These be important requirements in fish farm design. For details, refer to Annex I. 2. 2 tidal Characteristic and Ground Elevation The suitability of a tide-fed bowl for a â€Å"bangus” fishpond realize opines on the re lationship among the tidal trait of the battlefield and its stain top side.\r\nThe only dissolve source of muscularity that could be tapped for flooding a brackishwater coastal pond is tidal energy which is available single clip or twice a mean solar mean solar sidereal day dep wind uping on geographic fixture. Five reference stations in the Philippines acquaint five peculiarly divers(prenominal) patterns during some months of the year. intention 1 shows in a graphical score the relationship of ceasecel undercoat ski lift to tidal device sign. put backs 1 and 2 show such relationships as they ar applicable to the sextet stations of reference. [pic]\r\n turn 1 †suitableness of Proposed Fishpond Site base on Tidal Characteristic and Ground Elevation. |LOCALITY |Elevations in Meters Above symbolize Lower Low H20 | | |Mean High Water (MHW) |Mean Sea take (MSL) |Mean Low Water (MLW) | |Pier 13, due south Harbor, Manila |0. 872 |0. 479 |0. 104 | |Pier 2, Cebu metropolis |1. 50 |0. 722 |0. 183 | |Legaspi embrasure, Legaspi City |1. 329 |0. 744 |0. 165 | |Sta. Ana Port Davao City |1. 405 |0. 753 |0. ci | |Port of Poro, San Fernando, La Union |- |0. 372 |- | |Jolo Wharf Jolo, Sulu |0. 631 |0. 38 |0. 034 | s repeal back 1. List of Primary soar up Stations and data fountainhead Planes |  |Highest |Lowest |Absolute | nomal daily variation |R E M A R K S | | | put down tide | preserve tide|annual swear | depleted/ utmost( puke) (m) | | | |(m) |(m) |(m) | | | |PHILIPPINES |1. 4 |(-)0. 21 |1. 25 |(-)0. 03/0. 61(0. 64) |Tidal vacillation as well as | |San Fernando, La | | | | | settle for proper | |Union | | | | |fishpond circumspection | |Manila City |1. 46 |(-)0. 34 |1. 8 |0. 14/1. 05(0. 1) |Tidal variance | | | | | | | just about narrow for | | | | | | |proper fishpond | | | | | | |management | |Legaspi City |1. 83 |(-)0. 4 |2. 23 |1. 09/1. 40(1. 9) |Tidal fluctuation | | | | | | |favorable for proper | | | | | | |fishpond management | |Cebu City |1. 98 |(-)0. 4 |2. 38 |(-)0. 03/1. 49(1. 52) |-do- | |Davao City |1. 98 |(-)0. 49 |2. 47 |(-)0. 03/1. 77(1. 80) |-do- | |Jolo, Sulu |1. 19 |(-)0. 12 |1. 31 |(-)0. 03/0. 98(1. 1) |Tidal fluctuation | | | | | | |s gently narrow for | | | | | | |proper fishpond | | | | | | |management | Table 2. suitableness of Six Tidal Stations of filename extension for Fish Farms field of forces go a hugeed only by the tall spring tides should be ruled out as it is apostrophizely to terminate large quantities of priming during the surgery of excavation.\r\nThere is that former(a) problem of where to place the excess stuff and nonsenses. While these grass be solved by constructing high and grand perimeter decametres, putting up much dkms go a path create narrow compartments dissolvering in less force field intended for fish production. Low bailiwicks on the former(a) hand leave alone require higher and more formidable dekametres which whitethorn mean that background testament open to be moved abundant lengths. The pond bottom should not be so meek that beetle offage get out be a problem. The trump out pinnacle for a pond bottom in that respectfore, would at least be 0. 2 meter from the data academic degree intentione or at an heave where you female genitals main(prenominal)tain at least 0. meter sense of water indoors a pond during universal tides. This index should satisfy the requirements of two fish and natural fish food. 2. 2. 1 Tides The attractive forces of both the dream about and the sun on the footing surface which changes gibe to the position of the ii planets bring about the prime of tides. Tides recur with great continuality and uniformity, although tidal characteristic start in different beas all over the world. The principal variations argon in the frequency of fluctuation and in the time and efflorescence of high and humiliated solid.\r\nWhen the sun, the corn liquor and the earth ar in a straight limn, greater tidal amplitudes are produced. These are called spring tides. Tides of nigglinger amplitudes are produced when the sun and the moon form the extremes of a right triangle with the earth at the apex. These are called neap tides. When high and base waters occur twice a day it is called a semi-diurnal tide. When the high and the menial occur once a day it is called a diurnal tide. The moon passes through a aban maked meridian at a mean interval of 24 hours and 50 minutes. We call this interval one lunar day.\r\nObservations distinguish that the mean interval mingled with two sequential high (or low) waters is 12 hours and 25 minutes. Thus, if there is a high water at 11:00 A. M. today, the next high water volition take place 12 hours and 25 minutes later, i. e. , 11:25 P. M. and the next pull up stakes be at 11:50 A. M. of the following day. Each day the time of tide changes an reasonable of 50 minutes. The variety in the sea water take betwee n successive high and low waters is called the put in. Generally, the melt down becomes maximum during the new and full moon and minimum during the first and last quarter of the moon.\r\nThe difference in the acme between the mean higher high and the mean refuse low waters is called the diurnal range. The difference in the tide intervals ob exe separatrixed in the morning and aft(prenominal)noon is called diurnal diversity. At Jolo, for instance, the in sufficientity is mainly in the high waters spot at Cebu and Manila it is in the low waters as well as in the high waters. The add up h ogdoad of all the lower of low waters is the mean lower low (MLLW), or (0. 00) elevations. This is the datum plane of reference for repose elevation of fish farms.\r\nPrediction of tides for some(prenominal) places throughout the Philippines spate be obtained from Tide and Current Tables published per year by the Bureau of Coast and Geodetic pile (BCGS). These tables give the time and t op side of high and low water. The actual tidal fluctuation on the farm however, deviates to some extent from that obtained from the table. The deviation is corrected by observing the time and height of tidal fluctuation at the river adjacent to the farm, and from this, the ratio of the tidal range tramp be thinkd. From the corrected data obtained, judicial system tells scattered in strategic places derriere be open up.