Integrating fuzzy set function into floating catchment area measures: a determination of spatial accessibility of service points

The aim of the work was to develop a new empirical model for calculating the peak annual flows of a given frequency of occurrence (QT) in the ungauged catchments of the upper Vistula basin in Poland. The approach to the regionalization of the catchment and the selection of the optimal form of the empirical model are indicated as a novelty of the proposed research. The research was carried out on the basis of observation series of peak annual flows (Qmax) for 41 catchments. The analysis was performed in the following steps: statistical verification of data; estimation of Qmax flows using kernel density estimation; determination of physiographic and meteorological characteristics affecting the Qmax flow volume; determination of the value of dimensionless quantiles for QT flow calculation in the upper Vistula basin; verification of the determined correlation for the calculation of QT flows in the upper Vistula basin. Based on the research we conducted, we found that the following factors have the greatest impact on the formation of flood flows in the upper Vistula basin: the size of catchment area; the height difference in the catchment area; the density of the river network; the soil imperviousness index; and the volume of normal annual precipitation. The verification procedure that we performed made it possible to conclude that the developed empirical model functions correctly.

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DETERMINATION OF OPTIMAL BIDDING PROFIT RATE BY FUZZY SET THEORY

Cybernetics & Systems ◽

10.1080/019697297126137 ◽

1997 ◽

Vol 28 (4) ◽

pp. 337-343 ◽

Cited By ~ 3

Author(s):

ZIVOJIN PRASCEVIC AND SONJA PETROVI

Keyword(s):

Set Theory ◽

Fuzzy Set ◽

Fuzzy Set Theory ◽

Profit Rate ◽

Optimal Bidding

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An Enhanced Variable Two-Step Floating Catchment Area Method for Measuring Spatial Accessibility to Residential Care Facilities in Nanjing

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph121114490 ◽

2015 ◽

Vol 12 (11) ◽

pp. 14490-14504 ◽

Cited By ~ 26

Author(s):

Jianhua Ni ◽

Jinyin Wang ◽

Yikang Rui ◽

Tianlu Qian ◽

Jiechen Wang

Keyword(s):

Residential Care ◽

Catchment Area ◽

Spatial Accessibility ◽

Residential Care Facilities ◽

Area Method ◽

Care Facilities

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Evaluating Spatial Accessibility to General Hospitals with Navigation and Social Media Location Data: A Case Study in Nanjing

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17082752 ◽

2020 ◽

Vol 17 (8) ◽

pp. 2752 ◽

Cited By ~ 2

Author(s):

Tianlu Qian ◽

Jie Chen ◽

Ang Li ◽

Jiechen Wang ◽

Dingtao Shen

Keyword(s):

Social Media ◽

General Hospital ◽

Transit Time ◽

Catchment Area ◽

Spatial Accessibility ◽

Medical Services ◽

Basic Unit ◽

General Hospitals ◽

Important Indicator

Spatial accessibility to general hospitals is an important indicator of the convenience and ability of residents to obtain medical services. Therefore, developing a model for measuring accessibility to general hospitals by multiple transportation modes is necessary. In this study, considering that the increase in travel time will reduce the attractiveness of general hospitals, we used the Two-Step Floating Catchment Area with the Gaussian attenuation function, in which the supply was presented by capacity of hospitals (i.e., number of beds), and the demand was presented by population in each grid derived with social media data mapping real-time locations of active users. The Gaussian Two-Step Floating Catchment Area (Ga2SFCA) simulates the attenuation tendency of the general hospital service capabilities over transit time. To obtain a highly precise understanding of accessibility to hospitals, transit time on Baidu Maps’ navigation service was used as the impedance condition, and the study area was divided into 1 square kilometer grids as the basic unit of research. Taking Nanjing city as a case study, it is found that the accessibility distribution shape changes from a multi-centered circular pattern to a multi-peak distribution, as the time threshold increases. By comparing the accessibility among 11 districts varying from main urban area to suburbs, the accessibility to general hospitals in Nanjing is significantly regionally unbalanced in both travel modes. By calculating and mapping the Modal Accessibility Gap (MAG) of the two travel modes, different modes of transportation resulted in different general hospital accessibility distributions. Generally, private car is superior in access to general hospitals to public transit in most areas. In the central area, public traffic may not contribute to the access to medical services as much as we thought, rather it plays a role in areas far from hospitals along metro lines and bus routes.

