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| 1 | Changes in runoff and sediment load from major Chinese rivers to the Pacific Ocean over the period 1955-2010显示文摘Changes in runoff and sediment loads to the Pacific Ocean from 10 major Chinese rivers are presented in this paper.To quantitatively assess trends in runoff and sediment loads,a parameter called the 'Trend Ratio 7'' has been defined in this paper.To summarize total runoff and sediment load from these rivers,data from 17 gauging stations for the duration 1955 to 2010 has been standardized,and the missing data have been interpolated by different approaches according to specific conditions.Over the observed 56-year study period,there is a quite stable change in total runoff.Results show that the mean annual runoff flux entering the Pacific Ocean from these rivers is approximately 1,425billion cubic meters.It is found that all northern rivers within semi-arid and transitional zones including the Songhua,Liaohe,Haihe,Yellow and Huaihe rivers present declining trends in water discharge.Annual runoff in all southern rivers within humid zones including the Yangtze,Qiantang,Minjiang,Pearl and Lancang rivers docs not change much,except for the Qiantang River whose annual runoff slightly increases.The annual sediment loads of all rivers show significant declining trends;the exceptions are the Songhua and Lancang rivers whose annual sediment loads have increasing trends.However,the mean annual sediment flux carried into the Pacific Ocean decreased from 2,026million tonnes to 499 million tonnes over the 56-ycar period.During this time there were 4 distinct decreasing phases.The decrease in annual sediment flux is due to the integrated effects of human activity and climate change.The reduction in sediment flux makes it easy for reservoir operation;however,the decrease in sediment flux also creates problems,such as channel erosion,river bank collapse and the retreat of the delta area. | Cheng LIU Jueyi SUI Yun HE Faye HIRSHFIELD | 2013 | International Journal of Sediment Research2013，28，4： | 16 |
| 2 | 近半个世纪以来黄土高原侵蚀产沙的时空分异特征显示文摘为了摸清黄土高原主要产沙区在不同治理阶段的减沙成效及其空间分布特征,为水土保持远景规划提供参考依据,采用“水文-地貌法”,研究了近50年来黄土高原侵蚀产沙的时空分异特征。结果表明:研究区域的年均侵蚀产沙量由治理前(1955—1969年)的17.5亿t减少到一期治理(1970—1989年)的10.8亿t、二期治理(1990—2009年)的6.6亿t、及退耕后(2000—2009年)的4.0亿t;侵蚀产沙量占全区总量比例较大的类型区为黄土峁状丘陵沟壑区、黄土粱状丘陵沟壑区、干旱黄土丘陵沟壑区和黄土高塬沟壑区。4个类型区退耕后减沙幅度分别为79.0%、82.0%、69.1%和63.8%;今后黄土高原治理的重点区域为侵蚀产沙强度≥2500r/km2·a的区域(5.3km2,占21.2%),而侵蚀产沙强度为1000~2500t/km2·a的区域(6.3km2,占25.0%)仍需要加强治理,侵蚀产沙强度〈1000t/km2·a的区域(13.4km2,占53.8%)也需要预防监督。 | 王万忠 焦菊英 魏艳红 王志杰 | 2015 | 泥沙研究2015，40，2： | 7 |
| 3 | People’s perception and socioeconomic determinants of soil erosion:A case study of Samanalawewa watershed, Sri Lanka显示文摘Though soil erosion is an important concern in Sri Lanka, there is a dearth of baseline information on soil erosion in many ofits watersheds, which obstructs monitoring of soil erosion and mitigating its effects. In order to assess soil erosion in a critical watershed and to identify its determinants, the Samanalawewa watershed, which contains one of the main hydropower generating reservoirs in Sri Lanka, was selected for this study. Remote-sensing (RS) and geographic information system (GIS) based modeling as well as field experiments were employed to assess and map soil erosion rates. Results indicated that the current rate of soil erosion ranges from 0 to 289 t/ha/yr, and that the average rate of soil erosion has been declining from 20 to 4 t/ha/yr over a period from 1986 to 2008. The current rate of soil erosion is, however, still about 14 to 33 times greater than the natural soil generation rate. Socioeconomic factors and peoples' perception of soil erosion and soil conservation measures were examined using data collected through a household survey. Multiple regression analysis with eighteen covariates of socioeconomic characteristics yielded eleven socioeconomic variables, viz. household size, farm labor, education, land tenure, conservation cost, training, committee membership, professional competencies, income, distance, and financial capital as the predictor variables of soil erosion. Farmers identified improper soil and crop management practices as the major causes of erosion. The adoption of conservation measures, their effectiveness, and their impact on ecosystem services were also examined. | E.P.N. UDAYAKUMARA R.P.SHRESTHA L.SAMARAKOON D.SCHMIDT-VOGT | 2010 | International Journal of Sediment Research2010，25，4： | 3 |
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