QGIS Software Research Articles

Análise espacial de eventos pontuais para estimar o potencial produtivo da tilápia do Nilo (Oreochromis niloticus)

Devido ao crescimento da produção de tilápia e adaptabilidade a diferentes condições de criação, aos avanços da tecnologia e da sua aceitabilidade por parte do consumidor, esta pode ser uma alternativa viável para os pequenos e médios produtores rurais para o aumento da renda e diversificação da produção. Este trabalho teve como objetivo estimar o potencial de produção da tilápia do Nilo, em viveiros escavados, através de análise espacial utilizando Sistema de Informação Geográfica (SIG). Foram escolhidos 3 municípios localizados na região centro-sul do estado do Paraná, Brasil, os quais não são considerados produtores de tilápia. Utilizou-se imagens de satélite por meio do software QGIS para realizar o mapeamento dos viveiros escavados, o que possibilitou estimar o potencial produtivo do pescado, levando-se em consideração no cálculo uma produtividade média de 54 t/ha/ano. Por fim, utilizou-se a técnica da elipse de distribuição direcional, a fim de identificar o comportamento da distribuição espacial dos viveiros, proporcionando o conhecimento na sua densidade e orientação. Os resultados mostraram que para obter a melhor produção da tilápia é necessário trabalhar com uma margem segura de aproximadamente 300 dias para engorda dos peixes, justamente por respeitar o clima regional ao longo do ano e principalmente nos meses de inverno, onde ocorre menor incremento de peso na espécie. Ainda, estimou-se que há possibilidade de a região abater 34,12 t/peixe/dia, em condições padronizadas, o que é considerada uma produção relevante em relação aos dados de produção nacional, apresentados nos últimos anos pelos órgãos oficiais.

INTERPRETAÇÃO DA PAISAGEM DO SEMIÁRIDO PIAUIENSE: PRÁTICA DE CAMPO NO MUNICÍPIO DE PRATA DO PIAUÍ E NA CIDADE DE PEDRAS

O presente artigo teve como objetivo caracterizar as paisagens de trechos visitados nas atividades de campo, em Prata do Piauí e na Cidade de Pedras, buscando identificar sua adequação, ou não, à classificação de espaços semiáridos, a partir dos critérios de tipos climáticos e cobertura vegetal utilizado pela literatura para definir a região semiárida brasileira. Os procedimentos metodológicos foram embasados na abordagem dialética que teve início com a discussão em sala de aula, em momentos de articulação dos roteiros de observação nos municípios citados. Durante os trabalhos de campo utilizou-se do caráter descritivo-exploratório por meio de mapas, preenchimento de fichas, uso do aparelho Global Positioning System (GPS) e câmera fotográfica. Em laboratório fez-se uso do software Qgis para trabalhar os dados e informações levantados. Para alcançar o objetivo proposto, foi realizada a caracterização fisiográfica e a observação de forma comparativa, como subsídio à análise das paisagens locais em relação à conceituação de ambiente semiárido.

Accuracy of tree stem circumference estimation using close range photogrammetry: Does point-based stem disk thickness matter?

There is an increase in the use of photogrammetric point clouds for tree attribute mensuration. Stem diameter and circumference can be estimated from point clouds using stem disks of varying thicknesses along the bole. However, there is a dearth of information on the effect of the thickness of point cloud-based stem disks on the accuracy of diameter and circumference estimations. In this study, we outlined a GIS-based procedure for analysing Structure from Motion-derived photogrammetric point clouds with a view to providing an optimal disk thickness for accurate circumference estimates. Geo-referenced point clouds were created from photographs of 30 trees belonging to five savanna species. For each tree, 20 horizontal stem disks, with increasing thicknesses of 1 to 20 mm were made at breast height using the open source QGIS software. The resulting cross-sections were manually delineated and digitised. The difference between reference (manually measured) and point cloud-based circumferences at breast height was expressed as mean absolute percent error (MAPE) and compared across tree species, size and disk thickness. We found significant effects of species identity, tree size and disk thickness on MAPE. A stem disk of 7 mm in thickness provided consistently lower MAPE values (< 6%). This suggests that the accuracy of tree stem circumference estimations from photogrammetric point clouds depends on stem disk thickness.

