On the basis of expounding the basic ideas and principles of river ecological restoration, the basic tasks and main countermeasures of river ecological restoration are put forward. The task of river ecological restoration is to improve hydrological conditions, improve river geomorphological characteristics and restore endangered or special species. River ecological restoration measures include direct human intervention, natural restoration and enhanced restoration measures. Keywords: river; Water conservancy project; Picture classification number in ecological restoration: X 17 1 document identification number: b At present, river degradation has been recognized as a global ecological environment problem, and the basic principles of ecological restoration are: 1. The basic principles of ecological restoration and reconstruction generally include three aspects: natural principles, socio-economic and technical principles and aesthetic principles. The principle of nature is the basic principle of ecological restoration and reconstruction, that is to say, only the restoration and reconstruction that follows the laws of nature is the real restoration and reconstruction, otherwise it can only run counter to it and get half the result with half the effort. Social technology and economic conditions are the backing and pillar of ecological restoration and reconstruction, which restrict the possibility, level and depth of ecological restoration and reconstruction to a certain extent. Aesthetic principle means that the restoration and reconstruction of degraded ecosystem should give people beautiful enjoyment. According to the requirements of the above basic principles and the actual situation of rivers, the following guiding principles are formulated: (1) regional principle. Due to the different ecological environments in different regions, the international community pays more and more attention to them. With the enhancement of environmental awareness and ecological concept and the improvement of living standards, the social demand for repairing the seriously damaged river ecosystem is becoming more and more urgent. Therefore, it is necessary to carry out ecological restoration measures for rivers. In the actual restoration, if there is no human interference, it is difficult for the river to return to its original state. Generally, only under the premise of restoring the basic ecological functions of the river, proper restoration can be carried out to meet people's needs. 1 Basic ideas and principles of ecological restoration 1. 1 Basic idea of ecological restoration The restoration of river ecology must be based on the viewpoint of systematic, holistic and sustainable development, such as climatic conditions, landforms and hydrological conditions. This regional difference and particularity require us to adapt to local conditions when restoring and rebuilding degraded ecosystems. We must not copy the concrete analysis of specific problems, but base ourselves on long-term positioning and testing, sum up experience, obtain optimized and successful models and models, and then demonstrate and popularize them. (2) Principles of ecology and systematics. Ecological principles include: ecological succession is based on the whole ecosystem structure and function of rivers, starting from the development and utilization of water and soil resources and the present situation of ecological environment, combining with urban landscape planning, creating landscapes with water, fully considering the activity needs and environmental feelings of residents and tourists along urban rivers, and taking "green" and "water" as spatial substrates to form an open and hydrophilic human activity space for the public, thus creating a safe, comfortable and comfortable space. At present, the main task of water conservancy project is to focus on ecological restoration and reconstruction, comprehensively adopt engineering technology, biotechnology and management technical measures, change the previous practice of simply discussing rivers and environment, ensure the flow of general rivers, restore clean water flow, protect water quality, form a good river landscape and waterfront environment, build urban water network and strengthen greening. It is required that the waterfront open space should not only have comfortable open space, but also pay attention to its biodiversity, so as to build damaged rivers into ecological urban rivers, maintain the sustainable development of urban resources and environment, and restore urban water ecosystem. Date of receipt: 2008203226 Design. Then, the chain network of things, niche principle and so on. Ecological principles require us to follow the succession law of the ecosystem itself step by step, step by step, and not be eager for success. On the other hand, in the process of ecological restoration and reconstruction, we should start from the level of the ecosystem and have a holistic and systematic thinking, instead of "treating the symptoms only". According to the relationship between organisms and their environment, reciprocity and competition, and the principle of biodiversity, the ecosystem structure and biological community are constructed, so that the material cycle and energy conversion are in the state of maximum utilization and optimal cycle, and efforts are made to realize the synchronous and benign evolution of water, soil, vegetation and organisms. Only in this way can the restored ecosystem be maintained and developed stably and sustainably. (3) The principle of minimum risk and the principle of maximum income. Due to the complexity of the ecosystem and the mutation of some environmental factors, as well as the limitations of people's understanding of the ecological process and its internal mechanism, people often cannot accurately estimate and grasp the consequences of ecological restoration and reconstruction and the final direction of ecological succession. Author of a brief introduction: Luo Bo (19792), male, assistant engineer, mainly engaged in the basic ideas and countermeasures of river ecological restoration in water plants. Only by careful and thorough research and comprehensive analysis and evaluation of the repaired object can the risk be minimized. In view of the fact that ecological restoration and reconstruction is a high-cost investment project, it is a very realistic and interesting issue to consider the economic benefits and income cycle of ecological restoration while considering the current regional economic bearing capacity. Keeping the minimum risk and getting the maximum benefit is one of the important goals of ecosystem restoration and reconstruction, and it is an inevitable requirement to realize the unity of ecological benefits, economic benefits and social benefits. 