scholarly journals Mapping malaria risk using environmental and anthropic variables

2009 ◽  
Vol 12 (3) ◽  
pp. 338-354 ◽  
Author(s):  
Mauricio Edilberto Rincón-Romero ◽  
Julián Esteban Londoño

Despite much research in the identification of areas with malaria, it is urgent to further investigate mapping techniques to achieve better approaches in strategies to prevent, mitigate, and eradicate the mosquito and the illness eventually. By using spatial distributed modeling techniques with Geographical Information Systems (GIS), the study proposes methodology to map malaria risk zoning for the municipality of Buenaventura in Colombia. The model proposed by Craig et al.¹ using climatic information was adapted to the conditions of the study area regarding scale and spatial resolution. Geomorphologic and anthropic variables were added to improve spatial allocation of areas with higher risk of contracting the illness, refining zoning. Then, they were contrasted with the locations reported by health entities², taking into account spatial distribution. The comparison of results shows a decrease in the area obtained initially using the Craig et al. model¹ (1999), from 5,422.4 km² (89.1% of the municipality's territory) to 624.3km² (approximately 10% of the municipality's area), yielding a total reduction of 78.8% when environmental and anthropic variables were included in the model. Data show that of the 9,863 cases reported during 2001 to 2005 for 20 selected towns as basis for the amount of surveyed malaria cases², 1,132 were located in the very high-risk areas, 7,662 were in the areas of moderate risk, and 1,066 cases in low-risk areas, showing that 89% of the cases reported fell into the areas with higher risk for malaria.

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Amare Sewnet Minale ◽  
Kalkidan Alemu

The main objective of this study was to develop a malaria risk map for Bahir Dar City, Amhara, which is situated south of Lake Tana on the Ethiopian plateau. Rainfall, temperature, altitude, slope and land use/land cover (LULC), as well as proximity measures to lake, river and health facilities, were investigated using remote sensing and geographical information systems. The LULC variable was derived from a 2012 SPOT satellite image by supervised classification, while 30-m spatial resolution measurements of altitude and slope came from the Shuttle Radar Topography Mission. Metrological data were collected from the National Meteorological Agency, Bahir Dar branch. These separate datasets, represented as layers in the computer, were combined using weighted, multi-criteria evaluations. The outcome shows that rainfall, temperature, slope, elevation, distance from the lake and distance from the river influenced the malaria hazard the study area by 35%, 15%, 10%, 7%, 5% and 3%, respectively, resulting in a map showing five areas with different levels of malaria hazard: very high (11.2%); high (14.5%); moderate (63.3%); low (6%); and none (5%). The malaria risk map, based on this hazard map plus additional information on proximity to health facilities and current LULC conditions, shows that Bahir Dar City has areas with very high (15%); high (65%); moderate (8%); and low (5%) levels of malaria risk, with only 2% of the land completely riskfree. Such risk maps are essential for planning, implementing, monitoring and evaluating disease control as well as for contemplating prevention and elimination of epidemiological hazards from endemic areas.


2011 ◽  
Vol 30 (3) ◽  
pp. 13-18
Author(s):  
Piotr Dzieszko

Analogue aerial-photopraphs external orientation reconstruction based on geoportal data For acquisition of source data for geoinformation analyses is necessary to do some field works. This way of data acquisition is time-consuming. In this case, photogrammetric and remote sensed methods can be more effective choice. Especially orthophotomap extracting is more effective process in creation of geodata. It is good foundation for further analysis and nice extension of existing geographical information systems. Despite fast growth of photogrammetry there are plenty of analogue, archival airphotos which can be used for geoinformation analysis. They are quiet up to date and scanned in very high resolution which means they can be used for really reliable analysis. The problem is very important because many of analogue, archival air photos do not contain photogrammetric warp. The aim of this paper is expression of applicability of geoportal webpage, which is part of INSPIRE directive, that can be used for external orientation reconstruction when there is no other georeference data.


