民勤绿洲天然胡杨林生长季土壤水盐动态

利用经典统计学与地统计学方法研究民勤绿洲天然胡杨林生长季的土壤水盐动态变化规律。结果表明,民勤县双茨科乡和苏武乡土壤含水量随土层深度增加而增大,夹河乡土壤含水量则随土层深度增加先增大后减小。研究区0～20 cm土壤含水量较低,为8.5～34.0 g.kg-1,平均值为18.2 g.kg-1。土壤含水量属中等变异性,且呈中等程度的空间相关性。各季节土壤含水量从高到低依次为春季、秋季和夏季。土壤全盐量属中等变异性,总体变化趋势为随土层深度增加而减小,夹河、苏武和双茨科乡0～20 cm土壤全盐量平均值分别为15.4、28.0和11.1 g.kg-1。各季节土壤全盐量由高到低依次为春季、夏季和秋季。胡杨胸径与土壤水盐含量间呈负相关。     

Perceiving the Environment from the Lay Perspective in Desertified Areas,Northern China

Investigating local people’s environmental perceptions can produce useful information that could be incorporated into decision making processes that help resolve environmental problems. Although China is undergoing severe desertification, the perceptions of the local people toward their degraded environment and the related issues have so far not been actively solicited. This article, which is a supplement to Lee and Zhang’s (2004, 2005) studies, seeks to further investigate the lay public’s general environmental attitudes, perceptions of desertification, interpretations of land-degrading activities, and particularly their interrelations in severely desertified areas. Minqin County in Gansu Province, northern China, was chosen to be the study area. Data was collected via a questionnaire survey (n = 1138) administered in December 2002. Major findings were: (1) Most respondents had only weak altruistic environmental attitudes, with educational level to be a significant determinant. (2) Respondents’ perceptions of desertification and interpretations of land-degrading activities were contingent on personal attributes, general environmental attitudes, and other conceptions related to desertification. It is recommended that the interrelations between the various aspects of the public’s environmental perceptions should be thoroughly examined to facilitate their participation in environmental management.     

虚拟水战略:拯救民勤绿洲的新思路

位于甘肃石羊河下游的民绿洲，水资源极度缺乏，生产、生活和生态用水矛盾突出，出现了严重的生态危机，其中湖区的生态经济系统已呈“崩溃”之势。拯救民勤绿洲成为社会广泛关注的重大问题。“虚拟水”是20世纪90年代初Tony Allan提出的一个新概念，虚拟水战略是指贫水区域通过贸易的方式从富水地区购进水资源密集型产品来获得本区水资源安全的一种构想。本文通过对节水、调水、移民等常规方案与虚拟水战略的对比分析后，认为虚拟水战略是拯救民勤绿洲的一个全新思路，探讨了虚拟水战略实施的政策建议；提出了创新区域水资源管理体制和区域经济发展思路以及建立国家生态补偿机制的主张。     

Environmental characteristics of sandstorm in Minqin Oasis in China for Recent 50 years

IntroductionAsandstormis a kind of severe weather phenomenawhere strong winds blowa huge amount of sand and dust intothe air ,reducing the horizontal visibility to less than 1 km( Wang, 2003a) . It is not only an important process ofaccelerating land dese…     

沙区沙化土地封禁保护补偿标准的估算——最小数据方法在甘肃省民勤县的运用

论文以甘肃省民勤县沙化土地封禁保护实践工作为研究背景,运用最小数据方法,估算了激励沙区农户将沙化耕地自愿转化为封禁土地的生态补偿（封禁补偿）标准。以水资源服务表征土地管理方式转变之后的生态系统服务产出,由调查获得的农户机会成本推导出了水资源服务供给曲线,并计算出了封禁补偿标准与土地转化比例、水资源服务供给量之间的定量关系。研究结果表明：1）实施封禁补偿,可激励农户改变沙化耕地利用方式,减少农业用水需求量,增加生态用水供给量,对民勤和石羊河流域生态保护意义重大;2）民勤县规划封禁保护区总面积为1.55万hm²,期望水资源服务产出为1.02亿m³,需要按照19 770元·hm^-2的标准补偿才能激励农户实现这一政策目标;3）以新一轮退耕还林补偿标准3 600元·hm^-2为参照线,只能促使3.51%的沙化耕地转化为封禁土地,在设计封禁补偿机制时,需要提高封禁补偿标准。     

Water-saving Technologies,Solar Green House and Ecological Rehabilitation in Minqin Oasis of Gansu Province,China

