![]() ![]() Over the years the study and accurate determination of point elevations and topographic forms of land spaces and sea beds have been the exclusive preserve of Surveyors, Geodesists and Hydrographers and in a derivative sense, Cartographers. The failure of the existing drainages to conform with the guidelines explains why the study area would flood at every rain storm event. The efficiency factors determined for Owerri were used to test the existing drainage systems. A scheme of urban drainage network as a runoff collector system that conveys runoff from the entire landscape to the primary drainage routes is suggested. The size of each sub-catchment useful for computing volumes of runoff that would have to be conveyed by the constructed urban drainages were determined using GIS. The primary landscape unit for drainage design is the subcatchment. #Total war three kingdoms dilu softwareThe DEM was processed by the ArcHydro software to determine primary natural flow routes and the sub-catchments that flood them. ![]() ![]() The data was authenticated using three dimensional (3D) coordinates of sample points derived from Global Navigational Satellite Systems (GNSS) surveys. The research effort created a Digital Elevation Model (DEM) of Owerri in Southeast Nigeria, using data from topographical maps of the city. The aim of the drainage efficiency factors guidelines is to ensure that the drainages will serve to convey runoff in ways that eliminate the danger of either erosion or flooding to the environment. The research work reported here determined efficiency factors of drainages which include the locations, alignments, slopes and sizes of drainages on a Geographic Information Systems (GIS) platform. Urban flooding can only be taken care of by efficient landscape drainages. Where drainages are constructed they are mostly road edge drainages constructed to protect the roads instead of landscape drainages. Urban centres are growing very fast in Africa. Ill-advised urbanization practices lead to the blockage of natural flow routes. Urbanization creates impervious ground surfaces, inhibiting infiltration. Urban flooding has become a major global concern, and for obvious reasons it is mostly an urban phenomenon. Urban areas in the developing world are experiencing increasingly dangerous flood events due to urban constructions and climate change. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |