Study On Ecological Water Requirement Of River System In South China

With the rapid development of population and economy, water resource has been excessively exploited and the balance of ecosystem has been seriously changed and destroyed. The problem of water resource pollution and shortage is becoming more and more serious. The contradiction between exploitation water resource and environment is becoming more and more acute. Therefore we should study the ecological water requirement, consider the loading ability of water resource, probing into water resource's reasonable exploitation degree and configuration. And people's activity must be controlled to concern the loading ability of ecosystem, resource and environment. This work should be done without delay and it has attracted the domestic and international common focus.Systemic research in ecological water requirement inland is just in the start stage. The research in theory, method and application are still in the probing stage. Theory system and calculation method are still immature. Abroad research concentrates primarily in the aspect of river ecosystem. While domestic research mostly concentrates in drought, half drought or drought with seasonal change areas where the supply of water resource is hardly meets the demands and the environment is comparative weak. The research of ecological water requirement in south china is few. Now the contamination problem of water resource in south china appears sharply, especially in drought seasons. Therefore a certain part of water must be reserved to maintain the balance of ecosystem environment. So far, there is neither a completely definition of ecological water requirement nor a reasonable calculation method. Aiming at this kind of circumstance, this text regard river system in the south china as the object. Following contents will be principally discussed:(1) In this paper, Methods on ecological water requirement are summarized, its practicability and existent problem are analyzed.(2) The paper initially constracts the architecture of ecological water requirement consumption. The meaning and composition of ecological water requirement areprimarily discussed. The composition of ecological water requirement is thought to be made up of ecological water requirement for plant, river and marsh , sight, virescence and public entertainment. Eight types of ecological water are induced in this paper. The characteristic of ecological water are discussed from sustainability, dynamic, space and criticality, and its influence factor are analyzed.(3) Ecological water requirement of the river system is water demand that maintains and improves the natural ecological structure and function of the river within the definite standard of ecological environment. The composing and the corresponding calculation methods are carried out for ecological water requirement in the southern region. The paper deals with the calculation methods of river diluting and self-cleaning water demand. Optimal model is mentioned for the first time considering self-cleaning, sewage treatment extent and water fee, and the ecological water requirement is to be forecasted base on the change of sewage drainage in the near future. Lastly, calculating procedure for ecological water requirement in south china is presented.