scholarly journals On Complex Network Construction of Rain Gauge Stations Considering Nonlinearity of Observed Daily Rainfall Data

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1578 ◽  
Author(s):  
Kyunghun Kim ◽  
Hongjun Joo ◽  
Daegun Han ◽  
Soojun Kim ◽  
Taewoo Lee ◽  
...  

Rainfall data is frequently used as input and analysis data in the field of hydrology. To obtain adequate rainfall data, there should be a rain gauge network that can cover the relevant region. Therefore, it is necessary to analyze and evaluate the adequacy of rain gauge networks. Currently, a complex network analysis is frequently used in network analysis and in the hydrology field, Pearson correlation is used as strength of link in constructing networks. However, Pearson correlation is used for analyzing the linear relationship of data. Therefore, it is now suitable for nonlinear hydrological data (such as rainfall and runoff). Thus, a possible solution to this problem is to apply mutual information that can consider nonlinearity of data. The present study used a method of statistical analysis known as the Brock–Dechert–Scheinkman (BDS) statistics to test the nonlinearity of rainfall data from 55 Automated Synoptic Observing System (ASOS) rain gauge stations in South Korea. Analysis results indicated that all rain gauge stations showed nonlinearity in the data. Complex networks of these rain gauge stations were constructed by applying Pearson correlation and mutual information. Then, they were compared by computing their centrality values. Comparing the centrality rankings according to different thresholds for correlation showed that the network based on mutual information yielded consistent results in the rankings, whereas the network, which based on Pearson correlation exhibited much variability in the results. Thus, it was found that using mutual information is appropriate when constructing a complex network utilizing rainfall data with nonlinear characteristics.

2018 ◽  
Vol 10 (12) ◽  
pp. 1879 ◽  
Author(s):  
Véronique Michot ◽  
Daniel Vila ◽  
Damien Arvor ◽  
Thomas Corpetti ◽  
Josyane Ronchail ◽  
...  

Knowledge and studies on precipitation in the Amazon Basin (AB) are determinant for environmental aspects such as hydrology, ecology, as well as for social aspects like agriculture, food security, or health issues. Availability of rainfall data at high spatio-temporal resolution is thus crucial for these purposes. Remote sensing techniques provide extensive spatial coverage compared to ground-based rainfall data but it is imperative to assess the quality of the estimates. Previous studies underline at regional scale in the AB, and for some years, the efficiency of the Tropical Rainfall Measurement Mission (TRMM) 3B42 Version 7 (V7) (hereafter 3B42) daily product data, to provide a good view of the rainfall time variability which is important to understand the impacts of El Nino Southern Oscilation. Then our study aims to enhance the knowledge about the quality of this product on the entire AB and provide a useful understanding about his capacity to reproduce the annual rainfall regimes. For that purpose we compared 3B42 against 205 quality-controlled rain gauge measurements for the period from March 1998 to July 2013, with the aim to know whether 3B42 is reliable for climate studies. Analysis of quantitative (Bias, Relative RMSE) and categorical statistics (POD, FAR) for the whole period show a more accurate spatial distribution of mean daily rainfall estimations in the lowlands than in the Andean regions. In the latter, the location of a rain gauge and its exposure seem to be more relevant to explain mismatches with 3B42 rather than its elevation. In general, a good agreement is observed between rain gauge derived regimes and those from 3B42; however, performance is better in the rainy period. Finally, an original way to validate the estimations is by taking into account the interannual variability of rainfall regimes (i.e., the presence of sub-regimes): four sub-regimes in the northeast AB defined from rain gauges and 3B42 were found to be in good agreement. Furthermore, this work examined whether TRMM 3B42 V7 rainfall estimates for all the grid points in the AB, outgoing longwave radiation (OLR) and water vapor flux patterns are consistent in the northeast of AB.


2018 ◽  
Vol 20 (4) ◽  
pp. 784-797 ◽  
Author(s):  
Marija Ivković ◽  
Andrijana Todorović ◽  
Jasna Plavšić

Abstract Flood forecasting relies on good quality of observed and forecasted rainfall. In Serbia, the recording rain gauge network is sparse and rainfall data mainly come from dense non-recording rain gauges. This is not beneficial for flood forecasting in smaller catchments and short-duration events, when hydrologic models operating on subdaily scale are applied. Moreover, differences in rainfall amounts from two types of gauges can be considerable, which is common in operational hydrological practice. This paper examines the possibility of including daily rainfall data from dense observation networks in flood forecasting based on subdaily data, using the extreme flood event in the Kolubara catchment in May 2014 as a case study. Daily rainfall from a dense observation network is disaggregated to hourly scale using the MuDRain multivariate disaggregation software. The disaggregation procedure results in well-reproduced rainfall dynamics and adjusts rainfall volume to the values from the non-recording gauges. The fully distributed wflow_hbv model, which is under development as a forecasting tool for the Kolubara catchment, is used for flood simulations with two alternative hourly rainfall data. The results show an improvement when the disaggregated rainfall from denser network is used, thus indicating the significance of better representation of rainfall temporal and spatial variability for flood forecasting.


