scholarly journals Shrinkage of Nepal’s Second Largest Lake (Phewa Tal) Due to Watershed Degradation and Increased Sediment Influx

2019 ◽  
Vol 11 (4) ◽  
pp. 444 ◽  
Author(s):  
C. Watson ◽  
Jeffrey Kargel ◽  
Dhananjay Regmi ◽  
Summer Rupper ◽  
Joshua Maurer ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Urban Expansion ◽  
Lake Area ◽  
Historical Time ◽  
Hydroelectric Power ◽  
Power Facility ◽  
The City ◽  
Recreational Use ◽  
Watershed Degradation ◽  
Lake Phewa

Phewa Lake is an environmental and socio-economic asset to Nepal and the city of Pokhara. However, the lake area has decreased in recent decades due to sediment influx. The rate of this decline and the areal evolution of Phewa Lake due to artificial damming and sedimentation is disputed in the literature due to the lack of a historical time series. In this paper, we present an analysis of the lake’s evolution from 1926 to 2018 and model the 50-year trajectory of shrinkage. The area of Phewa Lake expanded from 2.44 ± 1.02 km2 in 1926 to a maximum of 4.61 ± 0.07 km2 in 1961. However, the lake area change was poorly constrained prior to a 1957–1958 map. The contemporary lake area was 4.02 ± 0.07 km2 in April 2018, and expands seasonally by ~0.18 km2 due to the summer monsoon. We found no evidence to support a lake area of 10 km2 in 1956–1957, despite frequent reporting of this value in the literature. Based on the rate of areal decline and sediment influx, we estimate the lake will lose 80% of its storage capacity in the next 110–347 years, which will affect recreational use, agricultural irrigation, fishing, and a one-megawatt hydroelectric power facility. Mitigation of lake shrinkage will require addressing landslide activity and sediment transport in the watershed, as well as urban expansion along the shores.

scholarly journals Urban Growth, Real Estate Development and Indigenous Property: Simulating the Expansion Process in the City of Temuco, Chile

2021 ◽  
Vol 10 (2) ◽  
pp. 101
Author(s):  
Francisco Maturana ◽  
Mauricio Morales ◽  
Fernando Peña-Cortés ◽  
Marco A. Peña ◽  
Carlos Vielma
Keyword(s):  
Real Estate ◽  
Urban Growth ◽  
Urban Expansion ◽  
Indigenous Communities ◽  
Objective Evaluation ◽  
Real Estate Development ◽  
Territorial Planning ◽  
The Future ◽  
Urban Scenario ◽  
The City

Urbanization is spreading across the world and beyond metropolitan areas. Medium-sized cities have also undergone processes of accelerated urban expansion, especially in Latin America, thanks to scant regulation or a complete lack thereof. Thus, understanding urban growth in the past and simulating it in the future has become a tool to raise its visibility and challenge territorial planners. In this work, we use Markov chains, cellular automata, multi-criteria multi-objective evaluation, and the determination of land use/land cover (LULC) to model the urban growth of the city of Temuco, Chile, a paradigmatic case because it has experienced powerful growth, where real estate development pressures coexist with a high natural value and the presence of indigenous communities. The urban scenario is determined for the years 2033 and 2049 based on the spatial patterns between 1985 and 2017, where the model shows the trend of expansion toward the northeast and significant development in the western sector of the city, making them two potential centers of expansion and conflict in the future given the heavy pressure on lands that are indigenous property and have a high natural value, aspects that need to be incorporated into future territorial planning instruments.

115 years of sediment deposition in the Urft reservoir (Eifel Mountains, western Germany)

2021 ◽  
Author(s):  
Georg Stauch ◽  
Alexander Esch ◽  
Lukas Dörwald ◽  
Verena Esser ◽  
Simone Lechthaler ◽  
...  
Keyword(s):  
Power Plant ◽  
Sediment Cores ◽  
Physical Geography ◽  
Sediment Deposition ◽  
Unmanned Aircraft ◽  
Lake Area ◽  
Hydroelectric Power ◽  
Eifel Mountains ◽  
Western Germany ◽  
Sediment Layers