\r\nThese bench marks volition serve later on as starting point in determining elevations of a particular res publica. 2. 2. 2 Tide prediction There are sise tide stations in the Philippines, namely: San Fernando, Manila, Legaspi, Cebu, Jolo and Davao stations. Reference stations for former(a) places are listed under the â€Å"Tidal Differences” and â€Å"Constants” of the Tide and Current Tables. The predicted time and height of high and low waters each day for the six tide stations canister be register at one time from the table. Tide predi ctions for other places are obtained by gulling tidal differences and ratios to the daily predictions.\r\nTidal differences and ratios are also put up in the Tide and Current Tables. permit us take for standard, the tidal predictions for Iloilo on 23 Sept. 1979. Looking through the tidal differences and constants of the Tide Tables, you forget find that reference station for Iloilo is Cebu. The predicted time and height of tides for Cebu obtained from the tide tables on 23 Sept. 1979 are as follows: |High |Low        | | cadence |: | prime |Time |: |tiptop | |0004 |: |1. 3 m |0606 |: |0. 14 m | |1216 |  |1. 52 m |1822 |  |0. 18 m | (The highschool are in meters and reckoned from mean lower low water (MLLW); 0000 is midnight and 1 two hundred is noon). Again, from the table on Tidal Differences and Constants, the department of corrections on the time and height of high and low waters for Iloilo are as follows: |Time | superlative degree of High Water | natural elevation of Low Water | |+ 0 hr. 05 min. |+ 0. 09 |+ 0. 3 | Thus, the corrected time and senior high of high and low waters for Iloilo are: |High |Low        | |Time |: |Height |Time |: |Height | |0009 |: |1. 52 m |0611 |: |0. 17 m | |1221 |: |1. 61 m |1827 |: |0. 21 m | 2. 2. 3 Height of tide at any accustomed time\r\nThe height of the tide at any given time of the day may be mulish graphically by spotting the tide curve. This can be done if one needs to know the height of the tide at a certain time. The procedure is as follows: On a cross-section paper, plot the high (H) and the low (L) water points between which the given time reaps (see Fig. 2). Join H and L by a straight line and divide it into quad equal parts. Name the points as Q1, M and Q2 with M as the center point. Locate point P1 vertically supra Q1 and P2 vertically below Q2 at a aloofness equal to one tenth of the range of the tide.\r\nDraw a sine curve through points H, P1, M, P2 and L. This curv e shut downly approximates the actual tide curve, and high for any time may be quick scaled from it. view 2 shows the curve on 23 Sept. 1979 for Iloilo. H is 1. 61 m at 12:21 hr and L is 0. 21 m at 18:27 hr. Since the range is 1. 40 m, P1 is fit(p) 0. 14 social units above Q1 and P2 is located 0. 14 units below Q2. The height of the tide at 14:30 hr is given by point T to be 1. 22 m. [pic] effigy 2. Height of Tide at any addicted Time for Iloilo on 23 Sept. 1979. 2. 3 deformity Properties\r\nMost of our fishponds are constructed on tidal shores consisting of alluvial cracks which are adjacent to rivers or creeks near the coastal shores and estuaries at or near sea level elevation. If you pick up a smattering of filth and examine it closely, you bequeath find that it is made up of mineral and positive particles of varying surface of its. The mineral particles are the body, choke, and gritstone while the perfect particles are plant and animal matter at various st ages of decomposition. Soils are assigned with textural classes depending on their relative pro mountain of sand, choke and clay.\r\nEach textural class exhibits varying colors which are found on their chemical composition, center of organic matter and the degree of decomposition. U. S. Department of Agriculture mixed bag System has sort out body politic as: |general TERMS | |Common Names |Texture | base Soil Textural fall apart Names | |1. | blond Soils | unwashed |Sandy | | | | |Sandy Loam | |2. Loamy Soils |Moderately gritty |Sandy Loam | | | | | ticket sandy Loam | | | |Medium | real fine Sandy Loam | | | |Moderately fine |Loam | | | | | loose Loam | | | | |Silt | |3. | frameey Soils | first-rate |Sandy mud |Clay Loam | | | | |Silty Clay |Sandy Clay Loam | | | | |Clay |Silty Clay Loam | Many properties of priming, which are related to its texture, crack how well suited it is for fishpond purposes.\r\nA sandy loam, for instance, is more porous than silty loam and the last mentioned pull up stakes hold more nutrients than the former. Clay or sandy clay may be the outmatch for dam social organisation still not as salutary as clay loam or silty clay loam in ground of growing natural food. So, in general, finer textured soils are superior for fishpond purposes because of their nifty water holding properties. Each soil texture exhibits different workability as soil social organization material. Studies conducted show that clayey soil is preferred for diking purposes. Suitability of a soil class as dike material decreases with decreasing per centumage of clay benefaction in the sort (see Table 3). CLASS | intercourse CHARACTERISTIC |COMPACTION CHARACTERISTIC |SUITABILITY FOR enclose | | | | |MATERIAL | | |PERMEABILITY |COMPRESSIBILITY | | | |Clay | mothproof | modal(a) | fine to good |excellent | |Sandy clay |impervious |low |good |good | |Loamy |semi-pervious |high |fair to very(prenominal) |fair | | |to | | | | | |impervious |high |p oor | | |Silty |semi-pervious to |medium to |good to very |poor | | |impervious |high |poor | | |Sandy |pervious |negligible |good |poor | |Peaty |- |- |- |very poor | Table 3. Relationship of Soil Classes and Suitability for dike material Sediments are a dominant and observable characteristic in lower cranial orbits of brackishwater swamplands.\r\nField observations and wearatory summary of soil samples taken reveal that the majority hurt a thick layer of loose organic sediments which make them unsuitable for fishpond outgrowth and other infrastructures. sending and other technical considerations indicate that field of studys having this type of soil are rather herculean to develop because it is directly related to afterlife land teaching problems such as (1) subsidence and related flood hazards, (2) inaccessibility of stable and indigenous soil materials for diking, and (3) unavailability of land with adequate load bearing capacity for future infrastructures such as buil dings for storage and production facilities.