Analysis and spatial distribution of schistosomiasis mansoni in a historically endemic area of northeastern Brazil.

To perform a descriptive analysis of the activities of the Schistosomiasis Control Program, as well as the spatial distribution of the condition in the state of Alagoas, Brazil, for the period from 2007 to 2016. Descriptive ecological study. Data from positive human cases and operational data were collected in the Information System of the Schistosomiasis Control Program, and data for spatial analysis were collected on the website of the Brazilian Institute of Geography and Statistics. An analysis of spatial autocorrelation (Moran statistics) was performed, where a spatial pattern was established, which showed the Q1 and Q2 patterns to be the most important, and Q3 and Q4 representing transition areas. In the years under study, at least 85% (n=60/70) of the municipalities carried out the activities recommended by the PCE (Schistosomiasis Control Program). Alagoas presented an average positivity rate of 7.1%, which is very high compared to the prevalence of 3.3% at the last national schistosomiasis survey conducted between 2010 and 2015. Moran's statistics showed 22/70 municipalities forming a Q1 cluster, of high/high pattern, and 32/70 municipalities forming a Q2 cluster, of low/low pattern, with the others in a transition area. Moran Map data, however, showed only 7/70 municipalities in the endemic area with a spatial autocorrelation, with these municipalities having the Mundau River as a common element. Schistosomiasis mansoni is of great importance for public health in Alagoas and that the use of spatial analysis can identify priority areas for preventive and control measures against schistosomiasis mansoni.

TYPOLOGICAL STUDY AND CATALOGUING OF LATE MEDIEVAL MANOR HOUSES OF THE BASQUE COUNTRY (SPAIN)

Abstract. Manor Houses were the homes and centres of operation of Basque noble families during the Late Medieval Period. From early defensive Tower Houses to the Palaces of the early 16th century, Manor Houses evolved during the Late Middle Ages, adapting to different historical periods. Despite their heritage value, these buildings are in danger of being lost. Investigations of past centuries encouraged the emergence of false beliefs around Manor Houses – excessively old constructive periods, assignment of defensive origins to most buildings, etc.–. This has resulted in serious errors in heritage catalogues and, subsequently, a high number of unfortunate architectural interventions. This paper aims to analyse and characterize the typological evolution of Basque Manor Houses, in order that the results be used as guideline for future protection strategies. The work was divided into three sections: field work, documentary research and historical-constructive analysis. Collected data was uploaded into QGIS software, which was then used to carry out a comparative analysis. An inventory of 2050 Manor Houses has been developed, which includes a “Red List” of 472 buildings in danger of being lost. Five typologies of Manor Houses have been identified: one with a defensive function – the Tower House – and four types of non-defensive constructions – Tower Palace, Rural Palatial House, Large Palace and Village Manor House –. Most of the existent Basque Manor Houses were built after the mid-15th century and were non-defensive from their original construction.

ESTIMASI NILAI CADANGAN KARBON MENGGUNAKAN ANALISIS NDVI (NORMALIZED DIFFERENCE VEGETATION INDEX) DI KHDTK UNIVERSITAS LAMBUNG MANGKURAT

This research aims to determine the value of carbon stock based on the NDVI and make a connection between the value of NDVI and the value of carbon stock. This research was conducted at KHDTK Lambung Mangkurat University, South Borneo. The time needed to carry out this research for four months, from january to April, which includes research preparation, data collection and preparation of research reports. Estimation of carbon stock calculated from 47% of biomass value with trees &gt;10 cm in diameter on three types of vegetation density. Vegetation density was predicted using the NDVI value processed using QGIS software and based on field observations. The value of NDVI at very rare densities with the range of value (0.52-0.59),at rare densities with the range of value (0.69-0.77), and at medium densities with the range of value (0.81-0.85). The value of carbon stock in three types of vegetation density each are 3.34 (ton/ha) at very rare densities, 11.61 (ton/ha) at rare densities to medium, and 32.04 (ton/ha) at medium densities. The relationship between the value of NDVI and the value of carbon stock uses the exponential regression equation model y = 0.0304e8.2416x and determination coefficient R2=0.909. determination coefficient R2&gt;0.40 show strong relationships, thus the greater the value of R2 between NDVI and stock carbon are better.