2009 ◽  
Vol 20 ◽  
pp. 51-56 ◽  
Author(s):  
S. C. Michaelides ◽  
K. Savvidou ◽  
K. A. Nicolaides ◽  
M. Charalambous

Abstract. The rainfall and lightning activity associated with three depressions which affected the area of Cyprus were studied in order to identify possible relationships between them. The lightning data were provided by the National Observatory of Athens, Greece, and were spatially and statistically related to the corresponding rainfall measurements from the rain gauge network of the Cyprus Meteorological Service. The study was carried out by using a rectangular grid-box methodology and various combinations of lightning and rainfall data filtering and time-lags were tested.


2011 ◽  
Vol 12 (3) ◽  
pp. 456-466 ◽  
Author(s):  
Dawit A. Zeweldi ◽  
Mekonnen Gebremichael ◽  
Charles W. Downer

Abstract The objective is to assess the use of the Climate Prediction Center morphing method (CMORPH) (~0.073° latitude–longitude, 30 min resolution) rainfall product as input to the physics-based fully distributed Gridded Surface–Subsurface Hydrologic Analysis (GSSHA) model for streamflow simulation in the small (21.4 km2) Hortonian watershed of the Goodwin Creek experimental watershed located in northern Mississippi. Calibration is performed in two different ways: using rainfall data from a dense network of 30 gauges as input, and using CMORPH rainfall data as input. The study period covers 4 years, during which there were 24 events, each with peak flow rate higher than 0.5 m3 s−1. Streamflow simulations using CMORPH rainfall are compared against observed streamflows and streamflow simulations using rainfall from a dense rain gauge network. Results show that the CMORPH simulations captured all 24 events. The CMORPH simulations have comparable performance with gauge simulations, which is striking given the significant differences in the spatial scale between the rain gauge network and CMORPH. This study concludes that CMORPH rainfall products have potential value for streamflow simulation in such small watersheds. Overall, the performance of CMORPH-driven simulations increases when the model is calibrated with CMORPH data than when the model is calibrated with rain gauge data.


2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Desni Triana Ruly Saragih ◽  
Meky Sagrim ◽  
Hendrik Fatem ◽  
Stepanus Pakage ◽  
Yosina Waromi ◽  
...  