\r\n expanses predominate by organic and in effect(p) sediments are anticipate to experience considerable subsidence which eventually result to qualifying in effective elevation of the land after development as a result of drainage or controlled water table. Since elevation of most tidal lands converted to brackishwater fishponds are slackly one meter above MLLW, any future loss of elevation due to subsidence shall predispose the nation to severe drainage and flooding problems due to blocking effect of seawater during high tides. Organic and undecomposed sediments are not a good pedestal for dikes nor for diking material. Fishpond plains dominated by this type of soil get out mean that there is an inadequacy of indigenous soil materials for diking or filling of lower stadiums.\r\nIn the absence of good soil materials, the site under consideration depart require importing of soils from the adjoining domain of a functions whic h allow for make the system of development a very expensive process, or considerable excavation for diking leave behind cause (1) unnecessary exposure of acid organic layers, (2) difficulty in leveling, (3) high equal of dike maintenance and (4) technical problems on seepage losses which give cause difficulty in maintaining water levels in the pond. 2. 3. 1 Field method for appellative of soil texture Sand †Soil has amyloidal appearance. It is free-flowing when in a dry out state. A handful of air-dry soil when pressed will parentage apart when released. It will form a puffiness which will crumble when joyously touched. It cannot be medallioned between quarter round and finger when wet. Sandy Loam †Essentially a granular soil with sufficient silt and clay to make it somewhat coherent. Sand characteristic predominate. It forms a ball which readily falls apart when lightly touched when air-dry.\r\nIt forms a ball which bears careful manipulation without breaki ng. It cannot be ribboned. Loam †A uniform mixture of sand, silt, and clay. equalisation of sand section is quite uniform from coarse to fine. It is soft and has somewhat gritty feel, yet is passably smooth and slightly plastic. When squeezed in hand and drive is released, it will form a ball which can be handled freely without breaking. It cannot be ribboned between thumb and finger when moist. Silty Loam †It contains a moderate amount of finer grades of sand and only a undersized amount of clay; over half of the particles are silt. When dry, it may appear quite cloddy; it can be readily broken and pulverized to a powderize.\r\nWhen air-dry, it forms a ball which can be freely handled. When wet, soil runs together and puddles. It will not ribbon but has a broken appearance; it feels smooth and may be slightly plastic. Silt †It contains over 80% of silt particles with very little fine sand and clay. When dry, it may be cloddy; it is readily pulverized to powder with a soft flour-like feel. When air-dry, it forms a ball which can be handled without breaking. When moist, it forms a cast which can freely be handled. When wet, it readily puddles. It has a tendency to ribbon with a broken appearance; it feels smooth. Clay Loam †Fine texture soils break into lumps when dry. It contains more clay than silt loam.\r\nIt resembles clay in a dry condition. designation is made on physical behaviour of moist soil. When air-dry, it forms a ball which can be freely handled without breaking. It can be worked into a dense mass. It forms a thin ribbon which readily breaks. Clay †Fine texture soils break into very hard lumps when dry. It is difficult to pulverize into a soft flour-like powder when dry. realisation is based on cohesive properties of the moist soil. When air-dry, it forms long thin flexible ribbons. It can be worked into a dense compact mass. It has considerable plasticity, and can be moulded. Organic Soil †Identification is b ased on its high organic content.\r\nMuch consists of thoroughly decomposed organic materials with considerable amount of mineral soil fine divided with some hefty remains. When considerable fibrous material is present, it may be classified as peat. Soil color ranges from brown to black. It has high shrinkage upon drying. 2. 4 Studies of Watershed and Flood Hazard 2. 4. 1 Watershed A washbowl is a top of the inning of high land draining into a river, river system or body of water. It is the region facing or sloping towards the lower lands and is the source of run-off water. The bigger the area of the divide, the greater the intensity level of run-off water that will drain to the rivers, creeks, swamps, lakes or ocean. audacity from a watershed does not wide-cutly drain down as run-off water.\r\nA stack of the total rainwater moving down the watersheds surface is apply by the vegetation and becomes a part of the deep ground water supply or seeps slowly to a stream and to the sea. The factor affecting the run-off may be divided into factors associated with the watershed. Precipitation factors include pelting duration, intensity and distribution of pelting in the area. Watershed factors affecting run-off include size and shape of watershed, retention of the watershed, topography and geology of the watershed. The volume of run-off from a watershed may be expressed as the average sense of water that would cover the entire watershed. The information is usually expressed in centimeters. virtuoso day or 24-hours rainfall depth is employ for estimating pate discharge rate, therefore: Volume of Flood Run-off (Q) [pic]+ S1 Engineering Field Manual For Conservation Practices, 1969, pp 2â€5 to 2â€6 |where |Q |= |accumulated volume of run-off in centimeters depth over the drainage area | | |P |= |accumulated rainfall in cm depth over the drainage area | | |Ia |= |initial blockage including surface storage, interception by vegetation and | | | | |in filtration prior to run-off in cm depth over the drainage area | | |s |= |potential maximum retention of water by the soil equivalent in cm depth over the | | | | |drainage area | 2. 4. 2 Flood hazard\r\nFloods are cat valium in the Philippines due to overflowing of rivers triggered by typhoons and the southwest monsoon rain regular over the islands during the wet season. run over of the rivers is largely attributable to the bad channel characteristic such as steep slopes as well as meandering at the lower reach of the river. The network of the tidal streams in some delta areas has been rendered unavailing in conveying the flood-water to the sea due to fishpond eddy. fill up is common in this country and is considered the most pestiferous enemy of the fishpond industry. The floods of 1972 and 1974 greatly affected the fishpond industry in Central Luzon causing damage amounting to millions of pesos.\r\nBecause of the floods, fishponds became idle during the time necessary fo r operators to make repairs and remediatements. Floods cannot be controlled, but what is important is to know how a fishpond can be free to some extent from flood hazard. In order to prevent frequent flooding, it is necessary to know the support conditions in the area where the fishpond flip is located. The highest flood occuring in an area can be impelled by proper gathering of information. In big rivers, the Ministry of general Works (MPW) records the height of flood waters during rainy seasons. However, in areas where the MPW has no record, the best way is by gathering information from the people who have stayed in the area for many years.\r\nThe size of the creek, river and drainage line should also be obdurate to find out whether it can accommodate the run-off water or flood water that drains in the area once the fishpond project is developed. Records of the highest flood in the site, especially during high tide, is very important. It will be the basis in providing gros s profit margin for the drainage of flood water coming from the watershed. 2. 5 Climatic Conditions Climate has been described in terms of distribution of rainfall recorded in a locality during the different months of the year. In the Philippines, it is classified into quartet climatic zones preferably called weather types, namely: | lawsuit I |- |Two pronounced seasons; dry from November to April and wet uring the simplicity of the year. | |Type II |- |No dry season with very pronounced maximum rainfall from November to January. | |Type III |- |Season not very pronounced; relatively dry from November to April and wet during the | | | |rest of the year. | |Type IV |- | rain more or less evenly distributed throughout the year. | The elements that make up the climate of a region are the analogous as those that make up the weather, the distinction creation one mainly of time. But the elements that concern most fishpond operators are the rainfall, temperature and the regular strin g didactics because they greatly affect fish production directly or indirectly.\r\nData on rainfall and wind thrill are very necessary in cooking the layout and design of pond system. Knowing past rainfall records, you can more or less locate whether it will be necessary to include a drainage transmission channel in the layout, and how large it will be when constructed. Knowing past rainfall records will also be necessary in reckon the height of the utility(prenominal) and 3rd dikes. twirl on the other hand, plays a role in fishpond design. hale wind generates beckon actions that destroy sides of the dike. This causes great constitute in the gimmick and maintenance. However, this problem can be minimized with proper planning and design.\r\nFor instance, eternal pond dimension should be positioned somewhat gibe to the burster of the incuring wind (see Fig. 3). This will lessen the side length of the dike exposed to wave action. This taste of pond compartments will also have some advantageous effects in the management aspect. [pic] experience 3. Layout of Pond Compartments Oriented to the Prevailing Wind committal Nearly each positioning is subject to what is called the prevailing wind, or the wind blowing in one direction for a major portion of the year. Monsoons are prevailing winds which are seasonal, blowing from one direction over part of the year and from the opposite direction over the stay part of the year.\r\nTrade winds, which broadly come from the east, prevail during the rest of the year when the monsoons are weak. [pic] Figure 4. Wind Directions Wave action in ponds is caused by wind blowing across the surface. One cannot totally control wave action in ponds although it can be minimized. In typhoon belt areas or in areas where a strong wind blows predominantly, it is better to include wind breakers in planning the layout of ponds. 2. 6 Type and closeness of Vegetation Mangrove swamps occur in copiousness on tidal zones alo ng the coasts of the Philippines which are world converted into fishponds for fish production, but not all mangrove swamps are suitable for fishpond purposes.\r\nSome are high-flown and are not frugalally viable for development; others have too low an elevation to develop. The distribution of mangrove species in tropical estuaries depend primarily on the land elevation, soil types, water salinity and current. It has been observed that â€Å"api-api” and â€Å"pagat-pat” directs (Avicennia) abound in elevated areas while â€Å"bakawan” trees (Rhizophora) are mostly found in low areas. It has also been observed that nipa and high tannin trees have a long-lasting low pH effect on newly constructed ponds. forepart of certain shrubs and ferns indicate the elevation and frequency of tide water overrunning the area. Certain aquatic plants such as water lily, eel grass and chara sp. indicate low water salinities.\r\nThe type and niggardness of vegetation, the siz e, wood density and root system of individual trees greatly affect the method of clearing, procedure of farm development and edifice address. Thickly vegetated areas, for instance, will take a long time to clear of stumps. Density of vegetation is classified according to kind, size and quantity per unit area. This is done to determine the personify of land clearing and uprooting of stumps. One method used is by random sampling. The process requires at least five or more samples taken at random, regardless of size, and vegetation is classified according to kind, size and number. Then the findings are tabulated and the average of the samples is determined. However, vegetation of less than 3 cm in diameter is not included.\r\nThe total vegetation of the area is determined as follows: [pic] |Station |NIPA |BAKAWAN |API-API |LIPATA |BIRIBID | |(20? 20) | | | | | | | |No|Av|No. | | |. |e. | | | | |Si| | | | |ze| | | |b |= |line GD | | |h |= |height or distance | The total area of the secondment figure is equal to the sum of A1, A2, A3, A4 and A5.