DEVELOPMENT OF TECHNOLOGY FOR FORMING THE BOUNDARIES OF POLLING STATIONS USING THE QGIS SOFTWARE PACKAGE

The article presents the results of production work on the implementation of a geoinformation project to create an electronic plan of the city of Novosibirsk. The digital plan shows the electoral districts for holding elections of deputies of the Novosibirsk city Council and voting on amendments to the Constitution of the Russian Federation in 2020. A special feature of the work is the use of free software QGIS. A sequence of works is presented, as well as a description of the author's algorithms for automating technological operations. The work is of a production nature and can be used as guidelines for creating digital thematic maps.

ANALISIS POTENSI TENAGA SURYA PADA PERMODELAN BANGUNAN TIGA DIMENSI BERDASARKAN DATA OPEN STREET MAP (STUDI KASUS: UNIVERSITAS GADJAH MADA YOGYAKARTA)

Energy crisis that occurred in the world after being exploited on a large scale against fossil energy caused people has to think again about renewable energy. In Indonesia, the electricity consumption always increases every year with fossil energy dominating energy sources. Based on the Government Regulation number 79 of 2014, concerning the National Energy Policy, the Government of Indonesia has a national target in the implementation of renewable energy of 23% in 2025 and 31% in 2050. Information disclosure and development of geospatial technology is shown through the availability of information on the dimensions, location, and the height of objects on the surface of the earth through the open street map (OSM) website, one of which is the building. Digital Elevation Model (DEM/DEMNAS) data can be accessed through the Geospatial Information Agency (BIG) website. Utilization of this information can be done by utilizing QGIS and ArcGIS Pro software. The existence of an energy crisis and technological developments led to calculate Solar Radiation (contained in ArcGIS Pro) which can calculate the solar potential at a location based on three-dimensional building data, DEM, and solar intensity. Universitas Gadjah Mada (UGM) has announced their commitment in realizing new and renewable energy in Indonesia. Therefore, researchers intend to find out the solar potential in the UGM region in order to realize government programs in the application of new renewable energy. Based on the analysis done in this research, we get the amount of solar energy potential of 369.543 kWh/ m2/ day. Through this research we hope that UGM can become a pilot campus in the application of renewable energy, solar energy and can reduce the use of conventional electricity using fossil energy.Keywords: Solar Energy Potential, Three Dimensional Building, Open Street Map, UGM.

FATORES GEOMORFOLÓGICOS NA CONTRIBUIÇÃO DE OCORRÊNCIA DE PROCESSOS EROSIVOS AS MARGENS DA RODOVIA TO-445, MUNICÍPIO DE MIRACEMA-TO

Processos erosivos são fenômenos nos quais materiais inconsolidados da crosta terrestre são desagregados e transportados por agentes da natureza como água, vento e gelo, podendo ser acelerado ou mesmo provocados por ações antrópicas. O presente trabalho é composto pelo levantamento de dados geograficos que permite a análise de trechos mais propensos ao surgimento de processos erosivos as margens da rodovia TO-445, entre as cidades de Miracema e Lajeado do Tocantins, no estado do Tocantins. Buscando entender como as variáveis do meio físico interagem e atuam no desenvolvimento das erosões próximas a rodovia e as patologias (defeitos) presentes na capa asfáltica da via, foram realizados o levantamento bibliográfico e a análise de dados disponibilizados pela SEFAZ, TOPODATA e INPE, sendo os dados processando-os por meio do Sistemas de Informação Geográfica (SIG) através do software QGIS. As áreas com presença de processos erosivos, foram identificadas por meio de geoprocessamentos utilizando-se imagens de satélite via Google Earth Pro. Através da correlação entre mapas de Curvatura vertical e horizontal, formas do terreno, declividade, hipsometria, geologia, geomorfologia, solos e uso e ocupação, foi possível compreender o comportamento dos fatores que influenciar e causar processos de erosão as margens da rodovia, bem como os pontos mais propensos ao surgimento de patologias na faixa de rolamento da rodovia em estudo.

