Assessing land use impacts on flood processes in complex terrain by using GIS and modeling approach

A distributed hydrologic modeling and GIS approach is applied for the assessment of land use impact in the Steinsel sub-basin, Alzette, Grand-Duchy of Luxembourg. The assessment focuses on the runoff contributions from different land use classes and the potential impact of land use changes on runoff generation. The results show that the direct runoff from urban areas is dominant for a flood event compared with runoff from other land use areas in this catchment, and tends to increase for small floods and for the dry season floods, whereas the interflow from forested, pasture and agricultural field areas contributes to the recession flow. Significant variations in flood volume, peak discharge, time to the peak, etc., are found from the model simulation based on the three hypothetical land use change scenarios.     

Using environmental stressor information to predict the ecological status of Maryland non-tidal streams as measured by biological indicators

In Maryland, U.S., an interim framework has recentlybeen developed for using biologically based thresholds, or `biocriteria', to assess the health of nontidal streams statewide at watershed scales. The evaluation of impairment is based on indices of biological integrity from the Maryland Biological Stream Survey (MBSS). We applied logistic regression to quantify how the biotic integrity of streams at a local scale is affected by cumulative effects resulting from catchment land uses, point sources, and nearby transmission line rights-of-way. Indicators for land use were developed from the remote sensing National Land Cover Data and applied at different scales. We determined that the risk of local impairment in nontidal streams rapidly increases with increased urban land use in the catchment area. The average likelihood of failing biocriteria doubled with every 10% points increment in urban land, thus an increase in urban land use from 0 to 20% quadruples the risk of impairment. For the basins evaluated in this study, catchments with more than 40–50% urban land use had greater than 80% probability of failing biocriteria, on average. Inclusion of rights-of-way and point sources in the model did not significantly improve the fit for this data set, most likely because of their low numbers. The overall results indicate that our predictive modeling approach can help pinpoint stream ecosystems experiencing or vulnerable to degradation.     

Land User Participation in Developing a Computerised Decision Support System for Combating Desertification

Combating desertification in natural rangelands has recently become a priority in large parts of southern Africa. Rangeland managers, farmers, scientists, conservationists and land users have been applying a variety of restoration technologies to address this problem. Bush encroachment, as part of the desertification process, involves the natural replacement of the herbaceous plant cover by undesirable problem woody species. The active and passive restoration technologies that are applied, are mainly based on indigenous knowledge and include the chemical, mechanical or manual reclamation of unproductive rangelands, as well as the combating of woody and alien species encroachment. Indigenous practices and knowledge play a major role in the effectiveness and success rate of these technologies. This project faces the challenge of bringing together both local and scientific knowledge in a single user-friendly, computerised Decision Support System (DSS) which is directly accessible by land users to support them in the process of decision making, concerning the combating of desertification. Case studies from central and northern Namibia were used to combine qualitative and quantitative data to develop this Decision Support System. The DSS currently consists of two databases and an expert system, which evaluates the results of land users’ management practices, and provides easily accessible information and advice for participants in the system, based on the incorporated data. The DSS is also linked to national and international web sites and databases to offer a wider range of information on technologies concerning agricultural and conservation practices.     

和田市土地利用结构变化研究

我国正处在城市化急速发展的时期。城市从数量、规模等各方面都在膨胀，这给城市土地利用带来了一系列问题。本文在综合分析和田市城市土地利用现状和未来发展要求的基础上，为解决人类在高强度经济活动中，特别是在农村经济建设和城乡建设快速发展的条件下。针对如何解决土地资源的合理利用、环境恶化及持续发展之间的矛盾。提出了和田市未来合理开发利用土地资源、产业结构的调整、城市功能区的布局和进行城市建设等方面可行性方案。     

土地复垦投资的政策法规建议

土地复垦投资的政策法规是为了克服市场经济本身的缺陷和不足,规范生产建设者（当事者）的行为以及强化其社会意识和责任,确保土地复垦投资机制的形成和运作。本文分析了我国土地复垦投资的相关政策和法规的现状和问题,有针对性地提出了一些政策和法规建议,且对《土地复垦规定》提出了具体的修改建议。     

Assessment of China's economic loss resulting from the degradation of agricultural land in the end of 20th century

Land degradation is a consequence stemming from both natural processes and social economic activities. On the bases of analyzing general situation of agricultural land degradation in China, the monetary estimating methods such as market value method and shadow engineering method were used to quantitatively assess the economic loss resulting from land deterioration. Results showed that the economic loss in 1999 was 326.8l billion RMB Yuan, which accounted for 4.1% of GDP in the same year of China. If taking five items namely farmland conversion, soil erosion, salinization, decline in reservoir functions, and siltation in waterways and, comparing with that in 1992, the percentage of economic loss to GDP has increased by 1.5 in the only 7 years.     

SBR法处理中药材有机废水工艺研究

应用ＳＢＲ法对中药材有机废水进行了研究。考察了ＣＯＤＣＲ、ＢＯＤ５、ＳＳ、ＮＨ３－Ｈ的处理效果，以及ＰＨ、水温、污泥负荷等条件对去除率的影响。运行结果表明，ＰＨＯ ６．０－９．０、ｔ为１５－３０℃、污沁荷０．３ｋｇＢＯＤ５／ｋｇＭＬＳＳ．ｄ，运行程序：进水０．５ｈ（限制曝气）、曝气１０ｈ、脱氮１．５ｈ，沉降０．５ｈ，排水０．５ｈ、闲置１１ｈ，周期时间２４ｈ时ＣＯＤＣＲ去除率８８％、ＢＯＤ５９４％、     

中国第二次北极科学考察沿线气溶胶可溶性离子分布特征和来源

对2003年7月15～9月28日间中国第二次北极科学考察沿线所采集的气溶胶样品进行分析,获得了Na 、NH4 、K 、Mg2 、Ca2 、Cl-、MSA、SO2-4、NO3-、C2O2-4和CH3COO-11种离子的浓度.离子组成表明,气溶胶主要以海盐颗粒为主,其中(Na Cl-)的贡献平均为60.2%;其次为硫酸盐.根据因子分析,11种离子归为4个因子,解释方差为83.7%.因子1包括Na 、nss-Mg2 、nss-Ca2 、Cl-和nss-SO2-4,代表陆地和海洋混合源,解释方差为41.2%;因子2包括NH 4、nss-K 和NO3-,来源于化石燃料燃烧和生物质燃烧所释放的二次污染物,解释方差为18.9%;因子3只有MSA,来源于海洋表层浮游植物排放的二甲基硫(DMS)的氧化,解释方差为11.9%;因子4包括CH3COO-和C2O2-4,主要来源于高纬度的北温带北部森林大火,解释方差为11.6%.     

海南省旅游地评价及其开发研究

旅游地资源评价和开发研究，是进行旅游开发宏观决策，确定对应的旅游活动类型和接待规模，指导旅游市场开发与景区、景点设计时一项重要的基础研究工作。本文以海南省为例，对旅游地资源的评价制图和旅游开发用地预测方法，进行了有益的探讨。     

井工煤矿建设工程对土地破坏的危险性评估

通过改变地表形态和降低土壤质量,井工煤矿生产对土地产生比较严重破坏.影响井工煤矿破坏土地的因素较多,针对所评估煤矿,煤层埋深与开采厚度、水文地质条件通常是主要因素,因此,选用土地利用类型、地表破坏程度和地面积水状况三个评估指标,采用单因素分析和叠加分析的方法进行土地破坏危险性评估.