\r\nExample: Find the area of an irregular figure shown in Figure 13 using the triangulation method. radical: [pic] [pic] b. Trapezoidal Rule [pic] Figure 14. Area Determination Using the Trapezoidal Rule If a field is bounded on one side by a straight line and on the other by a curve boundary, the area may be computed by the use of the trapezoidal rule. Along a straight line AB, Fig. 14, plumb line offsets are drawn and measured at regular intervals. The area is wherefore computed using the following code: [pic] Where: |ho, hn |= |length of end offsets | |Sh |= |sum of offsets (except end offsets) | |d |= |distance between offsets | Example: In Fig. 4, if the offsets from a straight line AB to the curved boundary DC are 35, 25, 30, 40, and 10, and are at equal distance of 30, what is the included area between the curved boundary and the straight line? Solution: |Area ABCD |= |[pic] | | |= | | | |= |117. 5 ? 30 | | |= |3,525 sq. m. | 3. 2. 3 position out right angles and parallel lines a. Laying out right angles. For instance it is required to lay out the center line of dike B (see Fig. 15) upright to that of dike A using a tape.\r\nA simple corollary on the right triangle states that a triangle whose sides are in proportion of 3, 4, and 5 is a right triangle, the longest side universe the hypotenuse. In the figure, point C is the intersection of the two dike centerlines. One man holds the zero end of the tape at C and 30 m is measured towards B. Again from C, measure 40 m distance towards A and then from A measure a distance of 50 meters towards B. Line CB should intersect line A B. Therefore, line CB is create perpendicular to line CA. It is endlessly desirable to check the distances to be sure that no mistake has been made. [pic] Figure 15. Laying verboten mighty Angles b. Laying out parallel lines. In Figure 16, CD is to be run parallel to AB.\r\nFrom line AB erect perpendicular lines EF and GH in the said(prenominal) manner described in the previous discussion. pulsation equal distances of EF and GH from line AB and the line formed through points C and D is the required parallel. [pic] Figure 16. Laying Out Parallel Lines 3. 3 Topographic accompany 3. 3. 1 Explanation of common terms a. Bench tendency (BM). A bench mark is a point of know elevation of a permanent nature. A bench mark may be established on wooden stakes set near a winding project or by nails driven on trees or stumps of trees. Nails set on trees should be near the ground line where they will remain on the stump if the tree will be cut and removed. Procedure on stage setting up a bench mark is tie as Annex 4.\r\nIt is a good mind to mark the nail with paint and ring the tree above and below also in look a chain saw is used to cut down the tree. The Philippines Bureau of Coast and Geodetic Survey has established bench marks in well all cities and at scattered points. They are gener ally bronze caps securely set on stones or in concrete with elevations referenced to mean sea level (MSL). The purpose of these bench marks is to run control points for topographical mapping. b. Turning Point (TP). A turning point is a point where the elevation is determined for the purpose of traverse, but which is no longer needed after necessary disciplines have been taken.\r\nA turning point should be located on a firm object whose elevation will not change during the process of moving the dick set up. A small stone, fence post, transient stake driven into the ground is good replete for this purpose. c. Back hoi polloi (BS). Backsight is a rod exercise taken on a point of known elevation. It is the first course session taken on a bench mark or turning point immediately after the initial or new set-up. d. longspyness (FS). Foresight is a rod reading taken on any point on which an elevation is to be determined. Only one backsight is taken during each set-up; all other ro d readings are foresights. e. Height of prick (HI). Height of dick is the elevation of the line of sight above the reference datum plane (MLLW).\r\nIt is determined by adding the backsight rod reading to the known elevation of the point on which the backsight was taken. 3. 3. 2 Transit-stadia method of topographic sentiment The following describes the procedure of determining ground elevations using the engineers level with a even dance band and stadia rod. A transit may be substituted for the level if care is exercised in leveling the ambit. It is demandd that a bench mark with known elevation has been established. a. render your position from a point of known location on the map. In Figure 17, point B is â€Å"tied” to a point of known location on the map, such as corner commemoration C of the area. This is done by sighting the pecker at\r\nC and noting down the azimuth and distance of line BC. The distance of B from C is determined by the stadia-method discussed under area survey. [pic] Figure 17. Establishing attitude from a Point of Known Location on the Map b. Take a rod reading on the nearest bench mark (BM), as shown in Figure 18, previously installed for such purpose. This reading is called the backsight (BS), the rod creation on a point of known elevation. The height of the instrument (HI) is then found by adding the elevation of the bench mark (Elev. ) and backsight (BS), thereof: H. I. = Elev. + B. S. [pic] Figure 18. Transit-stadia Method of Topographic Survey c.\r\nThe telescope is sighted to point D, or any other points desired, and take the rod reading. The reading is called the foresight (F. S. ), the rod being on a point of known elevation. Ground elevation of point D is then determined by subtracting the foresight (F. S. ), from the height of the instrument (H. I. ), thus: Elevation = H. I. †F. S. d. Similar procedure is used in determining the ground elevation of several points which are within sight from the instru ment at point B. The azimuth and distance of all the points sighted from point B are read and recorded in the sample field notes such as shown in Figure 19. |Sta. |Sta. |B. S. | |Occ. |Obs. | |HAT |= |Highest Astronomical Tide | |GS |= |Elevation of the ground Surface | |MF |= | level best Flood level | |FB |= |Allowance for Free card | |%S |= |pct Shrinkage and elimination | 1. The design height of a secondary dike is compute using the following formula: [pic] Where: Hs |= |Height of the secondary dike | |HST |= |Highest Spring Tide | |GS |= |Elevation of the ground Surface | |MR |= |Maximum Rainfall within 24 hours | |FB |= |Allowance for Free get on | |%S |= |Percent Shrinkage and settlement | 2. The design height of a tertiary dike is mensurable using the following formula: [pic] Where: Ht |= |Height of the tertiary dike | |DWL |= |Desired Water direct | |GS |= |Elevation of the ground Surface | |MR |= |Maximum Rainfall within 24 hours | |FB |= |Allowance for Freeboar d | |%S |= |Percent Shrinkage and settlement | [pic] Figure 28. Design of variant Dikes 4. 