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91.
A PCSWMM/GIS-based water balance model for the Reesor Creek watershed   总被引:1,自引:0,他引:1  
This paper presents the results of a study of a watershed experiencing the pressures of land-use change resulting from urban development. The study was undertaken to facilitate an understanding of the water balance of the watershed by developing and implementing watershed procedures that are to be addressed in a watershed plan. There were three components to the research: firstly, observation of the effects of spatially distributed rainfall measurements and their effect on modelling were assessed. Secondly, the model was then calibrated by observing how differing techniques can discretize both the landscape (e.g. land-use and soil type) and incoming precipitation. Finally, a modelling methodology was developed to integrate a Geographic Information System and a hydrologic model (e.g. Storm Water Management Model) in a water balance analysis on a watershed basis. Results show that, under certain conditions, kriging spatially distributed rainfall values can help predict rainfall at ungauged (virtual) sites. Discretization of a watershed was found to affect the differences between measured and generated runoff volumes; however, this can be refined with calibration. It was seen that a strong correlation between measured and predicted rainfall values did not always guarantee a strong relationship between measured and generated runoff Recommendations include the use of a longer time series of rainfall, streamflow and predicted rainfall to observe temporal variations, and the need to assess the differences in modelled rainfall values generated by various surface interpolation methods (e.g. Inverse Distance Weighting and other kriging options) currently available in GIS packages.  相似文献   
92.
A 3-year Mesoscale Convective Systems (MCSs) database, which extends from 2000 to 2002, has been built for the Iberian Peninsula and the Balearic Islands using the objective method MASCOTTE (MAximum Spatial COrrelation Technique). It was originally developed to track the evolution of convective systems over the Amazon region; after modifications, it is able to track MCS evolution even with an hour and a half of missed images and provides essential information of both dynamical and morphological characteristics of MCSs. MASCOTTE is tested against a visual and subjective method, and is found to offer advantages such as automation and a simple and efficient operation that make it very useful for building large MCS databases.Thirty-five MCSs were found between June and October, most of them originated along the Mediterranean coast and near the Pyrenees, showing an increasing occurrence from June to September, when the maximum is found. The regions most influenced by MCS occurrences are Balearic Islands, Valencia, Catalonia, Murcia and the Basque Country. The MCSs tend to be small, short-lived and linear, usually moving eastward or northeastward with low velocities.The MCSs-associated precipitation presents high variability, ranging from 80 to 0 mm h−1 as maximum hourly records. Two different convective regions are identified based on MCS behavior in extreme precipitation events: Northern Spain (the Basque Country) with abundant and continuous precipitation regime but little MCS influence, and the Mediterranean coast, where precipitation is sporadic but much more intense.  相似文献   
93.
镇旬盆地金矿成矿规律研究   总被引:3,自引:0,他引:3       下载免费PDF全文
文章总结了镇旬盆地金鸡岭复式向斜南北两带金矿的成矿条件、成矿规律、成矿模式、找矿标志,分析复式向斜南北两翼的成矿条件,认为运用北带的成矿规律、成矿模式、找矿标志可以指导在南带及其他地区微细浸染型金矿床的找矿工作.  相似文献   
94.
The groundwater in headwater region is an important recharge source for the adjacent mountain-front plain. In order to reveal the relationship among precipitation, soil water and groundwater, from June to September in 2004, stable isotopes (deuterium and oxygen-18) in precipitation and soil waters at the depths of 10, 20, 30, 50, 70, 90, and 110 cm were analyzed at two sites covered by black locust (Robinia Pseudoacia L.) (Site A) and grass predominated by Themeda triandra (T. japonica (Willd.) Tanaka) and Bothriochloa ischaemum (B. ischaemum (L.) Keng) (Site B) in an experimental catchment at Taihang Mt., North China, respectively. The δ18O of precipitation in daily rain events shows large variations (−13.3 to −4.3‰) with a mean of 8.1‰. The δ18O and δ D of soil waters along profiles in two sites suggest that the influence of canopy cover was just up to 10 cm in top soil water. The soil water moved over the zero flux plane at 70 cm in-depth is expected to escape the evaporative effect at the end of September in both sites. The results show that the stable isotope, instead of tritium as tradition, can be used to trace the soil water behaviors based on the movement of isotopic peak along the vertical profiles in this semi-arid and semi-humid mountainous region. The infiltration depths of soil water in Taihang Mt. are 12 and 10 mm/day from June to September in 2004 in Site A and Site B, respectively. Tracing by stable isotope, recharge fluxes of soil water to local groundwater are of 3.8 and 3.2 mm/day in Site A and Site B, respectively. The results provide desirable information for assessment of local groundwater resources. An erratum to this article can be found at  相似文献   
95.
