Spatiotemporal variation and driving forces of reference evapotranspiration in Jing River Basin,northwest China   总被引：1，自引：0，他引：1       下载免费PDF全文

Lihong Xu  Zhongjie Shi  Shulan Zhang  Xinzheng Chu  Pengtao Yu  Wei Xiong  Haijun Zuo  Yunni Wang 《水文研究》2015,29(23):4846-4862

Evapotranspiration is an important component of the hydrological cycle, which integrates atmospheric demands and surface conditions. Research on spatial and temporal variations of reference evapotranspiration (ET_o) enables understanding of climate change and its effects on hydrological processes and water resources. In this study, ET_o was estimated by the FAO‐56 Penman–Monteith method in the Jing River Basin in China, based on daily data from 37 meteorological stations from 1960 to 2005. ET_o trends were detected by the Mann–Kendall test in annual, seasonal, and monthly timescales. Sensitivity coefficients were used to examine the contribution of important meteorological variables to ET_o. The influence of agricultural activities, especially irrigation on ET_o was also analyzed. We found that ET_o showed a decreasing trend in most of the basin in all seasons, except for autumn, which showed an increasing trend. Mean maximum temperature was generally the most sensitive parameter for ET_o, followed by relative humidity, solar radiation, mean minimum temperature, and wind speed. Wind speed was the most dominant factor for the declining trend in ET_o. The more significant decrease in ET_o for agricultural and irrigation stations was mainly because of the more significant decrease in wind speed and sunshine hours, a mitigation in climate warming, and more significant increase in relative humidity compared with natural stations and non‐irrigation stations. Changes in ET_o and the sensitivity coefficient of meteorological variables in relation to ET_o were also affected by topography. Better understanding of ET_o response to climate change will enable efficient use of agricultural production and water resources, which could improve the ecological environment in Jing River Basin. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

全球洋岛和洋底高原海山中的中酸性岩——数据挖掘及其意义   总被引：1，自引：0，他引：1       下载免费PDF全文

杨富成张 旗李文昌刘学龙陈万峰  余海军王帅帅 彦廷龙罗 云 《地质科学》2017,(4):1369-1387

洋岛类型的海山和洋底高原类型的海山主要由玄武岩组成, 中酸性岩出露很少, 因此很少引起学术界的关注。 我们认为即便中酸性岩很少, 研究他们也是很有意义的, 因为这些中酸性岩不仅可能与洋岛和洋底高原玄武岩的构造背景有关, 也可能与洋岛和洋底高原在形成中酸性岩时的温度和压力变化有关, 这对正确认识洋岛和洋底高原形成的地球动力学背景是很有意义的。 本次研究收集了 GEOROC 数据库中的数据总量为 44 404 个, 经过清洗留下有效数据 3 908 个, 分为洋岛中酸性岩（OIG）、洋底高原中酸性岩（OPG）和洋底高原中酸性岩中的岛弧部分（OPAG）3 类。 学术界通常认为, 洋岛代表热点, 洋底高原温度相对较低, 属于大火成岩省。 然而, 本文对全球洋岛和洋底高原的中酸性岩浆岩的研究表明, 分布在洋岛和洋底高原的中酸性岩主要是板内环境的富碱性的粗面岩和碱性流纹岩, 洋底高原边缘可能受俯冲带的影响, 部分中酸性岩具有岛弧的地球化学特征。 按照中酸性岩的 Sr-Yb 分类, 可知洋岛中酸性岩大多属于南岭型和广西型, 洋底高原海山中酸性岩主要属于南岭型, 广西型很少, 指示洋底高原中酸性岩形成的深度比洋岛浅, 温度也比洋岛低, 同时表明中酸性岩大多形成的压力较低而温度很高, 指示伴有高热中酸性岩的洋岛和洋底高原是地球上的热点。 本文认为, 洋岛和洋底高原中酸性岩并非学术界普遍认为的是玄武岩和碧玄岩分离结晶形成的, 因为洋岛和洋底高原岩浆岩如果是双峰式分布的话, 则不大可能是分离结晶的, 其中的酸性岩部分可能是玄武岩部分熔融形成的。 同时有些岩浆演化的关系表明, 中酸性岩在哈克图解中与玄武岩受不同因素制约, 说明并非演化的关系。  相似文献   

