Geospatial files associated with the delineation and characterization of surface-moisture zones in the vicinity of mapped springs in Harney County, Oregon, 2017

This data collection includes spatial and tabular datasets related to the delineation and characterization of surface moisture zones (SMZs) in the vicinity of springs mapped in the National Hydrography Dataset (NHD) in southeastern Oregon using time-series analysis of Normalized Difference Vegetation Index (NDVI) data derived from Landsat Thematic Mapper 5 imagery from 1985-2011. The study area is within and adjacent to the Steens Mountain Cooperative Management and Protection Area (CMPA), which is a protected area of approximately 1,732 km2 managed by the Bureau of Land Management (BLM) in Harney County, Oregon. Within or adjacent to the Steens Mountain CMPA, approximately 1,100 springs are mapped in the NHD, however very little hydrologic data exists for these springs. Data in this data release were produced using a set of scripts written in the R programming language, which are also included in this data release (see ‘larger works citation’ to access R scripts and associated metadata). These data processing scripts, data products, and associated metadata provide documentation for a novel remote-sensing based approach to assess the potential resilience of spring-dependent ecosystems to inter-annual changes in water availability. This approach uses time-series analysis of NDVI to (1) delineate SMZs in the vicinity of mapped springs in a semi-arid sage-steppe landscape, (2) derive quantitative indicators of the relative resilience of these SMZs to inter-annual changes in water availability, and (3) synthesize these indicators into an overall resilience score for each cluster of springs. Specifically, for 39 spring clusters in Harney County, Oregon, USA, these scripts process Landsat-derived NDVI and precipitation data from 1985-2011 to derive 7 potential indicators of SMZ resilience to water-cycle changes. For detailed information on the resilience indicators, including their conceptual basis, methods of calculation, and interpretation, see Cartwright and Johnson (2018) and the R scripts and their associated metadata in this data release. References: Cartwright and Johnson (2018), Springs as hydrologic refugia in a changing climate? A remote sensing approach. Ecosphere X(X).

本数据集涵盖与俄勒冈州东南部国家水文数据集（National Hydrography Dataset, NHD）内已测绘泉水周边地表湿度带（surface moisture zones, SMZs）的圈定及特征表征相关的空间与表格数据集，相关数据基于1985-2011年陆地卫星5号专题制图仪（Landsat Thematic Mapper 5）影像提取的归一化植被指数（Normalized Difference Vegetation Index, NDVI）数据，通过时间序列分析生成。
研究区域位于斯蒂恩山联合管理与保护区（Steens Mountain Cooperative Management and Protection Area, CMPA）范围内及其周边，该保护区占地约1732平方千米，由俄勒冈州哈尼县土地管理局（Bureau of Land Management, BLM）负责管理。国家水文数据集（NHD）在此保护区及周边区域共测绘了约1100处泉水，但相关泉水的水文数据极为匮乏。
本次数据发布中的数据集由一套基于R编程语言（R programming language）编写的脚本生成，相关脚本亦包含于本数据发布包中（请参阅“关联成果引用”部分以获取R脚本及配套元数据）。这些数据处理脚本、数据产品及关联元数据，为基于新型遥感方法评估依赖泉水的生态系统对水资源可利用量年际变化的潜在恢复力提供了完整文档支撑。该方法通过NDVI时间序列分析完成三项核心任务：（1）在半干旱蒿灌草原景观中圈定已测绘泉水周边的地表湿度带（SMZs）；（2）推导这些SMZs应对水资源可利用量年际变化的相对恢复力定量指标；（3）将各指标整合为每处泉水集群的综合恢复力评分。
具体而言，针对美国俄勒冈州哈尼县的39处泉水集群，上述脚本处理了1985-2011年的陆地卫星NDVI数据与降水数据，最终推导出7项用于表征SMZs应对水循环变化潜在恢复力的指标。关于恢复力指标的详细信息，包括其理论基础、计算方法与解译规则，请参见Cartwright与Johnson（2018）的研究成果，以及本数据发布包中的R脚本及其关联元数据。
参考文献：Cartwright和Johnson（2018），《气候变化背景下作为水文避难所的泉水？一种遥感方法》，Ecosphere X(X).