Isotope of 137Cs appeared in the environment by nuclear weapon tests in the atmosphere in the 1950s and 1960s. When the 137Cs deposited to the ground, they were absorbed strongly and quickly by exchanging positions wi...Isotope of 137Cs appeared in the environment by nuclear weapon tests in the atmosphere in the 1950s and 1960s. When the 137Cs deposited to the ground, they were absorbed strongly and quickly by exchanging positions with other elements, and it had no ability to decompose in most of the environments. Redistribution of this isotope after settled down into the soil mainly occurs due to redistribution of soil surface. Research on the correlation between 137Cs loss and soil erosion was done in 2009, at 24 sites, on basaltic soil with slopes of 20%-25%. Statistical analysis by linear regression of experimental data according to equation ofy = a × xb got coefficients of a and b. They are 20.123 and 1.0967, respectively. The correlation ofy = 20.123 × x1.0967 was tested with error of 7.3%-35.8% between the actual soil loss and calculating. This correlation was applied to evaluate soil erosion rates in two catchments of Buon Yong and Ea Kao belonging to Dak Lak province, thereby giving soil erosion rates ranging from 3.44 t-ha-1 to 26.38 t-ha-1, depending on the conditions of sloping land and cover crops.展开更多
文摘基于丹江口坡地农田的田间试验数据,建立了WEPP模型坡面版所需的作物特性和种植管理措施参数、土壤物理特性参数、坡面特征参数等文件,并结合当地气象观测数据,模拟了丹江口地区4种植物篱(紫穗槐、金银花、黄花菜、龙须草)的坡面径流量和土壤侵蚀量.结果表明:WEPP模型坡面版能准确模拟研究区植物篱对坡面径流与土壤侵蚀的影响,该方法不仅可减少田间试验次数,而且省时省力,并能为植物篱的推广应用提供科学依据.4种植物篱中,紫穗槐的防蚀效果最好.在坡度5°下,研究区紫穗槐(1 m宽)的最佳种植间距为15m;坡度15°下,最佳种植间距为10 m;坡度25°下,最佳种植间距为3 m.
文摘Isotope of 137Cs appeared in the environment by nuclear weapon tests in the atmosphere in the 1950s and 1960s. When the 137Cs deposited to the ground, they were absorbed strongly and quickly by exchanging positions with other elements, and it had no ability to decompose in most of the environments. Redistribution of this isotope after settled down into the soil mainly occurs due to redistribution of soil surface. Research on the correlation between 137Cs loss and soil erosion was done in 2009, at 24 sites, on basaltic soil with slopes of 20%-25%. Statistical analysis by linear regression of experimental data according to equation ofy = a × xb got coefficients of a and b. They are 20.123 and 1.0967, respectively. The correlation ofy = 20.123 × x1.0967 was tested with error of 7.3%-35.8% between the actual soil loss and calculating. This correlation was applied to evaluate soil erosion rates in two catchments of Buon Yong and Ea Kao belonging to Dak Lak province, thereby giving soil erosion rates ranging from 3.44 t-ha-1 to 26.38 t-ha-1, depending on the conditions of sloping land and cover crops.
