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Validation of Satellite-Based PERSIANN Rainfall Estimates Using Surface-Based APHRODITE Data over Iran
Issue:
Volume 4, Issue 5, October 2015
Pages:
150-160
Received:
6 May 2015
Accepted:
18 May 2015
Published:
6 September 2015
Abstract: Surface-based precipitation measurements with high accuracy on different spatial-temporal scales have a crucial importance in different land-use planning sectors, especially in arid and semi-arid regions, such as Iran. Because the density of spatial distribution of rain-gauges is not uniform throughout the country, satellite sensor technology is considered useful for precipitation monitoring over the study area. In this study, PERSIANN satellite-based rainfall data were validated through comparison with the APHRODITE surface-based precipitation data. The validation was carried out for annual and seasonal precipitation, as well as an inter-annual comparison. Our analysis was based on a visual comparison and a statistical approach, including linear regression and spatial correlation between APHRODITE and PERSIANN datasets for each 0.25°×0.25° grid cell in the entire country, in the Caspian Sea region, and in the Zagros Mountains, indicating spatial correlation coefficients of 0.62, 0.62, 0.47, respectively. Both APHRODITE data and PERSIANN data showed that spatial distribution of mean annual and seasonal precipitation over Iran has two main patterns: along the Caspian Sea and along the Zagros Mountain chain. In general, PERSIANN underestimates high rainfall rates by 5.5 mm/day in winter but overestimates the low rainfalls in annual and seasonal scales by 0.9 mm/day in summer.
Abstract: Surface-based precipitation measurements with high accuracy on different spatial-temporal scales have a crucial importance in different land-use planning sectors, especially in arid and semi-arid regions, such as Iran. Because the density of spatial distribution of rain-gauges is not uniform throughout the country, satellite sensor technology is co...
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Geophysical and Geochemical Signature of Rare Metal Granites, Central Eastern Desert, Egypt: Implications for Tectonic Environment
Ibrahim M. Gaafar,
Khaled G. Ali
Issue:
Volume 4, Issue 5, October 2015
Pages:
161-179
Received:
8 June 2015
Accepted:
4 July 2015
Published:
22 September 2015
Abstract: Magnetic survey is usually used to delineate magnetic-structural lineaments, analyze their relationships to the inherited ductile fabrics and estimate the depth of perturbing body sources, probably granitic intrusions. These were conducted on the total magnetic intensity reduced to the pole map as well as First vertical derivative and Euler deconvolution maps to show various aeromagnetic structural lineaments which were interpreted as fault systems on the interpretation maps. The early deformational event (D1) produced sets of NE-SW striking local and regional fractures and faults. The second deformational event (D2) generated mainly NNW-SSE and NW-SE faults and fractures some of which intersected earlier (D1) structures. At the northern and eastern parts of the study area (D1/D2) intersections are observed. The last event (D3)created NNE-SSW set of fractures and faults brought out by splay of dykes and reactivated some (D1 and D2)fractures and faults. The study area is also characterized by a major, N-S trending, late-stage dyke system that extend through the area. In order to estimate source depths from gridded aeromagnetic data, 3-D Euler deconvolution method was applied. The calculated source depths are in the range of 200 m to 3500 m. The deepest structures are in the ENE-WSW direction and have depths ranging from about 1100 m to 3000 m in the southeastern part of the study area. On the other hand, the network of parallel major structures trending in NNW-SSE direction have a shallow depth of about 700 m. Rare-metal granites of the Central Eastern Desert of Egypt are classified chemically into alkaline to peralkaline and peraluminous granites. They display the typical geochemical characteristics of A-type granites, with high SiO2, Na2O+K2O, Rb, Zr, Nb, Ta, Sn, and Y, and low CaO, MgO, Ba and Sr. The magmatism of the rare metal granites of the Central Eastern Desert are related to anorogenic, within-plate, A-type, subvolcanic setting and emplaced in the extensional tectonic regime along to the inherited ductile fabrics.
Abstract: Magnetic survey is usually used to delineate magnetic-structural lineaments, analyze their relationships to the inherited ductile fabrics and estimate the depth of perturbing body sources, probably granitic intrusions. These were conducted on the total magnetic intensity reduced to the pole map as well as First vertical derivative and Euler deconvo...