ABSTRACT. Stakeholders and their network place top rank of value chain business and ruled prominent roles in the livestock development sector particularly poultry commodity. The involvement of many stakeholders and other parties is questionable because they perform and shape the market and business chain. The study was done in Manokwari using focus group discussion towards twenty-four various represented individuals, groups and mass organizations. The key queries discussed concerning the introduced background of the organization, shared resources, inter-connectivity amongst actors, intervention and innovation preferences and shared by actors. Stakeholder Network Analysis was employed to run the network and relationship between actors using the Pearson Correlation Coefficient and Hierarchical Clustering Analysis. The finding is that the stakeholders in the poultry farming systems are dominated by private group actors who are working in groups to manage the farms and its value chain process and officially have been under laws. These actors commonly act like positive important stakeholders, who ruled the farms. The threats are real and exist and should be lowering as much as possible to mitigate the turn-back effect. The top five shared resources are access, spaces, time, policy, knowledge and skills. Those resources will stay longer to sustain the strong needs of poultry farms. The relationship of actors is dominated by the ranges of correlation are varying in between negative, neutral to positive. Actors are not delivering the intervention and innovation yet. Actors with low interest and low power should then be promoted to high interest and high power by using aids, guidance, and services from each actor from its value chain and cooperation and farming business.  (Pemetaan Pemangku Produksi dan Bisnis Unggas Strategis dan Berkelanjutan Dengan Aplikasi Analisis Jaringan Stakeholder) ABSTRAK. Pemangku kepentingan dan jaringannya menempati peringkat teratas dalam bisnis rantai nilai dan memegang peran penting dalam sektor pengembangan peternakan khususnya komoditas unggas. Keterlibatan banyak pemangku kepentingan dan pihak lain patut dipertanyakan. Penelitian dilakukan di Manokwari dengan menggunakan FGD terhadap dua puluh empat perwakilan individu, kelompok dan ormas. Pertanyaan utama membahas tentang latar belakang organisasi yang diperkenalkan, sumber daya bersama, interkoneksi antar aktor, preferensi intervensi dan inovasi dan dibagikan oleh aktor. Analisis Jaringan Pemangku Kepentingan digunakan untuk menjalankan jaringan dan hubungan dengan menggunakan Koefisien Korelasi Pearson dan Analisis Pengelompokan Hirarkis. Temuannya adalah bahwa para pemangku kepentingan dalam sistem peternakan unggas didominasi oleh pelaku kelompok swasta yang bekerja dalam kelompok untuk mengelola peternakan dan proses rantai nilainya dan secara resmi berada di bawah undang-undang. Aktor ini biasanya bertindak seperti pemangku kepentingan penting yang positif, yang mengatur pertanian. Ancaman itu nyata dan ada dan harus diturunkan sebanyak mungkin untuk mengurangi efek balik. Lima sumber daya bersama teratas adalah akses, ruang, waktu, kebijakan, pengetahuan, dan keterampilan. Sumber daya tersebut akan bertahan lebih lama untuk menopang kebutuhan kuat peternakan unggas. Hubungan antar aktor didominasi oleh rentang korelasi yang bervariasi antara negatif, netral hingga positif. Para pelaku belum melakukan intervensi dan inovasi. Pelaku dengan kepentingan rendah dan kekuasaan rendah kemudian harus dipromosikan menjadi kepentingan tinggi dan kekuasaan tinggi dengan menggunakan bantuan, bimbingan, dan layanan dari masing-masing pelaku dari rantai nilai dan koperasi dan usaha tani.


2020 ◽  
Vol 9 (11) ◽  
pp. e5509119470
Author(s):  
Aminda Tri Handayani

This study took the relationship of self-confidence and body image to students at FKIP UMN Alwashliyah. In this case, self-confidence and body image as independent variables and personal fable as dependent variables. Adolescence is one of the stages in human life which is a period of transition from childhood to adulthood. At this stage adolescents will experience changes both physically, cognitively and psychosocial. In line with physical changes, young women tend to develop a high level of concern for their physical changes. The way adolescents perceive their physical condition will affect the level of their personal ability. With high trust and a positive body image will increase the personal level of the teenager. The objectives of this study were to determine: (i) the relationship between self-confidence and body image with personal fable in UMN AW students; (ii) The relationship between self-confidence and personal ability in UMN AW students; (iii) The relationship between body image and personal fable in UMN AW students. The research method used in this research is quantitative method with a sample of 2 classes from semester 2, each class totaling 30 people. Thus the data taken is in the form of a questionnaire, using Pearson Correlation analysis. Data analysis was performed using SPSS 23 for windows.     


2018 ◽  
Author(s):  
Ankit Agarwal ◽  
Norbert Marwan ◽  
Maheswaran Rathinasamy ◽  
Ugur Ozturk ◽  
Bruno Merz ◽  
...  

Abstract. Hydrometric networks play a vital role in providing information for decision-making in water resources management. They should be set up optimally to provide as much and as accurate information as possible, and at the same time, be cost-effective. We propose a new measure, based on complex network analysis, to support the design and redesign of hydrometric station networks. The science of complex networks is a relatively young field and has gained significant momentum in the last years in different areas such as brain networks, social networks, technological networks or climate networks. The identification of influential nodes in complex networks is an important field of research. We propose a new node ranking measure, the weighted degree-betweenness, to evaluate the importance of nodes in a network. It is compared to previously proposed measures on synthetic sample networks and then applied to a real-world rain gauge network comprising 1229 stations across Germany to check its applicability in the optimal design of hydrometric networks. The proposed measure is evaluated using the decline rate of network efficiency and the kriging error. The results suggest that it effectively quantifies the importance of rain stations. The new measure is very useful in identifying influential stations which need high attention and expendable stations which can be removed without much loss of information provided by the station network.


