The relation of surface environmental factor to depth of groundwater on Horqin sandy land in Tong Liao city, China

摘要

This paper reports the relationship between surface environmental factors and depth of groundwater on Horqin sandy land in Tongliao dry, China. The main findings are: 1) The plants in Horqin area are divided into three basic kinds (1) The plant typewhich is not affected directly by groundwater in drifting sand dunes, and the fixation and semi-fixation sand dunes, (2) The transitional plant type which exists in transitional zone between sand dunes and lower ground for pasture, and (3) The plant type affected by groundwater. which exists in bog hole and lower ground ranked between sand dunes and lower ground for pasture. 2) Groundwater table in Horqin sandy land shows a cyclic variation due to hydro-meteorological element. The lowering of the groundwater table is accelerated by the prevalent speed of wind erosion and desertification arid frequency of sandstorm. 3) Thickness of annual rings of tree showed a significant positive correlation with the amount of precipitation and their correlation coefficient increases wirh rhe depth of groundwarer. When rhe depth of groundwater reaches 6m or so, the growth of the kind of tree used in an experiment depends on the amount of precipitation in general. 4) The average thickness of annual rings of a tree for years has a negative exponential correlation with the depth of groundwater. 5) The wind erosion depth increases with the depth of groundwarer. and desertification is accelerated through excessive production activity by human beings.