scholarly journals Cadastral Information and Erosion Modeling for Monitoring Gullies in Mpazi Catchment Area, Kigali City

Author(s):  
J.P Bizimana, ◽  
E Ndahigwa

Due to the lack of sediment load monitoring system, erosion model calibration is challenging in Rwanda. Based on the reports of parcels boundaries corrections from Rwanda Land Management and Use Authority, there are quite consistent losses of land due to gullies development in Mpazi River watershed. This study analysed the possibility of integrating cadastral information, erosion and hydrological modelling data for identifying potential gullies development in hilly urban area of Mpazi catchment. The orthophoto of 2008 coupled with ancillary data were used to delineate the shifts of parcel boundaries from 2012 to 2016. Hydrological modelling based on DEM was also applied to investigate geo-physical characteristics and potential gullies. The differential GPS was used to locate the potential gullies that were then uploaded into GIS. Gullies intersecting with rectified parcels boundary were measured with tape meter. The gully length was measured using hydrological modelling tools and GPS coordinates captured during the field verification. The results showed that gully system expanded from 7.5 to 20 meters while neighboring parcels shift was between 3 and 12.5 meters. The highest average rate of soil loss ranged between 100 and 150 tons/ha/year. The research findings from this study are salient for policy- and decision-makers who need to review the current land and environment policies and laws so that gully erosion can be assigned appropriate mitigation measures for ecologically sustainable management of hilly urban landscapes within Kigali City. More periodic data are required to feed the model and validating this approach brings the government institutions’ responsibility. The developed methodology has the potential to quantify the gully systems in urban context with scarce hydrological, soil and geomorphological data availability and where urban planning and environmental protection are constrained by limited financial and human resources. Keywords: Cadastral Maintenance Data, Erosion Modelling, Gully, Urban Areas

2020 ◽  
Vol 12 (12) ◽  
pp. 2007
Author(s):  
Kathryn Sheffield ◽  
Tony Dugdale

Weeds can impact many ecosystems, including natural, urban and agricultural environments. This paper discusses core weed biosecurity program concepts and considerations for urban and peri-urban areas from a remote sensing perspective and reviews the contribution of remote sensing to weed detection and management in these environments. Urban and peri-urban landscapes are typically heterogenous ecosystems with a variety of vectors for invasive weed species introduction and dispersal. This diversity requires agile systems to support landscape-scale detection and monitoring, while accommodating more site-specific management and eradication goals. The integration of remote sensing technologies within biosecurity programs presents an opportunity to improve weed detection rates, the timeliness of surveillance, distribution and monitoring data availability, and the cost-effectiveness of surveillance and eradication efforts. A framework (the Weed Aerial Surveillance Program) is presented to support a structured approach to integrating multiple remote sensing technologies into urban and peri-urban weed biosecurity and invasive species management efforts. It is designed to support the translation of remote sensing science into operational management outcomes and promote more effective use of remote sensing technologies within biosecurity programs.


2017 ◽  
Vol 26 (3) ◽  
pp. 259-275 ◽  
Author(s):  
Tony Rey ◽  
Loic Le De ◽  
Frederic Leone ◽  
David Gilbert

Purpose The purpose of this paper is to develop a multidimensional approach for effectively managing natural disasters; this paper has three research objectives. First, it provides an analysis on the hydro-geomorphological effects of the cyclone in the urban context. Second, it proposes an analysis for the vulnerability and resilience recovery of the populations living in urban areas. Third, it specifies the implications for sustainable recovery and longer-term disaster risk reduction. Design/methodology/approach A detailed case study of the tropical cyclone Pam was carried out to identify hydro-geomorphologic effects and damages in an urban area and specific problems associated with managing natural disaster in Vanuatu. Findings The investigations reveal that living in an urban area increases a population’s exposure to hydrological, weather and sea-related risks. Whereas advice on cyclones seems to work very well, the coastal risks and floods seem to be underestimated with a very high exposure and vulnerability to risk. Pre-existing vulnerabilities were exacerbated after cyclone Pam. However, other communities have been able to reinforce their resilience through local initiatives. The government and outside aid were very quick to react, despite problems of coordination, exchange of information, communication and long-term strategy. Practical implications The bottom-up, top-down, local and global approaches, applied on the time scales, should lead to actions that will reinforce the ability of the people of Vanuatu to adapt to high-energy events and to the effects of climate change. Originality/value This paper highlights the importance of understanding how the urban communities are vulnerable to natural hazards and of strategies for increasing their resilience.