Proposta de Zoneamento Ambiental para o Parque Estadual Mata do Pau Ferro, Paraíba, Brasil

O bioma Mata Atlântica é uma das áreas de maior biodiversidade do mundo e uma das mais degradadas pela ação antrópica, em vista disso, constitui uma área prioritária para a implantação de Unidades de Conservação da Natureza. A escassez de recursos financeiros e baixa disponibilidade de pessoal representam as principais dificuldades enfrentadas pelos órgãos ambientais para a manutenção das áreas protegidas. No estado da Paraíba, o Parque Estadual Mata do Pau Ferro abriga um dos fragmentos de Mata Atlântica mais representativos do estado. Situado no Planalto da Borborema, o fragmento está circundado pelo bioma Caatinga, apresentando-se assim, como um Refúgio Florestal. O Parque ainda não possui Plano de Manejo implementado, pelo que não dispõe de zoneamento, o que tem dificultado a sua gestão. Diante do exposto, o presente trabalho se propõe a elaborar uma proposta de Zoneamento Ambiental para o Parque Estadual Mata do Pau Ferro. Para a elaboração da proposta de Zoneamento Ambiental foram realizadas as seguintes etapas: levantamento bibliográfico, aquisição de imagens do satélite Sentinel – 2B, levantamento das bases cartográficas da área de estudo e trabalhos de campo para mapeamentos, coleta de dados e registros fotográficos. Os dados foram processados através do software livre QGIS 2.18.25, e posteriormente utilizados para elaboração dos mapas ambientais. A partir da análise dos mapas e com base nos critérios do Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis – IBAMA foi realizada a delimitação das zonas. Os resultados evidenciaram o potencial do Parque para preservação da biodiversidade, manutenção do sistema hídrico da barragem Vaca Brava, turismo e educação ambiental. Foi identificada também a presença de conflitos e áreas degradadas no interior da unidade. A cobertura da Zona de Amortecimento apresentou dominância de pastagens e presença de fragmentos florestais com potencial para o estabelecimento de corredores ecológicos. Com o Zoneamento Ambiental foram estabelecidas sete zonas: Zona Intangível; Zona Primitiva; Zona de Uso Extensivo; Zona de Recuperação; Zona de Uso Conflitante; Zona de Ocupação Temporária; e Zona de Uso Especial. O zoneamento apontou a necessidade de mudança de uso das áreas, resolução de conflitos internos e maior fiscalização por parte dos órgãos gestores. As elaborações cartográficas e dados levantados podem ser utilizadas como subsídios ao planejamento e manejo da Unidade de Conservação, visando o alcance dos objetivos traçados para a categoria.

Comparative Assessment of the Unsupervised Land Use Classification by Using Proprietary GIS and Open Source Software

Mapping and investigating land use land cover (LULC) changes over a particular region is crucial for resource management, sustainability development, and holistic planning. An increasing rate of urban growth and urban sprawl could induce changes in land use as well as land transformation. However, accurate and up-to-date information about LULC is required for providing better understanding and assessing the environmental consequences of such changes. In this study, the 2017 image from the Sentinel-2A Satellite was utilized to demonstrate the land cover classification analysis in Iskandar Malaysia. Usually, land use classification analysis is conducted through proprietary GIS software. However, this decade shows the advancement in software development, thus the emerging of free/open source software in the geospatial world. Hence, to execute land cover analysis using the Unsupervised Classification technique, the proprietary GIS software (ArcGIS) and free/open source software (QGIS) were deployed. Then, the examination of accuracy assessment was carried out for the selected software. The sum of 250 random points was established for the assessment purpose. The results showed the overall accuracy for ArcGIS and QGIS were 82.80% and 80.40% respectively. The kappa coefficient for ArcGIS was 0.7395, while kappa coefficient for QGIS was 0.7094. Besides that, ArcGIS demonstrated better producer’s accuracy in the forest and agriculture land covers classification. Meanwhile, QGIS exhibited better producer’s accuracy in the built-up and water features classification. To summarize, ArcGIS and QGIS software are reliable to be used in the land cover classification.

