Slope flow velocity spatial distribution estimation method based on terrain and vegetation characteristics

Abstract

The invention discloses a slope flow velocity spatial distribution estimation method based on terrain and vegetation characteristics. The slope flow velocity spatial distribution estimation method mainly comprises the following steps of calculating a gradient and a confluence accumulation value of each grid unit in a drainage basin based on digital elevation data; calculating a basin average flow rate factor by combining the basin average gradient and the basin area; estimating roughness spatial distribution in the watershed according to the vegetation coverage type data; and estimating slope flow velocity spatial distribution based on the gradient, the roughness factor and the average flow velocity factor. The method is mainly applied to remote sensing observation data such as a watershed digital elevation model and a vegetation coverage type, the data source is stable and reliable, the function relation between variables in the method is clear, and computer automation execution of slope flow velocity spatial distribution estimation is facilitated. Meanwhile, the extraction steps are simplified through the digital watershed technology, objective rationality of the result is guaranteed, and popularization and application of a distributed hydrological model and deep development of digital hydrology research are facilitated.

Description

technical field [0001] The invention belongs to the technical field of hydrology, and in particular relates to a method for estimating the spatial distribution of slope flow velocity based on terrain and vegetation characteristics. Background technique [0002] There are many rivers in my country, with a drainage area of ​​200 to 3000 km 2 There are nearly 9,000 small and medium watersheds in China. In recent years, affected by climate change, sudden floods in small and medium-sized rivers caused by local heavy rainfall have occurred frequently and have become the main disaster causing casualties. Small and medium-sized watersheds are mostly located in remote mountainous areas with complex terrain and steep slopes, which are not convenient for long-term hydrometeorological observations. The floods in the watersheds usually have the characteristics of steep rise and fall, which can easily endanger the lives and property of local residents and hinder social and economic devel...

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Problems solved by technology

[0005] At present, establishing the functional relationship between slope, runoff depth and other factors and slope velocity is the main method for estimating slope velocity. There is also a big difference. It is difficult to reasonably quantify the spatial distribution characteristics of slope flow velocity in different watersheds by only using terrain factors such as slope to estimate the velocity of slope flow.

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