Preface

Water is an important part of natural resources, which is the main material basis of the structure and life activities of all organisms. From a global perspective, water is the link that connects all ecosystems. Natural ecosystems can not only control the flow of water, but also continuously promote the purification and circulation of water. Therefore, water in the natural environment is of decisive significance for the survival of organisms and human beings. At the same time, water is an indispensable and precious natural resource for human beings. It is an irreplaceable and extremely precious natural resource for industrial and agricultural production, economic development and environmental improvement. It plays an important role in the development of human society. The water environment is one of the basic elements that constitute the environment and an important place for the survival and
development of human society. In recent years, with the development of production and population growth, natural water pollution has intensified, and the contradiction between water supply and demand has become increasingly acute. In order to ensure water safety, predict and evaluate the water environment quality, and carry out water environmentalprotection planning has become an indispensable content of project planning, design, management and water pollution control which has a very important significance and role in ensuring the sustainable development of economy and society.

This article mainly describes the investigation and evaluation of water environment and the prevention and control of water pollution. The implementation of environmental impact assessment (EIA) has indeed made a lot of contributions to China's environmental protection. It is one of the effective measures to control the occurrence of new pollution. It requires scientific prediction and evaluation of the possible environmental problems before the formal occurrence of social and economic activities, and puts forward effective technical measures and regulations to prevent and control environmental damage, so as to nip in the bud.

前 言

水是自然资源的重要组成部分，是所有生物的结构组成和生命活动的主要物质基础。从全球范围来讲，水是连接所有生态系统的纽带，自然生态系统既能控制水的流动，又能不断促使水的净化和循环。因此，水在自然环境中，对于生物和人类的生存来说具有决定性的意义。同时，水是人类不可缺少的非常宝贵的自然资源，是工农业生产、经济发展和环境改善不可替代的极为宝贵的自然资源，它对人类社会的发展起着重要作用。水环境是构成环境的基本要素之一，是人类社会赖以生存和发展的重要场所。近年来，随着生产发展和人口增长，天然水体污染加剧，水资源供需矛盾日益尖锐。为了确保用水安全，预测、评价相应的水环境质量状况，进行水环境保护规划， 已成为工程规划设计管理和控制水污染的一项必不可少的内容，这对于保障经济社会的可持续发展具有非常重要的意义和作用。
      本文主要讲述了水环境调查评价和水污染防治的情况。环境影响评价的实施确实为我国的环境保护工作做出了许多贡献， 它是有效地控制新污染发生的措施之一，它要求在社会和经济活动正式发生之前对其可能发生的环境问题给出科学的预测与评价，并提出有效防治环境损害的技术措施及规定，以便防患于未然。