Estimation of the environmental impact of Military Exercises on a bombing range by employing radionuclide mapping and drone imaging

A Gamma In Situ Potable Device (GISPI) was used to map naturally occurring radionuclides in an abandoned South African Air Force (SAAF) bombing range on the west coast of South Africa. The concentrations of potassium and radioactive progeny of thorium and uranium were measured and plotted with the help of QGIS software. The results demonstrated changes in radionuclide concentrations in specific areas of the ranges. These areas were correlated with areas where weapon testing and live bombing exercises were conducted. The areas were also surveyed and photographed with a drone. The article finally draws conclusions as to the environmental impact of the bombing on the area. This method can be used to investigate other bombing ranges in future quickly and effectively.

Geospatial clustering of newly diagnosed HIV infected adults in Cross River State helps define new “hotspots”

Introduction: A hotspot is a geographical location having evidence of high STIs/HIV prevalence, and/or behaviors that put people at high risk of becoming infected. Therefore, Nigeria, with almost two million people living with HIV, could be considered a giant “hotspot.” The main aim was to describe how the geospatial clustering of newly diagnosed HIV-infected adults in Cross River State helps define new “hotspots.”Methods: Secondary data collected between January 2020 and March 2020, identified and mapped around a presumed hotspot’s radius of influence (ROI), were analyzed using a “Hotspot Analysis” plugin in QGIS software. With a sample size of 3019, both seropositive and seronegative results were geo-referenced and the resultant map was analyzed to determine HIV-positive clusters.Results: From the 3019 spatial locations mapped, 720 (23.9%) were positive cases. Of these, 328 (45.6%) were thus estimated as being associated with the presumed hotspots. The remaining 392 (54.4%) were positive cases identified outside of the ROI of the originally presumed hotspots. The total number of mapped HIV testing services (HTS) points (both negative and positive cases) within the hotspot ROI was 1319, while those outside of the hotspot ROI were 1700.Discussion: Collectively, the clustering of the HTS points into various groups indicating that hard-to-reach communities along the borders with the Republic of Cameroon on the east and Akwa Ibom State on the southwest had a majority of the new clusters.Conclusion: Unique hotspots where social gatherings occur tended to have a wider ROI. Targeted testing in these hard-to-reach communities is recommended.

Interconnected ecological network design using lcp algorithm and cohesion index in urban scale

The structure of interconnected ecological network in cities includes corridors and large green spots continuity which provides ecosystem services, e.g. biodiversity conservation. From a functional perspective, green infrastructure would be one of the most adapted ways of solving environmental issues caused by restricted vegetation in intensive urban areas with high density of gray infrastructures. In this study, green infrastructures of Hamadan with an area of ​​about 74.22 km2 across 75 districts, (including agricultural lands, Parks, gardens and vacant lands) were classified as Service Providing Units (SPUs). Gardens and parks classes with dense tree cover as well as high ecosystem standards, were selected as green habitat patches, including 205 patches in the study area. Considering the highest quality of habitats, 14 patches were chosen as habitat cores based on having the highest level of COHESION metric, and the area of more than 12 ha. We performed the Least Cost Path (LCP) method through QGIS software at the study area to see core habitats connectivity; using a simple algorithm to calculate the cumulative cost of moving through landscape. Results show that a total of 91 potential corridors were identified connecting the main cores. Optimal corridor selection was based on two scenarios, the shortest and the least costly route. Therefore 23 and 54 corridors were selected. By combination of two scenarios and considering the overlap of some routes, the final corridors were also identified. To keep up network connectivity, in the case of Corridor 6–9 with high costs over threshold, stepping-stones have been defined to reduce costs and distance.

