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991.
Quang A. Phung Allen L. Thompson Claire Baffaut Christine Costello E. John Sadler Bohumil M. Svoma Anthony Lupo Sagar Gautam 《Journal of the American Water Resources Association》2019,55(5):1196-1215
Anticipating changes in hydrologic variables is essential for making socioeconomic water resource decisions. This study aims to assess the potential impact of land use and climate change on the hydrologic processes of a primarily rain‐fed, agriculturally based watershed in Missouri. A detailed evaluation was performed using the Soil and Water Assessment Tool for the near future (2020–2039) and mid‐century (2040–2059). Land use scenarios were mapped using the Conversion of Land Use and its Effects model. Ensemble results, based on 19 climate models, indicated a temperature increase of about 1.0°C in near future and 2.0°C in mid‐century. Combined climate and land use change scenarios showed distinct annual and seasonal hydrologic variations. Annual precipitation was projected to increase from 6% to 7%, which resulted in 14% more spring days with soil water content equal to or exceeding field capacity in mid‐century. However, summer precipitation was projected to decrease, a critical factor for crop growth. Higher temperatures led to increased potential evapotranspiration during the growing season. Combined with changes in precipitation patterns, this resulted in an increased need for irrigation by 38 mm representing a 10% increase in total irrigation water use. Analysis from multiple land use scenarios indicated converting agriculture to forest land can potentially mitigate the effects of climate change on streamflow, thus ensuring future water availability. 相似文献
992.
The potential impacts driven by climate variability and urbanization in the Boise River Watershed (BRW), located in southwestern Idaho, are evaluated. The outcomes from Global Circulation Models (GCMs) and land use and land cover (LULC) analysis have been incorporated into a hydrological and environmental modeling framework to characterize how climate variability and urbanization can affect the local hydrology and environment at the BRW. The combined impacts of future climate and LULC change are also evaluated relative to the historical baseline conditions. For modeling exercises, Hydrological Simulation Program‐Fortran (HSPF) is used in parallel computing and statistical techniques, including spatial downscaling and bias correlation, are employed to evaluate climate consequences derived from GCMs as well. The implications of climate variability and land use change driven by urbanization are then observed to evaluate how these overall global challenges can affect water quantity and quality conditions at the BRW. The results show the combined impacts of both climate change and urbanization can lead to more seasonal variability of streamflow (from ?27.5% to 12.5%) and water quality, including sediment (from ?36.5% to 49.3%), nitrogen (from ?24% to 124.2%), and phosphorus (from ?13.3% to 21.2%) during summer and early fall over the next several decades. 相似文献
993.
Chen Lin 《International Journal of Green Energy》2019,16(2):185-199
To study the effects of the tectonic stress environment on the tectonophysical features of deformed coal, No.8 Mine in the Pingdingshan mine area is used as a study area and the relationship between the development of deformed coal, distribution of fractures, formation of deformed coal and tectonic stress environment are analyzed. The results indicate that the thickness of the bedrock layer should be included in the analysis of the tectonic stress environment for a region of intense tectonic activity. Although the reverse faulting stress regime can control the development of deformed coal, the C seam is extremely sensitive to the stress regime. The most advantageous direction of the deformed coal fractures is consistent with the regional maximum principal stress, and the development of fractures is closely related to the evolution of the tectonic stress environment. The fracture density of the E seam presents a uniform distribution, yet that of the C seam is completely heterogeneous. Superposition and compounding of the tectonic communities evidently increase the fracture density of the deformed coal. There is a relatively apparent boundary between the different types of deformation, which gradually transform from brittle to ductile with a decreasing lateral pressure coefficient. A generalized deformation pattern of the deformed coal is proposed and can be divided into frictional sliding and solid flow. 相似文献
994.
995.
2014年通过的《环境保护法》第31条规定:国家建立、健全生态保护补偿制度.紧随其后,2014年5月苏州市人大常委会正式批准了《苏州市生态补偿条例》,彰显了国家和地方政府对于生态补偿这一法律制度的重视.农业生态补偿作为生态补偿的一个具体分支,法律制度的建设,将对当前中国日趋严重的农业面源污染问题,提供一个现实的解决路径.文中找出农业生态补偿法律制度存在的问题,并提出具体的建设意见,为中国农业生态补偿法律制度的建设提供理论上的支撑. 相似文献
996.
中国西南喀斯特森林土壤有机碳空间变化及影响因素 总被引:4,自引:0,他引:4
喀斯特地区土壤碳储量及其影响因素的认识是评估我国陆地土壤生态系统碳汇能力不可或缺的内容。本文通过对中国西南北起秦岭北坡南至中越边境一条剖面上土壤有机碳的分析,研究了喀斯特森林0~10cm土壤有机碳空间变化及其控制因素。研究发现西南地区土壤有机碳含量和碳密度平均为32.3 g/kg和33.1t/hm2。无论是在整个西南区还是其省市范围内,二者均低于非喀斯特森林土壤。通径分析表明,影响喀斯特表层土壤碳含量和密度的主要因素有土壤容重、地形海拔和有机质C/N;粘粒含量和年平均气温的影响很小,而降水量仅在地处最北部的陕西省构成了土壤碳密度的影响因素。此现象与世界许多地区特别是高纬度地区形成鲜明对比。本研究结果表明,不同区域/气候带土壤碳库的主要影响因素会存在很大差异,这对认识气候变化背景下土壤碳库的反馈作用具有重要意义。 相似文献
997.
石英灯辐射式瞬态热环境试验关键技术分析 总被引:4,自引:4,他引:0
结合石英灯辐射式加热器的特性,从传感器弱信号传输、无功补偿、智能控制、仿形加热器、开环试验技术等角度出发,分析了对型号瞬态热试验性能的影响。结合瞬态热试验的实施,给出了上述几个角度制约热试验实施的改进措施,以期提高试验系统瞬态热试验的有效性。 相似文献
998.
资源环境综合绩效评估是建设节约型社会的一项基础工作.在传统的资源环境综合绩效指数中,各种资源消耗和污染物排放绩效的权重相等,导致综合评价结果的合理性受到影响.针对该问题,通过构建投影指标函数和采用遗传算法对投影方向进行优化,提出了基于投影寻踪的资源环境综合绩效评估方法,并应用于2007年中国各省、直辖市和自治区的资源环境绩效评估.研究结果表明,中国资源环境绩效水平空间差异明显,呈现东部高西部低的特征,因此必须合理调整西部地区的经济结构,提高资源利用效率和加强环境保护,实现可持续发展.该方法的权重取值较为客观和科学,评估结果合理,值得推广应用. 相似文献
999.
1000.
作为核燃料循环过程中一种兼具辐射危害和化学毒性的中间产物,UF6的泄漏事故,特别是事故的环境评价技术越来越受到人们的重视.SAFUIT/UF6是专门针对此类事故的环境评价模型,目前已经开展了初步的验证工作.根据1987年法国UF6释放实验条件,对SAFUIT/UF6模型计算结果进行了误差分析,并与HG-SYSTEM/UF6模型进行了对比.初步认为SAFUIT/UF6模型可准确地模拟UF6扩散.此外,SAFUIT/UF6模型在某设施核事故应急评价系统中也得到了应用. 相似文献