scholarly journals Rapid Urbanization Impact on the Hydrological Processes in Zhengzhou, China

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1870
Author(s):  
Jingyi Wang ◽  
Caihong Hu ◽  
Bingyan Ma ◽  
Xiaoling Mu
Keyword(s):  
Land Use ◽  
Urban Areas ◽  
Flood Control ◽  
Hydrological Process ◽  
Rapid Urbanization ◽  
Flood Peak ◽  
Island Effect ◽  
Hourly Rainfall ◽  
Impact Of Urbanization ◽  
The Impact

Changes in the hydrological process caused by urbanization lead to frequent flooding in cities. For fast-growing urban areas, the impact of urbanization on the hydrological process needs to be systematically analyzed. This study takes Zhengzhou as an example to analyze the impact of urbanization on the hydrological process based on 1971–2012 hourly rainfall-runoff data, combining Geographic Information Systems with traditional hydrological methods. Our study indicates that the rain island effect in different districts of city became stronger with the increase of its built-up. The uneven land use resulted in the difference of runoff process. The flood peak lag was 25–30% earlier with the change of land use. The change of flood peak increased by 10–30% with the change of built-up. The runoff coefficient increases by 20–35% with the increase of built-up, and its change increased with the change of land use. Affected by the rain island effect, precipitation tends to occur in areas where built-up is dominant, which overall magnifies the impact of urbanization on the hydrological process. This provides new ideas for urban flood control. Refine flood control standards according to regional land use changes to cope with the hydrological process after urbanization.

scholarly journals The impact of urbanization expansion on agricultural land in Ethiopia: A review

2020 ◽  
Vol 8 (4) ◽  
pp. 73-80
Author(s):  
Assefa Ayele ◽  
Kassa Tarekegn
Keyword(s):  
Urban Areas ◽  
Agricultural Land ◽  
Urban Expansion ◽  
Rural Livelihoods ◽  
Vital Role ◽  
Rapid Urbanization ◽  
Economic Resource ◽  
House Construction ◽  
Impact Of Urbanization ◽  
The Impact

AbstractIn a country like Ethiopia where the vast majority of the populations are employed in agriculture, land is an important economic resource for the development of rural livelihoods. Agricultural land in peri-urban areas is, however, transformed into built-up regions through horizontal urban expansion that has an effect on land use value. In recent years Ethiopia has been experiencing rapid urbanization, which has led to an ever-increasing demand for land in peri-urban areas for housing and other nonagricultural activities that pervades agricultural land. There is a high demand for informal and illegal peri-urban land which has been held by peri-urban farmers, and this plays a vital role in the unauthorized and sub-standard house construction on agricultural land. This urbanization has not been extensively reviewed and documented. In this review an attempt has been made to assess the impacts of rapid urbanization on agricultural activities. Urban expansion has reduced the areas available for agriculture, which has seriously impacted upon peri-urban farmers that are often left with little or no land to cultivate and which has increased their vulnerability. Housing encroachments have been observed to be uncontrolled due to a weak government response to the trend of unplanned city expansion. This has left peri-urban farmers exposed to the negative shocks of urbanization because significant urbanization-related agricultural land loss has a positive correlation with grain production decrease. Appropriate governing bodies should control urban development in order to control the illegal and informal spread of urbanization on agricultural land that threatens food production.

scholarly journals Assessing the Effect of Land Use Change on Surface Runoff in a Rapidly Urbanized City: A Case Study of the Central Area of Beijing

Land ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 17 ◽  
Author(s):  
Shanshan Hu ◽  
Yunyun Fan ◽  
Tao Zhang
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Correlation Analysis ◽  
Surface Runoff ◽  
Flood Control ◽  
Central Area ◽  
Dominant Factor ◽  
Landsat Images ◽  
Rapid Urbanization ◽  
The Impact