PPSTS: Privacy Preservation in Geographical Data by Spatio-Temporal Shifting Using Elliptic Curve Cryptography

Footprints of an individual moving around on the surface of earth with location enabled handheld device are saved and can be accessed by him anytime using his credentials. This data is very sensitive and should be handled in very secure way. This data may reveal huge information about an individual like office address, home address, behavior pattern, daily schedule to name a few. Taking into consideration the sensitivity of the information, highest level of security is required for storing, retrieving and sending it. To achieve this level of security this paper proposes way of encrypting this historical geographical data, the proposed work is divided into three modules. Firstly, individually identifiable information is removed from the data, secondly latitude and longitude coordinates in source and destination are shifted and finally temporal aspects of geographical data are shifted. Three modules of proposed work were implemented in QGIS software and identity, time and location were encrypted.

Mapeamento da COVID-19 no Estado da Paraíba: Elementos para a espacialização e análise em ambiente SIG

O Brasil foi um dos primeiros países da América Latina com casos de Covid-19, academicamente, desde o início de janeiro de 2020 observamos no Portal de Periódicos da Capes o crescimento de produções sobre esse tema. Contudo, percebemos a ausência de análises sobre o Estado da Paraíba, o que nos proporcionou a curiosidade de compreendermos como esse fenômeno vem de manifestando e de que forma o uso de um Sistema de Informações Geográficas poderia contribuir para essa reflexão. Nesse sentido, o presente artigo apresenta por objetivo realizar uma análise sobre o processo de disseminação e distribuição dos casos e óbitos de Covid-19 no Estado da Paraíba através de um Sistema de Informações Geográficas. Para o alcance desse objetivo realizamos a busca de boletins epidemiológicos na Secretaria Estadual de Saúde dentre o período de 31 de março até 16 de Maio de 2020. Esses dados foram sistematizados a partir dos casos e óbitos existentes no Estado através do software QGIS, no qual geramos um total de nove mapas temáticos. Nossos resultados indicam pelo menos três tendências da pandemia no Estado: a) distribuição espacial da Covid-19 na Paraíba segue o fluxo na BR-230; b) existência de três principais núcleos de disseminação: região metropolitana de João Pessoa; Campina Grande e as cidades de Sousa e Patos; c) padrão elevado de contaminação entre profissionais da saúde. Tais resultados nos apresenta outra demanda, a necessidade de entendermos como numa escala intra-urbana a pandemia vem se manifestando, especialmente nos três principal polos de disseminação do Estado.

Weekly sea surface temperature from SNPP-VIIRS data using open source software

The objective of this study is to make weekly mean sea surface temperature (SST) from SNPP-VIIRS satellite data. The data used were SST data every afternoon pass, from 13 to 19 May 2019. The data were obtained from Remote Sensing Technology and Data Center, LAPAN. From 12 samples data used showed that pixel size of each data are different, with range between 0.006737548 - 0.006858158 degree. The pixel size should be exactly the same to do data overlay. Then, the pixel size was resized become 0.00675 degree. This process was carried out using Reprojection Menu in QGIS software. The next process was calculating weekly mean SST every pixel. The mean SST was calculated only on pixels that have SST values. The calculation was not carried out on cloud, cloud shadow, land, and out of coverage data. The tolerance of coordinate position between pixels are less than 0.5 of pixel size. Weekly mean SST calculation process was executed using mean function in R software. The result of mean SST showed some possible error SST values. The errors were found in these conditions: 1) in coastal areas where possible mixed pixels of land and water 2) near cloud, where possible mixed pixel of cloud, cloud shadow, and water, 3) pixels with (extremely) high SST values near clouds. To overcome these conditions, some median type filters were applied. Therefore, weekly mean SST from SNPP-VIIRS data that smooth and minimum cloud cover can be obtained.

