Sub-Daily Temperature Heterogeneity in a Side Channel and the Influence on Habitat Suitability of Freshwater Fish
Sub-Daily Temperature Heterogeneity in a Side Channel and the Influence on Habitat Suitability of Freshwater Fish
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DOI：
10.3390/rs11202367
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发表时间：
2019-10-01
期刊：
影响因子：
5
通讯作者：
Leuven, Rob S. E. W.
中科院分区：
文献类型：
--
作者：
Collas, Frank P. L.;van Iersel, Wimala K.;Leuven, Rob S. E. W.
河流系统地表水温度的上升日益对河流生态系统的生物多样性产生不利影响，预计物种耐热水平的更频繁变化将使当地物种组合减少。可靠的预测水温升高对栖息地适宜性的影响，需要详细的温度测量随着时间的推移。我们评估了（1）使用安装在无人驾驶飞行器（UAV）上的消费级热成像仪获得的河流漫滩侧槽水温高分辨率图像的准确性，以及（2）本地和外来鱼类组合的相关栖息地适宜性。在整个炎热的夏天，水表面温度被映射了四次，并使用线性回归在水面以下0.1米的水中用24个原位温度记录仪进行校准。校准的热成像被用来计算潜在发生的分数（POF）的淡水鱼物种敏感性分布。我们发现中午时侧沟的高温（25-30摄氏度）导致栖息地适宜性降低。在所有飞行中，基于RMSE的水温估计的准确度为0.53摄氏度（R-2 = 0.94）。平均每日POF为0.51和0.64本地和外来鱼类在侧通道。POF估计的误差是76%，当水温估计与热无人机图像相比，在上游测量站测得的温度。准确地量化水温及其异质性是河流生态系统适应气候变化的关键步骤。我们的研究结果表明，地表水温的测量可以准确和容易地使用热图像从无人机允许改善栖息地管理，但同时收集长波辐射需要一个更物理为基础的水温预测。由于气候变化，河流生态系统的管理应考虑热污染控制，并促进冷水避难所和洪泛区水体与夏季酷热期间鱼类洄游的较冷主航道之间的连通。
Rising surface water temperatures in fluvial systems increasingly affect biodiversity negatively in riverine ecosystems, and a more frequent exceedance of thermal tolerance levels of species is expected to impoverish local species assemblages. Reliable prediction of the effect of increasing water temperature on habitat suitability requires detailed temperature measurements over time. We assessed (1) the accuracy of high-resolution images of water temperature of a side channel in a river floodplain acquired using a consumer-grade thermal camera mounted on an unmanned airborne vehicle (UAV), and (2) the associated habitat suitability for native and alien fish assemblages. Water surface temperatures were mapped four times throughout a hot summer day and calibrated with 24 in-situ temperature loggers in the water at 0.1 m below the surface using linear regression. The calibrated thermal imagery was used to calculate the potentially occurring fraction (POF) of freshwater fish using species sensitivity distributions. We found high temperatures (25-30 degrees C) in the side channel during mid-day resulting in reduced habitat suitability. The accuracy of water temperature estimates based on the RMSE was 0.53 degrees C over all flights (R-2 = 0.94). Average daily POF was 0.51 and 0.64 for native and alien fish species in the side channel. The error of the POF estimates is 76% lower when water temperature is estimated with thermal UAV imagery compared to temperatures measured at an upstream gauging station. Accurately quantifying water temperature and the heterogeneity thereof is a critical step in adaptation of riverine ecosystems to climate change. Our results show that measurements of surface water temperature can be made accurately and easily using thermal imagery from UAVs allowing for an improved habitat management, but coincident collection of long wave radiation is needed for a more physically-based prediction of water temperature. Because of climate change, management of riverine ecosystems should consider thermal pollution control and facilitate cold water refugia and connectivity between waterbodies in floodplains and the cooler main channel for fish migration during extremely hot summer periods.