Results the mutagenicity of water body displayed a rule of well < river < pool ; the mutagenicity detected in dry season was higher than that in rainy season ; the numbers of micronucleus induced by river and pool water in dry season were found to be positively correlated with the incidence of stomach , esophagus and liver cancer , whereas only pool water showed significant relationship with stomach cancer occurrence in rainy season ; well , river and pool water in taixing city all can cause dna damage in peripheral blood lymphocytes , and water of river cause dna damage heavily 结果：水体致突变性呈塘水河水井水的规律；相同地区水体的致突变性在枯水期比丰水期强；枯水期河水和塘水诱发的微核效应与当地肝癌、胃癌和食管癌发病率有高度的正相关，而丰水期仅塘水微核效应与胃癌发病率有正相关；诱发微核率较高的井水、河水和沟塘水对人淋巴细胞都具有致突变性，其中尤以河水为甚。
The main conclusions are as follows : the hco3 - ion content of zhujiang river changes notably in one hydrological year , especially in wet season and dry season . as for the content of inorganic carbon , that of the xijiang river is the highest , then the beijiang river , and then the dongjiang river . the xijiang river ' s inorganic carbon source was major from karst process in the drainage basin 得出如下的结论：珠江水体hco _ 3 ~ -离子含量在一个水文年中发生显著变化，特别是丰水期与枯水期之间波动幅度较大；无机碳含量西江含量最高，其次是北江，东江最低；西江无机碳主要来源于岩溶作用，由于受河流冲刷效应影响，丰水期hco _ 3 ~ -离子含量升高；东江流域无机碳主要来源于硅酸盐岩的碳酸盐风化过程，丰水期hco _ 3 ~ -离子含量无显著变化；北江无机碳来源于岩溶作用和硅酸盐岩的碳酸盐风化过程，受稀释效应影响，无机碳含量随水量增加而降低。
In order to avoid short supply at the semi - highland in yangmingshan area , it is planned to increase distribution basin and boost station , supplement with the water supply from lowland . this will be aided with increased coagulation sedimentation facilities at lujiaokeng water source to maintain water supply quality during heavy rainfall period resulted high turbidity raw water , to upgrade the supply quality at highland to attain the target of " sufficient quality supply fro customer satisfaction " 为免枯水期阳明山次高地区水源不足，未来规划增设配水池及加压站，以平地水源上送调度补充，并增建鹿角坑水源的混凝沉淀等前处理净水设备，以稳定暴雨原水高浊度时的供水水质，持续以质优量足顾客满意为目标，致力提升高地供水品质。
Many organic and inorganic contaminants of the shallow groundwater in city zone and close suburb of beijing were investigated on the spot , more than 100 samples were got . by spatial analysis , modeling calculation and spatial interpolation , maps of each contaminant distributions are made and divided into two parts , the beyond the standard and below the standard . with those maps , the total environmental quality of the groundwater is evaluated 利用本系统提供的空间分析、模型运算等分析工具，对2000 2001年北京城近郊区浅层地下水环境污染进行了如下评价分析工作： ( 1 )对地下水调查中检测出的各种有机污染物和无机污染物进行了空间插值分析，划定了超标区的分布范围； ( 2 )对2000年枯水期的浅层地下水综合环境质量进行了分析和评价； ( 3 )对1996 、 1999和2000年的综合水质评价图进行了对比分析，发现北京城近郊区浅层地下水环境综合质量逐年下降；预知未来几年内，浅层地下水环境质量不会有明显好转。
During the calculation of reactive power and voltage in the power network , reactive power insufficiency and the system under - voltage are always concerned . in the same way , we should consider the problem that reactive power surplus and over - voltage during the period of low - water and low load 在无功电压优化计算中，对于无功功率不足和系统电压偏低的情况一直是研究者关注的问题；同样在枯水期轻负荷时，电网运行中也要考虑到无功功率过剩，系统电压偏高的问题。
The new research progress in the effect of forest on rainfall , interception annual runoff , was summarized . the main issues show that the most function of forest vegetation aims at protecting water resources and water environment , adjusting water amount , controlling erosion , decreasing run - off silt , decreasing maximum flow as well as increasing discharge of river in dry season and purifying water quality 本文一方面通过介绍森林水文学的概念、研究进展和实际运用，分析了森林与水相互作用的特点，并从降水、截留、径流等方面综合研究森林植被在涵养水源、调节水量、减少径流泥沙、降低洪峰、增加枯水期流量、改善水质等方面具有的重要功能。
