摘要
依据定西关川河流域1995—2010年的水文站监测数据,分析了该地区降雨特征及其水土流失效应。结果表明:(1)流域降雨事件主要发生在5—9月,7—8月降雨量达到全年最高值,而侵蚀性降雨主要发生在7—8月;15a间侵蚀性降雨日数占总降雨日数的9.53%;侵蚀性降雨量占总降雨量的39.41%。(2)15a间共观测到1 123d降雨,降雨总量达4 866.98mm;多年平均降雨量304.19mm,年际变化趋势不明显,每年约10%的侵蚀性降雨事件造成土壤侵蚀。(3)河川径流量与输沙量呈极显著正相关关系(p<0.001),二者均呈波动减少的趋势;当表层土壤处于缺水状态时,降雨对土壤侵蚀的影响延迟。(4)由于影响土壤水蚀的因素错综复杂,降雨量、侵蚀性降雨量和降雨侵蚀力均不能独立反映流域土壤侵蚀过程。
Based on field hydrological data from 1995 to 2010, the article analyzed the characteristics of pre- cipitation and its effect on soil erosion in Guanchuan River basin, Dingxi County, Gansu Province and conclu- ded that： Firstly, most of the rainfall occurred from May to September, while erosive rainfall concentrated in July and August. Within the 15 years, erosive rainfall days accounted for 9.53~/oo of annual rainy days and erosive precipitation accounted for 39.41% in total amounts. Secondly, about 1 123 rainy days were observed during the 15 years with a total precipitation amount of 4 866.98 mm and mean precipitation of 304.19 mm. No obvious trend was found during the 15 years. The proportion of days with erosive rainfall was about 10 %annually. Thirdly, a strong positive relationship were found between river runoff and soil erosion （p 〈0. 001）, both of which decreased over time. The precipitation effect on soil erosion delayed when soil was dry. Finally, because water erosion process is quite complex, rainfall amount, erosive rainfall amount, rain- fall erosivity can not reflect soil erosion independently.
出处
《水土保持通报》
CSCD
北大核心
2013年第6期84-87,93,共5页
Bulletin of Soil and Water Conservation
基金
国家杰出青年科学基金项目"景观生态学"(40925003)
国家自然科学基金项目"黄土丘陵区坡面尺度不同整地方式的生态水文效应"(41371123)
关键词
降雨
水土流失
黄土高原
关JiI河流域
precipitation
soil and water losses
the Loess Plateau
Guanchuan River basin
