Rainfall analysis

Author(s):  
James C. Y. Guo
Keyword(s):  
Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 191
Author(s):  
Dong-IK Kim ◽  
Dawei Han ◽  
Taesam Lee

Nonstationarity is one major issue in hydrological models, especially in design rainfall analysis. Design rainfalls are typically estimated by annual maximum rainfalls (AMRs) of observations below 50 years in many parts of the world, including South Korea. However, due to the lack of data, the time-dependent nature may not be sufficiently identified by this classic approach. Here, this study aims to explore design rainfall with nonstationary condition using century-long reanalysis products that help one to go back to the early 20th century. Despite its useful representation of the past climate, the reanalysis products via observational data assimilation schemes and models have never been tested in representing the nonstationary behavior in extreme rainfall events. We used daily precipitations of two century-long reanalysis datasets as the ERA-20c by the European Centre for Medium-Range Weather Forecasts (ECMWF) and the 20th century reanalysis (20CR) by the National Oceanic and Atmospheric Administration (NOAA). The AMRs from 1900 to 2010 were derived from the grids over South Korea. The systematic errors were downgraded through quantile delta mapping (QDM), as well as conventional stationary quantile mapping (SQM). The evaluation result of the bias-corrected AMRs indicated the significant reduction of the errors. Furthermore, the AMRs present obvious increasing trends from 1900 to 2010. With the bias-corrected values, we carried out nonstationary frequency analysis based on the time-varying location parameters of generalized extreme value (GEV) distribution. Design rainfalls with certain return periods were estimated based on the expected number of exceedance (ENE) interpretation. Although there is a significant range of uncertainty, the design quantiles by the median parameters showed the significant relative difference, from −30.8% to 42.8% for QDM, compared with the quantiles by the multi-decadal observations. Even though the AMRs from the reanalysis products are challenged by various errors such as quantile mapping (QM) and systematic errors, the results from the current study imply that the proposed scheme with employing the reanalysis product might be beneficial to predict the future evolution of extreme precipitation and to estimate the design rainfall accordingly.


2021 ◽  
Vol 13 (15) ◽  
pp. 2922
Author(s):  
Yang Song ◽  
Patrick D. Broxton ◽  
Mohammad Reza Ehsani ◽  
Ali Behrangi

The combination of snowfall, snow water equivalent (SWE), and precipitation rate measurements from 39 snow telemetry (SNOTEL) sites in Alaska were used to assess the performance of various precipitation products from satellites, reanalysis, and rain gauges. Observation of precipitation from two water years (2018–2019) of a high-resolution radar/rain gauge data (Stage IV) product was also utilized to give insights into the scaling differences between various products. The outcomes were used to assess two popular methods for rain gauge undercatch correction. It was found that SWE and precipitation measurements at SNOTELs, as well as precipitation estimates based on Stage IV data, are generally consistent and can provide a range within which other products can be assessed. The time-series of snowfall and SWE accumulation suggests that most of the products can capture snowfall events; however, differences exist in their accumulation. Reanalysis products tended to overestimate snow accumulation in the study area, while the current combined passive microwave remote sensing products (i.e., IMERG-HQ) underestimate snowfall accumulation. We found that correction factors applied to rain gauges are effective for improving their undercatch, especially for snowfall. However, no improvement in correlation is seen when correction factors are applied, and rainfall is still estimated better than snowfall. Even though IMERG-HQ has less skill for capturing snowfall than rainfall, analysis using Taylor plots showed that the combined microwave product does have skill for capturing the geographical distribution of snowfall and precipitation accumulation; therefore, bias adjustment might lead to reasonable precipitation estimates. This study demonstrates that other snow properties (e.g., SWE accumulation at the SNOTEL sites) can complement precipitation data to estimate snowfall. In the future, gridded SWE and snow depth data from GlobSnow and Sentinel-1 can be used to assess snowfall and its distribution over broader regions.


2013 ◽  
Vol 13 (4) ◽  
pp. 887-912 ◽  
Author(s):  
A. Mugnai ◽  
E. A. Smith ◽  
G. J. Tripoli ◽  
B. Bizzarri ◽  
D. Casella ◽  
...  