2020 ◽  
Author(s):  
Esmail Ghaemi ◽  
Ulrich Foelsche ◽  
Alexander Kann ◽  
Gottfried Kirchengast ◽  
Juergen Fuchsberger

<p>Precipitation is one of the most important inputs of meteorological and hydrological models and also flood warning systems. Thus, accurate estimation of rainfall is essential for improving the reliability of the models and systems. Although remote sensing (RS) techniques for rainfall estimation (e.g., weather radars and satellite microwave imagers) have improved significantly over the last decades, rain gauges are still more reliable and widely used for this purpose and also for the evaluation of RS estimates. Since the characteristics of a rainfall event can change rapidly in space and time, the accuracy of rain gauge estimation is highly dependent on the spatial and temporal resolution of the gauge network.</p><p>The main aim of this study is to evaluate the ability of the Integrated Nowcasting through Comprehensive Analysis (INCA) of the Central Institute for Meteorology and Geodynamics (ZAMG) to detect and estimate rainfall events. This is done by using 12 years of data from a very dense rain gauge network, the WegenerNet Feldbach region, as a reference, and comparing its data to the INCA analyses. INCA rainfall analysis data are based on a combination of ZAMG ground station data, weather radar data, and high-resolution topographic data. The system provides precipitation rate data with a 1 km spatial grid resolution and 15 minutes temporal resolution. The WegenerNet includes 155 ground stations, almost uniformly spread over a moderate hilly orography area of about 22 km × 16 km.</p><p>After removing outliers and scale WegenerNet data to 1 km, the accuracy of INCA to detect and estimate rainfall events was investigated using 12 years of the dataset. The results show that INCA can detect rainfall events relatively well. It was found that INCA overestimates the rainfall amount between 2012 and 2014, and generally overestimates precipitation for light rainfall events. For heavy rainfall events, however, an underestimation of INCA is prominent in most events. Based on the results, the difference between INCA and WegenerNet estimates is relatively higher during the wet season in the summer half-year (May-September). It is worth pointing out that INCA performs better in detecting and estimating rainfall around the two ZAMG stations located within the study area.</p>


2006 ◽  
Vol 7 ◽  
pp. 65-72 ◽  
Author(s):  
A. De Luque ◽  
T. Porja ◽  
A. Martín ◽  
J. A. Guijarro ◽  
S. Alonso

Abstract. This paper presents results of daily rainfall estimates for the flood event in Albania occurred during the end of September 2002 (from the 21 until the 23). Estimated precipitations based on Meteosat-7 data and computed using various techniques, are compared with surface based observations. The two techniques, developed for convective clouds, were employed to screen the Albanian Flood. On one hand a single Infrared band technique known as Auto-estimator and on the other hand a three-channel Convective Rainfall Rate technique known as CRR. Secondly, for both methods, a number of corrections, such as, moisture, cloud growth rate, cloud top temperature gradient, parallax and orographic corrections were, also, performed and tested during the flood case. Preliminary results show that auto-estimator over-measure significantly daily rainfall with respect to the observed while CRR gives much closer rain quantities. The Auto-estimator power law curve was adjusted to the specific conditions using all the available rain rate gauge measurements. Satellite daily rainfall estimated by the two methods, corrected and calibrated were finally evaluated using the Albanian rain gauge network as ground true.


Jurnal MIPA ◽  
2014 ◽  
Vol 3 (1) ◽  
pp. 25
Author(s):  
Febriany Florence Rey ◽  
Seni H. J. Tongkukut ◽  
Wandayantolis .

Telah dilakukan analisis terhadap distribusi curah hujan yang dipengaruhi oleh dinamika suhu muka laut untuk mengetahui hubungan distribusi curah hujan dan dinamika suhu muka laut di Sulawesi Utara, serta telah dibuat peta spasial hubungan distribusi curah hujan dengan dinamika suhu muka laut menggunakan ArcMap 9.3. Analisis yang dilakukan menggunakan data curah hujan bulanan selama 10 tahun dari 5 stasiun BMKG dan 10 pos hujan kerjasama di Sulawesi Utara, dan data dinamika suhu muka laut berdasarkan nilai Indeks Osilasi Selatan dengan metode korelasi. Hasil penelitian diperoleh nilai korelasi positif antara 0,50 hingga 0,90 terjadi pada periode tiga bulanan yaitu Agustus-September-Oktober pada seluruh wilayah pengamatan.Analysis of the precipitation that caused by the dynamics of sea surface temperature has been made to find the correlation between the precipitation and the dynamics of sea surface temperature, with its spatial map of the correlation between precipitation and the dynamics of sea surface temperature using ArcMap 9.3. The analysis use the monthly rainfall data for 10 years from 5 BMKG Stations and 10 rain-gauge network in North Sulawesi, and Southern Oscillation Index monthly value using correlation method. The result of this research is the positive correlation between 1,50 to 0,90 occur in the period of August-September-October.


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