<p>The sediments of the artificial Urft reservoir represent a unique archive of human influence on late Holocene sediment composition. The Urft dam, located in the Eifel Mountains in western Germany, was built between 1900 and 1905. At the time of its construction, the Urft reservoir was the largest reservoir and, with 12 MW, drove the most powerful water storage power plant in Europe. The reservoir has a length of 12 km and, when fully dammed, has a volume of 45.51 million m³ over an area of 2.16 km². The most important inflow is the river Urft. Today, the Urft Lake is completely enclosed by the Eifel National Park.</p><p>Consequently, sediments were deposited in the lake almost undisturbed over the last 115 years. Due to construction work on the Urft dam and the inspection of the 2.7 km long Kermeter Tunnel, which powers the Heimbach hydroelectric power plant, the reservoir was almost completely drained in November 2020. This offered the rare opportunity to sample the deposits in detail and to record the entire lake area photogrammetrically using an Unmanned Aircraft System (UAS). The work was carried out in cooperation between the Water Board Eifel-Rur (WVER) and the Chair of Physical Geography and Geoecology (PGG) at RWTH Aachen University.</p><p>Within the framework of the project, the sediments in the reservoir will be investigated in detail. The comparison of the high-resolution UAS digital elevation models and historical maps will give insights in the amount of sediment deposition in the different areas of the lake during the last 115 years. Geochemical markers will be used to quantify the anthropogenic influence on the sediments in the form of mining-induced pollutant contamination (e.g., heavy metals) and to relate this to the history of use in the catchment area. Another focus will be on recording the microplastics content of the different sediment layers. Since microplastics have only been introduced into the natural system by humans for the last 70 years since the beginning of mass production around 1950, the sediment layers can also be differentiated in terms of time. For these investigations, a total of ten sediment cores with a length of up to 4 m were taken from the deposits.</p>

The influence of urban expansion in the socio-economic, demographic, and environmental indicators in the City of Arapiraca-Alagoas, Brazil

2021 ◽  
pp. 100662
Author(s):  
Washington Luiz Félix Correia Filho ◽  
José Francisco de Oliveira-Júnior ◽  
Carla Taciane Brasil dos Santos ◽  
Bárbara Alves Batista ◽  
Dimas de Barros Santiago ◽  
...  
Keyword(s):  
Urban Expansion ◽  
Environmental Indicators ◽  
The City

scholarly journals Understanding Urban Growth in Beijing-Tianjin-Hebei Region over the Past 100 Years Using Old Maps and Landsat Data

2021 ◽  
Vol 13 (16) ◽  
pp. 3264 ◽  
Author(s):  
Shuang Li ◽  
Zhongqiu Sun ◽  
Yafei Wang ◽  
Yuxia Wang
Keyword(s):  
Remote Sensing ◽  
Urban Area ◽  
Spatial Data ◽  
Urban Expansion ◽  
Remote Sensing Images ◽  
The Past ◽  
Old Maps ◽  
The World ◽  
The City

Studying urban expansion from a longer-term perspective is of great significance to obtain an in-depth understanding of the process of urbanization. Remote sensing data are mostly selected to investigate the long-term expansion of cities. In this study, we selected the world-class urban agglomeration of Beijing-Tianjin-Hebei (BTH) as the study area, and then discussed how to make full use of multi-source, multi-category, and multi-temporal spatial data (old maps and remote sensing images) to study long-term urbanization. Through this study, we addressed three questions: (1) How much has the urban area in BTH expanded in the past 100 years? (2) How did the urban area expand in the past century? (3) What factors or important historical events have changed the development of cities with different functions? By comprehensively using urban spatial data, such as old maps and remote sensing images, geo-referencing them, and extracting built-up area information, a long-term series of urban built-up areas in the BTH region can be obtained. Results show the following: (1) There was clear evidence of dramatic urban expansion in this area, and the total built-up area had increased by 55.585 times, from 126.181 km2 to 7013.832 km2. (2) Continuous outward expansion has always been the main trend, while the compactness of the built-up land within the city is constantly decreasing and the complexity of the city boundary is increasing. (3) Cities in BTH were mostly formed through the construction of city walls during the Ming and Qing dynasties, and the expansion process was mostly highly related to important political events, traffic development, and other factors. In summary, the BTH area, similarly to China and most regions of the world, has experienced rapid urbanization and the history of such ancient cities should be further preserved with the combined use of old maps.

scholarly journals Цифровізація розвитку міст: Urban Atlas на основі відкритих даних для міст України

2021 ◽  
pp. 19-28
Author(s):  
Андрій Юрійович Шелестов ◽  
Алла Миколаївна Лавренюк ◽  
Богдан Ялкапович Яйлимов ◽  
Ганна Олексіївна Яйлимова
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Urban Growth ◽  
Urban Expansion ◽  
The European Union ◽  
Project Smart ◽  
Unified Algorithm ◽  
High Level ◽  
The Impact ◽  
The City