Abstract. Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) is a EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites) program, designed to deliver satellite products of hydrological interest (precipitation, soil moisture and snow parameters) over the European and Mediterranean region to research and operations users worldwide. Six satellite precipitation algorithms and concomitant precipitation products are the responsibility of various agencies in Italy. Two of these algorithms have been designed for maximum accuracy by restricting their inputs to measurements from conical and cross-track scanning passive microwave (PMW) radiometers mounted on various low Earth orbiting satellites. They have been developed at the Italian National Research Council/Institute of Atmospheric Sciences and Climate in Rome (CNR/ISAC-Rome), and are providing operational retrievals of surface rain rate and its phase properties. Each of these algorithms is physically based, however, the first of these, referred to as the Cloud Dynamics and Radiation Database (CDRD) algorithm, uses a Bayesian-based solution solver, while the second, referred to as the PMW Neural-net Precipitation Retrieval (PNPR) algorithm, uses a neural network-based solution solver. Herein we first provide an overview of the two initial EU research and applications programs that motivated their initial development, EuroTRMM and EURAINSAT (European Satellite Rainfall Analysis and Monitoring at the Geostationary Scale), and the current H-SAF program that provides the framework for their operational use and continued development. We stress the relevance of the CDRD and PNPR algorithms and their precipitation products in helping secure the goals of H-SAF's scientific and operations agenda, the former helpful as a secondary calibration reference to other algorithms in H-SAF's complete mix of algorithms. Descriptions of the algorithms' designs are provided including a few examples of their performance. This aspect of the development of the two algorithms is placed in the context of what we refer to as the TRMM era, which is the era denoting the active and ongoing period of the Tropical Rainfall Measuring Mission (TRMM) that helped inspire their original development. In 2015, the ISAC-Rome precipitation algorithms will undergo a transformation beginning with the upcoming Global Precipitation Measurement (GPM) mission, particularly the GPM Core Satellite technologies. A few years afterward, the first pair of imaging and sounding Meteosat Third Generation (MTG) satellites will be launched, providing additional technological advances. Various of the opportunities presented by the GPM Core and MTG satellites for improving the current CDRD and PNPR precipitation retrieval algorithms, as well as extending their product capability, are discussed.


2017 ◽  
Vol 97 ◽  
pp. 243-258 ◽  
Author(s):  
Javier Diez-Sierra ◽  
Manuel del Jesus
Keyword(s):  

2021 ◽  
Author(s):  
◽  
Jane Marie Niemeyer

A historical analysis of precipitation using 72 years of data from Midwest stations focuses on the implications of climate change for agricultural interests. The number of precipitation events, consecutive days of precipitation, and a Fourier transformation on precipitation are included. Although increased precipitation can be of benefit in agricultural production resulting in yield benefits in the Midwest, excessive rainfall events lead to runoff, which does not improve soil water content and plant available water. To examine the beneficial nature of rainfall events in the Midwest, rainfall retention is estimated using the United States Department of Agriculture Soil Conservation Service (USDA-NRCS/SCS) method. This method can be described briefly as an empirical formula estimating the soil's ability to store water and the amount of runoff. It was found that not only has rainfall increased but so have the number of rainfall days and the number of consecutive days of rainfall. To appricultural focus, spring and fall rainfall days were also found to increase implying that farmers may have fewer days to complete fieldwork in the current climate. With increasing precipitation, the potential for runoff also increases, losing valuable water needed for crops and contributing to lost nutrients in the soil.


2020 ◽  
Vol 9 (2) ◽  
pp. 39
Author(s):  
PRIMA D. RIAJAYA ◽  
F. T. KADARWATI ◽  
MOCH. MACHFUD

<p>Curah hujan merupakan salah salu unsur iklim yang sangal berpengaruh terhadap produksi kapas Variasi hujan di lahan tadah hujan sangat linggi. Waklu tanam yang telah dilentukan sebelumnya hanya berdasarkan data curah hujan selama 1 0 Uihun Untuk mcmpcrbaiki waktu tanam tersebut, perlu dilakukan analisis hujan berdasarkan data curah hujan selama lebih dari 20 tahun untuk mendapatkan angka peluang yang lebih stabil. Analisis dilakukan berdasarkan data curah hujan lebih dari 20 tahun yang lerkumpul dari 16 slasiun hujan yang tersebar di Kabupaten Lombok Timur. lombok Tengah. Lombok Barat, Sumbawa, Bima, dan Dompu. Data dianalisis menggunakan metode peluang Markov Ordc Pertama dan perhilungan peluang sclang kering beturut-turut Waktu tanam kapas di sebagian besar I-ombok dan Sumbawa berkisar minggu pertama sampai minggu kedua Desember, minggu ketiga sampai keempal Desember di Kawo, Lombok Tengah dan Rasanae, Bima, dan minggu pertama Januari di Moyohilir, Sumbawa dan Bayan, Lombok Barat. Daerah yang beresiko linggi untuk pengembangan kapas adalah di wilayah sekilar Pringgabaya (Lombok Timur), Ulhan (Sumbawa), Donggo dan Wawo di Bima Daerah lainnya dengan kandungan air tersedia yang rendah dengan kandungan pasir lebih dari 50% seperti di 1-ape (Sumbawa) penanaman kapas hendaknya dilakukan lebih awal. Tipe iklim didominasi iklim kering dengan musim hujan yang sangat pendek sehingga tidak memungkinkan adanya pergiliran tanaman palawija-kapas Kapas hendaknya ditanam bersamaan dengan palawija mcngingal pendeknya periode hujan.</p><p>Kata kunci : Gossypium hirsutum, waktu tanam. periode kering, masa tanam</p><p> </p><p><strong>ABSTRACT </strong></p><p><strong>Prediction of rainfall probability for determination of cotton sowing times in West Nusa Tenggara</strong></p><p>Climatic elements paticularly rainfall strongly influences successful prediction of rainfed cotton yield. Rainfall vaiability varies amongst Ihe season The previous planting times were determined based on 10 years daily rainfall data. I-ongterm rainfall data arc required for rainfall analysis to get reliable probabilities. The rainfall analysis was done using Markov Chain First Order Probability and dryspell probability methods Ihe rainfall data were collected from 16 rainfall stations in West Nusa Tcnggara (Eas( Lombok, Central I-ombok, West Lombok, Sumbawa, Bima, and Dompu). Ihe planting times varied from the irst week to the second week of December for most areas of I-ombok and Sumbawa The planting limes in Kawo, Central Lombok and Rasanae, Bima were mid December: and early January in Moyohilir, Sumbawa and Bayan, West l.ombok The areas which high risk to drought are around Pringgabaya (Hast lombok), Uthan (Sumbawa), Donggo and Wawo (Bima). On sandy- areas such as I-ape (Sumbawa) cotton should be planted earlier Type of climate in most areas is dry with limited rainy season, thai relay-planting of these areas is not practiced.</p><p>Key words: Gossypium hirsutum, planting time, dryspcll, seasonal patern</p>


