scholarly journals Simulation and Optimization of Urban–Rural Settlement Development from the Perspective of Production–Life–Ecology Space: A Case Study for Aksu City

2021 ◽  
Vol 13 (13) ◽  
pp. 7452
Author(s):  
Jiayao Heng ◽  
Hongwei Wang ◽  
Ying Fan ◽  
Zhengwei Wang ◽  
Yibo Gao
Keyword(s):  
Model Simulation ◽  
Main Function ◽  
Rural Settlements ◽  
Growth Trend ◽  
Simulation Accuracy ◽  
Simulation And Optimization ◽  
Urban Rural ◽  
Ca Model ◽  
Development State ◽  
Settlement Distribution

To explore the future development state of urban and rural settlements, we combined random forest algorithm (RFA) and cellular automata (CA) to simulate high precision in urban and rural settlements in Aksu city. The settlement distribution was predicted for the next 10 years, and suggestions for urban and rural settlements were proposed based on a “production–life–ecology” space. The results show the following: Transportation factors and administrative location have an important influence on the development of settlements, and infrastructure has a greater impact on the development of settlements. The overall accuracy of the 2019 settlement distribution obtained through the RFA–CA model simulation is 93.8%, with a G-mean coefficient of 0.815. The simulation accuracy is better and more suitable for the simulation and prediction of settlement expansion than the logistic-CA model. The forecasted settlement expansion in 2029 for Aksu city is 58.36 km2 of settlement expansion compared to the 2019 settlement distribution, with an overall growth trend for sparse north-south and dense central areas. This study analyzed the causes of settlement expansion in 19 regions of Aksu city, explored the main function of “production–life–ecology” space in different areas, and proposed layout optimizations from the perspective of production, life, and ecology. The results of this study can provide a reference for the spatial planning and rural revitalization strategy of Aksu city.

scholarly journals Calibration approaches for distributed hydrologic models in poorly gaged basins: implication for streamflow projections under climate change

2015 ◽  
Vol 19 (2) ◽  
pp. 857-876 ◽  
Author(s):  
S. Wi ◽  
Y. C. E. Yang ◽  
S. Steinschneider ◽  
A. Khalil ◽  
C. M. Brown
Keyword(s):  
Climate Change ◽  
High Performance ◽  
Climate Models ◽  
Optimization Problems ◽  
Model Simulation ◽  
Model Fitting ◽  
Hydrologic Model ◽  
Simulation Accuracy ◽  
Distributed Models ◽  
Spatially Distributed

Abstract. This study tests the performance and uncertainty of calibration strategies for a spatially distributed hydrologic model in order to improve model simulation accuracy and understand prediction uncertainty at interior ungaged sites of a sparsely gaged watershed. The study is conducted using a distributed version of the HYMOD hydrologic model (HYMOD_DS) applied to the Kabul River basin. Several calibration experiments are conducted to understand the benefits and costs associated with different calibration choices, including (1) whether multisite gaged data should be used simultaneously or in a stepwise manner during model fitting, (2) the effects of increasing parameter complexity, and (3) the potential to estimate interior watershed flows using only gaged data at the basin outlet. The implications of the different calibration strategies are considered in the context of hydrologic projections under climate change. To address the research questions, high-performance computing is utilized to manage the computational burden that results from high-dimensional optimization problems. Several interesting results emerge from the study. The simultaneous use of multisite data is shown to improve the calibration over a stepwise approach, and both multisite approaches far exceed a calibration based on only the basin outlet. The basin outlet calibration can lead to projections of mid-21st century streamflow that deviate substantially from projections under multisite calibration strategies, supporting the use of caution when using distributed models in data-scarce regions for climate change impact assessments. Surprisingly, increased parameter complexity does not substantially increase the uncertainty in streamflow projections, even though parameter equifinality does emerge. The results suggest that increased (excessive) parameter complexity does not always lead to increased predictive uncertainty if structural uncertainties are present. The largest uncertainty in future streamflow results from variations in projected climate between climate models, which substantially outweighs the calibration uncertainty.