2020 ◽  
Vol 8 (1) ◽  
pp. 1-13
Author(s):  
Ana Laura Lira Cortes ◽  
Carlos Fuentes Silva

This work presents research based on evidence with neural networks for the development of predictive crime models, finding the data sets used are focused on historical crime data, crime classification, types of theft at different scales of space and time, counting crime and conflict points in urban areas. Among some results, 81% precision is observed in the prediction of the Neural Network algorithm and ranges in the prediction of crime occurrence at a space-time point between 75% and 90% using LSTM (Long-ShortSpace-Time). It is also observed in this review, that in the field of justice, systems based on intelligent technologies have been incorporated, to carry out activities such as legal advice, prediction and decisionmaking, national and international cooperation in the fight against crime, police and intelligence services, control systems with facial recognition, search and processing of legal information, predictive surveillance, the definition of criminal models under the criteria of criminal records, history of incidents in different regions of the city, location of the police force, established businesses, etc., that is, they make predictions in the urban context of public security and justice. Finally, the ethical considerations and principles related to predictive developments based on artificial intelligence are presented, which seek to guarantee aspects such as privacy, privacy and the impartiality of the algorithms, as well as avoid the processing of data under biases or distinctions. Therefore, it is concluded that the scenario for the development, research, and operation of predictive crime solutions with neural networks and artificial intelligence in urban contexts, is viable and necessary in Mexico, representing an innovative and effective alternative that contributes to the attention of insecurity, since according to the indices of intentional homicides, the crime rates of organized crime and violence with firearms, according to statistics from INEGI, the Global Peace Index and the Government of Mexico, remain in increase.


Information ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 309 ◽  
Author(s):  
Guma Ali ◽  
Mussa Ally Dida ◽  
Anael Elikana Sam

Smartphone technology has improved access to mobile money services (MMS) and successful mobile money deployment has brought massive benefits to the unbanked population in both rural and urban areas of Uganda. Despite its enormous benefits, embracing the usage and acceptance of mobile money has mostly been low due to security issues and challenges associated with the system. As a result, there is a need to carry out a survey to evaluate the key security issues associated with mobile money systems in Uganda. The study employed a descriptive research design, and stratified random sampling technique to group the population. Krejcie and Morgan’s formula was used to determine the sample size for the study. The collection of data was through the administration of structured questionnaires, where 741 were filled by registered mobile money (MM) users, 447 registered MM agents, and 52 mobile network operators’ (MNOs) IT officers of the mobile money service providers (MMSPs) in Uganda. The collected data were analyzed using RStudio software. Statistical techniques like descriptive analysis and Pearson Chi-Square test was used in data analysis and mean (M) > 3.0 and p-value < 0.05 were considered statistically significant. The findings revealed that the key security issues are identity theft, authentication attack, phishing attack, vishing attack, SMiShing attack, personal identification number (PIN) sharing, and agent-driven fraud. Based on these findings, the use of better access controls, customer awareness campaigns, agent training on acceptable practices, strict measures against fraudsters, high-value transaction monitoring by the service providers, developing a comprehensive legal document to run mobile money service, were some of the proposed mitigation measures. This study, therefore, provides a baseline survey to help MNO and the government that would wish to implement secure mobile money systems.


2021 ◽  
Vol 6 (2) ◽  
pp. 143-161 ◽  
Author(s):  
Rob Roggema ◽  
Nico Tillie ◽  
Greg Keeffe ◽  
Wanglin Yan

In this article a planning approach is proposed to accommodate different paces of urbanisation. Instead of responding to a single problem with a Pavlov-type of response, analysis shows that the transformational tempi of different urban landscapes require multiple deployment strategies to develop urban environments that are sustainable and resilient. The application of nature-based solutions, enhancing both human and natural health in cities, is used as the foundation for the design of deployment strategies that respond to different paces of urban change. The results show that urban characteristics, such as population density and built space is, partly, dependent on the underlying landscape characteristics, therefore show specific development pathways. To create liveable and sustainable urban areas that can deal holistically with a range of intertwined problems, specific deployment strategies should be used in each specific urban context. This benefits the city-precinct as a whole and at the local scale. Even small nature-based solutions, applied as the right deployment strategy in the right context, have profound impact as the starting point of a far-reaching urban transformation. The case-study for Oimachi in Japan illustrates how this planning approach can be applied, how the different urban rhythms are identified, and to which results this leads.