Author(s):  
D. Al-Dogom ◽  
K. Schuckma ◽  
R. Al-Ruzouq

<p><strong>Abstract.</strong> Assessing and analyzing the spatial distribution of earthquake events aids in identifying the presence of clustering and reveals hot and cold spots across the study area. Combining the spatial analysis of earthquake events with other geographical and geophysical parameters leads to more understanding of the vulnerability of critical infrastructure and the demographics of the affected population. This study will use Geographical Information Systems (GIS) to examine the spatiotemporal occurrence of earthquake events throughout the Arabian plate and their effect on the United Arab Emirates (UAE). Spatial pattern analysis techniques, including Moran I and Getis–Ord Gi*, were applied to 115 years of earthquakes (1900&amp;ndash;2015) that have occurred throughout the Arabian plate. The directional distribution (standard deviational ellipse) of earthquake magnitudes was analyzed to determine the spatial characteristics and the directional tendency of the earthquakes throughout the Arabian plate. Afterword, geophysical parameters of UAE, specifically Peak Ground Acceleration (PGA), fault line distance, slope, soil type, and geology were ranked, weighted based on its contribution and combined using an Analytic Hierarchy Process (AHP) to identify and locate seismic hazard zones. The resulted Seismic Hazard Zonation Map (SHZM) was classified to five hazard zones ranging from very high to very low. It has been found that Fujairah city sited in the “very High” zone, Sharjah and Dubai cities located from “High” to moderate zones while Abu Dhabi city stands relatively far from seismic hot spots and major faults and placed in the low seismic hazard zone. The results of this study could help improve urban planning and emergency mitigation strategies in UAE.</p>


2021 ◽  
Vol 10 (9) ◽  
pp. 598
Author(s):  
Luís Russo Vieira ◽  
José Guilherme Vieira ◽  
Isabel Marques da Silva ◽  
Edison Barbieri ◽  
Fernando Morgado

Coastal erosion is considered a major worldwide challenge. The vulnerability assessment of coastal areas, in relation to climate change, is a key topic of worldwide increasing interest. The integration of methodologies supported by Remote Sensing, Geographical Information Systems (GIS) and in situ monitoring has allowed a viable identification of vulnerable areas to erosion. In the present study, a model was proposed to the assessment of the estuarine system of Cananéia-Iguape (Brazil), by applying the evaluation and prediction of vulnerability models for the conservation and preservation of mangroves. Approximately 1221 Km2 were classified, with 16% of the total presenting high and very high vulnerability to erosion. Other relevant aspects, were the identification and georeferencing sites that showed strong evidence of erosion and, thus, having a huge influence on the final vulnerability scores. The obtained results led to the development of a multidisciplinary approach through the application of a prediction and description model that resulted from the adaptation of the study system from a set of implemented models for coastal regions, in order to contribute to the erosion vulnerability assessment in the mangroves ecosystems (and associated localities, municipalities and communities).


2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Soma Sarkar ◽  
Poonam Singh ◽  
Mercy Aparna L. Lingala ◽  
Preeti Verma ◽  
Ramesh C. Dhiman

Mapping the malaria risk at various geographical levels is often undertaken considering climate suitability, infection rate and/or malaria vector distribution, while the ecological factors related to topography and vegetation cover are generally neglected. The present study abides a holistic approach to risk mapping by including topographic, climatic and vegetation components into the framework of malaria risk modelling. This work attempts to delineate the areas of Plasmodium falciparum and Plasmodium vivax malaria transmission risk in India using seven geo-ecological indicators: temperature, relative humidity, rainfall, forest cover, soil, slope, altitude and the normalized difference vegetation index using multi-criteria decision analysis based on geographical information system (GIS). The weight of the risk indicators was assigned by an analytical hierarchical process with the climate suitability (temperature and humidity) data generated using fuzzy logic. Model validation was done through both primary and secondary datasets. The spatio-ecological model was based on GIS to classify the country into five zones characterized by various levels of malaria transmission risk (very high; high; moderate; low; and very low. The study found that about 13% of the country is under very high malaria risk, which includes the malaria- endemic districts of the states of Chhattisgarh, Odisha, Jharkhand, Tripura, Assam, Meghalaya and Manipur. The study also showed that the transmission risk suitability for P. vivax is higher than that for P. falciparum in the Himalayan region. The field study corroborates the identified malaria risk zones and highlights that the low to moderate risk zones are outbreak-prone. It is expected that this information will help the National Vector Borne Disease Control Programme in India to undertake improved surveillance and conduct target based interventions.