Studies on Thermal Performance of Closed Type Parabolic Trough Solar Collector

2011 ◽  
Vol 347-353 ◽  
pp. 812-821
Author(s):  
Zhong Zhu Qiu ◽  
Peng Li ◽  
Shao Lin Gong ◽  
Ye Wang ◽  
Wen Wen Guo ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Solar Collector ◽  
Model Simulation ◽  
Test Bed ◽  
Parabolic Trough ◽  
Simulation Accuracy ◽  
Closed Type ◽  
Efficiency Test ◽  
Set Up ◽  
Parabolic Trough Solar Collector

To a closed type parabolic trough solar collector, thermal performance was analyzed, a mathematical model was set up, and test-bed of collector to heat efficiency test was built. According to the experiment test data, the accuracy of the thermal mathematics model was validated. The results show that the model simulation accuracy is so higher that the model is reasonable and available.

CA-PRI, A CELLULAR AUTOMATA PHENOMENOLOGICAL RESEARCH INVESTIGATION: SIMULATION RESULTS

2013 ◽  
Vol 24 (05) ◽  
pp. 1350027 ◽  
Author(s):  
G. IANNONE ◽  
A. TROISI
Keyword(s):  
Cellular Automata ◽  
Urban Sprawl ◽  
Model Simulation ◽  
Initial Growth ◽  
New Born ◽  
Population Evolution ◽  
Urban Settlements ◽  
Ca Model ◽  
Urban Pattern ◽  
Evolution Function

Following the introduction of a phenomenological cellular automata (CA) model capable to reproduce city growth and urban sprawl, we develop a toy model simulation considering a realistic framework. The main characteristic of our approach is an evolution algorithm based on inhabitants preferences. The control of grown cells is obtained by means of suitable functions which depend on the initial condition of the simulation. New born urban settlements are achieved by means of a logistic evolution of the urban pattern while urban sprawl is controlled by means of the population evolution function. In order to compare model results with a realistic urban framework we have considered, as the area of study, the island of Capri (Italy) in the Mediterranean Sea. Two different phases of the urban evolution on the island have been taken into account: a new born initial growth as induced by geographic suitability and the simulation of urban spread after 1943 induced by the population evolution after this date.

scholarly journals Calibration approaches for distributed hydrologic models using high performance computing: implication for streamflow projections under climate change

2014 ◽  
Vol 11 (9) ◽  
pp. 10273-10317 ◽  
Author(s):  
S. Wi ◽  
Y. C. E. Yang ◽  
S. Steinschneider ◽  
A. Khalil ◽  
C. M. Brown
Keyword(s):  
Climate Change ◽  
High Performance Computing ◽  
High Performance ◽  
Climate Models ◽  
Model Simulation ◽  
Model Fitting ◽  
Hydrologic Model ◽  
Simulation Accuracy ◽  
Distributed Models ◽  
Performance Computing

Abstract. This study utilizes high performance computing to test the performance and uncertainty of calibration strategies for a spatially distributed hydrologic model in order to improve model simulation accuracy and understand prediction uncertainty at interior ungaged sites of a sparsely-gaged watershed. The study is conducted using a distributed version of the HYMOD hydrologic model (HYMOD_DS) applied to the Kabul River basin. Several calibration experiments are conducted to understand the benefits and costs associated with different calibration choices, including (1) whether multisite gaged data should be used simultaneously or in a step-wise manner during model fitting, (2) the effects of increasing parameter complexity, and (3) the potential to estimate interior watershed flows using only gaged data at the basin outlet. The implications of the different calibration strategies are considered in the context of hydrologic projections under climate change. Several interesting results emerge from the study. The simultaneous use of multisite data is shown to improve the calibration over a step-wise approach, and both multisite approaches far exceed a calibration based on only the basin outlet. The basin outlet calibration can lead to projections of mid-21st century streamflow that deviate substantially from projections under multisite calibration strategies, supporting the use of caution when using distributed models in data-scarce regions for climate change impact assessments. Surprisingly, increased parameter complexity does not substantially increase the uncertainty in streamflow projections, even though parameter equifinality does emerge. The results suggest that increased (excessive) parameter complexity does not always lead to increased predictive uncertainty if structural uncertainties are present. The largest uncertainty in future streamflow results from variations in projected climate between climate models, which substantially outweighs the calibration uncertainty.

scholarly journals Multiobjective calibration of the MESH hydrological model on the Reynolds Creek Experimental Watershed

