Critical determinant factors (CDFs) for developing concentrated rural settlement in post-disaster reconstruction: a China study

Housing reconstruction is always the top priority issue in post-disaster reconstruction of rural areas in developing countries. However, the traditional reconstruction approaches, including reconstruction in situ, and resettlement are not sustainable enough for post-disaster reconstruction. Against the dispersion pattern of settlement, this study argues that developing concentrated rural settlement is able to increase the resilience of rural villages and to provide a basis for sustainable development post-disaster. Little study has reported developing concentrated rural settlement in post-disaster reconstruction until the reconstruction post 5.12 Sichuan Earthquake. Yet, there is still an unclear understanding of the factors taken into account when developing concentrated rural settlement in post-disaster reconstruction. This study aims to explore the critical determinant factors to be considered for developing concentrated rural settlement in post-disaster reconstruction with particular reference to the reconstruction post of 5.12 Sichuan Earthquake in China. Through content analysis, a preliminary list of determinant factors was firstly identified. Interviews with the local government officers, planners, and rural victims were conducted to collect opinions on the critical factors. It was found that governmental guidance, victims’ willingness, and economic development condition are three critical dimensions. The findings from this research can help understand the preconditions for developing concentrated rural settlement in post-disaster reconstruction and promote this approach in future.     

A GIS model for settlement suitability regarding disaster mitigation, a case study in Bolu Turkey

A GIS (Geographic Information Systems) model was developed for Bolu Province in Turkey primarily for earthquake disaster mitigation purposes. The model served as the basis for investigating earthquake disaster vulnerability of existing settlements and identifying areas for new settlements in the Bolu Provincial Center and its counties. The set of criteria investigated in the GIS model was the following: distance from the main fault, ground acceleration, geologic basement type and terrain slope. Based on these criteria, a settlement suitability map was created, which classified the province into low, medium and high settlement suitable areas. This map was then augmented with other criteria for refinement purposes. These included the land use capability classes map of the province, the contemporary land use map derived from satellite images and the historical and contemporary earthquake occurrences within the region. Finally, the road network of the province derived from satellite images was overlaid on the settlement suitability map so that the provincial administrators could leave an evacuation zone of 200 m around the roads. This settlement suitability map is also intended to assist provincial administrators in making plans for reinforcement of existing settlements in low settlement suitable regions and opening new areas for urbanization and industrialization in high settlement suitable regions.     

喀斯特地区不同岩性上农村居民点分布特征——以平果市为例

以典型喀斯特地区广西平果市的农村居民点为研究对象,运用GIS空间分析方法、Voronoi图和景观格局指数分析方法,揭示平果市喀斯特地区不同岩性上农村居民点的空间分布特征.结果表明:(1)平果市农村居民点总面积为4825.15 hm2,喀斯特地区与非喀斯特地区的农村居民面积比值约为2.8:1;(2)平果市的农村居民点属于...     

Determinants of migration decision-making for rural households: a case study in Chongqing,China

Migration is a global strategy for promoting economic growth and sustainable urbanization, specifically in developing countries. It is critical for governments to understand the determinants of migration decision for rural households so that proper migration measures can be taken. Different from previous studies that mainly focus on migration determinants without considering migration patterns, this paper divides migration patterns into three types—no migration, labor migration, and family migration, and examines the determinants for “no migration–migration” and “labor migration–family migration,” respectively. The binary logistic model is adopted to analyze the impacts of various migration factors in Chongqing city. Results show that: (1) per capita non-agricultural income plays the most significant positive role in driving “no migration–migration.” This is followed by the number of household labor force, whereas road accessibility is the key factor for inhibiting migration. (2) The key contributory factor for “labor migration–family migration” is per capita non-agricultural income. This is followed by the residential distance from towns, whereas the number of household labor force and the average age of labor force are restraining factors. The research results can effectively provide scientific reference for local governments to advance the transfer of the surplus rural labor force to promote sustainable urbanization.

