METHOD OF HYDROMETRIC MEASUREMENTS OF RIVER BOTTOM AND FLOOD LAND PROFILE

摘要

FIELD: construction.;SUBSTANCE: method includes selection of a hydrometric section across a river, installation of survey points on the hydrometric section with measurement of their position in plan and river depth in the survey points from water surface to the bottom, calculation of the absolute elevation of the river bottom in each survey point with account of corrections. Besides, depth measurements are arranged from the left coast to the right one along the line of the hydrometric section. Then the measurement profile of the river water section is built by the hydrometric section, and hydraulic characteristics of the profile are calculated near the river water section. Besides, to build the river water section to the elevation of the highest level, measurements are made, or the flood plan is levelled down to this elevation, and the wetted perimetre and area of the water section at the various river level are identified with analytic calculations. At the same time additionally to building of the river water section down to the elevation of the highest level, a steep slope is selected on the river steep coast or the flood plant terrace, where the highest point is marked on the line of transition to the plain landscape. This highest point is accepted as the reference point of levelling for survey points arranged in the flood land in specific areas of the landscape. Then the flood land is levelled by heights of survey points arrangement relative to the geodesic reference point on the highest elevation of the steep coast. Besides, a zero point of river depth measurements is also included into the measurements. Afterwards, above the river water surface, a total depth is identified to the river bottom from the geodesic reference point on the steep coast by summation of the river water section depth to the height from the zero point of the river depth measurements to the geodesic reference point on the steep coast. The zero common point in the system of coordinates for measurement of distances along the hydrometric section to survey points in the river bottom and flood land is the point of crossing of the horizontal sighting line from the geodesic reference point on the steep coast with the surface of the flood land on the other side of the river opposite to the steep coast. After production of the table data of measurements, the statistic modelling is used to determine laws in change of total depth of the flood land and the river bottom from the horizontal sighting line depending on distances, starting from the point of crossing of the horizontal line with the flood land surface on the other side of the river from the steep coast.;EFFECT: improved accuracy of hydrometric measurements of the river flood land in the hydrometric section, expanded functional capabilities of hydrometric measurements in cross section of both the river bottom with its flood land and terraces, reduced labour intensiveness of calculations of the main hydraulic characteristics on the basis of application of statistical laws of the river flood land and bottom form in each hydrometric section.;6 cl, 12 dwg