2010 ◽  
Vol 7 (2) ◽  
pp. 2121-2155 ◽  
Author(s):  
A. J. MacLean ◽  
B. A. Tolson ◽  
F. R. Seglenieks ◽  
E. Soulis
Keyword(s):  
Snow Water Equivalent ◽  
Model Simulation ◽  
Hydrologic Model ◽  
Simulation Accuracy ◽  
Mesh Model ◽  
Reynolds Creek ◽  
Spatially Distributed ◽  
Multiobjective Calibration ◽  
Computationally Intensive ◽  
Computational Budget

Abstract. The spatially distributed MESH hydrologic model (Pietroniro et al., 2007) was successfully calibrated and then validated for the prediction of snow water equivalent (SWE) and streamflow in the Reynolds Creek Experimental Watershed in Idaho, USA. The tradeoff between fitting to SWE versus streamflow data was assessed and showed that both could be simultaneously predicted with good quality by the MESH model. Not surprisingly, calibrating to only one objective (e.g. SWE) yielded poor simulation results for the other objective (e.g. streamflow). The multiobjective calibration problem in this study was efficiently solved via a simple weighted objective function approach and analyses showed that the approach yielded a balanced solution between the objectives. Our approach therefore eliminated the need to rely on a potentially more computationally intensive evolutionary multiobjective algorithm to approximate the entire tradeoff surface between objectives. Additional calibration experiments showed that for our calibration computational budget (2000 model evaluations), the autocalibration procedure would fail without being initialized to a model parameter set carefully determined for this specific case study. This study serves as a benchmark for MESH model simulation accuracy which can be compared with future versions of MESH.

scholarly journals Analyzing the Influence of Mobile Phone Use of Drivers on Traffic Flow Based on an Improved Cellular Automaton Model

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Yao Xiao ◽  
Jing Shi
Keyword(s):  
Cellular Automaton ◽  
Traffic Flow ◽  
Flow Rate ◽  
Traffic Safety ◽  
Model Simulation ◽  
Cellular Automaton Model ◽  
Mobile Phone Use ◽  
Traffic Efficiency ◽  
A Value ◽  
Ca Model

This paper aimed to analyze the influence of drivers’ behavior of phone use while driving on traffic flow, including both traffic efficiency and traffic safety. An improved cellular automaton model was proposed to simulate traffic flow with distracted drivers based on the Nagel-Schreckenberg model. The driving characters of drivers using a phone were first discussed and a value representing the probability to use a phone while driving was put into the CA model. Simulation results showed that traffic flow rate was significantly reduced if some drivers used a phone compared to no phone use. The flow rate and velocity decreased as the proportion of drivers using a phone increased. While, under low density, the risk of traffic decreased first and then increased as the distracted drivers increased, the distracted behavior of drivers, like using a phone, could reduce the flow rate by 5 percent according to the simulation.

An urban–rural continuum? A spatial comparison in mid-eighteenth-century northern Germany

Urban History ◽  
2020 ◽  
Vol 47 (3) ◽  
pp. 421-447
Author(s):  
Olaf März
Keyword(s):  
Eighteenth Century ◽  
Geographical Information ◽  
Rural Settlements ◽  
North West ◽  
The North ◽  
Urban Rural ◽  
Land Survey ◽  
Micro Structures ◽  
German Cities ◽  
Modern Era

AbstractThe spatial growth of German cities in the years of upheaval in the nineteenth century has been, and remains, the subject of intense historical research. However, the origins of the socio-economic processes underlying these transformations actually predate the epochal transition into the modern era. This article deals critically with the popular conception of a ‘town–country dichotomy’ by comparing, on an empirical basis, urban, semi-urban and rural settlements in a sub-region of the north-west of Germany in the mid-eighteenth century. With the aid of a Geographical Information System (GIS), the cartographic and serial material of the ‘Brunswick Land Survey’ is evaluated in terms of its relevance to a socio-topographic comparison of the spatial micro-structures of the three respective settlement segments. The comparison focuses on the general morphology of the settlement segments, the conditions accompanying the growth of the settlements and the spatial structures of the agricultural activities pursued. In addition, it identifies the factors which led to the erosion of differences between town and country.

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