2020 ◽  
Vol 13 (6) ◽  
pp. 2963
Author(s):  
Gastão Cerquinha da Fonseca Neto ◽  
Marcos Antonio Barbosa da Silva Junior ◽  
Arivânia Bandeira Rodrigues ◽  
Alfredo Ribeiro Neto ◽  
Jaime Joaquim da Silva Pereira Cabral

O processo de densificação nas cidades provoca a perda de ambientes naturais, consequentemente reduz as áreas permeáveis, ampliando os fenômenos das inundações urbanas. As medidas mitigadoras geralmente envolvem elevados custos e nem sempre são confiáveis, devido às incertezas de projeto e variáveis naturais de difícil controle e quantificação, principalmente relacionadas às mudanças climáticas. Nesse cenário, a bacia do rio Fragoso, localizada em sua maior parte na cidade costeira de Olinda, registrou recentemente inundações que afetaram extensas áreas, provocando o poder público a realizar obras de canalização e alargamento da calha do rio. Assim, este trabalho objetiva avaliar a confiabilidade de medidas estruturais implementadas em ambientes urbanos costeiros e de baixa elevação, sujeitos às variações da maré. Para isso, foram utilizados os softwares: HEC-GeoHMS para processamento dos dados geoespaciais de topografia, com dados de alta resolução; HEC-HMS 4.2.1 para modelagem hidrológica; e HEC-RAS 5.0.3 para modelagem hidráulica bidimensional, com representação de manchas de inundação através da ferramenta RAS Mapper. Foi simulado o evento chuvoso de 30 de maio de 2016 para dois cenários: o atual, nas condições naturais do rio; e o futuro, com a obra de canalização concluída. Os resultados mostraram que a intervenção seria hidraulicamente satisfatória, permitiria o escoamento das vazões, conseguiria reduzir cerca de 42,32% das áreas urbanas inundadas, mas não evitaria o alagamento de áreas marginais que são naturalmente muito baixas. Bidimensional Modeling for the Hydraulic Verification of the Channeling of a Stretch of the Fragoso river in Olinda (Pernambuco, Brazil). A B S T R A C TThe densification process in cities causes the loss of natural environments, consequently reducing the permeable areas, increasing the phenomena of urban floods. Mitigation measures generally involve high costs and are not always reliable, due to uncertainties in the design and natural variables that are difficult to control and quantify, mainly related to climate change. In this scenario, the Fragoso River basin, located mostly in the coastal city of Olinda, recently registered floods that affected extensive areas, causing the government to carry out canalization and widening the river channel. Thus, this work aims to evaluate the reliability of structural measures implemented in coastal and low elevation urban environments, subject to tidal variations. For this, the following softwares were used: HEC-GeoHMS for processing geospatial topography data, with high resolution data; HEC-HMS 4.2.1 for hydrological modeling; and HEC-RAS 5.0.3 for two-dimensional hydraulic modeling, with representation of flood spots through the RAS Mapper tool. The rainy event of May 30, 2016 was simulated for two scenarios: the current one, in the natural conditions of the river; and the future, with the enlargement and channeling work designed. The results showed that the intervention would be hydraulically satisfactory, would allow the flow of flows, would reduce about 42.32% of the flooded urban areas, but would not prevent the flooding of marginal areas that are naturally very low.Keywords: flood; macrodrainage, Hydrologic Modeling System, River Analysis System.


2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Alan K. L. Chan ◽  
Colin K. C. Wong ◽  
Robin H. N. Lee ◽  
Mike W. H. Cho

The existing Kai Tak Nullah flows from Po Kong Village Road along Choi Hung Road and Tung Tau Estate into Kai Tak Development Area before discharging into the Victoria Harbour. Historically its upstream has been subject to flooding under storm conditions and this has had serious repercussions for the adjacent urban areas. A study has been commissioned by the Drainage Services Department of the Government of the Hong Kong Special Administrative Region (HKSAR), China to investigate the flood mechanisms and to provide flood alleviation measures by improving the capacity of the Kai Tak Nullah. In addition to flood alleviation, there is a strong public aspiration to rehabilitate the Kai Tak Nullah by a comparatively natural river design. Since the Kai Tak Nullah is located within a heavily urbanized area, traffic and environmental impacts are also highly concerned. The final flood alleviation scheme has thus had to strike a balance among the aforesaid factors with assistance from the hydraulic modelling utilizing InfoWorks Collection Systems (CS) software. This paper presents the public engagement exercise, design considerations, methodologies, and recommendations regarding the reconstruction and rehabilitation of the Kai Tak Nullah.


