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Influence of land use on runoff components
CIML, Jiří
The constant movement of water is known as the hydrological cycle. The main power of this gigantic, phenomenal and continuous cycle is solar energy. Its effect is the evaporation of water from the ground. The dominant role is played by the oceans again as their surface evaporates five as much water as the land surface. After a short delay, most of the evaporated water returns into the ocean in the form of precipitation. This cycle is called the small hydrological cycle. The main components of the hydrological balance in relation to the amount of precipitation fallen as follows: Evaporation, soil moisture and groundwater sources (71.2%) Surface runoff (28.8%) Surface water As defined by Surface water law No. 254/2001, surface water is water naturally occurring in the Earth's surface. It does not lose this characteristics if they flow through temporarily covered stretches, natural cavities in the ground or in the overhead lines. Subsurface water Subsurface water, as a part of the hydrosphere which is below ground, is essential for plant life and is the main source of drinking water. They are used for the purposes of healthcare, industry, agriculture, etc. The occurrence of subsurface water, its movement and quality are contingent on the environment in which they are located. They arise mainly from infiltration of surface water below the surface and classified according to various criteria. The most frequently in accordance with - state, origin, mobility, bonding, depth of occurrence, etc. Groundwater As defined by Groundwater law No. 254/2001, groundwaters are water naturally occurring under the surface in the saturation zone and in direct contact with rocks. The water flowing through drainage systems and water wells is also considered groundwater. Runoff The hydrological concept tells us how much water is drained over a specified period of our catchment area. Factors that tell us that there will be a runoff are soil saturation and soil surface saturation due to an increased precipitation. It can also be a snow blanket with which the snow mass and composition (water content) would play their role. Runoff components Runoff is part of the hydrological balance and is divided into several components. 1. Overland flow 2. Subsurface flow 3. Groundwater flow Overland flow It is largest in deforested and urbanized areas. Subsurface flow It is largest in karst areas and naturally forested watersheds. Groundwater flow It is largest in naturally forested areas and steep watersheds. Genesis 1. Direct flow 2. Base flow Factors affecting runoff: Relief: appearance, slope, topography and terrain, orientation, exposure Physical geographical conditions: drainage basin area, basin shape Geological and hydrological conditions: porosity, subsoil Pedological properties: soil conditions, physical properties Land cover (Vegetation cover) Climate: precipitation, extreme precipitation, infiltration of rainwater Methods of separation: Kliner - Kněžek method Analysis of subsidence branches Digital filters Separation according to radioactivity CN Curve Land use: Arable land (Agriculture land) Pasture, meadow, grassland (TTP) Forests Urban, road network
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