23 banks, making it an ecological river with multiple ecological functions such as habitat, habitat corridor, coastal filter belt and biological dike. Linear and banded vegetation corridors will be built along the banks of the river, criss-crossing with green belts such as mountain vegetation, plain shelterbelts and urban gardens, forming a multi-level green corridor network. Besides preventing soil erosion, it also has the function of biological migration. Therefore, in the dry floodplain, biological protection projects should be mainly built on both sides of the river, so as to gradually reduce the adverse impact of cut-off on the ecological environment, make rational use of the river according to local conditions, and plant trees and shrubs on the exposed floodplain under the condition of ensuring flood discharge. For the ecological restoration of rivers, any restoration scheme should not be limited to the river course, but should consider the river basin as a whole. This is because human influence on nature is large-scale, and the causes of water quality degradation are not mainly formed in water bodies, but mostly in other connected biological systems, which are caused by water discharge. The difficulty and time of river ecological restoration and reconstruction are closely related to the degradation degree, self-recovery ability and recovery direction of the ecosystem. Generally speaking, ecosystems with less degradation and strong self-recovery ability are easier to recover and take less time. The self-recovery of ecosystem is often slow, and artificial reconstruction can change the direction and speed of ecosystem succession to a certain extent and shorten its recovery period. In different regions, there are great regional differences in the self-recovery ability and time required by ecosystems. Generally speaking, in warm and humid climate conditions, the natural recovery speed is relatively fast; However, in cold or dry climate, the natural recovery speed is relatively slow. Therefore, in order to realize the effective restoration and reconstruction of their own ecosystems, each region must follow the basic laws of restoration ecology and choose a reasonable reconstruction model and technical system in combination with the actual situation. References: [1] Pu Deming, He Gangqiang. Urban river regulation and eco-city construction [J]. Jiangsu Water Conservancy, 2003, (5). [2] Sun Zongfeng. Theory and Practice of Ecological Water Conservancy [J]. Water Conservancy and Hydropower Technology, 2003, (4). [3], Li Legend. River Corridor and Ecological Restoration [J]. Water Resources and Hydropower Technology, 2003, Wang Wei (9). [4] Dong Zheren. Theoretical Framework of Ecological Hydraulics [J]. Journal of Hydraulic Engineering, 2003, (1). [5] Li Chaofang, Lai Bingxiu. Ecological control project of clear lake section of Guanlan River. The first is the improvement of hydrological conditions. The improvement of hydrological conditions refers to the improvement of water quantity and water quality, and the simulation of natural hydrological cycle. Including: maintaining the minimum ecological water demand through rational allocation of water resources; Improve river water quality through sewage treatment, control sewage discharge and advocate clean production; In addition to meeting social and economic needs, reservoir operation should be as close as possible to the pulsating hydrological cycle of natural rivers. The second is the improvement of river geomorphological characteristics. The improvement of river geomorphological features includes: restoring the longitudinal continuity and lateral connectivity of rivers as much as possible, maintaining the diversity of vertical and horizontal forms of rivers and preventing the hardening of riverbed materials. The third is the recovery of endangered or special species. Emphasis is placed on strengthening the construction of river biological habitats and attaching importance to the ecological reconstruction of reservoir areas. 2.2 Measures for River Ecological Restoration Human activities have had a great impact on the river ecosystem, leading to the deterioration of water quality, the disappearance of habitats, flooding, and the reduction of suitability and aesthetic value. People gradually realize the importance of a good river ecosystem and take various technologies and measures to restore the degraded river ecosystem. Ecological restoration measures of similar projects abroad include: ① direct artificial intervention measures, such as rebuilding vegetation and building artificial wetlands; (2) Natural restoration measures, including restoring the buffer zone, reducing the river slope, reshaping the curved valley, etc. ③ Strengthen the restoration measures, including the restoration of shoals and deep ponds, and the restoration of waterside wetlands (swamps and wetlands) and forest ponds. There are different vegetation in natural rivers, ranging from river courses and floodplains to buffer zones on both sides. However, after artificial regulation, the water ecological environment of the river has changed greatly, destroying the original vegetation community and reducing biodiversity. By establishing a green corridor along the river bank, the existing river channel is not only as wide and natural as possible, but also mainly replaces the manual construction of rural water conservancy and hydropower in the form of establishing vegetation buffer zones.