宁波市水土流失重点治理区域研究

Study on key region of water and soil conservation in Ningbo

2016年宁波市城镇化率达71.1%,规划到2020年达75%以上。因此,“十三五”仍是宁波市城镇化进程的重要时期。城镇化进程中造成的水土流失将引发一系列生态环境问题。江河源头区、水源地和城镇重要生态屏障等生态敏感区域的水土流失籍此产生的面源污染将严重削弱水源涵养能力,威胁城镇供水安全和生态环境安全。城镇空间扩展对低丘缓坡的不合理开发利用造成的水土流失会严重制约城镇化的进程,威胁人居环境安全。一方面根据宁波市的自然环境特点和水土流失现状,考虑地形坡度及降水等影响水土流失的自然因素,另一方面根据区域水土保持生态服务功能的重要性,采用叠图分析法,综合考虑区域土地利用、生态安全、防洪安全、水源涵养与水质保护等制约宁波市城镇化进程的社会经济因素,确定四明山区、白溪水源地和天童-东钱湖区域为宁波市“十三五”期间水土流失重点治理区域。四明山区应严格控制花卉苗木种植规模,并划定禁止开发区、水源涵养林区和花卉经济林区,分别实施退耕还林,封山育林,建设水源涵养林,实施小流域综合治理等各项水土保持和生态修复措施。白溪水源地采取季节封禁和相应的育林技术措施治理疏林地、灌丛地、采伐迹地及荒山荒地。天童-东钱湖区域采取林草恢复等措施治理工矿用地和山体开挖裸露面、疏林地,并结合坡改梯、面源污染治理、生态湿地、人居环境整治等方式保护和恢复现有植被。

By 2016,the urbanization of Ningbo reached 71.1%,up to 75%by 2020."Thirteen-Five-Year-Plan"is also an important period for the urbanization of Ningbo.Soil erosion and water loss producing in the process of urbanization will trigger a series of ecological and environmental problems.Soil and water loss accompanies non-point source pollution in ecologically sensitive areas such as source region,ecological barrier of city and town and water source area would seriously undermines water conservation capacity,threatening urban water supply security and eco-environmental safety.Soil and water loss in the process of urban expansion caused by unreasonable development and utilization of low-slope hilly region would seriously restrict urbanization,threaten human settlements safety.On the one hand,based on the natural environment and current soil erosion in Ningbo,topography and precipitation are taken into account as natural factors which impact on soil and water loss;on the other hand,based on the importance of regional ecological function of water and soil conservation,land use,ecological safety,flood control security,water conservation and water quality protection are taken into account as Socio-economic factors which constrain urbanization of Ningbo.The author designates Simingshan,Baixi water source and Tiantong-Dongqian are key regions of water and soil conservation in Ningbo during the period of"Thirteen-Five-Year-Plan".In Simingshan region,the cultivation area of flowers and seedling should be strictly controlled,and areas prohibited to exploitation,water conservation forest and flowers and seedling should be delimited.returning farmland to forests,respectively,to facilitate afforestation,construction of water resource conservation forest,small watershed comprehensive control of soil and water conservation and ecological restoration measures.Measures of water and soil conservation and ecological restoration such as removal lands from cultivation for afforestation,fenced off for afforestation,cultivation of water conservation forest and comprehensive management of small watershed.In Baixi water source region,measure of seasonal closing hillside and cultivation technology for forest to rehabilitate open woodlands,shrubs lands,clear-cutting lands and bare lands should be took.In Tiantong-Dongqian region,measures of vegetation reconstruction should be taken to rehabilitate exposed surface of hills and open woodlands.To protect and rehabilitate existing vegetation,measures combined with changing slop into terrace,non-point source pollution control,ecological wetlands and habitat environmental improvement should be took.