     

The role of social capital,personal networks,and emergency responders in post-disaster recovery and resilience: a study of rural communities in Indiana

The factors that explain the speed of recovery after disaster remain contested. While many have argued that physical infrastructure, social capital, and disaster damage influence the arc of recovery, empirical studies that test these various factors within a unified modeling framework are few. We conducted a mail survey to collect data on household recovery in four small towns in southern Indiana that were hit by deadly tornadoes in March 2012. The recovery effort is ongoing; while many of the homes, businesses, and community facilities were rebuilt in 2013, some are still under construction. We investigate how households in these communities are recovering from damage that they experienced and the role of social capital, personal networks, and assistance from emergency responders on the overall recovery experience. We used an ordered probit modeling framework to test the combined as well as relative effects of (a) damage to physical infrastructures (houses, vehicles, etc.); (b) recovery assistance from emergency responders (FEMA) as well as friends and neighbors; (c) personal network characteristics (size, network density, proximity, length of relationship); (d) social capital (civic engagement, contact with neighbors, trust); and (e) household characteristics. Results show that while households with higher levels of damage experienced slower recovery, those with recovery assistance from neighbors, stronger personal networks, and higher levels of social capital experienced faster recovery. The insights gained in this study will enable emergency managers and disaster response personnel to implement targeted strategies in facilitating post-disaster recovery and community resilience.     

Regional effects of natural disasters in China: investing in post-disaster recovery

We examine the effects of natural disasters on income and investment in China. Using macroeconomic province-level data and the provincial history of disaster exposure over the past two decades, we describe the relationship between disaster mortality and morbidity, disasters’ economic damages, government investment and regional economic activity, and infrastructure development. The Chinese government’s aggressive investment in post-disaster reconstruction is discussed, and the implications of this investment for post-disaster private sector economic activity are analyzed empirically. We further investigate the differential effects of natural disasters on economic activity in China’s diverse geographical regions.     

Regional effects of natural disasters in China: investing in post-disaster recovery

We examine the effects of natural disasters on income and investment in China. Using macroeconomic province-level data and the provincial history of disaster exposure over the past two decades, we describe the relationship between disaster mortality and morbidity, disasters’ economic damages, government investment and regional economic activity, and infrastructure development. The Chinese government’s aggressive investment in post-disaster reconstruction is discussed, and the implications of this investment for post-disaster private sector economic activity are analyzed empirically. We further investigate the differential effects of natural disasters on economic activity in China’s diverse geographical regions.

     

Cellular automata-based model for developing land use ecological security patterns in semi-arid areas: a case study of Ordos, Inner Mongolia, China

The semi-arid areas in Northern China are home to a large population and have great ecological vulnerability. Contemporary land use pressures cause these areas to suffer from a severe land use conflict between human activities and environmental conservation. Ignoring the livelihood of humans and the development of semi-arid areas is not possible. However, the rapid increase in human activity recently exposes both the human race and local environment to potential adverse effects. To balance this contradiction, this research puts forth a framework to optimize the land use patterns in these areas in the context of ecological security and land use suitability. Considering the expansion of particular land use forms to meet the land use demand of social development, a revised cellular automata model is employed to shape the path of land expansion. Meanwhile, additional adjustment rules are set to adjust the unreasonable land use units to a suitable form. The city of Ordos is chosen as a case to put this framework into practice, and several landscape pattern indexes are used to evaluate the results. The results reveal that this framework could maintain the environment in a stable state while simultaneously meeting the land use demand of social development.     

Stochastic model for settlement: footings on cohesionless soil

In this paper, given an estimate of the bearing capacity of the soil, by treating settlement at a given load as a random variable and the evolution of settlement of footing on cohesionless soil with the increasing load as a stochastic process, a tri-level homogeneous Markov chain (TLHMC) model is proposed for prediction of settlement. Comparison of the predicted mean and bounds on settlements, obtained using TLHMC, with the respective field values obtained from literature shows that the stochastic evolution can be modelled using TLHMC with a correlation coefficient of 0.90. A methodology for reliability-based design of footings is also presented and its use is demonstrated through a numerical example.     

地面沉降的GM(2,1)模型预测研究

运用灰色理论建立地面沉降的GM(2,1)模型,其中非等时距位移序列采用拉格朗日插值函数转变为等时距序列。采用非等时距GM(2,1)及GM(1,1)模型对西安市地面沉降观测点进行安全预测。计算结果表明,非等时距GM(2,1)模型预测地面沉降精度总体较GM(1,1)模型高,预测结果与实际吻合较好。     