中国西北地区植被NDVI的时空变化及其影响因子分析   总被引：6，自引：0，他引：6  

戴声佩  张勃  王海军 《地球信息科学学报》2010,12(3):315-321

利用GIMMS/NDVI数据分析了中国西北地区1982-2006年植被NDVI时空变化特征及其影响因子。近25年来,中国西北地区年均植被NDVI增速为0.5%/10a,并存在明显的空间差异。天山、阿尔泰山、祁连山、青海的中东部等地区植被NDVI显著增加;青海南部地区、陕西和宁夏交界地区、甘肃部分地区,以及新疆部分地区的植被NDVI下降。从不同植被类型看:林地、草地和耕地的年均NDVI都在提高。研究表明:中国西北地区植被NDVI变化是各种自然和人为因素综合作用的结果。植被NDVI与气温、降水的年际变化整体上都呈弱的正相关。但与其年内变化则都呈显著的线性关系,当月均温量超过20℃时,植被NDVI呈下降趋势;当月降水量在0¹00mm期间,植被NDVI随降水线性增长,当月降水量超过100mm之后,不再有明显的增长趋势。农业生产水平提高和植被生态建设等人类活动对西北地区植被NDVI增加有重要影响。  相似文献   

Global Warming Potential in an Intensive Vegetable Cropping System as Affected by Crop Rotation and Nitrogen Rate   总被引：3，自引：0，他引：3       下载免费PDF全文

Ju Min  Kouping Lu  Haijun Sun  Longlong Xia  Hailin Zhang  Weiming Shi 《洁净——土壤、空气、水》2016,44(7):766-774

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祁连山黑河山区土地适宜性评价     

王海军  孔祥冬  张勃 《冰川冻土》2016,38(5):1440-1446

以黑河山区为研究区域,利用Logic回归模型和空间分析技术对山区土地利用进行适宜性评价.以2011年土地利用现状数据作为背景值,构建气温、降水、海拔、坡度、人口密度、水系、交通网、村镇分布8种因子的评价指标体系.采用多尺度训练的方法确定适宜性评价最佳模拟尺度,对土地利用数据和评价因子进行Logic回归分析,得到评价因子对土地利用适宜性的影响程度.利用Spatial Analyst模块对对黑河山区土地适宜性进行评价,为区域土地资源合理利用提供科学参考.结果表明：（1）适宜性评价最佳尺度为210 m（ROC=0.79）.（2）Logic回归结果显示,坡度、气温（β_Temp=1.11）、降水对林地、草地的影响程度较高,同时距道路距离、人口密度（β_Pop=-0.555）对其分布也有重要影响.（3）山区土地利用适宜性排序为：Max_林地=Max_耕地 > Max_建设用地 > Max_裸地 > Max_草地 > Max_水域,林地与耕地最高,适宜性达到0.99.  相似文献   

Regularity and formation mechanism of large-scale abrupt karst collapse in southern China in the first half of 2010   总被引：1，自引：0，他引：1  

Haijun Zhao  Fengshan Ma  Jie Guo 《Natural Hazards》2012,60(3):1037-1054

From winter 2009 to spring 2010, southern China suffered from an extensive and lengthy drought. Subsequently, southern China experienced torrential rains a dozen times during the flood season of April–June. The prolonged drought and subsequent intensive rainfall dramatically altered the hydrodynamic conditions of the karst areas, causing hundreds of widely distributed karst collapses, with extensive damage to houses and fields and necessitating the evacuation of many people. Understanding the causes of these collapses will provide a scientific basis for the prediction or prevention of the related risk. Thus, a geologic survey of karst collapses was performed that systematically allowed to analyze the basic geological conditions, groundwater hydrodynamic conditions, overlying strata properties, and environmental and climatic conditions in southern China. The results showed that environmental and climatic changes, especially the drastic changes in rainfall, gave rise to striking changes in karst hydrodynamic conditions that accelerated infiltration, suffosion, dissolution, and transportation rates and also changed the physical and mechanical properties of the strata overlying karst caves. These stressors triggered or facilitated both cave formation and collapse.  相似文献   

塔里木盆地巴楚隆起北缘阿恰基底卷入构造   总被引：1，自引：0，他引：1  

杨庚  李本亮  杨海军  陈竹新  王晓波  张朝军  雷永良 《地质论评》2012,58(1):32-40

塔里木盆地巴楚隆起为第四系不整合覆盖的古隆起,在其西北缘发育NW走向的阿恰断裂、萨拉姆布拉克背斜、向斜和隐伏的乔来麦提断裂。地震剖面和钻井资料显示,阿恰断裂为倾向南的基底卷入逆冲断裂,向北逆冲,错断层位从前寒武系基底一直到中寒武统膏岩,从西向东逆冲断距减少。乔来麦提断裂则以中寒武统膏岩为滑动面,向南逆冲,并在断层端部发育萨拉姆布拉克断层扩展褶皱。这两种类型构造样式的断裂(基底卷入断裂和盖层滑脱断裂),在剖面上组成典型的楔形构造几何形态,平面上形成三角形构造。遥感影像解译指出阿恰断裂和萨拉姆布拉克向斜向北西方向延伸进入柯坪逆冲带,并在该带有相应方向的地表构造显现,与北东走向的柯坪逆冲带组成叠加构造。生长地层分析确定基底卷入构造形成于始新世—中新世,而柯坪逆冲带形成于第四纪,明显晚于巴楚隆起形成时代。  相似文献   