The change in land use during the process of urbanization affects surface runoff and increases flood risk in big cities. This study investigated the impact of land use change on surface runoff in Beijing’s central area during the period of rapid urbanization from 1984 to 2019. Land use maps of 1984, 1999, 2009, and 2019 were generated by image classification of Landsat images. Surface runoffs were calculated with the Soil Conservation Service curve number (SCS-CN) model. Correlation analysis was used to identify the dominant factor of land use change affecting surface runoff. The result showed that the variation trend of surface runoff was consistent with the trend of impervious land in Beijing’s central area, which increased during 1984~2009 and decreased during 2009~2019. Correlation analysis showed that changes in surface runoff were most strongly correlated with changes in impervious surfaces when compared with the correlation of runoff with other types of land use. The results of this study may provide a reference for city flood control and urban planning in fast growing cities worldwide, especially in developing countries.

scholarly journals Spatial evaluation of complex non-point source pollution in urban–rural watershed using fuzzy system

2013 ◽  
Vol 16 (1) ◽  
pp. 114-129 ◽  
Author(s):  
Haijun Wang ◽  
Wenting Zhang ◽  
Song Hong ◽  
Yanhua Zhuang ◽  
Hongyan Lin ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Point Source ◽  
Fuzzy System ◽  
Urban Areas ◽  
Rapid Urbanization ◽  
Nps Pollution ◽  
Urban Rural ◽  
Rural Place ◽  
The Impact

Non-point source (NPS) pollution has become the major reason for water quality deterioration. Due to the differences in the generation and transportation mechanisms between urban areas and rural areas, different models are needed in rural and urban places. Since land use has been rapidly changing, it is difficult to define the study area as city or country absolutely and the complex NPS pollution in these urban–rural mixed places are difficult to evaluate using an urban or rural model. To address this issue, a fuzzy system-based approach of modeling complex NPS pollutant is proposed concerning the fuzziness of each land use and the ratio of belonging to an urban or rural place. The characteristic of land use, impact of city center and traffic condition were used to describe spatial membership of belonging to an urban or rural place. According to the spatial membership of belonging to an urban or rural place, the NPS distributions calculated by the urban model and rural model respectively were combined. To validate the method, Donghu Lake, which is undergoing rapid urbanization, was selected as the case study area. The results showed that the urban NPS pollutant load was significantly higher than that of the rural area. The land usage influenced the pollution more than other factors such as slope or precipitation. It also suggested that the impact of the urbanization process on water quality is noteworthy.

scholarly journals Numerical Evaluation of the Impact of Urbanization on Summertime Precipitation in Osaka, Japan

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hikari Shimadera ◽  
Akira Kondo ◽  
Kundan Lal Shrestha ◽  
Ken Kitaoka ◽  
Yoshio Inoue
Keyword(s):  
Land Use ◽  
Heat Flux ◽  
Urban Areas ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Temporal Distribution ◽  
Urban Land Use ◽  
Sensible Heat ◽  
Impact Of Urbanization ◽  
The Impact

This study utilized the Weather Research and Forecasting (WRF) model version 3.5.1 to evaluate the impact of urbanization on summertime precipitation in Osaka, Japan. The evaluation was conducted by comparing the WRF simulations with the present land use and no-urban land use (replacing “Urban” with “Paddy”) for August from 2006 to 2010. The urbanization increased mean air temperature by 2.1°C in urban areas because of increased sensible heat flux and decreased mean humidity by 0.8 g kg−1because of decreased latent heat flux. In addition, the urbanization increased duration of the southwesterly sea breeze. The urbanization increased precipitation in urban areas and decreased in the surrounding areas. The mean precipitation in urban areas was increased by 20 mm month−1(27% of the total amount without the synoptic-scale precipitation). The precipitation increase was generally due to the enhancement of the formation and development of convective clouds by the increase in sensible heat flux during afternoon and evening time periods. The urbanization in Osaka changes spatial and temporal distribution patterns of precipitation and evaporation, and consequently it substantially affects the water cycle in and around the urban areas of Osaka.

