广州市饮用水源保护地土地利用格局与水安全

Relationship between Land Use Pattern and Water Security of Drinking Water Conservation Areas in Guangzhou

水源保护与饮用水安全是城市发展的必要条件,划定饮用水源地保护区和规范人们的生产与生活方式是保证饮用水安全的重要举措。基于3S技术,本文对广州市饮用水源地保护区的土地利用结构、空间配置及其与饮用水安全的关系进行探讨。主要结论为:①广州市饮用水源地保护区在一定程度上保证了饮用水安全,但仍存在滞后与跨区协调等问题;②二级保护区和准保护区内土地利用数量结构不一,前者建设用地面积最大,耕地次之,后者正好相反,暗示不同区域采取水质保护措施时,应关注不同的污染源;③景观格局特征显示,各保护区土地利用的特征或者特征某一方面不同,如凝聚度和分维数指数的差异较小,多样性和破碎度则正好相反。结果还表明,已有的保护区内仍有较强烈的人为活动。

Water conservation and drinking water safty are the prerequisite and basis for urban development. Both delimitation of dringking water conservation areas and rationalization of people ＇ s mode of life and production are important measures to guarantee regional water quality and drinking water security. Based on TM images, historical environmental data for water quality, and 3S technology, a preliminary study is performed to discuss land use quantity and spatial allocation of water conservation area and its relationship with dringking water safly. This can help us understand the importance of conserving ecological elements around water sources. The main conclusions we reached are： 1） Nowadays, with rapid urban expansion, water security should be ensured by a new appropriate conservation area, but the new area planned lags behind practical requirements, and there is an obvious insufficiency of limiting human activities in that area of Guangzhou. Besides, coordination between two regions also limits the effectiveness of conservation area of water supply; 2）The quantitative structures of land use in secondary conservation area and prearrangement area are different. In secondary conservation area, construction land area takes the biggest proportion of land use and cultivated land takes the second place while the area structures of the two types of land use in the prearrangement zone are just reverse. It means that when we take measures to protect water quality for the two different areas, we should concern about different pollution sources ; 3 ） The characteristics of landscape of land use show that land use patterns are difference in various areas. The differences between indices of FRAC MN and COHESION are small, but appear quite significant between the indices of SHDI and PD. The characteristic variation of batch shapes was small, but the characteristic difference of landscape fragmentation was significant. What is more, these above results also reveal that human activities in the conversation areas are still intense. Therefore, it is absolutely necessary and important to take measures to protect water source areas and water quality, so that urban ecological security can be guaranteed.