Ukraine is an associate member of the European Union and in the coming years it is expected that all data and services already used by EU countries will be available to Ukraine. The lack of quality national products for assessing the development and planning of urban growth makes it impossible to assess the impact of cities on the environment and human health. The first steps to create such products for the cities of Ukraine were initiated within the European project "SMart URBan Solutions for air quality, disasters and city growth" (SMURBS), in which specialists from the Space Research Institute of NAS of Ukraine and SSA of Ukraine received the first city atlas for the Kyiv city, which was similar to the European one. However, the resulting product had significantly fewer types of land use than the European one and therefore the question of improving the developed technology arose. The main purpose of the work is to analyze the existing technology of European service Urban Atlas creation and its improvement by developing a unified algorithm for building an urban atlas using all available open geospatial and satellite data for the cities of Ukraine. The development of such technology is based on our own technology for classifying satellite time series with a spatial resolution of 10 meters to build a land cover map, as well as an algorithm for unifying open geospatial data to urban atlases Copernicus. The technology of construction of the city atlas developed in work, based on the intellectual model of classification of a land cover, can be extended to other cities of Ukraine. In the future, the creation of such a product on the basis of data for different years will allow to assess changes in land use and make a forecast for further urban expansion. The proposed information technology for constructing the city atlas will be useful for assessing the dynamics of urban growth and closely related social and economic indicators of their development. Based on it, it is also possible to assess indicators of achieving the goals of sustainable development, such as 11.3.1 "The ratio of land consumption and population growth." The study shows that the city atlas obtained for the Kyiv city has a high level of quality and has comparable land use classes with European products. It indicates that such a product can be used in government decision-making services.

Geographical Analysis of Entertainment Services in the City of Daratu Using Geographical Information Systems (GIS)

2021 ◽  
Vol 8 (3) ◽  
pp. 618-644
Author(s):  
Hoshmand Jawhar Abbas ◽  
Sanger Ahmed Hussein ◽  
Fatimah Qader Mustafa
Keyword(s):  
Geographical Information Systems ◽  
Urban Expansion ◽  
Well Being ◽  
Geographical Information ◽  
Population Increase ◽  
Recreational Facilities ◽  
Financial Gain ◽  
Recreational Services ◽  
The Impact ◽  
The City

 The impact of the recreational services that exist within the group of services that are practiced within the geographical framework of the city, is not limited to the lives of its residents and their activities, but also on the residents of the surrounding areas. Recreational services contribute to providing diversified investment opportunities for leisure time, so that they are appropriate and beneficial to the health, comfort and well-being of the population at the lowest possible cost, without the goal of their establishment being financial gain, as they lead to the creation of mental, psychological and physical balance on the level of one individual and on the basis of society in a way. In general, recreational services are an integral part of urban activities in most cities of the world. Rather, the concept of modernity and urbanization in contemporary urban centers is measured to some extent by the availability of recreational facilities for their inhabitants, and the study also showed the low level of efficiency of recreational services in terms of their spatial distribution and numbers. As it is concentrated in some neighborhoods of the city, while it is less or absent in other neighborhoods, as well as not taking into account the planning standards in its distribution and during its construction in line with the population increase, urban expansion and the residents' needs for these services. The success in providing these different types of recreational facilities depends on how they are distributed geographically. The balanced distribution of these activities determines the success of the adopted plans in achieving the required goals and policies.

Development of a Control Strategy to Reduce Combined Sewerage Overflows: The Case of Bremen – Left of the Weser

1991 ◽  
Vol 24 (6) ◽  
pp. 201-208 ◽  
Author(s):  
Amar Khelil ◽  
Stefan Schneider
Keyword(s):  
Storage Capacity ◽  
Control Strategies ◽  
Drainage System ◽  
West Germany ◽  
Real Time Control ◽  
Time Control ◽  
On Line ◽  
Line Survey ◽  
The City

In recent years, the population and authorities in West Germany have become very concerned with water pollution. In this respect, combined sewage discharges have been pointed out as a major source. Various measures can be considered, which can be ordered into three categories: a redefinition of the objectives of the Urban Drainage System (UDS), the reshaping of the UDS (e.g. extension of the storage capacity) or the modification of its operation. Among the latter measures, Real-Time Control (RTC) constitutes the main option. It aims at a better exploitation of the existing storage potential. As the city of Bremen (Germany) decided, several years ago, to renew the on-line survey and monitoring system of its UDS, the determination of on-line strategies to operate the pumps came to the fore. Methods and tools to investigate the possibility to reduce the pollution loads through improved control strategies have been developed. Some results are presented.

scholarly journals Periurbanization and conservation pressures over remnants of native vegetation: impact on ecosystem services for a Latin-American capital city

2019 ◽  
Vol 4 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Francisco de la Barrera ◽  
Cristián Henríquez ◽  
Fanny Coulombié ◽  
Cynnamon Dobbs ◽  
Alejando Salazar
Keyword(s):  
Ecosystem Services ◽  
Latin American ◽  
Urban Areas ◽  
Urban Expansion ◽  
Capital City ◽  
Local Climate ◽  
Urban Green Spaces ◽  
Vegetation Impact ◽  
Development Alternatives ◽  
The City

