海河流域洪水资源利用评价研究

为给流域洪水资源利用合理性评价提供基本的阈值标准,有效协调洪水资源利用与河流生态环境保护和流域防洪安全的关系,建立了流域洪水资源利用评价的基本框架.指出洪水资源利用评价应解决洪水资源量计算、洪水资源利用水平分析、洪水资源可利用量评价和洪水资源利用潜力评估四个基本问题.在对洪水资源利用量、洪水资源可利用量、洪水资源利用潜力等基本概念进行系统阐述的基础上,建立了流域洪水资源利用的评价方法.根据所建立的基本概念和评估方法,对1980～2006年海河流域及4个二级区的洪水资源利用状况及合理性进行了全面评价.结果表明,1980～2006年海河流域平均年洪水资源可利用量和利用潜力分别为62.8亿m~3和5.35亿m~3.海河流域洪水资源利用总体而言处于比较不合理的状态,洪水资源利用量频繁超过洪水资源可利用量,洪水资源利用潜力不大.多数年份洪水资源利用量超过了河道内必要需水量允许的限度,少数丰水年份超过了流域洪水资源调控利用能力的范围.今后,海河流域洪水资源利用合理性的提高,需要逐步调整目前洪水资源利用主要集中于山区的空间格局,提高平原区洪水资源调控利用能力,有效保障洪水期河道内必要需水量.     

Introduction: Racialized Poverty in U.S. Cities: Toward a Refined Racial Economy Perspective

This discussion hones and refines one conceptual orientation in geography and urban studies increasingly used to understand racialized poverty and marginalization in U.S. cities: racial economy. The article illuminates two aspects of this perspective, as an ongoing ontological project with six dominant features and as a base of epistemological understandings about contemporary racialized realities in current U.S. cities and society. This discussion shows racial economy to be still developing and in need of deeper theorizing.     

A multi‐dimensional analysis of the impacts of the Mahatma Gandhi National Rural Employment Guarantee Scheme: A tale from Tamil Nadu

This paper provides a multi‐dimensional analysis of the impacts of the Indian Mahatma Gandhi National Rural Employment Guarantee Scheme using a case study from rural Tamil Nadu. Drawing on structured interviews in households and semi‐structured interviews with local employers and officials, we analyse the effects of the workfare scheme when it is widely and properly implemented. We distinguish between different conceptualizations of the work scheme as a means of welfare provision, labour market policy and intervention directed towards other objectives. We found that the goals of the scheme were fulfilled unevenly in the given context. Among other findings, we show that positive effects on the welfare of participating and non‐participating households were accompanied by adverse effects on the local economy and negligible impact on out‐migration for work.     

Residential mobility and neighborhood inequality during the transition to adulthood

There is ongoing interest on the outcomes of residential mobility during the young adulthood. In this paper, we examine movement in and out of disadvantaged and advantaged neighborhoods as individuals move out of the family home and experience significant life course events. Using longitudinal data on young adults in the United States from the National Longitudinal Study of Adolescent to Adult Health, we find that while the point-in-time measure of the neighborhood poverty gap (the difference between the most and least advantaged neighborhoods) remained nearly identical from adolescence to young adulthood. But the neighborhood poverty gap between individuals starting out in the least and most disadvantaged residential settings decreased by 18.2 percentage points. In other words, cross sectional estimates of the poverty gap do not capture the dynamism of changes in poverty with young adult transitions. Partner formation, home ownership, and educational attainment are important life course transitions associated with significant moves up and down the neighborhood poverty distribution.     

Commentary: Neoliberal Landscapes of Deception: Detroit,Ford Field,and the Ford Motor Company

Microfinance is often presented as a solution to rural poverty. However, increasingly, many countries across the world are turning to it as a mechanism for dealing with the contingencies arising from the marketization of basic services and shrinking welfare provisions. Using examples of urban microfinance from India, this essay shows how, through microfinance, market rationalities are increasingly finding their way into food and housing provision for the urban poor and are displacing social relations that have traditionally sustained them.     

Local Labor Market Restructuring and the Employment of Welfare Recipients in Los Angeles County

Although welfare rolls have dropped considerably in recent years, most welfare recipients who find work are employed in low-wage, insecure jobs. The problem of "working poverty" is especially acute in large city-regions such as Los Angeles, where local labor market restructuring has created an expanding, low-wage economy, increasingly dependent on immigrant labor. This paper analyzes the employment outcomes of 6,931 women who completed the county's welfare-to-work program in 1996. I evaluate their earnings, labor market segmentation, and job stability. The results show that women were highly concentrated in low-wage service jobs and experienced high levels of turnover and unemployment. Many were unable to obtain employment in the formal labor market. I argue that the struggles of the working poor in a growing regional economy are explained not solely by human capital limitations, but by processes of local labor market restructuring that have contributed to widespread economic insecurity in Los Angeles County.     

Spatial Segregation of the Poor in Southern California: A Multidimensional Analysis

Poverty segregation increased in Southern California during the 1990s. A comparison of four indices reflecting various dimensions of segregation (e.g., evenness, concentration, isolation, and clustering) suggests that poor people are increasingly concentrated and isolated. However, cities within the region experienced different levels and types of segregation, with significant changes over time. Regression analysis using 1990 and 2000 census data highlights the role of demographic, economic, and fiscal variables in explaining the changing landscape of poverty. Whereas historically poor and older cities have seen a rise in poverty that translated into an increase in concentration and isolation, newer suburban communities have evolved differently. Cities where poverty has been high and increasing often maintained a high level of clustering and unevenness, but experienced higher levels of concentration and clustering in 2000. In contrast, wealthier cities typically faced a rise in unevenness and clustering as small pockets of poverty population emerged in the midst of high-income neighborhoods.     

安丘市建设用地需求预测及供需矛盾研究

以安丘市为例,通过对1999—2008年间建设用地面积变化趋势的分析,以及对安丘市建设用地增加的驱动力研究,采用平均增长率法、回归分析法和趋势分析法,预测分析安丘市2020年的建设用地需求量;通过对安丘市土地利用现状分析,依据上级规划和其他相关规定,分析安丘市2020年建设用地供给量,以此来探讨安丘市建设用地可能的供需矛盾,提出有效的解决方案。     

张掖市城市湿地土壤盐分、pH值和含水量的空间异质性分析

基于区域变量化理论,运用传统统计学和地质统计学方法,以张掖市城市湿地为研究区,定量分析湿地土壤盐分、pH值和含水量的空间异质性.结果表明:土壤盐分较高,呈一定的碱化趋势;盐分属于强变异程度,pH值属于弱变异程度,含水量属于中等变异程度;根据半方差函数理论模型分析,盐分受结构性因素较大影响表现为强空间相关性,pH值受随机...     

基于GIS和BP神经网络的区域农村贫困空间模拟分析——一种区域贫困程度测度新方法

基于区域农村贫困程度测定方式不完善及缺乏地理视角的现状,选取四川省36个国家级扶贫县为实证对象,构建自然社会经济全面耦合的农村贫困测度指标体系,分析区域农村贫困的影响机制,并运用GIS与BP神经网络模拟区域自然致贫指数、社会致贫指数和经济消贫指数的空间分布格局。在此基础上,提出了全面表征区域农村贫困程度的区域扶贫压力指数——一种新的区域农村贫困测度方法,为国家扶贫政策文件《财政扶贫资金管理办法》中关于财政扶贫资金基于区域农村贫困程度分配提供实践基础。