Remote sensing-based detection of agricultural land losses around Greater Cairo since the Egyptian revolution of 2011

Over the last four decades, the loss of agricultural land has been observed in Egypt at high rates. However, the highest rates of losses have occurred since the January 25th revolution in 2011. Greater Cairo (GC), which is the largest metropolitan in Egypt, has witnessed a massive loss of agricultural land since the 2011 revolution. However, until now, no study or official report has revealed the volume of agricultural land losses in this region. This study quantifies agricultural land losses around the GC using Landsat satellite images from 2010 and 2018. Supervised classification was performed using the maximum likelihood algorithm in QGIS software. A post-classification comparison method was applied to detect the land use/land cover changes between the classified images; then, the loss of agricultural land was quantified using Arc GIS software. Visualizations of the gains and losses in agricultural land and the spatial trends of agricultural land losses were created using TerrSet software. The results show that 9600 ha of agricultural land were converted to urban use during 2010–2018, which means that the annual rate of agricultural land loss has tripled and now reaches approximately 1200 ha per year. Decay of executive authority, rapid population growth, real estate market speculation and fragmentation of agricultural land were the main driving factors of agricultural land losses during this period. The results of this research may help decision makers understand the current high rate of agricultural land loss. Hence, appropriate strategies may be adopted to prevent future losses of this valuable land.

Open-Source Software Application for Hydrogeological Delineation of Potential Groundwater Recharge Zones in the Singida Semi-Arid, Fractured Aquifer, Central Tanzania

This study attempted to delineate and map potential groundwater recharge zones of the Singida, semi-arid, fractured crystalline basement aquifer using open source remote sensing and GIS software. Various thematic maps such as lithology/hydrogeology, soil, land-cover/use, slope, lineament density, drainage density and rainfall distribution were integrated in QGIS software. Vector input layers were rasterized and resampled using QGIS wrap projection function to make sure that the grid cells are of the same size. Reclassification using SAGA and GRASS reclass algorithms in QGIS was carried out to realign the factor classes in a consistent scale, and reclassification to a scale of 1 to 5 was carried out to harmonize the results. The study identified a number of potential areas for groundwater recharge, groundwater exploration, groundwater development and potential areas for artificial groundwater recharge. Potential groundwater recharge zones for the Singida semi-arid fractured aquifer are restricted to areas with high lineament density, cultivated areas, grassland and flat to gentle slopes. The potential of groundwater recharge is also observed in areas with low drainage density. The delineated zones provide a good understanding of the potential recharge zones, which are a starting point for recharge zone protection. This blended approach can be utilized for carrying out suitability analysis using the weighted overlay analysis approach. Areas designated good and very good are recommended for artificial recharging structures as an alternative technique for enhancing groundwater recharge through rainwater harvesting. This will help to augment groundwater storage in this semi-arid environment.

Remote Sensing and Multi-Criteria Evaluation for Malaria Risk Mapping to Support Indoor Residual Spraying Prioritization in the Central Highlands of Madagascar

The National Malaria Control Program (NMCP) in Madagascar classifies Malagasy districts into two malaria situations: districts in the pre-elimination phase and districts in the control phase. Indoor residual spraying (IRS) is identified as the main intervention means to control malaria in the Central Highlands. However, it involves an important logistical mobilization and thus necessitates prioritization of interventions according to the magnitude of malaria risks. Our objectives were to map the malaria transmission risk and to develop a tool to support the Malagasy Ministry of Public Health (MoH) for selective IRS implementation. For the 2014–2016 period, different sources of remotely sensed data were used to update land cover information and substitute in situ climatic data. Spatial modeling was performed based on multi-criteria evaluation (MCE) to assess malaria risk. Models were mainly based on environment and climate. Three annual malaria risk maps were obtained for 2014, 2015, and 2016. Annual parasite incidence data were used to validate the results. In 2016, the validation of the model using a receiver operating characteristic (ROC) curve showed an accuracy of 0.736; 95% CI [0.669–0.803]. A free plugin for QGIS software was made available for NMCP decision makers to prioritize areas for IRS. An annual update of the model provides the basic information for decision making before each IRS campaign. In Madagascar and beyond, the availability of the free plugin for open-source software facilitates the transfer to the MoH and allows further application to other problems and contexts.