河口区营养物基准制定方法

Methods for developing nutrient criteria in estuarine waters

河口区营养物基准是河口环境监测、评估和管理的基础。然而,如何从营养盐基准制定的角度分析相关的科学基础问题,提出有效操作方式和制定方法仍然缺乏系统研究,国内外营养物基准制定亦处于探索阶段。从基准状态的判断、基准关注的营养物质、河口生态系统对营养盐的响应特征3个方面分析了基准制定的科学基础问题,认为基准值的判断可以参照状态为基础,N、P、Si、Fe等对植物生长具有较明显限制作用,实践中均应纳入考虑,复杂的物理特征使河口营养物敏感性具有显著差异,地理区域和河口类型的划分有利于基准的制定。结合上述分析及国内外经验,提出了基准制定的6个步骤,认为河口分类与分区、参照状态确立是基准制定的核心步骤,其分析方法较多,需要针对河口特征选择并调整。结合我国营养物基准研究现状和管理需求,提出了建立我国河口基础数据库、制定河口营养物基准技术指南、建立基于生态系统健康的河口营养物基准及标准体系等建议。

Nutrient criteria in estuarine waters are essential to water environment monitoring, assessment and management However, its development is in a preliminary stage. With regard to the correlative scientific problem and approaches, specific researches are still limited. As viewed from criteria judgment, right nutrient control and estuarine ecosystem responses to nutrient, scientific basis for criteria development was analyzed. It is presented that reference condition can help to identify the state of criteria. Nitrogen, phosphorus, silicon and iron impose obvious limitation on phytoplankton growth, and they should be included in the control. Complex physical characteristics of estuaries result in different nutrient susceptibility, and geographical classification can contribute much to the practice. Resting on the above analysis and abroad experiences, methods for developing nutrient criteria in estuarine waters were put forward. Building up Regional Technical Assistance Group （RTAG）, background investigation, estuary classification and partition, variables selection, data collection and in-situ observation, reference condition determination and criteria recommendation, and criteria evaluation and modification are the six main steps. Considered as the most vital one, estuary classification and partition as well as reference condition determination were particularly addressed. Several ways are available to achieve them while detailed selection and proper modulation should be applied to the process. In view of Chinese situation, establishing national estuarine database, developing national nutrient criteria manual, and setting up ecosystem-health-based estuarine nutrient criteria and standard system are highly suggested.