Abstract Urban expansion in Latin-American cities is faster than urban planning. In order to implement sustainable planning the capacity of peri-urban areas to provide ecosystem services must be evaluated in the context of competing urbanization and conservation pressures. In this study we analyzed the effect of urban expansion on peri-urban vegetation of the Metropolitan Area of Santiago and what ecosystem services are provided by El Panul, land rich in biodiversity embedded in the fringe of the city. The city has lost vegetation while urbanized areas grow. Under this context, we evaluated the multi-functionality of El Panul through the quantification of three ecosystem services (ES): sense of place through the interviews of 60 residents, recreation via GIS analyses, and local climate regulation determined with air temperature measurements. El Panul increased the provision of urban green spaces, where inhabitants recognize and appreciate ES, and it plays a significant role in mitigating the urban heat island on summer nights. ES have emerged as a concept and framework for evaluating competing urban development alternatives.

A Novel Indicator for Assessing the Spatial Sustainability of Cities in Developing Countries - A Case Study of Xi’an City

2012 ◽  
Vol 616-618 ◽  
pp. 1335-1342 ◽  
Author(s):  
Xiao Hui Ding ◽  
Shuo Xin Zhang ◽  
Wei Zhou Zhong ◽  
Yu Jiang
Keyword(s):  
Landscape Ecology ◽  
Spatial Scales ◽  
Urban Expansion ◽  
Negative Effects ◽  
Rapid Urbanization ◽  
Social Ecological Systems ◽  
Sensing Technology ◽  
The City ◽  
Geographical Dimension

The geographical dimension of urbanization is of major importance in depicting the influences of urbanization on the development of a city, since complex social-ecological systems interact in a multitude of ways at many spatial scales across time. This research introduced an indicator for assessing the spatial sustainability of a city from the perspective of landscape ecology, to provide a reasonable way for quantifying the spatial dynamic of the urban area of a city and how close the pattern of urban expansion close to a ‘compact’ way. A case study has been done in Xi’an. With the application of remote sensing technology, landscape ecology and other necessary software, the spacial sustainability of Xi’an from 1988 to 2010 were calculated, the rapid urbanization in Xi’an has significantly promoted the spatial sustainability of city from 1988 to 2000 and 2006 to 2010, whereas exerted negative effects on the spatial sustainability of the city from 2000 to 2006.

scholarly journals Twinning and Multiple Birth Rates According to Maternal Age in the City of São Paulo, Brazil: 2003–2014

2016 ◽  
Vol 19 (6) ◽  
pp. 679-686 ◽  
Author(s):  
Emma Otta ◽  
Eloisa de S. Fernandes ◽  
Tiziana G. Acquaviva ◽  
Tania K. Lucci ◽  
Leda C. Kiehl ◽  
...  
Keyword(s):  
Maternal Age ◽  
Sao Paulo ◽  
Multiple Births ◽  
Strong Increase ◽  
Multiple Birth ◽  
São Paulo ◽  
Historical Time ◽  
Birth Rates ◽  
Time Period ◽  
The City

The present study investigates the twinning rates in the city of São Paulo, Brazil, during the years 2003–2014. The data were drawn from the Brazilian Health Department database of Sistema de Informações de Nascidos Vivos de São Paulo—SINASC (Live Births Information System of São Paulo). In general, more information is available on the incidence of twinning in developed countries than in developing ones. A total of 24,589 twin deliveries and 736 multiple deliveries were registered in 140 hospitals of São Paulo out of a total of 2,056,016 deliveries during the studied time period. The overall average rates of singleton, twin, and multiple births per 1,000 maternities (‰) were 987.43, 11.96 (dizygotic (DZ) rate was 7.15 and monozygotic (MZ) 4.42), and 0.36, respectively. We further regressed maternal age and historical time period on percentage of singleton, twin, and multiple birth rates. Our results indicated that maternal age strongly positively predicted twin and multiple birth rates, and negatively predicted singleton birth rates. The historical time period also positively, although weakly, predicted twin birth rates, and had no effect on singleton or multiple birth rates. Further, after applying Weinberg's differential method, we computed regressions separately for the estimated frequencies of DZ and MZ twin rates. DZ twinning was strongly positively predicted by maternal age and, to a smaller degree, by time period, while MZ twinning increased marginally only with higher maternal age. Factors such as increasing body mass index or air pollution can lead to the slight historical increase in DZ twinning rates. Importantly, consistent with previous cross-cultural and historical research, our results support the existence of an age-dependent physiological mechanism that leads to a strong increase in twinning and multiple births, but not singleton births, among mothers of higher age categories. From the ultimate perspective, twinning and multiple births in later age can lead to higher individual reproductive success near the end of the reproductive career of the mother.

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