scholarly journals TWO-DIMENSIONAL HYDRODYNAMIC MODELLING OF URBAN FLOOD INUNDATION CAUSED BY THE SOUTHWEST MONSOON TO CHARACTERIZE THE IMPACT OF TWENTY-YEAR DIFFERENCE IN LAND USE IN VALENZUELA-OBANDO-MEYCAUAYAN (VOM) USING FLO-2D

2019 ◽  
Vol XLII-4/W19 ◽  
pp. 133-140
Author(s):  
A. C. E. Cruz ◽  
J. M. D. Dizon ◽  
R. B. L. M. Mediavillo ◽  
B. O. Nepomuceno ◽  
A. Cunanan-Yabut ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Flood Control ◽  
Southwest Monsoon ◽  
Hydrodynamic Modelling ◽  
Two Dimensional ◽  
Rapid Urbanization ◽  
Substantial Impact ◽  
Area Of Interest ◽  
The Impact

Abstract. The intensity of urban flooding area due to rapid urbanization in Metro Manila has been worsening over the years caused by the torrential rains brought by the Southwest Monsoon. To further characterize the impact of land use change influenced by urbanization, we compared the flood map generated from two periods (Year 200 & Year 2020) using a two-dimensional hydrodynamic modelling simulated in FLO-2D software. In our simulations, we assigned roughness coefficient values to corresponding land use category derived from an earlier study in the area previously spearhead by JICA in 2001. Each model will incorporate the implemented Year 2000 land use and the projected Year 2010 land use classification respectively, which were used in this earlier study. Meanwhile, both models will use the same sets of parameters for the simulation: IFSAR-derived DEM elevation model and a rainfall event with 10-yr return period. The area of interest of this study is located near Valenzuela-Obando-Meycauayan (VOM) with its boundaries defined from the National Mapping and Resource Information Authority. The flood simulations conducted do not take into consideration in existing flood control measures such as drainage systems and floodwalls to minimize the complexity of the model. The results are evaluated both quantitatively and qualitatively. According to the results, the impact of the land use change on flood formation in most areas are insignificant due to a low degree of land use change. However, there has been substantial impact on flooding in specific areas where there is a major change in the land use. For further studies, we recommend the use of a longer land use change period and the consideration of more varied and precise Manning’s n-values.

scholarly journals Agricultural Land Transition in the “Groundnut Basin” of Senegal: 2009 to 2018

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 996
Author(s):  
Bonoua Faye ◽  
Guoming Du
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Urban Areas ◽  
Agricultural Land ◽  
Farming System ◽  
Point Of View ◽  
Dynamic Index ◽  
Impact Of Urbanization ◽  
Agricultural Land Management ◽  
The Impact

The study aims to reveal the transition features of agricultural land use in the Groundnut Basin of Senegal from 2009 to 2018, especially the impact of urbanization on agricultural land and the viewpoint of farmland spatiotemporal evolution. Integrated data of time series MCD12Q1 land-use images of 2009, 2012, 2015, and 2018 were used to provide a land transition in agricultural and urban areas through the synergistic methodology. Socio-economic data was also used to serve as a basis for the argument. The results highlight that: (1) Agricultural land increased by 14.53%, with a dynamic index of 1.45 from 2009–2018. (2) Over the same period, urbanization increased by 2.80%, with a dynamic index of 0.28. (3) In different regions, the transition of agricultural land in Kaffrine is most intense (expansion rate: 22.80%). The same situation of urbanization happened in Thiès Region with a value of 7.94%. Except for Thiès, agricultural land in other regions has not yet been subject to major pressure due to urbanization. Overall, the farming system in Groundnut Basin is an extensive model, the recommendations from the point of view of land-use planning and land law are necessary to ensure efficient agricultural land management in the area.