The stable isotopes of oxygen and hydrogen were used to determine the seasonal contributions of precipitation to groundwater recharge at a forested catchment area in the upper North Han River basin, Korea. A comparison of the stable isotopic signatures of groundwater and precipitation indicates that the precipitations which occurred during both the dry and rainy seasons are the important source of groundwater recharge in this region. A stable isotopic signature shown in the stream waters at the upstream reaches is similar to that of groundwaters, indicating that stream waters are mostly fed by groundwater discharge. Reservoir waters in the downstream flood control dams have lower deuterium excess values or d-values compared with those of the upstream waters, indicating a secondary evaporative enrichment. These results can provide a basis for the effective management of groundwater and stream water resources in the North Han River basin.  相似文献   
96.
河南商城鲢鱼尖变形花岗岩岩体的地质、地球化学特征、成因及含矿性研究表明,岩体具有贫SiO2、K2O,富Al2O3、TiO2、CaO、MgO、Fe2O3+FeO之特征,Na2O+K2O为7.65%~8.84%。K2O/Na2O为0.66~0.9;分异指数(Dr)为71.2~80.7,ASI值为0.81~0.98,氧化指数(OX)为0.55~0.32,8值为3.1~4.05,为准铝质钙碱性岩石系列。在An—Ab—Or图解及R1-R2多阳离子图解上多落于花岗闪长岩一二长花岗岩区,为斑状二长花岗岩-斑状花岗闪长岩。岩体与围岩接触带上可形成Cu、Pb、Zn、Ag、Mo多金属矿(床)。  相似文献   
97.
Aerosols can affect the cloud-radiation feedback and the precipitation over the Indian monsoon region. In this paper, we propose that another pathway by which aerosols can modulate the multi-scale aspect of Indian monsoons is by altering the land–atmosphere interactions. The nonlinear feedbacks due to aerosol/diffuse radiation on coupled interactions over the Indian monsoon region are studied by: (1) reviewing recent field measurements and modeling studies, (2) analyzing the MODIS and AERONET aerosol optical depth datasets, and (3) diagnosing the results from sensitivity experiments using a mesoscale modeling system. The results of this study suggest that the large magnitude of aerosol loading and its impact on land–atmosphere interactions can significantly influence the mesoscale monsoonal characteristics in the Indo-Ganges Basin.  相似文献   
98.
文中分析了庆阳地区春季降水气候特征和环流形势 ,用 1995~ 1998年 3~ 5月T10 6资料建立了该区 8县 (市 )春季降水、温度MOS预报方程 ,进行了回代检验和试报 ,并提出了模式更换后的处理方法  相似文献   
99.
利用1961~2000年雷州半岛5个气象站的月平均降水量、平均最高、最低气温等资料,对雷州半岛40年和近10年的变化作了较为全面的分析。  相似文献   
100.
秦长学 《气象》2001,27(7):20-23
对用液氮消过冷雾和冷云催化增雨作业的宏、微观条件进行比较,找出其异同点,并根据消冷雾作业所出现的物理响应推演冷云催化后应出现的结果,以弥补飞机云中催化后缺少直接观测资料的缺陷,进而对液氮(LN)增雨效果进行探讨。  相似文献   
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