A framework toward developing a groundwater conceptual model

Developing an accurate conceptual model is the most important step in the process of a groundwater numerical modeling. Disorganized and limited available data and information, especially in the developing countries, make the preparation of the conceptual model difficult and sometimes cumbersome. In this research, an integrative and comprehensive method is proposed to develop groundwater conceptual model for an unconfined aquifer. The proposed method consists of six steps. A preliminary step (step 0) is aimed at collecting all the available data and information. The output of the first step as “controlling observations” is conceptual model version 00. This step should be rigorously checked due to its critical role in the controlling of final conceptual model. Step 2 determines the aquifer geometry. The output of this step is conceptual model version 01. Step 3 is responsible to determine hydrodynamic properties and its output develops conceptual model version 02. Step 4 evaluates the surface and subsurface interactions and lateral in/out groundwater flows. The output of this step is conceptual model version 03. Step 5 is to integrate the results from other steps and to deliver the final conceptual model version. The accuracy level of the conceptual model and the annual groundwater balance is also determined at this step. The presented groundwater conceptual model procedure was implemented for the Neishaboor plain, Iran. Results showed its usefulness and practicality in developing the conceptual model for the study area.     

Mubrooka: A study in the food system of a squatter settlement in Omdurman,Sudan

This paper is based on a survey supported by the IGU Commission on Geography of Famine and Vulnerable Food Systems. The support received is especially acknowledged.     

A coupled model for prediction of settlement and gas flow in MSW landfills

Prediction of long‐term settlement and control of gas pollution to the environment are two principle concerns during the management of municipal solid waste (MSW) landfills. The behavior of settlement and gas flow in MSW landfills is complicated due to the combined effect of mechanical deformation of the solid skeleton and continuous biodegradation of the waste. A one‐dimensional settlement and gas flow model is presented in this paper, which is capable of predicting time evolution of settlement as well as temporal and spatial distribution of gas pressure within multi‐layered landfills under a variety of operating scenarios. The analytical solution to the novel model is evaluated with numerical simulation and field measurements. The resulting efficiency and accuracy highlight the capability of the proposed model to reproduce the settlement behavior and gas flow in MSW landfills. The influences of operating conditions and waste properties on settlement and gas pressure are examined for typical MSW landfills. Copyright © 2009 John Wiley & Sons, Ltd.     

Retailing in rural areas: A case study in Norfolk

In Britain the decline of facilities in rural settlements in the face of increasing urban dependence is becoming a major policy issue; despite high mobility, many people still lack access to essential facilities. This paper is based on fieldwork carried out mostly during 1976 in two rural areas of Norfolk, as part of a Government-sponsored study of rural transport and accessibility. It looks first at the pattern of shops and their location related to parish size, and then discusses levels of use in comparison with urban facilities, drawing on household activity surveys. The paper then analyses in depth the ownership and operation of village shops, using the results of a survey carried out among the proprietors of the shops in the two study areas, and also considers the issues that concern shopkeepers and villagers. Finally it notes changes over the past two years in the pattern of facilities and discusses the case of two villages. The implications for rural planning are examined, and the author concludes that development of rural settlements must be based on sensitive and local understanding, rather than directive blanket policies, if reasonable access to shops and similar facilities is to be retained.     

Implementing post-earthquake reconstruction plans in China: a resilience perspective

This paper offers a critical investigation on the implementation of reconstruction plans in China following Wenchuan Earthquake through the lens of disaster resilience. The analysis is built upon a resilience in planning framework which consists of nine attributes. Empirical cases of two typical towns in Wenchuan County, Weizhou and Yingxiu, are discussed and compared. This paper upholds an evolutionary perspective of resilience and argues that reconstruction planning is a contested and politically laden field for different stakeholders, such that social aspect resilience is key to understanding plan implementation.

     

Integration of root systems into a GIS-based slip surface model: computational experiments in a generic hillslope environment

