• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of the American Water Resources Association >APPLICATION OF A MULTIPURPOSE UNEQUAL PROBABILITY STREAM SURVEY IN THE MID-ATLANTIC COASTAL PLAIN
【24h】

APPLICATION OF A MULTIPURPOSE UNEQUAL PROBABILITY STREAM SURVEY IN THE MID-ATLANTIC COASTAL PLAIN

机译：多用途不等概率流调查在中大西洋沿海平原中的应用

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

A stratified, spatially balanced sample with unequal probability selection was used to design a multipurpose survey of headwater streams in the Mid-Atlantic Coastal Plain. Objectives for the survey include unbiased estimates of regional stream conditions, and adequate coverage of unusual but significant environmental settings to support empirical modeling of the factors affecting those conditions. The design and field application of the survey are discussed in light of these multiple objectives. A probability (random) sample of 175 first-order nontidal streams was selected for synoptic sampling of water chemistry and benthic and riparian ecology during late winter and spring 2000. Twenty-five streams were selected within each of seven hydrogeologic subre-gions (strata) that were delineated on the basis of physiography and surficial geology. In each subregion, unequal inclusion probabilities were used to provide an approximately even distribution of streams along a gradient of forested to developed (agricultural or urban) land in the contributing watershed. Alternate streams were also selected. Alternates were included in groups of five in each subregion when field reconnaissance demonstrated that primary streams were inaccessible or otherwise unusable. Despite the rejection and replacement of a considerable number of primary streams during reconnaissance (up to 40 percent in one subregion), the desired land use distribution was maintained within each hydrogeologic subregion without sacrificing the probabilistic design.
机译：采用分层的，空间平衡的，具有不等概率选择的样本来设计大西洋中部沿海平原上游水流的多用途调查。调查的目标包括对区域河流状况的无偏估计，以及对异常但重要的环境设置的足够覆盖，以支持对影响这些状况的因素进行经验建模。鉴于这些多个目标，对调查的设计和现场应用进行了讨论。在2000年冬末和春季期间，选择了175个一级非潮汐流的概率（随机）样本用于水化学，底栖和河岸生态学的天气学抽样。在七个水文地质分区（地层）中的每一个中选择了25个水流。根据生理学和表面地质学来描述。在每个次区域中，不平等的包含概率被用来在贡献流域内沿着森林到发达（农业或城市）土地的梯度提供溪流的近似均匀分布。还选择了备用流。当野外侦查表明主要水流无法通行或无法使用时，每个分区的替代物被分为五个小组。尽管在侦察期间拒绝并替换了大量的主要河流（在一个分区中高达40％），但在每个水文地质分区内仍保持了所需的土地利用分布，而没有牺牲概率设计。

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