2018 ◽  
Vol 21 (1) ◽  
pp. 104-122 ◽  
Author(s):  
P. Sanzana ◽  
J. Gironás ◽  
I. Braud ◽  
N. Hitschfeld ◽  
F. Branger ◽  
...  

Abstract 2D non-uniform polygonal meshes allow representation of the impact of landscape elements and small infrastructures on water flows. The initial vectorial mesh, derived from the intersection of several geographical information systems' layers, can have highly non-convex or sliver polygons. These bad-shaped elements compromise accurate numerical flow computation. We propose a flexible divide-and-conquer strategy to decompose polygons into physiographical meaningful parts using shape descriptors to better represent the surface terrain and hydrologic connectivity. We use the convexity index (CI) and the form factor (FF) to consider convex and square like optimum shapes. The strategy was applied to two peri-urban areas whose hydrologic response was simulated using distributed modeling. Good-quality meshes were generated with threshold values of CI≈0.8 and FF≈0.2, and CI≈0.95 and FF≈0.4 for undeveloped and highly urbanized zones, respectively. We concluded that the mesh segmentation facilitates the representation of the spatially distributed processes controlling not only the lumped response of the catchment, but also the spatial variability of water quantity and fluxes within it at medium and small scales.


2021 ◽  
Vol 9 (8) ◽  
pp. 815
Author(s):  
Muhammad Irham ◽  
Ichsan Rusydi ◽  
Haekal A. Haridhi ◽  
Ichsan Setiawan ◽  
Yopi Ilhamsyah ◽  
...  

The purpose of this study was to determine how vulnerable the west coast of Aceh Besar, Aceh province, Indonesia, is in terms of its coastal morphology. This research was conducted from August to December 2020 and data processing was carried out at the Geographical Information Systems Laboratory, Faculty of Marine Affairs and Fisheries, Syiah Kuala University. The method used was the coastal vulnerability index (CVI) with four geological parameters, namely geomorphological parameters, beach elevation, beach slope and shoreline changes. The results obtained from the CVI method show that 20.60% of the west coast of Aceh Besar, which has a total coastline length of 93.2 km, is in the very high vulnerability category (19.2 km), while 23.18% (21.6 km) is in the high vulnerability category, 8.80% (8.2 km) in the moderate category, 6.44% (6 km) in the low category and 40.99% (38.2 km) in the very low category. Sub-districts classified as having very high vulnerability are Peukanbada (7.94%), Leupung (6.22%), Lhoong (4.94%), and Lhoknga (1.50%). The geomorphology of areas that have very high vulnerability is generally in the form of sandy beaches with a very gentle slope, while, geomorphologically, areas that have very low vulnerability have a high elevation and cliff beaches.


2018 ◽  
Vol 42 (6) ◽  
pp. 575-587 ◽  
Author(s):  
Alice Alonzo Steinmetz ◽  
Felício Cassalho ◽  
Tamara Leitzke Caldeira ◽  
Vinícius Augusto de Oliveira ◽  
Samuel Beskow ◽  
...  

ABSTRACT Soil erosion is currently one of the main concerns in agriculture, water resources, soil management and natural hazards studies, mainly due to its economic, environmental and human impacts. This concern is accentuated in developing countries where the hydrological monitoring and proper soil surveys are scarce. Therefore, the use of indirect estimates of soil loss by means of empirical equations stands out. In this context, the present study proposed the assessment of the Revised Universal Soil Loss Equation (RUSLE) with the aid of Geographical Information Systems (GIS) and remote sensing for two agricultural watersheds in southern Rio Grande do Sul - Brazil. Among all RUSLE factors, LS showed the closest patterns to the local when compared to the total annual soil loss, thus being a good indicator t of risk areas. The total annual soil loss varied from 0 to more than 100 t ha-1 yr-1, with the vast majority (about 65% of the total area) classified from slight to moderate rates of soil loss. The results estimated according to RUSLE indicated that over 10% of the study area presented very high to extremely high soil loss rates, thus requiring immediate soil conservation practices. The present study stands out as an important scientific and technical support for practitioners and decision-makers, being probably the first of its nature applied to extreme southern Brazil.


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