Root systems of trees reinforce the underlying soil in hillslope environments and therefore potentially increase slope stability. So far, the influence of root systems is disregarded in Geographic Information System (GIS) models that calculate slope stability along distinct failure plane. In this study, we analyse the impact of different root system compositions and densities on slope stability conditions computed by a GIS-based slip surface model. We apply the 2.5D slip surface model r.slope.stability to 23 root system scenarios imposed on pyramidoid-shaped elements of a generic landscape. Shallow, taproot and mixed root systems are approximated by paraboloids and different stand and patch densities are considered. The slope failure probability (P_f) is derived for each raster cell of the generic landscape, considering the reinforcement through root cohesion. Average and standard deviation of P_f are analysed for each scenario. As expected, the r.slope.stability yields the highest values of P_f for the scenario without roots. In contrast, homogeneous stands with taproot or mixed root systems yield the lowest values of P_f. P_f generally decreases with increasing stand density, whereby stand density appears to exert a more pronounced influence on P_f than patch density. For patchy stands, P_f increases with a decreasing size of the tested slip surfaces. The patterns yielded by the computational experiments are largely in line with the results of previous studies. This approach provides an innovative and simple strategy to approximate the additional cohesion supplied by root systems and thereby considers various compositions of forest stands in 2.5D slip surface models. Our findings will be useful for developing strategies towards appropriately parameterising root reinforcement in real-world slope stability modelling campaigns.     

Laboratory model tests for cyclic load-induced settlement of a strip foundation on a clayey soil

Laboratory model test results are presented for the cyclic load-induced settlement of a strip foundation supported by a saturated clayey soil. In performing the tests, the foundation was initially subjected to an allowable static load, after which a cyclic load with a frequency of one cycle per second was superimposed on it. The magnitudes of the static load and the amplitude of the cyclic load were varied. Based on the model test results, relationships for the foundation settlement and intensities of the static and cyclic loads are presented.     

GEMSFIT: a generic fitting tool for geochemical activity models

GEMSFIT, a parallelized open-source tool for fitting thermodynamic activity models has been developed. It is the first open-source implementation of a generic geochemical-thermodynamic fitting tool coupled to a chemical equilibrium solver which uses the direct Gibbs energy minimization (GEM) approach. This enables speciation-based fitting of complex solution systems such as solid solutions and mixed solvents. The extendable framework of GEMSFIT provides a generic interface for fitting geochemical activity models at varying system compositions, temperatures and pressures. GEMSFIT provides the most common tools for statistical analysis which allow thorough evaluation of the fitted parameters. The program can receive input of measured data from a PostgreSQL database server or exported spreadsheets. The fitting tool allows for bound, linear, and nonlinear (in)equality-constrained minimization of weighted squared residuals of highly nonlinear systems over a wide temperature and pressure interval only limited by user-supplied thermodynamic data. Results from parameter regression as well as from statistical analysis can be visualized and directly printed to various graphical formats. Efficient use of the code is facilitated by a graphical user interface which assists in setting up GEMSFIT input files. The usage and resulting output of GEMSFIT is demonstrated by results from parameter regression of the extended universal quasichemical aqueous activity model for geothermal brines.     

A method for mineral prospectivity mapping integrating C4.5 decision tree,weights-of-evidence and m-branch smoothing techniques: a case study in the eastern Kunlun Mountains,China

In this study, a novel method that integrates C4.5 decision tree, weights-of-evidence and m-branch smoothing techniques was proposed for mineral prospectivity mapping. First, a weights-of-evidence model was used to rank the importance of each evidential map and determine the optimal buffer distance. Second, a classification technique that uses a C4.5 decision tree in data mining was used to construct a decision tree classifier for the grid dataset. Finally, an m-branch smoothing technique was used as a predictor, which transformed the decision tree into a probability evaluation tree. The method makes no conditional independence assumption and can be applied for class imbalanced datasets like those collected during mineral exploration for prospectivity mapping of an area. The traits of comprehensibility, accuracy and efficiency were derived from the C4.5 decision tree. In addition, a case study for iron prospectivity mapping was performed in the eastern Kunlun Mountains, China. Sixty-two Skarn iron deposits and eight evidential maps related to iron mineralization were studied. On the final map, areas of low, moderate and high potential for iron deposit occurrence covered areas of 71,491, 14,298, and 9,532 km², respectively. For the goodness-of-fit test, 91.94 % of the total 62 iron deposits were within a high-potential area, 8.06 % were within a moderate-potential area and 0 % were within a low-potential area. For ten-fold cross-validation, 82.26 % were within a high-potential area, 14.52 % were within a moderate-potential area and 3.22 % were within a low-potential area. To evaluate the predictive accuracy, Receiver Operating Characteristic (ROC) curves and Area Under ROC Curve (AUC) were employed. The accuracy of the goodness-of-fit test reached 97.07 %, and the accuracy of the ten-fold cross-validation was 95.10 %. The majority of the iron deposits were within high-potential and moderate-potential areas, which covered a small proportion of the study area.