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Associated Microorganisms in Marine Cnidarians, Their Ecological Function in Symbiotic Relationship
Zhi-Gang Qiu,
Yihua Lyu,
Jin Zhou
Issue:
Volume 4, Issue 5, October 2015
Pages:
180-187
Received:
20 November 2015
Published:
20 November 2015
Abstract: Cnidarians (e.g. coral reefs) are among some of the most diverse and highly productive coastal ecosystems in tropical and subtropical regions. Microbes play pivotal roles in maintaining this productivity and are directly responsible for the well-being of a coral-based ecosystem. Microbes have important ecological functions in this ecosystem. With the acceleration of globalization and the deepening of molecular researches, the role and functions of microbes in the corals are increasingly highlighted. In this paper, the recent achievements were analyzed to summarize the research status of coral-associated microbial ecology, including the formation of coral-microbe symbionts, characteristics of symbiotic microbes (specificity, plasticity and co-evolution), as well as the microbial signaling strategies. The aims are help to define the crucial ecological interactions between coral reefs and microbes, and provide a better understanding of microbial ecosystem function and coral remediation.
Abstract: Cnidarians (e.g. coral reefs) are among some of the most diverse and highly productive coastal ecosystems in tropical and subtropical regions. Microbes play pivotal roles in maintaining this productivity and are directly responsible for the well-being of a coral-based ecosystem. Microbes have important ecological functions in this ecosystem. With t...
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Application of Chaotic Time-Series Optimization Algorithm in Solving the Parameters of Leakage Aquifer
Zhang Xiao-zhou,
Lu Yu-dong,
Guo Jian-qing
Issue:
Volume 4, Issue 5, October 2015
Pages:
188-192
Received:
1 December 2015
Published:
1 December 2015
Abstract: Applied the chaotic time-series optimization algorithm to solve hydrogeological parameters through analysis the pumping test data of the first type leakage aquifer, then explored the influence of the initial value of aquifer parameters and other factors on the convergence and results of the algorithm. The results shown that: ①chaotic time-series optimization algorithm could be effectively applied to the calculation problem of aquifer parameters; ②the initial value of the coefficient of storage and conductivity don’t have too much obvious effect on the search and results of the algorithm; ③The upper limit of algorithm had no obvious effect on the search ability but reduce the accuracy of results. Compared with other methods, the chaotic optimization method had such advantages as simple in principle of algorithm, easy to make program and to conduct, and the precision of aquifer parameters calculated was not affected by artificial subjective factors.
Abstract: Applied the chaotic time-series optimization algorithm to solve hydrogeological parameters through analysis the pumping test data of the first type leakage aquifer, then explored the influence of the initial value of aquifer parameters and other factors on the convergence and results of the algorithm. The results shown that: ①chaotic time-series op...
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Analysis on the Precipitation in Multiple Scales in Xi’an of China
Xu Panpan,
Yang Mi,
Qian Hui
Issue:
Volume 4, Issue 5, October 2015
Pages:
193-200
Received:
30 November 2015
Published:
1 December 2015
Abstract: Based on the data of precipitation from 1951 to 2014 in Xi’an,Shanxi Province,China(hereinafter referred to as Xi’an),after analyzing the characteristics of changes in precipitation over the last 64 years,the multiple scale analysis of annual precipitation and flood season precipitation are analyzed by wavelet analysis in Xi'an.The conclusions are as follows:(1)Flood season precipitation accounts for 79.32% of annual precipitation, and the correlation coefficient is 0.94,so,the contribution of precipitation in flood season to annual precipitation is very great.(2) Annual precipitation and flood season precipitation shows a decreasing trend, with a decreasing rate of -11.3mm/10a and -3.17mm /10a, respectively,which shows 72% of the annual precipitation decreases in the non flood season.(3)Annual precipitation sequence and flood season precipitation sequence have the similar main cycle in Xi'an.Their first main periods are 29 years and 31 years, respectively, and the second, the third,the forth main cycles all are 13 years, 6 years and 3 years.(4)Over any time scale,the annual precipitation and the precipitation in flood season will be into a less period after 2014.Since the oscillation intensities of the first and the second main cycles of annual precipitation is basically same,the possibilities of the less period of annual precipitation continuing to 2020 or 2017 are the same.However,the oscillation intensity of the first main cycle of precipitation in flood season is much greater than that of the second main cycle,so the probability of the less period of precipitation in the flood season is more likely to continue to 2020 than 2017.
Abstract: Based on the data of precipitation from 1951 to 2014 in Xi’an,Shanxi Province,China(hereinafter referred to as Xi’an),after analyzing the characteristics of changes in precipitation over the last 64 years,the multiple scale analysis of annual precipitation and flood season precipitation are analyzed by wavelet analysis in Xi'an.The conclusions are ...
