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481.
Research Status and Prospect of the Subsurface Hydrology and Ecological Effect in Arid Regions 总被引:1,自引:1,他引:1
Centering on the scientific problems faced by subsurface hydrology in arid regions and ecological effect, the urgency of national ecological civilization and the Belt and Road construction towards the research of groundwater discipline, this article analyzed the formation and evolution mechanisms of groundwater and studied the groundwater function of arid regions. Based on the analysis and research, this article discussed domestic and overseas research status, existing problems and developing trend from six aspects, raised key and scientific problems which urgently need to be addressed, aiming at the existing bottlenecks of subsurface hydrology and ecological effect in arid regions and national requirement, so as to make some contribution to the innovative development of China’s groundwater science and national economic construction. 相似文献
482.
Stream temperature (Ts) is a key water quality parameter that controls several biological, ecological, and chemical processes in aquatic systems. In forested headwaters, exchanges of energy across air-water-streambed interfaces may influence Ts regimes, especially during storm events as the sources of runoff change over space and time. Analysis of the hysteretic behaviour of Ts during storm events may provide insights into rainfall-runoff responses, but such relationships have not been thoroughly investigated. As such, our objectives were to (a) quantify the variability of stream temperature hysteresis across seasons in different sub-regions and (b) investigate the relationship between the hysteretic response and catchment characteristics. Ts hysteresis during storm events was assessed based on the hysteresis index (HI), which describes the directionality of hysteresis loops, and the temperature response index (TRI), which indicates whether Ts increased or decreased during a storm event. We analysed Ts data from 10 forested headwater reaches in two sub-regions (McGarvey and West Fork Tectah) in Northern California. We also performed a clustering analysis to examine the relationship amongst HI, TRI, topographic metrics, and meteorological characteristics of the study areas. Overall, the hysteretic behaviour of Ts varied across seasons—the greatest HI occurred during spring and summer. Interestingly, in the McGarvey streams the variability in Ts hysteresis co-varied strongly with topographic metrics (i.e., upslope accumulative area, average channel slope, topographic wetness index). Comparatively, in West Fork Tectah the variability of Ts hysteresis co-varied most strongly with meteorological metrics (i.e., antecedent rainfall events, solar radiation, and air temperature). Variables such as the gradient between stream and air temperatures, slope, and wetted width were significant for both sub-regional hysteretic patterns. We posit that the drivers of Ts response during storms are likely dependent on catchment physiographic characteristics. Our study also illustrated the potential utility of stream temperature as a tracer for improving the understanding of hydrologic connectivity and shifts in the dominant runoff contributions to streamflow during storm events. 相似文献