Preliminary Study on The Standard Plot of Soil Wind Erosion in Farmland
Abstract
Reliable measurements and a large amount of basic data are required in the study of soil wind erosion in order to improve the prediction accuracy of soil wind erosion model. Although there were many methods for measuring the factors affecting soil wind erosion, the shape and size of the observation plot and also arrangement of the observation instruments were not under the guidance of the common principles, which leaded to the loss of comparability of a large number of precious data. To solve this problem, we carried out an experimental study in the field in semi-arid areas of northern China. The field was 250m×127m, showing a NW-SE trend. The non-eroding boundary was set up on the windward side in the northwest of the field. Two group of flat-mouth sand sampler were set up paralleling along the field to collect the wind erosion grains. The sand samplers were at intervals of 20m in the test group, and at intervals of 40m in the validation group. The vertical anemometer was arranged at the distance of the 100m from the non-eroding boundary, which was used to measure the wind speed at 9 heights, and the wind vane was set at the height of 358cm above the field surface, and wind data were recorded every 30 seconds. Seven soil wind erosion events were monitored during the observation. Based on the published results, equation was established by summing wind erosion amounts of different direction and different speed. The equation was solved by the method of programming solution. At last, the laws that wind erosion amounts varied with distance for different wind speed were obtained. The laws were applied to the field to calculate the soil wind erosion amounts through the boundary of the field. To determine the size of the standard plot of soil wind erosion in farmland, soil wind erosion amounts calculated by the observed data of all sand collectors and by using part sand collectors within different distances in the test group were compared. According to the calculation results, we suggest that the standard plot of soil wind erosion in farmland is a circular with diameter of 120m. The difference between soil wind erosion amounts calculated by data observed in circular standard plot with diameter of 120m and observed in the whole field with a larger size are not more than 25% for each strong wind erosion event, and only about 7.3% when the seven wind erosion events summed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMEP51C1834Y
- Keywords:
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- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSESDE: 1625 Geomorphology and weathering;
- GLOBAL CHANGEDE: 5210 Planetary atmospheres;
- clouds;
- and hazes;
- PLANETARY SCIENCES: ASTROBIOLOGY