【摘要】 汉江流域是南水北调中线工程的水源地,其水土保持能力对维持生态环境安全与区域可持续发展具有重要意义。基于GIS技术,运用水土流失方程,估算了汉江流域3个时期的水土保持量,探讨了丹江口大坝上、下游水土保持量的时空变化特征。2001—2017年汉江流域水土保持量总体呈增长趋势,累计增加了392 649. 99 t/km~2,2017年水土保持量是2001年的2. 15倍。从分区看,2017年上、下游的水土保持量分别是2001年的2. 16倍和2. 09倍。汉江流域的水土保持量总体呈现山区高(增加),平原低(减少)的分布格局。水土保持量的低等级面积占比较大,总体处于低等级状态;低、较低、中等级的面积呈减少趋势;高、较高等级的面积呈增加趋势,除少量高等级区域的水土保持量向低等级转移外,其他等级均为低向高转移,近17年来,汉江流域水土保持趋于好转。更多还原

【Abstract】 Based on the GIS technology,the study uses the soil erosion equation to estimate the water and soil conservation in the Hanjiang River basin during three periods,and discusses the temporal and spatial variation characteristics of the water and soil conservation on the upper and lower reaches of the Danjiangkou dam. The results show that the soil and water conservation in the Hanjiang River basin in 2001—2017 showed an overall growth trend,with an increase of 392 649. 99 t/km~2,and the soil and water conservation in 2017 was 2. 15 times that of 2001. From the perspective of the district,the amount of water and soil conservation in the upstream and downstream in 2017 was 2. 16 times and 2. 09 times that of 2001 respectively. The water and soil conservation in the Hanjiang River basin generally shows a high( increased) in mountainous area and a low( decreased) distribution pattern in the plain. The low-grade area of soil and water conservation accounts for a relatively large area,and the overall level is at a low level; the areas of low and medium grades showed a decreasing trend; the areas of high and high grades showed an increasing trend. Except for a small number of high-grade areas,the water and soil reserves are transferred to low levels,and other grades are low to high. In the past 17 years,the soil and water conservation in the Hanjiang River basin has improved.更多还原