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Possibility of Using Selected Rainfall-Runoff Models for Determining the Design Hydrograph in Mountainous Catchments: A Case Study in Poland

Water ◽

10.3390/w12051450 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1450 ◽

Cited By ~ 3

Author(s):

Dariusz Młyński ◽

Andrzej Wałęga ◽

Leszek Książek ◽

Jacek Florek ◽

Andrea Petroselli

Keyword(s):

Catchment Area ◽

Peak Flow ◽

Rainfall Runoff ◽

Peak Flows ◽

Mountainous Catchment ◽

Mountainous Catchments ◽

Relative Errors ◽

Runoff Hydrographs

The aim of the study was to analyze the possibility of using selected rainfall-runoff models to determine the design hydrograph and the related peak flow in a mountainous catchment. The basis for the study was the observed series of hydrometeorological data for the Grajcarek catchment area (Poland) for the years 1981–2014. The analysis was carried out in the following stages: verification of hydrometeorological data; determination of the design rainfall; and determination of runoff hydrographs with the following rainfall-runoff models: Snyder, NRCS-UH, and EBA4SUB. The conducted research allowed the conclusion that the EBA4SUB model may be an alternative to other models in determining the design hydrograph in ungauged mountainous catchments. This is evidenced by the lower values of relative errors in the estimation of peak flows with an assumed frequency for the EBA4SUB model, as compared to Snyder and NRCS-UH.

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A critical evaluation of the methods for the determination of required volumes for detention tank

E3S Web of Conferences ◽

10.1051/e3sconf/20184500088 ◽

2018 ◽

Vol 45 ◽

pp. 00088 ◽

Cited By ~ 6

Author(s):

Mariusz Starzec

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Catchment Area ◽

Critical Evaluation ◽

Design Parameters ◽

Method Of Calculation ◽

Rainfall Duration ◽

Detention Tank ◽

Artificial Neural

Simplified methods allow a straightforward and quick determination of parameters of interest. A simplified method of calculation to be used must provide sufficiently accurate simulation results. This paper presents the results of tests completed to evaluate the effects of the parameters which describe a sewer catchment area and network on the value of Tp, a parameter applied in the Dziopak method [18]. The results of 2997 hydrodynamic simulations allowed to formulate an artificial neural network the application of which enabled the determination of the value of Tp dependent on the design parameters of a sewer catchment area and network. The artificial neural network had a very low error R2 = 0.9972 between the expected and determined values of Tp. The completed tests indicated a relationship by which an increase of the rainfall duration, a parameter used in the dimensioning of detention tank, is concomitant to an increase in the value of Tp. The calculations made so far included an assumption that the Tp value is constant irrespective of the design rainfall duration for the dimensioning of detention tank; this assumption has led to gross calculation errors. The paper also provides proof that the inclusion of these relationships allows a more precise determination of the service volume required for a multi-chamber detention tank.

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Multi-Mode Two-Step Floating Catchment Area (2SFCA) Method to Measure the Potential Spatial Accessibility of Healthcare Services

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi8050236 ◽

2019 ◽

Vol 8 (5) ◽

pp. 236 ◽

Cited By ~ 2

Author(s):

Jianhua Ni ◽

Ming Liang ◽

Yan Lin ◽

Yanlan Wu ◽

Chen Wang

Keyword(s):

Travel Behavior ◽

Urban Areas ◽

Catchment Area ◽

Methodological Approach ◽

Open Data ◽

Healthcare Services ◽

Spatial Accessibility ◽

Urban Residents ◽

Transportation Modes ◽

Multi Mode

While great progress in the development of a methodological approach to measure the accessibility of healthcare services has been made, the exclusion of the complex multi-mode travel behavior of urban residents and a rough calculation of travel costs from the origin to the destination limit its potential for making a detailed assessment, especially in urban areas. In this paper, we aim to describe and implement an enhanced method that enables the integration of multiple transportation modes into a two-step floating catchment area (2SFCA) method to estimate accessibility. We used a travel-mode choice survey, based on distance sections, to determine the complex multi-mode travel behavior of urban residents. Taking Nanjing as a study area, we proposed complete door-to-door approaches to determine every aspect of basic transportation modes. Additionally, we processed open data to implement an accurate computing of the origin-destination (OD) time cost. We applied the enhanced method to estimate the accessibility of residents to hospitals and compared it with three single-mode 2SFCA methods. The results showed that the proposed method effectively identified more accessibility details and provided more realistic accessibility values.

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