基于水环境保护的流域景观格局 优化理念初探

流域范围内因水体的联系使得不同类型景观斑块之间的相互作用变得更为紧密, 因而景 观格局的变化会显著影响流域内水体质量。着眼于流域尺度上水环境保护的需要, 必须合理考虑 景观斑块的类型、格局和空间分异等特征, 尽可能地减少非点源污染输出量, 从而降低水体遭受 污染的威胁程度。本研究从水环境保护的角度出发, 以“源”“汇”景观在镶嵌组合和空间分异方面 利用的适宜性作为优化依据, 以“源”“汇”景观空间分布的关键地段作为研究战略点, 同时考虑 “源”“汇”景观在数量、空间和转换成本等方面的客观约束条件, 将景观数量结构优化和空间结构 优化进行有机结合, 最终确定了流域尺度上以调控非点源污染、保护水体质量为目标的景观格局 优化研究的概念框架。本研究不仅为解决流域尺度上非点源污染问题提供了一个全新的研究视 角, 而且为降低景观类型及其格局对水体质量的威胁程度提供了一个行之有效的优化方案。

The Conceptual Fr amework of Water shed Landscape Optimization Concerning Water Environmental Protection

Landscape pattern, function and process all have close relationship with certain scale. Watershed with clear boundary and special scale and character becomes a focus region in studying landscape ecological process. For the collection of water by the gravitation at the watershed scale, the change of landscape pattern will heavily influence the water quality. Because the change of landscape pattern will dramatically influence the non-point pollution, it is necessary to control the non-point pollution from the perspective of landscape optimization. Considering the needs of water environmental protection at watershed scale, it is necessary to study how the type, pattern and spatial difference of landscape influence water pollution process. By reasonable allocation and complex design of landscape pattern, optimal landscape will change the distribution characteristics of pollution and stop the diffusion of pollution at spatial space. This will do good to water environmental protection and non-point pollution decrease. In order to realize this target, this paper constructs a conceptual framework for landscape pattern optimization concerning water environmental protection. This framework mainly considers four aspects as follows:(1) the feasible usage of 'Source' and 'Sink' landscape with spatial differences as optimization rules; (2) the key points in 'Source' and 'Sink' landscape pattern optimization; (3) some limits such as quantity, cost and other things that influence the change of 'Source' and 'Sink' landscape; and (4) the combination of the landscape quantity optimization with the landscape spacial optimization. On the basis of these results, this paper fulfills a conceptual framework of landscape optimization concerning the water environmental protection and non-point pollution decrease. According to an optimal combination of these four aspects, we could analyze the studying area characteristics, clear studying aims, confine optimal rules and carry out the research step by step. With some controlling methods of landscape ecology optimization, the landscape pattern optimization and water protection will be also realized. This study supplies not only a new view for resolving non-point pollution problem at watershed scale, but also a valid measure for decreasing the influence of landscape type and pattern on water quality.