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Using Monte Carlo Method for Predicting Rainfall -- Taking Xi'an Area, Shaanxi Province, China, as an Example
Wang Haike,
Xu Panpan,
Qian Hui
Issue:
Volume 4, Issue 5, October 2015
Pages:
201-204
Received:
30 November 2015
Published:
1 December 2015
Abstract: Rainfall forecasting plays a vital role in the national economy, social development and human life. Based on Monte Carlo method, this paper uses P- III distribution function to fitting precipitation data in the past 63 years so as to forecast precipitation. Using this model to forecast the rainfall for the past ten years (2003 ~~2013) in Xi'an city, Shaanxi province, China, based on the past 63 years data. The predicted results indicate that the prediction has a high accuracy in normal rainfall year, but in extremely in dry condition and high rainfall year, the relative error is huge. So that，the method is more suitable for the prediction of rainfall in the flat water.
Abstract: Rainfall forecasting plays a vital role in the national economy, social development and human life. Based on Monte Carlo method, this paper uses P- III distribution function to fitting precipitation data in the past 63 years so as to forecast precipitation. Using this model to forecast the rainfall for the past ten years (2003 ~~2013) in Xi'an city...
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The Application of SWMM Model in the Urban Planning Study on Sponge City
Zhang Bin,
Gu Jin,
Shi Xiangrong,
Weng Xiaohua,
Zhong Hua
Issue:
Volume 4, Issue 5, October 2015
Pages:
205-210
Received:
30 November 2015
Published:
1 December 2015
Abstract: With urbanization, the proportion of land surface hardening increases, urban stormwater issues have become increasingly prominent. Based on "sponge city" by China, Quzhou old town used infiltration trenchs, permeable pavements, and rain gardens taking the total amount of runoff and peak control as goal in this paper.The paper established city rainwater model of the study area with SWMM and simulated every LID facility using LID module in the model.The research shows that infiltration trenchs had not only best effects on controlling node flooding ,but also strongest control on reducing peak flow and delaying time of appearance of flood peak.The control of total runoff valume with permeable pavements was the most effective way.
Abstract: With urbanization, the proportion of land surface hardening increases, urban stormwater issues have become increasingly prominent. Based on "sponge city" by China, Quzhou old town used infiltration trenchs, permeable pavements, and rain gardens taking the total amount of runoff and peak control as goal in this paper.The paper established city rainw...
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Based on DPSR Model of Urban Land Intensive Utilization and Regional Urbanization Coordinated Development Evaluation of Space and Time -- A Case Study of the Wuhan City Circle in China
Issue:
Volume 4, Issue 5, October 2015
Pages:
211-217
Received:
1 December 2015
Published:
1 December 2015
Abstract: Based on the interaction of urbanization in the urban land intensive utilization and coordination mechanism, this paper constructed the coordination degree between the two and the relative development degree model, quantitative evaluation of urban land intensive utilization and urbanization coordinated development status, and can be divided into low level coordination, antagonism, running-in, high level of coordination of four stages. Using SPSS16.0 and ArcGIS10.0 nine cities of Wuhan city circle the space-time difference of empirical study. The results of the study showed that the coordination degree of status in the stage of low level coordination, antagonism in reducing the number of cities, in the running-in, high level of coordination number of cities is increasing; Based on the relative state development degree, development degree level has been basically assumes the growth tendency, although occasionally there are one or two years a city there are some changes, but can't deny showed a trend of spiral. Relative degree of development of urbanization in the urban land intensive utilization and spatial layout, tend to be reasonable, hand in hand with the development of most cities are in uniform.
Abstract: Based on the interaction of urbanization in the urban land intensive utilization and coordination mechanism, this paper constructed the coordination degree between the two and the relative development degree model, quantitative evaluation of urban land intensive utilization and urbanization coordinated development status, and can be divided into lo...
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Research on the Law of the Irrigation Water Infiltration in YaoBa Oasis Based on Hydrus-1D Model
Zheng Ce,
Lu Yu-dong,
Li Huan-huan
Issue:
Volume 4, Issue 5, October 2015
Pages:
218-222
Received:
3 December 2015
Published:
3 December 2015
Abstract: To study the law of irrigation water infiltration in soil is the basis of putting forward reasonable irrigation system. This paper takes YaoBa Oasis in Alxa Zuoqi,Inner Mongolia, China as the research object, based on field investigations and data collection, and chooses three test sites at the field to obtain the parameters of the model. The change of soil water content in different depth was simulated by Hydrus-1D model in 30 days after irrigation. The results shows that under the local existing irrigation system, the groundwater recharge is limited, and loam is an ideal agricultural soil. The results of the simulation are in good agreement with the experimental results, so the research results can provide scientific basis for the development of a more reasonable irrigation scheme in YaoBa Oasis.
Abstract: To study the law of irrigation water infiltration in soil is the basis of putting forward reasonable irrigation system. This paper takes YaoBa Oasis in Alxa Zuoqi,Inner Mongolia, China as the research object, based on field investigations and data collection, and chooses three test sites at the field to obtain the parameters of the model. The chang...
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