Author(s):  
Kalaichelvi Sivaraman ◽  
Rengasamy Stalin

This research paper is the part of Research Project entitled “Impact of Elected Women Representatives in the Life and Livelihood of the Women in Rural Areas: With Special Reference to Tiruvannamalai District, Tamil Nadu” funded by University of Madras under UGC-UPE Scheme.The 73rd and 74th amendments of the Constitution of India were made by the government to strengthen the position of women and to create a local-level legal foundation for direct democracy for women in both rural and urban areas. The representation for women in local bodies through reservation policies amendment in Constitution of India has stimulated the political participation of women in rural areas. However, when it’s comes to the argument of whether the women reservation in Panchayati Raj helps or benefits to the life and livelihood development of women as a group? The answer is hypothetical because the studies related to the impact of women representatives of Panchayati Raj in the life and livelihood development of women was very less. Therefore, to fill the gap in existing literature, the present study was conducted among the rural women of Tiruvannamalai district to assess the impact of elected women representatives in the physical and financial and business development of the women in rural areas. The findings revealed that during the last five years because of the women representation in their village Panjayati Raj, the Physical Asset of the rural women were increased or developed moderately (55.8%) and Highly (23.4%) and the Financial and Business Asset of the rural women were increased or developed moderately (60.4%) and Highly (18.7%).


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 171
Author(s):  
Lihui Zhang ◽  
Xuezhong Wang ◽  
Hong Li ◽  
Nianliang Cheng ◽  
Yujie Zhang ◽  
...  

To better evaluate the variations in concentration characteristics and source contributions of atmospheric volatile organic compounds (VOCs) during continuous haze days and non-haze days, hourly observations of atmospheric VOCs were conducted using a continuous on-line GC-FID (Airmo VOC GC-866) monitoring system during 1–15 March 2019, in urban areas of Beijing, China. The results showed that the total VOC concentrations during haze days and non-haze days were 59.13 ± 31.08 μg/m3 and 16.91 ± 7.19 μg/m3, respectively. However, the average O3 concentrations during the two haze days were lower than those of non-haze days due to the extremely low concentrations at night instead of the reported lower photochemical reaction in daytime. The ratio of OH radical concentration during haze and non-haze days indicating that the rate of photochemical reaction during haze days was higher than those of non-haze days from 13:00–19:00. The stable air conditions and the local diesel emission at night were the main reasons for the decreased O3 concentrations during haze days. Six major sources were identified by positive matrix factorization (PMF), namely, diesel exhaust, combustion, gasoline evaporation, solvent usage, gasoline exhaust, and the petrochemical industry, contributing 9.93%, 25.29%, 3.90%, 16.88%, 35.59% and 8.41%, respectively, during the whole observation period. The contributions of diesel exhaust and the petrochemical industry emissions decreased from 26.14% and 6.43% during non-haze days to 13.70% and 2.57%, respectively, during haze days. These reductions were mainly ascribed to the emergency measures that the government implemented during haze days. In contrast, the contributions of gasoline exhaust increased from 34.92% during non-haze days to 48.77% during haze days. The ratio of specific VOC species and PMF both showed that the contributions of gasoline exhaust emission increased during haze days. The backward trajectories, potential source contribution function (PSCF) and concentration weighted trajectory (CWT) showed that the air mass of VOCs during haze days was mainly affected by the short-distance transportation from the southwestern of Hebei province. However, the air mass of VOCs during non-haze days was mainly affected by the long-distance transportation from the northwest.


Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 358
Author(s):  
François Brassard ◽  
Chi-Man Leong ◽  
Hoi-Hou Chan ◽  
Benoit Guénard

The continuous increase in urbanization has been perceived as a major threat for biodiversity, particularly within tropical regions. Urban areas, however, may still provide opportunities for conservation. In this study focused on Macao (China), one of the most densely populated regions on Earth, we used a comprehensive approach, targeting all the vertical strata inhabited by ants, to document the diversity of both native and exotic species, and to produce an updated checklist. We then compared these results with 112 studies on urban ants to illustrate the dual roles of cities in sustaining ant diversity and supporting the spread of exotic species. Our study provides the first assessment on the vertical distribution of urban ant communities, allowing the detection of 55 new records in Macao, for a total of 155 ant species (11.5% being exotic); one of the highest species counts reported for a city globally. Overall, our results contrast with the dominant paradigm that urban landscapes have limited conservation value but supports the hypothesis that cities act as gateways for exotic species. Ultimately, we argue for a more comprehensive understanding of ants within cities around the world to understand native and exotic patterns of diversity.


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