scholarly journals Evaluating land use change impacts on rainfall in various categories using the Weather Research and Forecasting-mosaic approach

2018 ◽  
Vol 20 (1) ◽  
pp. e870
Author(s):  
Deming Zhao ◽  
Jian Wu
Author(s):  
Alessio Golzio ◽  
Silvia Ferrarese ◽  
Claudio Cassardo ◽  
Gugliemina Adele Diolaiuti ◽  
Manuela Pelfini

AbstractWeather forecasts over mountainous terrain are challenging due to the complex topography that is necessarily smoothed by actual local-area models. As complex mountainous territories represent 20% of the Earth’s surface, accurate forecasts and the numerical resolution of the interaction between the surface and the atmospheric boundary layer are crucial. We present an assessment of the Weather Research and Forecasting model with two different grid spacings (1 km and 0.5 km), using two topography datasets (NASA Shuttle Radar Topography Mission and Global Multi-resolution Terrain Elevation Data 2010, digital elevation models) and four land-cover-description datasets (Corine Land Cover, U.S. Geological Survey land-use, MODIS30 and MODIS15, Moderate Resolution Imaging Spectroradiometer land-use). We investigate the Ortles Cevadale region in the Rhaetian Alps (central Italian Alps), focusing on the upper Forni Glacier proglacial area, where a micrometeorological station operated from 28 August to 11 September 2017. The simulation outputs are compared with observations at this micrometeorological station and four other weather stations distributed around the Forni Glacier with respect to the latent heat, sensible heat and ground heat fluxes, mixing-layer height, soil moisture, 2-m air temperature, and 10-m wind speed. The different model runs make it possible to isolate the contributions of land use, topography, grid spacing, and boundary-layer parametrizations. Among the considered factors, land use proves to have the most significant impact on results.


2019 ◽  
Vol 12 (3) ◽  
pp. 801
Author(s):  
Marcones De Oliveira Silva ◽  
Rosiberto Salustiano da Silva Júnior

Este trabalho tem como objetivo avaliar a qualidade do ar na cidade de Maceió-AL utilizando o modelo numérico de mesoescala WRF/CHEM (Weather Research and forecasting/Chemistry) durante o período de 23 a 25 de abril de 2011. O WRF/CHEM foi configurado para realizar quatro tipos de simulações: Default - simulação com a topografia e uso do solo padrões do modelo; Topo - simulação com a topografia atualizada e uso do solo padrão; IGBP - simulação com a topografia padrão e uso do solo atualizado e Topo_IGBP - simulação com a atualização da topografia e uso do solo. O inventário de emissões veiculares necessário para servir como dado de entrada no modelo foi construído de acordo com a metodologia proposta pela Companhia Ambiental do Estado de São Paulo (CETESB) onde se calculou as emissões totais em toneladas anuais de monóxido de carbono (CO), óxidos de nitrogênio (NOx), hidrocarbonetos não metano (NMHC) e material particulado (MP). O modelo WRF/CHEM foi executado com duas grades aninhadas com espaçamento de grade de 5 e 1 km. Os resultados obtidos mostraram que a resolução de 1 km obteve resultados melhores, em relação às observações, para as simulações de temperatura, umidade relativa e concentrações de dióxido de nitrogênio (NO2) do que os resultados obtidos pelas simulações utilizando a grade de 5 km, porém a variabilidade horária foi melhor representada pela resolução de 5 km. A simulação Topo foi a que apresentou melhor acurácia das simulações nas duas resoluções adotadas mostrando que a atualização da topografia é mais eficiente do que a atualização do uso do solo.Palavras-Chave: WRF/CHEM; inventário; topografia; uso do solo; resolução.   A B S T R A C TThis work aims to evaluate the air quality in the city of Maceió-AL using the numerical model of the WRF/CHEM (Weather Research and forecasting / Chemistry) during the period from April 23 to 25, 2011. The WRF/CHEM was configured to perform four types of simulations: Default - simulation with topography and land use patterns of the model; Topo - simulation with updated topography and standard soil use; IGBP - simulation with the standard topography and updated soil use and Topo_IGBP - simulation with updating topography and land use. The vehicle emissions inventory required to serve as input data in the model was constructed according to the methodology proposed by the Environmental Company of the State of São Paulo (CETESB) where the total emissions in annual tons of carbon monoxide (CO), nitrogen oxides (NOx), non-methane hydrocarbons (NMHC) and particulate matter (MP). The WR /CHEM model was run with two nested grids with grid spacing of 5 and 1 km. The results obtained showed that the resolution of 1 km obtained better results, relative to the observations, for the simulations of temperature, relative humidity and nitrogen dioxide (NO2) concentrations than the results obtained by the simulations using the 5 km grid, the hourly variability was best represented by the resolution of 5 km. The Topo simulation was the one that presented better accuracy of the simulations in the two adopted resolutions showing that the updating of the topography is more efficient than the update of the land use.Keywords: WRF/CHEM; inventory; topography; land use; resolution.


2021 ◽  
Vol 14 (6) ◽  
pp. 3939-3967
Author(s):  
Carlos Román-Cascón ◽  
Marie Lothon ◽  
Fabienne Lohou ◽  
Oscar Hartogensis ◽  
Jordi Vila-Guerau de Arellano ◽  
...  

