摩洛哥南部采矿区的重金属污染：监测壤中径流和地下水的金属含量和毒性

进行这项工作的目的是利用微生物的生物测定法MetPLATEM^TM，评价径流、被金属污染的土壤、Marrakech区两个采矿点的地下水中的金属毒性。这种生物测定方法主要是根据金属污染引起的Esther ichia大肠菌突变株的β半乳糖苷酶的特异性抑制。两个矿区所有采样站的河水样全部都是毒性的．而且呈现出的酶抑制超过87％．矿区C中SWA4和SWB1站除外。这些河水的Cu和Zn的浓度高。说明MetPLATE表现出了剧毒性。B和C矿河水的pH值在2．1和6．2之间变化，可能是金属的活化作用造成的，这就提出了这些矿区酸性矿山排水的问题。生物测定的MetPLATE方法还应用于酸性水污染的尾矿和土壤的测定。结果表明．由于可溶性Zn和Cu的浓度较高导致这些土壤和尾矿的毒性高。地下水毒性测试使用的MetPLATE方法说明。除了B矿GW3外、（潮湿季节抑制作用95.3％，干燥季节抑制作用82．9％），其余的呈现出的金属的毒性都低，抑制作用为2．7—45．5％。这种毒性高的原因主要是铜（189μg Cul^-1）和锌（505μgZnl^-1）的浓度高于常见的浓度。这些结果说明这两个含金属矿附近的不同生态系统的潜在风险。观察的总的趋势是MetPLATE测定的金属毒性随着研究的母岩中总金属浓度和移动的金属浓度的增加而增加。因此。MeIPLATE生物测定是评估水样和土样金属毒性的可靠而且快速的生物测定方法。

关于降雨产流机制的几个问题的讨论

本文就当前国内外关于产流机制研究中的几个问题进行了讨论，提出了一些新的见解．这些问题是：特殊包气带的产流机制，产流机制的统一和转化，基本产流模式，地形坡度。土层各向异性及非饱和侧向流的作用等．

Effects of Bahia Grass Cover and Mulch on Runoff and Sediment Yield of Sloping Red Soil in Southern China

Rainfall,runoff (surface runoff,interflow and groundwater runoff) and soil loss from 5 m × 15 m plots were recorded for 5 years (2001-2005) in an experiment with three treatments (cover,mulch and bare ground) on sloping red soil in southern China.Surface runoff and erosion from the Bahia grass (Paspalum notatum Flugge) cover plot (A) and mulch plot (B) during the 5 years were low,despite the occurrence of potentially erosive rains.In contrast,the bare plot (C) had both the highest surface runoff coefficient and the highest sediment yield.There were significant differences in interflow and surface runoff and no significant difference in groundwater runoff among plots.The runoff coefficients and duration of interflow and groundwater runoff were in the order plot B > plot A > plot C.Effects of Bahia grass cover were excellent,indicating that the use of Bahia grass cover can be a simple and feasible practice for soil and water conservation on sloping red soil in the region.