中国西部叠合盆地油气藏形成、演化与分布预测     

庞雄奇  周新源  姜振学  王招明  李素梅  田军  向才富  杨海军  陈冬霞  杨文静  庞宏 《地质学报》2012,86(1):1-103

中国西部叠合盆地经历了多期构造变动和多旋回的油气成藏作用,研究叠合盆地油气藏的形成、演化和分布预测具有重要的意义。叠合盆地指不同时期形成的不同类型的沉积盆地或地层在同一地理位置上的叠加和复合,具有地层沉积不连续、地层构造不连续、地层应力应变作用不连续等三大标志性特征,依据构造剖面上地层年代的关联性,将叠合盆地分为五种类型,即连续沉积型叠合盆地、中晚期地层叠合盆地、早晚期地层叠合盆地、早中期地层叠合盆地、长期暴露型叠合盆地。叠合盆地普遍发育复杂油气藏,三种作用（剥蚀作用、断裂作用、褶皱作用）六种机制（渗漏、扩散、溢散、氧化、降解和裂解）形成复杂油气藏,依据成因特征分为五类,原成型油气藏,圈闭调整型油气藏,组分变异型油气藏,相态转换型油气藏,规模改造型油气藏。研究表明,复杂油气藏中天然气的地下产状特征和分布特征与地表产状特征和分布特征有很大差异。中国西部叠合盆地油气分布主要受烃源灶、古隆起、沉积相、断裂带、构造变动和区域盖层等六大因素的控制。其中烃源灶（S）、古隆起（M）、沉积相（D）和盖层（C）等四大要素控制着油气成藏的形成和分布,并建立了多要素匹配（T-CDMS）成藏模式,用以预测有利成藏领域。油气藏形成之后,多期的构造变动对早成的油气藏进行调整、改造和破坏,主要受构造变动强度、构造变动时间、构造变动次数、构造变动时盖层的封油气性能等四大要素控制,并以此建立了多期构造变动破坏油气藏后剩余潜力评价模型,利用这一模型可以预测出有利勘探区带并评价出有利勘探区带中的剩余资源潜力。油气藏经过改造,表现出晚期成藏效应,并受相势耦合作用的控制最后定位,利用晚期成藏效应和相势耦合理论可以预测有利勘探目标,并指出潜在有利勘探目标。  相似文献   

气候变化对山东降水及极端天气气候事件的影响分析   总被引：2，自引：0，他引：2  

张胜平  张鑫  王海军  向征  杜子龙 《水文》2011,(4):62-65

根据新中国成立以来山东省气温资料进行分析,从温度变化来反映山东气候变暖的趋势;在此基础上根据山东省近60年的水文资料分析气候变化对山东降水及极端天气气候事件的影响。结果表明,60年来山东气候呈变暖趋势,随着气候的变化,山东省年降水量呈减少的趋势,并导致极端天气气候事件出现频率及强度呈增大趋势。  相似文献   

Geochemistry of Palaeozoic marine petroleum from the Tarim Basin, NW China: Part 3. Thermal cracking of liquid hydrocarbons and gas washing as the major mechanisms for deep gas condensate accumulations   总被引：2，自引：0，他引：2  

Shuichang Zhang  Jin Su  Xiaomei Wang  Guangyou Zhu  Haijun YangKeyu Liu  Zhenxi Li 《Organic Geochemistry》2011,42(11):1394-1410

The Lunnan Lower Uplift in the Tarim Basin, NW China contains a composite petroleum system with mainly biodegraded heavy oil in the west, normal oil in the center and gas condensate in the east. Twenty-three gas samples and 37 oil samples taken from three major hydrocarbon bearing intervals in the Lunnan lower bulge were analyzed for their stable carbon isotopes and molecular biomarkers. On the basis of their isotopic compositions, biomarkers, especially diamondoids, and integrating the physical properties of the hydrocarbons including densities, GOR and PVT relationships, it has been concluded that the recently discovered deep (6500 m) eastern Lungu giant Ordovician gas condensate pool with an estimated reserve of 723 million bbl oil equivalent is a secondary hydrocarbon accumulation derived from the mixing of an early formed oil and a late formed gas. The extremely dry gases with a gas dryness of >0.98 were derived from thermal cracking of crude oils and charged to an existing oil reservoir causing extensive gas washing and secondary alteration. Compared with most of the hydrocarbons in the Lunnan area, the gas from the eastern Lungu gas condensate pool has a heavier carbon isotopic composition, higher dryness and a higher maturity level. The unique physical, chemical and isotopic compositions of the gas condensate are believed to be a direct result of gas flushing of an early formed eastern Lungu oil pool by a late formed dry gas from oil cracking. The eastern Lungu gas condensate pool is presently characterized by containing “dry gas, heavy oil, abundant aromatics and high wax”.  相似文献