• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Transactions in GIS: TG >Analysis of Patterns in Diadromous Fish Distributions Using GIS
【24h】

Analysis of Patterns in Diadromous Fish Distributions Using GIS

机译：基于GIS的鱼类分布规律的分析。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Understanding the factors limiting migratory behaviour is fundamental to conservation of diadromous fish. Applications of indices of habitat suitability are problematic for diadromous fish because fish presence and abundance in relation to habitat quality are confounded by barriers to fish migration. An alternative approach is to assess diadromous fish distributions in proportion to distance inland and altitude above mean sea level, and subsequently generate trajectories for the various species. This approach, however, may be problematic. We show that river distance inland and elevation are only weakly correlated in our study area. Thus, in areas where steep slopes are not encountered, fish migrations to significant elevations and inland distances can be expected. In other areas, coastal cliffs and geologic fault lines provide for steep stream gradients close to the sea, and fish do not migrate far inland. To solve this issue, we developed methods for improving species trajectory approaches to explain the distribution of diadromous fish using a GIS. We adjusted distance and altitude categories so that each stratum was represented by the same number of site records, with flexible intervals for each stratum. For species capable of forming land-locked populations we manipulated input values for elevation and river distance inland to account for migrations from lakes, rather than sea. Additionally, a new GIS derived variable was introduced to better explain the distribution of diadromous fish; the maximum stream slope a fish would encounter during upstream migration. This new slope variable, independent of distance inland and elevation, is likely to be a better predictor of migratory fish occurrences than elevation above mean sea level, as the different species will have different slope-thresholds that they can overcome.
机译：了解限制迁徙行为的因素是保护缺水鱼类的基础。栖息地适应性指数的应用对于缺水鱼类是有问题的，因为鱼类的存在和丰富度与栖息地质量有关，这与鱼类迁移的障碍相混淆。一种替代方法是根据距内陆的距离和平均海平面以上的海拔高度来评估过缺鱼类的分布，然后生成各种物种的轨迹。但是，这种方法可能会出现问题。我们表明，在我们的研究区域内河的距离与内陆和海拔高度之间的关系很小。因此，在没有遇到陡坡的地区，可以预期鱼类会迁移到明显的高度和内陆距离。在其他地区，沿海峭壁和地质断层线在靠近海的地方提供陡峭的溪流坡度，鱼类不会向内陆迁移。为解决此问题，我们开发了改进物种轨迹方法的方法，以使用GIS解释过鳍鱼类的分布。我们调整了距离和高度类别，以使每个阶层由相同数量的站点记录表示，每个阶层的间隔都灵活。对于能够形成内陆种群的物种，我们操纵了内陆海拔和河流距离的输入值，以说明从湖泊而非海洋的迁移。此外，引入了新的GIS衍生变量，以更好地解释过水鱼类的分布;鱼在上游迁移过程中会遇到的最大溪流坡度。与不同的内陆距离和海拔无关，这种新的坡度变量可能比在平均海平面以上的海拔高度更好地预测移徙鱼类的发生，因为不同物种的坡度阈值可以克服。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号