Study On The Influence Of Coal Mining Subsidence On Community Evapotranspiration In Mu Us Desert

In order to clarify the effect of coal mining subsidence on soil water content and evapotranspiration,a soil temperature and humidity monitor was used to monitor the soil water content of 10-60 cm soil layer.The method of "three-temperature model and thermal infrared remote sensing" was used to determine the transpiration rate and daily transpiration rate and daily transpiration of soil evaporation and main dominant species Artemisia ordosica and Salix psammophila in subsidence and non-subsidence areas in different months,and to determine the main limiting factors of coal mining subsidence on soil evaporation and plant transpiration.The conclusions are as follows:(1)When there is no supplementary precipitation,the soil water content of all soil layers in the subsidence area is lower than that in the non-sinking area.In summer,the soil water content of the subsidence area is 83.5% of that of the non-sinking area.77% in autumn.Precipitation of >20mm mainly supplements the soil water content at 10-40 cm in the nonsinking area and 10-20 cm in the sinking area.After precipitation,the soil water content of10 cm in the non-sinking area starts to change about 1 hour earlier than the sinking area.After precipitation,the evapotranspiration in the study area increased by more than 50% compared with before precipitation,and the evapotranspiration intensity gradually decreased with time.(2)The average daily soil evaporation in the subsidence area in summer is 0.37 mm lower than that in the non-sinking area.Soil evaporation is in the second stage,and soil water content is the main factor limiting soil evaporation;the average daily soil evaporation in the subsidence area in autumn is lower than that in the non-sinking area.The height of the area is 0.23 mm.The moisture in the soil provides sufficient "raw material" for soil evaporation,and the subsidence increases the evaporation area of the soil surface,resulting in higher soil evaporation in the subsidence area than in the non-sink area.(3)The daily transpiration of Artemisia ordosica and Salix psammophila in the subsidence area is lower than that in the non-subsidence area.The average daily transpiration of Artemisia ordosica in the non-subsidence area during the summer is 0.70 mm higher than that of the subsidence area,and the difference in daily transpiration is the highest 0.84mm;The average daily transpiration of Salix psammophila in the non-subsidence area is 0.78 mm higher than that in the non-subsidence area,and the maximum difference in daily transpiration is 1.44 mm.The average daily transpiration of Artemisia ordosica in the nonsubsidence area during theautumn is 0.33 mm higher than that of the subsidence area,and the maximum daily transpiration difference is 0.73mm;The average daily transpiration of Salix psammophila in the non-subsidence area is 0.45 mm higher than that in the nonsubsidence area,and the maximum daily transpiration difference is 1.00 mm.Subsidence mainly reduces plant transpiration indirectly by reducing soil water content.