scholarly journals Impact of Urbanization on Agricultural Land in Makurdi Local Government Area of Benue State, Nigeria

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Terwase Shabu ◽  
Sussan Fate ◽  
Mfanyo Keziah Ukula
Keyword(s):  
Land Use ◽  
Local Government ◽  
Urban Areas ◽  
Agricultural Land ◽  
Negative Impact ◽  
Local Government Area ◽  
Farm Size ◽  
Detection Analysis ◽  
Impact Of Urbanization ◽  
The Impact

This study assessed the Impact of Urbanization on Agricultural Land in Makurdi Local Government Area of Benue State. The data collected were population figures and land use for three Epoch (1997, 2007 and 2017). The satellite images were sourced from the National Center for Remote Sensing and Geographic Information System, Jos. In the analysis, cross change detection analysis and overlay analysis using ArcGIS 9.0 was performed to detect where land-use change has occurred and which type of land use agricultural land has transformed too. The GIS analysis revealed that there is an increase in settlement and a decrease in Agricultural land from 1997 – 2017. It also revealed that 99.51ha of agricultural land use has been converted to settlement between 1997 and 2017. The results reveal that urbanization has significant effects on Agricultural Land in the study area and these effects include; decreasing agricultural land, decreasing agricultural activities and decrease in farm size. If the growth in the population of Makurdi LGA continues unchecked, agricultural land will be significantly depleted in the future. The study recommended that there should be effective law and policy to control population growth sustainably to minimize the negative impact of urbanization in the study area. Also, urban agriculture should be encouraged to sustain the food supply in urban areas.

scholarly journals Urbanization Impacts on Vegetation Phenology in China

2018 ◽  
Vol 10 (12) ◽  
pp. 1905 ◽  
Author(s):  
Qiang Ren ◽  
Chunyang He ◽  
Qingxu Huang ◽  
Yuyu Zhou
Keyword(s):  
Rural Areas ◽  
Land Surface ◽  
Urban Areas ◽  
Growing Season ◽  
Vegetation Phenology ◽  
Rapid Urbanization ◽  
Climate Zone ◽  
Growing Season Length ◽  
Impact Of Urbanization ◽  
The Impact

Urbanization can affect the ecological processes, local climate and human health in urban areas by changing the vegetation phenology. In the past 20 years, China has experienced rapid urbanization. Thus, it is imperative to understand the impact of urbanization on vegetation phenology in China. In this study, we quantitatively analyzed the impact of urbanization on vegetation phenology at the national and climate zone scales using remotely sensed data. We found that the start of the growing season (SOS) was advanced by approximately 2.4 days (P < 0.01), and the end of the growing season (EOS) was delayed by approximately 0.7 days (P < 0.01) in the urban areas compared to the rural areas. As a result, the growing season length (GSL) was extended by approximately 3.1 days (P < 0.01). The difference in the SOS and GSL between the urban and rural areas increased from 2001 to 2014, with an annual rate of 0.2 days (R2 = 0.39, P < 0.05) and 0.2 days (R2 = 0.31, P < 0.05), respectively. We also found that the impact of urbanization on vegetation phenology varied among different vegetation types at the national and climate zone levels (P < 0.05). The SOS was negatively correlated with land surface temperature (LST), with a correlation coefficient of −0.24 (P < 0.01), and EOS and GSL were positively correlated with LST, with correlation coefficients of 0.56 and 0.44 (P < 0.01), respectively. The improved understanding of the impact of urbanization on vegetation phenology from this study will be of great help for policy-makers in terms of developing relevant strategies to mitigate the negative environmental effects of urbanization in China.

scholarly journals Sources of and Control Measures for PTE Pollution in Soil at the Urban Fringe in Weinan, China