Abstract. The water and energy transfers at the interface between the Earth's surface and the atmosphere should be correctly simulated in numerical weather and climate models. This implies the need for a realistic and accurate representation of land cover (LC), including appropriate parameters for each vegetation type. In some cases, the lack of information and crude representation of the surface lead to errors in the simulation of soil and atmospheric variables. This work investigates the ability of the Weather Research and Forecasting (WRF) model to simulate surface heat fluxes in a heterogeneous area of southern France using several possibilities for the surface representation. In the control experiments, we used the default LC database in WRF, which differed significantly from the actual LC. In addition, sub-grid variability was not taken into account since the model uses, by default, only the surface information from the dominant LC category in each pixel (dominant approach). To improve this surface simplification, we designed three new interconnected numerical experiments with three widely used land surface models (LSMs) in WRF. The first one consisted of using a more realistic and higher-resolution LC dataset over the area of analysis. The second experiment aimed at investigating the effect of using a mosaic approach; 30 m sub-grid surface information was used to calculate the final grid fluxes based on weighted averages from values obtained for each LC category. Finally, in the third experiment, we increased the model stomatal conductance for conifer forests due to the large flux errors associated with this vegetation type in some LSMs. The simulations were evaluated with gridded area-averaged fluxes calculated from five tower measurements obtained during the Boundary-Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign. The results from the experiments differed depending on the LSM and displayed a high dependency of the simulated fluxes on the specific LC definition within the grid cell, an effect that was enhanced with the dominant approach. The simulation of the fluxes improved using the more realistic LC dataset except for the LSMs that included extreme surface parameters for coniferous forest. The mosaic approach produced fluxes more similar to reality and served to particularly improve the latent heat flux simulation of each grid cell. Therefore, our findings stress the need to include an accurate surface representation in the model, including soil and vegetation sub-grid information with updated surface parameters for some vegetation types, as well as seasonal and man-made changes. This will improve the modelled heat fluxes and ultimately yield more realistic atmospheric processes in the model.


2018 ◽  
Vol 38 (3) ◽  
Author(s):  
廉丽姝 LIAN Lishu ◽  
李宝富 LI Baofu ◽  
陈忠升 CHEN Zhongsheng ◽  
陈亚宁 CHEN Yaning ◽  
孙小银 SUN Xiaoyin

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 350
Author(s):  
Huoqing Li ◽  
Hailiang Zhang ◽  
Ali Mamtimin ◽  
Shuiyong Fan ◽  
Chenxiang Ju

The USGS (United States Geological Survey) land-use data used in the Weather Research and Forecasting (WRF) model have become obsolete as they are unable to accurately represent actual underlying surface features. Therefore, this study developed a new multi-satellite remote-sensing land-use dataset based on the latest GLC2015 (Global Land Cover, 2015) land-use data, which had 300 m spatial resolution. The new data were used to update the default USGS land-use dataset. Based on observational data from national meteorological observing stations in Xinjiang, northwest China, a comparison of the old USGS and new GLC2015 land-use datasets in the WRF model was performed for July 2018, where the simulated variables included the sensible heat flux (SHF), latent heat flux (LHF), surface skin temperature (Tsk), two-meter air temperature (T2), wind speed (Winds), specific humidity (Q2) and relative humidity (RH). The results indicated that there were significant differences between the two datasets. For example, our statistical verification results found via in situ observations made by the MET (model evaluation tools) illustrated that the bias of T2 decreased by 2.54%, the root mean square error (RMSE) decreased by 1.48%, the bias of Winds decreased by 10.46%, and the RMSE decreased by 6.77% when using the new dataset, and the new parameter values performed a net positive effect on land–atmosphere interactions. These results suggested that the GLC2015 land-use dataset developed in this study was useful in terms of improving the performance of the WRF model in the summer months.


Author(s):  
Verónica Lango-Reynoso ◽  
Karla Teresa González-Figueroa ◽  
Fabiola Lango-Reynoso ◽  
María del Refugio Castañeda-Chávez ◽  
Jesús Montoya-Mendoza

Objective: This article describes and analyzes the main concepts of coastal ecosystems, these as a result of research concerning land-use change assessments in coastal areas. Design/Methodology/Approach: Scientific articles were searched using keywords in English and Spanish. Articles regarding land-use change assessment in coastal areas were selected, discarding those that although being on coastal zones and geographic and soil identification did not use Geographic Information System (GIS). Results: A GIS is a computer-based tool for evaluating the land-use change in coastal areas by quantifying variations. It is analyzed through GIS and its contributions; highlighting its importance and constant monitoring. Limitations of the study/Implications: This research analyzes national and international scientific information, published from 2007 to 2019, regarding the land-use change in coastal areas quantified with the digital GIS tool. Findings/Conclusions: GIS are useful tools in the identification and quantitative evaluation of changes in land-use in coastal ecosystems; which require constant evaluation due to their high dynamism.


Author(s):  
H. Lilienthal ◽  
A. Brauer ◽  
K. Betteridge ◽  
E. Schnug

Conversion of native vegetation into farmed grassland in the Lake Taupo catchment commenced in the late 1950s. The lake's iconic value is being threatened by the slow decline in lake water quality that has become apparent since the 1970s. Keywords: satellite remote sensing, nitrate leaching, land use change, livestock farming, land management


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