Triangulation system -If shorelines filled by vegetation.It is advisable to run transverse line only along one of the banks -If water body is narrow.It is advisable to run traverses along each shore, connecting each other by frequent tie lines –If water body > 1km wide.No rules are kept for establishing horizontal control as topography, vegetation, type, size of topography affect the rules.īut in general a rules can be kept for type of control say: Tachometric and plane table survey can be conducted in order to undergo rough works. Hence a series of lines whose lengths and azimuths are determined by means of either triangulation or any other methods. The horizontal control is necessary to locate all features of the land and marine in true relative positions. Aerial photographs would help this study. This would facilitate satisfactory completion of the survey in accordance with the requirements and specifications governing such work. A complete reconnaissance of whole survey area to choose the best way of performing the survey. Before this procedure certain preliminary steps have to be made:Īs every project require a start-up plan to complete it effectively and economically, reconnaissance has to be undergone. Sounding locations can be either made from boat to the control points or by fixing a point in the boat and taking sounding from the control point. The sounding method is employed to determine the depth at various points by means of stationary boats. The method starts by locating special control points along the shore line. Preliminary Steps in Hydrographic Surveying Massive structures like bridges, dams harbors are planned.Scouring, silting and irregularities of the bed can be identified.Locate sewer fall by measuring direct currents.Uses of hydrographic surveying are given below: Preliminary Steps in Hydrographic Surveyingįollowing are the applications of hydrographic surveying:.
0 kommentar(er)