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 762
Author(s):  
Lei Han ◽  
Rui Chen ◽  
Zhao Liu ◽  
Shanshan Chang ◽  
Yonghua Zhao ◽  
...  
Keyword(s):  
Land Use ◽  
Urban Expansion ◽  
Pollution Sources ◽  
Urban Fringe ◽  
Control Measures ◽  
Atomic Fluorescence Spectrometry ◽  
Human Beings ◽  
Rapid Urbanization ◽  
Kriging Interpolation Method ◽  
The Impact

The environment of the urban fringe is complex and frangible. With the acceleration of industrialization and urbanization, the urban fringe has become the primary space for urban expansion, and the intense human activities create a high risk of potentially toxic element (PTE) pollution in the soil. In this study, 138 surface soil samples were collected from a region undergoing rapid urbanization and construction—Weinan, China. Concentrations of As, Pb, Cr, Cu, and Ni (Inductively Coupled Plasma Mass Spectrometry, ICP-MS) and Hg (Atomic Fluorescence Spectrometry, AFS) were measured. The Kriging interpolation method was used to create a visualization of the spatial distribution characteristics and to analyze the pollution sources of PTEs in the soil. The pollution status of PTEs in the soil was evaluated using the national environmental quality standards for soils in different types of land use. The results show that the content range of As fluctuated a small amount and the coefficient of variation is small and mainly comes from natural soil formation. The content of Cr, Cu, and Ni around the automobile repair factory, the prefabrication factory, and the building material factory increased due to the deposition of wear particles in the soil. A total of 13.99% of the land in the study area had Hg pollution, which was mainly distributed on category 1 development land and farmland. Chemical plants were the main pollution sources. The study area should strictly control the industrial pollution emissions, regulate the agricultural production, adjust the land use planning, and reduce the impact of pollution on human beings. Furthermore, we make targeted remediation suggestions for each specific land use type. These results are of theoretical significance, will be of practical value for the control of PTEs in soil, and will provide ecological environmental protection in the urban fringe throughout the urbanization process.

scholarly journals Impact of Land Use Change on Water Conservation: A Case Study of Zhangjiakou in Yongding River

2020 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Tianshi Pan ◽  
Lijun Zuo ◽  
Zengxiang Zhang ◽  
Xiaoli Zhao ◽  
Feifei Sun ◽  
...  
Keyword(s):  
Land Use ◽  
Sustainable Development ◽  
Water Conservation ◽  
Land Use Changes ◽  
Water Yield ◽  
Special Focus ◽  
Hydrological Process ◽  
Significant Difference ◽  
The Impact ◽  
Yongding River

The implementation of ecological projects can largely change regional land use patterns, in turn altering the local hydrological process. Articulating these changes and their effects on ecosystem services, such as water conservation, is critical to understanding the impacts of land use activities and in directing future land planning toward regional sustainable development. Taking Zhangjiakou City of the Yongding River as the study area—a region with implementation of various ecological projects—the impact of land use changes on various hydrological components and water conservation capacity from 2000 to 2015 was simulated based on a soil and water assessment tool model (SWAT). An empirical regression model based on partial least squares was established to explore the contribution of different land use changes on water conservation. With special focus on the forest having the most complex effects on the hydrological process, the impacts of forest type and age on the water conservation capacity are discussed on different scales. Results show that between 2000 and 2015, the area of forest, grassland and cultivated land decreased by 0.05%, 0.98% and 1.64%, respectively, which reduces the regional evapotranspiration (0.48%) and soil water content (0.72%). The increase in settlement area (42.23%) is the main reason for the increase in water yield (14.52%). Most land use covered by vegetation has strong water conservation capacity, and the water conservation capacity of the forest is particularly outstanding. Farmland and settlements tend to have a negative effect on water conservation. The water conservation capacity of forest at all scales decreased significantly with the growth of forest (p < 0.05), while the water conservation capacity of different tree species had no significant difference. For the study area, increasing the forest area will be an effective way to improve the water conservation function, planting evergreen conifers can rapidly improve the regional water conservation capacity, while planting deciduous conifers is of great benefit to long-term sustainable development.

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