2021 ◽  
Vol 893 (1) ◽  
pp. 012006
Author(s):  
F Aditya ◽  
E Gusmayanti ◽  
J Sudrajat

Abstract Climate change has been a prominent issue in the last decade. Climate change on a global scale does not necessarily have the same effect in different regions. Rainfall is a crucial weather element related to climate change. Rainfall trends analysis is an appropriate step in assessing the impact of climate change on water availability and food security. This study examines rainfall variations and changes at West Kalimantan, focusing on Mempawah and Kubu Raya from 2000-2019. The Mann-Kendall (MK) and Sen's Slope estimator test, which can determine rainfall variability and long-term monotonic trends, were utilized to analyze 12 rainfall stations. The findings revealed that the annual rainfall pattern prevailed in all locations. Mempawah region tends to experience a downward trend, while Kubu Raya had an upward trend. However, a significant trend (at 95% confidence level) was identified in Sungai Kunyit with a slope value of -33.20 mm/year. This trend indicates that Sungai Kunyit will become drier in the future. The results of monthly rainfall analysis showed that significant upward and downward trends were detected in eight locations. Rainfall trends indicate that climate change has occurred in this region.


2012 ◽  
Vol 4 (5) ◽  
pp. 897 ◽  
Author(s):  
Luana Portz ◽  
Laurindo Antonio Guasselli ◽  
Iran Carlos Stalliviere Corrêa

Neste estudo foram analisadas as variações espaciais e temporais do Índice de Vegetação por Diferença Normalizada (NDVI) na lagoa do Peixe, no litoral do Rio Grande do Sul. Para alcançar o objetivo proposto foram utilizadas imagens de satélite Landsat TM5, entre os anos de 1986 e 2009, seguindo os procedimentos de elaboração de mosaico das cenas, verificação de campo, geração das imagens de NDVI, análise de dados de precipitação acumulada, geração dos mapas finais e análise qualitativa dos resultados obtidos. Os resultados obtidos com a geração de imagens de NDVI mostraram que a análise espaço-temporal associada aos dados de precipitação fornecem informações de valiosa importância sobre a dinâmica da lagoa do Peixe. A importância  do NDVI neste estudo se destaca pelo contraste existente entre água e vegetação, realçando os diferentes níveis de água sobre os bancos vegetados presentes na borda oeste da lagoa. Estes bancos são um importante controlador da dinâmica de circulação lagunar, onde em períodos de seca ocorre a compartimentação da lagoa, enquanto que em épocas de grande precipitação e acumulação de água estes bancos ficam submersos. Palavras-chave: Landsat TM, série temporal, Parque Nacional.  Spatial and Temporal Variation of NDVI in the Peixe Lagoon, RS  ABSTRACTThis paper analyzed the spatial and temporal variation of Normalized Difference Vegetation Index (NDVI) in the Peixe lagoon. To reach the purpose,  the NDVI time-series were collected from the study area between year 1986 and 2009 derived from Landsat TM5 satellite. The adopted methodology may be subdivided into the following steps: mosaic of scenes, fild verification, generation of NDVI time-series and qualitative analysis, in addition, it was complemented with rainfall analysis.  The results obtained with the NDVI time-series associated with the rainfall analysis data provide valuable information about the environmental dynamics. The importance of NDVI in this work is given by the contrast between water and vegetation, highlighting the different levels of water over vegetated banks present on the western edge of the lagoon. These banks are an important driver circulation in the lagoon, where in periods of drought occurs the partitioning of the lagoo, while in periods of high precipitation and accumulation of water they are submerged.    Keywords: Landsat TM, time-series, National Park.


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