长汀县水土流失动态变化及防治对策研究

长汀县是福建省水土流失最严重的区域,2000年以长汀县为重点的水土流失综合治理被列为福建省委省政府为民办实事项目,并已连续几年实施重点治理。应用2000年和2003年的SPOT数据,对长汀县水土流失进行了动态监测研究。结果表明,长汀县水土流失集中分布在以河田为中心的中部低丘区,向周围山区呈辐射下降趋势,87.21%水土流失分布在海拔200~500m的丘陵地带;近4a来,长汀县水土流失面积和强度都呈下降趋势,尤其以河田镇下降最大,但是剧烈流失在空间分布上呈扩散的现象。多年有效的治理是水土流失面积减少且强度下降的主要原因,而燃料结构的变化保护了植被也是重要因素。由于开发建设项目和山地农业开发过程中未采取有效的水土保持措施是造成新的水土流失的主要原因。和全省其它地方相比,长汀县水土流失仍然严重,治理任务还相当艰巨,应继续加大自然生态修复的力度,落实开发建设项目水土保持措施,加强水土流失综合治理,正确处理保护和开发利用的关系,开展水土流失监测等有效措施进行治理。

Monitoring Soil and Water Loss Dynamics and Its Management Measures in Changting County

Changting county is the region in Fujian Province which most seriously affected by soil and water loss. Soil and water loss dynamics is studied with SPOT data of 2000 and 2003. It was observed that soil and water loss occurs mainly in the mid to low hill area around the center of Hetian town, and decreases rapidly to wards the mountains. Eighty-seven percent of soil and water loss occurs at elevations of 200 to 500 meters. Over the last 4 years, the area and intensity of soil and water loss has decreased, especially in Hetian town, but severe loss has diffused from around the center of the town to surrounding areas. The declining soil and water loss is caused form several years of sound management work, including vegetation protection. However, lack of soil and water conservation measures under current development and construction projects, and agriculture expansion into steeper areas, is generating new soil and water loss. The net effect is an ongoing, serious soil and water loss problem, which will continue to be difficult to manage. Thus, management measures must continue to be developed and implemented, including ecological restoration and development impact mitigation.