Land degradation and desertification have become severe environmental problems in arid areas due to excessive use of water resources. It is urgent to reduce agricultural water use for ecological rehabilitation, which may result in a decrease in agricultural production and farmer＇s welfare. This paper focused on the impacts of some main measures including extensions of watersaving irrigation, expanding solar green house and increasing off-farm employment, which are generally recognized to be important to alleviate water shortage and poverty. A bioconomic model is applied taking Minqin Oasis in Gansu Province as a case study site. Simulation results showed that the effect of expanding solar greenhouse was more positive than other ones so it drew more attention. On the view of the different effects between each irrigation zone, mixed policy patterns suitable for them are suggested. In Baqu, expanding solar greenhouse should be the most important, auxiliary with encouraging pipe irrigation. Inversely, with regard to Quanshan, the major attention should be paid to subsidy for pipe irrigation and it would be better to supply the off-farm employment opportunities to the households in Huqu, where the expanding of solar greenhouse should also be summoned. Finally, it should be noted that farmer＇s income would only resume to 90% of the current level in the short run by putting more effort into local policies. Thus, the ecological compensation is needed to ensure farmer＇s welfare.     

Perceiving Land-Degrading Activities from the Lay Perspective in Northern China

Investigation into local peoples’ perceptions can produce useful information that could be incorporated into the decision-making process to help resolve environmental problems. Within the arena of land degradation, a number of studies have also been conducted to explore local peoples’ views of the problem. However, the perceptions of land-degrading practices of the general public have so far not been actively solicited. This study aimed to contribute to this area of research by adopting the psychometric scaling technique to empirically explore the lay public’s ecological risk perceptions of land-degrading activities in Minqin County in Gansu Province, northern China. The primary data were collected via a questionnaire survey (n = 1,138) administered between 14 and 31 December 2002. The major findings of the survey were: (1) Respondents perceived the ecological risks posed by different land-degrading activities to be different. (2) There was a considerable incongruence in the way in which mining of groundwater was conceived by experts and laymen, respectively. (3) Respondents were pretty unsure of expert knowledge. (4) Respondents’ ecological risk perceptions were significantly affected by their personal attributes. As far as the policy implications of these findings are concerned, this study accentuates that we must be aware of, and involved in, the environmental perceptions of the lay public in order to succeed in guiding any human-environment tensions along more sustainable trajectories and navigating the transition to sustainability.     

民勤盆地水资源承载力指标体系及评估

水资源是民勤盆地社会经济发展最主要的限制因子,水资源承载力研究对民勤盆地实现可持续发展具有重要意义。论文采用定性和定量相结合的方法,从水资源承载力的定义、内涵、影响因素出发,结合民勤盆地的生态环境特点、社会经济发展状况,构建了由对象层指标和影响层指标组成、能够对水资源承载力进行测度和评价的指标体系。依据各指标的含义,利用可得数据初步估算、预测了民勤盆地2001、2010和2020年的水资源承载力,并对计算结果进行了简要评价。     

Emission Patterns under Alternative Congestion and Motor Vehicle Pollution Mitigation Policies in Shanghai

Abstract

Minqin Oasis is located in the lower reaches of the Shiyanghe River Basin, northeast of the Heixi Corridor, at the middle of the Silk Road. Because of the its existence, Badain Jaran Desert and Tengger Desert cannot converge and develop in the south. It has always been an important green barrier to guarantee the eco-security of Hexi Corridor and the Silk Road for thousands of years. But in recent decades, Minqin Oasis is becoming smaller and the desert is becoming larger. Many people, especially the governmental officials in the lower reaches think that the upper and middle reaches have robbed the lower reaches of water resources, and caused insufficient water usage and the deteriorated eco-environment, in the lower reaches, However, the governmental officials in the upper and middle reaches claim that the whole river basin should take the upper and middle reaches as the key regions to develop economy. To address the above argument, we analyze the reasons why Minqin Oasis is disappearing, and find that there are two main factors. One is the quick development of population and economy in the upper and middle reaches; the other is the rapid development of population and economy in the lower reaches. The two factors both have great effect on the water utilization for eco-environment in the lower reaches. So Minqin Oasis is disappearing not only because of the upper and middle reaches but also because of the growth of population and economy itself. The lower reaches should not completely blame the upper and middle reaches. The upper and middle reaches should also pay more attention to the eco-environment in the lower reaches. The whole river basin should develop a harmonious and sustainable relationship among the upper, middle and lower reaches.