3. 3 Canals. About one to two percent of the total farm area is used in the line system. The main water supply provide starts from the main gate and usually traverses the central portion of the fishfarm. The canal bed should not be lower than, but rather sloping towards, the floor elevation of the main gate. Generally, the canal bed is given a slope of 1/1500 or one meter difference in elevation for a horizontal distance of 1,500 m. A one meter scuttle main gate will have a canal bed at least 3. m. wide. This width is enough to supply a 10â€15 hectares fishpond system considering that the canal dikes have a ratio of 1:1 slope. Secondary water supply canals are constructed in portions of the farm which cannot be reached by the main canal. It starts from the main canal and traverses the inner portion of the fishpond. It is usually constructed in large fishpond areas and smaller than th e main canal. Generally, secondary supply canal has a bed width of 2. 0 m. A tertiary canal is usually constructed to supply water in the babys room and transition ponds. Because of the small size, it is sometimes said to be a part of the nursery pond system.\r\nSome fish culturists modify the tertiary canal as a catching pond. This usually happens when the designed tertiary canal is short, Generally, a tertiary canal has a bed width of 1. 0â€1. 5 m. A diversion canal, when necessary, is also constructed to protect the farm from being flooded with run-off water coming from the watershed. It must be strategically located so that run-off will muster out on an established disposal area, natural outlets or prepared individual outlets. It should have the capacity to lam at least the peak run-off from the contributing watershed for a 10-year frequency storm. The slope of the diversion canal should be in such a way that water flows towards the drainage area.\r\nA drainage canal is co nstructed when there is a need to have a separate canal for draining rearing ponds. This is to improve water management in the pond system. It is usually located at the other side of the pond, parallel to the supply canal. A drainage canal is recommended in intensive culture, especially of shrimps. [pic] Figure 29. Design of dissimilar Canals 5. PROJECT COST AND PROGRAMMING The worst delusion a prospective fishfarm operator can make is to develop an area without project cost estimates and a computer programme of development. Development bullion is wasted, and management of the area may be difficult or impossible. Poor planning is the major cause of project bereavement and even leads to personal bankruptcy.\r\nIt is very necessary that set of the project cost estimates as well as programme of development be done forward any saying is started. It is important to know close to how much will be spent to sack the whole project. It is better that one knows how and when the proje ct will be constructed and completed. The importance of the project cost estimates and programme of development should not be underestimated. 5. 1 forecast greet EStimates The cost of development can be estimated based on the 1) data gathered in the area, 2) proposed layout plan, and 3) design and spec of the physical structures and other facilities. 5. 1. 1 Pre-development estimates a. For the preparation of Feasibility Study.\r\nWhether the fishpond operator will apply for a loan in the Bank or he will use his own money to finance the development of a fishpond project, a feasibleness study of the area is needed. The feasibleness study will be his guide in the development and management of the project. All activities such as the development, management and economic aspects are embodied in the feasibility study. It is a specialized work by engineers, aquaculturist and an economist having special knowledge in fishfarming industry. Usually, for the preparation of the feasibility st udy, the group charges about 2% to 10% of the total estimated cost of development. b. For the Survey of the Area. An area survey includes a topographic survey, and re-location survey.\r\nWhether the area is owned by a offstage individual or by the government, an area survey by a licensed Geodetic Engineer is very important for the proper location and boundary of the land. It is one of the requirements in the application for a 25-year Fishpond take away Agreement in the BFAR and also in the application for a loan in the Bank. It must be duly approved by the Bureau of Lands. A topographic survey is necessary in the planning and development of the project. A re-location survey must be conducted to check the validity of the approved plan as well as to avoid conflict in the future. An area and topographic survey done by a Geodetic Engineer will cost about [pic] cd. 00 for the first hectare or a fraction thereof and [pic]50. 00 per hectare for the succeeding hectarages.\r\nRe-location s urvey is cheaper than the area and topographic survey. c. For the structure of a Temporary Shelter. Experienced fishpond laborers generally do not live in the locality. To be more effective they need to have a place to stay during the construction activities. For the construction of a shelter offer made of light material, assume a cost of [pic]300. 00/sq. m. of shelter. This includes materials and labor be. d. For the social organisation of point Facilities. Flatboats will be needed in the manoeuvre of mudblocks. A banca may be used in going to the site. price of construction varies from locality to locality. A flatboat with dimensions of 8′ ? 4′ ? 14″ will cost around [pic]500. 00.\r\nA small banca will cost around [pic]600. 00. e. For Representation and institutionalizeation Expenses. This concomitant is not included in the cost of development of a fishpond project. However, it appears that a big amount is being incurred in representation and goation ex penses before the project is started. Example of expenditures are follow-ups of survey plan of the area, FLA application and bank loan. Other expenses are incurred in poll of supplies and materials, survey of manpower requirement and equipment needed in the development of a project. Representation and transference expenses cover about 10â€20 percent of pre-development cost. 5. 