Methodology for the establishment of physical and geometric properties of a drainage basin

Abstract

Factors which affect runoff are closely related to properties of the basin from which the water flows and its environment. They have an effect not only on the size of the runoff but also its origination and mainly its temporal distribution. These factors can be divided into two main groups. The first group contains climatic factors, which are besides precipitation meteorological quantities affecting the overall evaporation of water in the drainage basin. These include the actual temporal and spatial progress of a rainfall, the moisture of air, evaporation, air temperature, the velocity and direction of wind, atmospheric pressure, etc. The other group consists of geographic factors of the drainage basin, which describe the environment in which the process of runoff occurs.The presented study focuses on a theoretical analysis of physical and geometric properties of a basin, the practical methods and the possible ways of their determination and possible uses of results. In the past the determination of physical a geometric watershed attributes had been working out on the basis of analogue maps. These methods were very labour-intensive and lengthy. The report deals with new determination methods based on digital data processing – utilization of digital terrain model (DTM). These problems are quite actual because of research of rainfall-runoff process, flood process and soil erosion within watershed.

Keywords

• digital terrain model
• drainage basin
• hydrology
• physical and geometric factors
• rainfall-runoff process