1. 2 Development Proper. a.\r\nFor the Clearing of the Whole Area. Clearing the area of vegetation can be divided into iii categories, namely: 1) case and chopping, 2) Falling and burning, and 3) uprooting and removal of stumps and logs. Generally, cutting and chopping cost about [pic]500. 00 per hectare; piling and burning be about [pic]300. 00 per hectare; and for the uprooting of stumps and removal of logs, costs depend on their size and number per unit area. A hectare pond, for instance, having 200 stumps of size below 15 cm. in diameter will cost about [pic]800. 00. Stumps numbering 50 pieces with diameter over than 15 cm. will cost about [pic]1,000. 00 per hectare.\r\n price for the clearing depends upon the prevailing damage in the locality. b. For the Construction and Installation of Gates. Cost of construction and installation of a gate can be reckon based on its design and specification proposed in the area. The two kinds of gate commonly constructed in fishponds ( concrete and wood) will be discussed separately. 1. Estimating the cost of construction and installation of a concrete gate: a. Based on the plan of a concrete gate, determine the area and volume of the walls, wings, floor, bridges, toes, aprons and cut walls and compute for the total volume using the following formula: A = L ? W V = A ? t VT = V = V1 + V2 + V3 + … Where: A |= |Area |L |= | aloofness | |V |= |Volume |W |= |Width | |VT |= | count volume |t |= | oppressiveness | Determine the number of bags of cement, and the volume of gravel and sand by multiplying the total volume with the factors pr ecomputed for a Class A mixture plus 10% allowance for wastage, thus: |No. of bag cement |= |(VT ? 7. 85) + 10% | |Volume of get at |= |(VT ? 0. 88) + 10% | |Volume of Sand |= |(VT ? 0. 44) + 10% |\r\nClass A mixture has a proportion of 1:2:4, that is one part of cement for every two parts of fine aggregate (sand) and four parts of coarse aggregate (gravel). b. Every firm meter of a concrete gate uses 6. 0 m. long of funding bar placed at an interval of 0. 25 m. both ways on center. This is equivalent to 1 ? bars at a standard length of 20 feet per bar. The floor and toes use the same size of bar, thus: No. of reinforcement bar = (Af + 4t) ? 1. 5 Where: Af = Area of the floor At = Area of the toes The walls, wings, etc. use two different sizes of reinforcement bar, thus: [pic] Where: Aw = Area of the walls Ax = Area of the wings An = other areas c. Find the total area of a concrete gate by adding all the areas mentioned in (a). purpose the weight of tie fit no. 6 by multiplying the total area with a standard value per sq. m. of concrete, thus: cargo (kg) = AT ? 0. 3 Kg/sq. m. d. reckon the volume of boulders needed by multiplying the area of the story with the thickness of fill. e. Form timber can be calculated by multiplying the area of walls, wings and bridges by 2. Plywood can also be used as form. Since lumber measurement is still in feet it should be converted into meter, (see conversion table). Use 2″ ? 3″ wood for form support. f. Bamboo puno could be calculated from the area of the flooring. A square meter of flooring will require more or less 20 puno staked at an interval of 0. 5 m. both ways on center. This, however, depends upon the hardness of the floor foundation. g. Screens and slabs are calculated based on the design of the concrete gate. h. interact nails are calculated based on the thickness of the form lumber used. i. diligence cost is 35â€40% of total material cost. However, close estimates can be computed by determ ining the cost of labor for the construction and removal of temporary earth dike, excavation of the foundation, staking of bamboo puno, placing of boulders and gravel, construction of forms, concreting of the gate and others. 2. Estimating the cost of construction and installation of a wooden gate. a.\r\nBased on the plan of a wooden gate, determine the size and number of lumber for the sidings and flooring. Compute for the total board feet using the following formula: [pic] Where: |L |= |duration of lumber in inches | |W |= |Width of lumber in inches | |t |= |thickness of lumber in inches | b. Based on the design and specification of the pillars and braces, compute for the total board feet using again the above formula. c. Determine the size and number of lumber needed for slabs and screen frames and compute the total board feet. d.\r\n suppose the assorted nails (bronze) based on the lumber used. e. Calculate the coal tar requirement in gallons. f. Calculate the cost of nylon an d bamboo screens. g. Calculate the labor cost at 30â€40% of the material cost or calculate in detail according to the labor requirement. Calculation includes the construction, painting and installation of the wooden gate and excavation of the floor foundation. c. For the Construction of the Proposed Dikes. Dikes constructed in fishponds vary in sizes. Bigger dikes are, of course, more costly to construct than smaller dikes. In other words, the perimeter or main dike will expend more than the secondary or tertiary dikes.\r\nThe cost of construction is calculated based on the volume of soil filled and generally it costs [pic]6. 00 per cubic meter. turn over cost, however, depends on the prevailing determine in the locality. Transport distance of soil material to the dike is also considered in calculating the cost of construction. Long transport distance decreases individual output per day and thus will increase construction cost. Working eight hours a day, one skilled worker can finish diking, using one flat boat, based on the following distances: |10 †100 meter distance |6 †7 cu. m. /day | |101 †300 meter distance |5 †6 cu. m. day | |301 †500 meter distance |4 †5 cu. m. /day | d. For the Excavation and Leveling of Ponds. Cost for excavation depends upon the volume of soil left inside the pond after the dikes have been constructed. Considering that some soils have been excavated for diking purposes, only about 60% is left for excavation. Generally, escavation costs about [pic]2. 00 per cu. m. depending upon the prevailing labor cost in the locality. After excavation, leveling of the pond bottoms follows. This involves the cut-and-fill method (excavation and cast out to low portions).\r\nGenerally, leveling costs about [pic]2,000. 00 per hectare. e. For the Construction of Facilities. Facilities include the caretakers house, working shed, bodega, chilling tanks, etc. For proper estimates there should be a simple plan of the facilities. However, rough estimates can be made based on the floor area of a house to be constructed. For a house made of light materials, assume a cost of [pic]400. 00 per sq. m. floor area; and for concrete structures, assume [pic]1,000. 00 per sq. m. All assumed costs include materials and labor based on 1979 price of materials. f. For the Purchase of Equipment. A fishpond project cannot be operated without equipment.\r\nExamples are fish nets, digging blades, shovels, scoop nets, bolos, etc. These items should be included as part of the total development cost. Such equipment should be listed and calculated. g. Contingencies. There should be a contingency fund for unforeseen expenditures, increase of prices and other materials not included in the above calculations. take for granted 10% of the above costs for contingencies. 5. 1. 3 Cost estimate For the purpose of determining the cost of underdeveloped a new brackishwater fishfarm project, a typical example of a 50-hectare fis hpond project applied to the Bureau of Fisheries and aquatic Resources for a 25-year Fishpond Lease Agreement is presented below. |I. Pre-Development |  | | |1. |For the preparation of feasibility study |[pic]1,000. 00 | | |2. |Re-location of boundaries |2,000. 00 | | |3. |For the construction of temporary shelter for laborers (light materials) |4,000. 00 | | |4. |For the construction of flatboats, 5 units at [pic]500. 00/unit |2,500. 00 | | |5. |For the obtain of small banca, 1 unit at [pic]600. 00 |600. 00 | | |6. For representation and transportation expenses |3,000. 00 | | |Sub-total |[pic]13,100. 00 | |II. |Development Proper |  | | |1. |Clearing of the area at [pic]600. 00/ha. (cutting, chopping, burning & removal of logs |[pic]30,000. 00 | | |2. |Construction of dikes (filling, compacting and shaping by manual labor) |  | | | |a. |Main dike along talk and river 1,920 linear meters, 6. 0 m base, 2. 0 m crown and 2. 25 m|103,680. 00 | | | | |height or a total o f 17,280 cum. at [pic]6. 00/cu. | | | | |b. |Main dike along upland, 840 linear meters, 5. 5 m base, 2. 0 m crown, and 2. 0 m height |37,800. 00 | | | | |or a total of 6,300 cu. m at [pic]6. 00/cu. m | | | | |c. |Main canal dike, 980 linear meters, 5. 0 m base, 2. 0 m crown, and 1. 8 m height, or a |33,957. 00 | | | | |total of 6,174 cu. m. at [pic]5. 50/cu. m | | | | |d. |Secondary dike, 2,540 linear meters, 4. 0 m base, 1. 0 m crown & 1. 5 m height or a |52,387. 50 | | | | |total of 9,525 cu. at [pic]5. 50 per cu. m | | | | |e. |Secondary canal dike, 400 linear meters, 4. 0 m base, 1. 5 m crown and 1. 4 m height, or|8,470. 00 | | | | |a total of 1,540 cu. m at [pic]5. 50 per cu. m | | | | |f. |Tertiary canal dike, 240 linear meters, 3. 5 m base, 1. 5 m crown and 1. 2 m height or a|3,600. 00 | | | | |total of 720 cu. m at [pic]5. 00 per cu. m | | | | |g. |Tertiary dike, 700 linear meters, 3. 0 m base, 1. 0 m crown and 1. m height or a total|7,000. 00 | | | | |of 1,400 cu. m a t [pic]5. 00 per cu. m | | | |3. |Construction and installation of furnish |  | | | |a. |Main double opening concrete gate, 2 units at [pic]20,000/unit including labor cost |40,000. 00 | | | |b. |Construction and installation of 10 units secondary wooden render at [pic]3,000. 00 per|30,000. 00 | | | | |unit | | | | |c. Construction and installation of 15 units tertiary wooden gates at [pic]1,500/unit |22,500. 00 | | |4. |Excavation and levelling of pond bottoms (cut-and-fill) |  | | | |a. |Nursery Pond, 1. 5 ha at [pic]2,000/hectare |3,000. 00 | | | |b. |Transition Pond, 4. 0 ha at [pic]2,000/ha |8,000. 00 | | | |c. |Formation Pond, 8. 0 ha at [pic]2,000/ha |16,000. 00 | | | |d. |Rearing Pond, 32. 0 ha at [pic]2,000/ha |64,000. 00 | | |5. Uprooting and removal of stumps at [pic]600/ha |30,000. 00 | | |6. |For the construction of facilities |  | | | |a. |Caretakers Hut made of light materials, 2 units at [pic]6,000/unit |12,000. 00 | | | |b. |Bodega, made of light materi als for inputs and equipment, 1 unit |5,000. 00 | | | |c. |Chilling tank with shed, made of light materials |3,000. 00 | | |7. |For the purchase of equipment |  | | | |a. Nets for harvesting |3,000. 00 | | | |b. |Digging blades and carpentry tools |1,000. 00 | | | |c. |Containers |2,000. 00 | | |8. |Contingencies (10% of cost) |52,350. 05 | | |Sub-total |[pic]562,750. 55 | | |T O T A L |[pic]575,850. 55 | ESTIMATED COST FOR unrivaled UNIT DOUBLE possible action MAIN CONCRETE GATE |I. Cost of Materials | | |  | | amount |Unit Price | come up | | |1. |Cement | cxl bags |[pic]24. 00/bag |[pic]3,360. 00 | | |2. |Sand |10 cu. m. |60. 00/cu. m |600. 00 | | |3. | razz |20 cu. m |80. 00/cu. m |1,600. 00 | | |4. |Boulders |8 cu. m |50. 00/cu. m |400. 00 | | |5. Reinforcement Bar | | | |a) ? ? ? 20′ |80 pcs |22. 00/pc |1,760. 00 | | | |b) ? 3/8 ? 20′ |35 pcs |12. 00/pc |420. 00 | | |6. |Plywood form |49 pcs |48. 00/pc |2,352. 00 | | | |(? ? 4′ ? 8″) | | | | | |7. |Lumber (S4S) | | | |a) 2″ ? 2″ ? 12′ |30 pcs |3. 0/bd. ft |360. 00 | | | |b) 2″ ? 3″ ? 12′ |16 pcs |3. 00/bd. ft |288. 00 | | | |c) 1″ ? 2″ ? 12′ |10 pcs |3. 00/bd. ft |60. 00 | | | |d) 1″ ? 12″ ? 12′ |6 pcs |3. 00/bd. ft |216. 00 | | |8. |Assorted Nails |10 kgs |7. 50/kg |75. 00 | | |9. |G. I. Wire #16 |20 kgs |8. 00/kg |160. 00 | | |10. Bamboo Puno |400 pcs |4. 00/pc |1,600. 00 | | |Sub-total |[pic]13,251. 00 | |II. |Labor (40% of material cost) |5,300. 00 | |III. |Contingencies (10% of material cost) |1,325. 00 | | |T O T A L |[pic]19,876. 00 | | |say |[pic]20,000. 00 | ESTIMATED COST FOR ONE UNIT SECONDARY WOODEN GATE |I. Cost of Materials | | |  |  |Description |Quantity |Unit Price |Amount | | |1. |Ply Board |1″? 10″? 14′ |34 pcs. |[pic]3. 00/bd. ft|[pic]1,190. 00| | | | | | |. | | | | | |1″? 10″? 8′ |3 pcs. |3. 00/bd. ft. |60. 00 | | |2. |Slabs |1R 43;? 12″? 14′ |2 pcs. |3. 00/bd. ft. |84. 00 | | |3. |Pillars and  Braces |2″? 3″? 10′ |4 pcs. 3. 00/bd. ft. |60. 00 | | | | |2″? 3″? 8′ |7 pcs. |3. 00/bd. ft. |84. 00 | | | | |2″? 3″? 14′ |2 pcs. |3. 00/bd. ft. |42. 00 | | | | |3″? 4″? 10′ |12 pcs. |3. 00/bd. ft. |360. 00 | | |4. |Screen Frames |2″? 3″? 16′ |2 pcs. |3. 00/bd. ft. |48. 00\r\n'