INCREASED BASEFLOW IN IOWA OVER THE SECOND HALF OF THE 20TH CENTURY1

ABSTRACT: Historical trends in annual discharge characteristics were evaluated for 11 gauging stations located throughout Iowa. Discharge records from nine eight‐digit hydrologic unit code (HUC‐8) watersheds were examined for the period 1940 to 2000, whereas data for two larger river systems (Cedar and Des Moines Rivers) were examined for a longer period of record (1903 to 2000). In nearly all watersheds evaluated, annual base flow, annual minimum flow, and the annual base flow percentage significantly increased over time. Some rivers also exhibited increasing trends in total annual discharge, whereas only the Maquoketa River had significantly decreased annual maximum flows. Regression of stream discharge versus precipitation indicated that more precipitation is being routed into streams as base flow than as storm flow in the second half of the 20th Century. Reasons for the observed stream flow trends are hypothesized to include improved conservation practices, greater artificial drainage, increasing row crop production, and channel incision. Each of these reasons is consistent with the observed trends, and all are likely responsible to some degree in most watersheds.     

SPATIO-TEMPORAL CHANGE OF DROUGHT DISASTER IN CHINA IN RECENT FIFTY YEARS

Foreword　Inglobalview ,droughtdisasterisregardedasthemostserioustypeofnaturaldisasterintheworld ,whichhascausedthewidestrangeofeffectsandthebiggesteconomiclosses .Se veredroughtsmainlyoccurinAfrica ,India ,China ,formerSovietUnion ,NorthAmerica ,andAustralia,accountingforalmosthalfofcountriesintheworld .Droughtdisasteroccursfre quentlyinChina ,withwiderangeofinfluence ,whichisthemostseriousmeteorologicaldisas ter ,causingeconomiclossesinagriculture .Fromthe 50’stothe 80’sinthe 2 0thcent…     

Comparing Environmental Conditions Using Indicators of Pollution Hazard

/ Land use/land cover classifications for 1973 and 1991, derived from the interpretation of satellite imagery, are quantified on the basis of biophysical land units in a study area in southeastern Australia. Nutrient export potentials are estimated for each land unit based on their composition of land use/land cover classes. Spatial and temporal comparisons are made of the land units based on the calculated pollution hazard indicators to provide an insight into changes in the state of the environment and the regional significance of land use changes. For example, one ecosystem, unique to the study, showed a large increase in pollution hazard over the study period as a manifestation of an 11-fold rise in cleared area and an expansion of cropping activities. The benefits to environmental management in general are discussed.KEY WORDS: Land cover change; Nutrient export; Environmental condition; Pollution hazard; Agricultural pollution; Nonpoint source pollution; Diffuse pollution; Environmental degradation     

Climate Convention Implementation: An Opportunity for the Pacific Island Nations to Move Toward Sustainable Energy Systems

This article does not focus on adaptation or mitigation policy directly but on an allied opportunity that exists for the Pacific Islands via the auspices of the Climate Convention, because the existing very costly energy systems used in the Pacific Island region are fossil-fuel dependent. It is argued here that efforts can be made towards the development of energy systems that are ecologically sustainable because Pacific Island nations are eligible to receive assistance to introduce renewable energy technology and pursue energy conservation via implementation mechanisms of the Climate Convention and, in particular, through transfer of technology and via joint implementation. It is contended that assistance in the form of finance, technology, and human resource development from developed countries and international organizations would provide sustainable benefits in improving the local Pacific Island environments. It is also emphasized that mitigation of greenhouse gas emissions is not the responsibility of the Pacific Islands as they contribute very little on a per capita global scale and a tiny proportion of total global greenhouse gas emissions.     

Biodiversity laws: State experiences

The Western Governors' Association (WGA) includes both the public lands states with their issues and the plains states, which are 98% privately owned. WGA deals with most legislation affecting biodiversity, whether the effect is direct or tangential. It will probably not be possible, or desirable, for one entity to be in charge of biodiversity conservation. The Endangered Species Act, public lands laws, agricultural laws, water law, environmental laws, and funding legislation all affect biodiversity conservation and the responsibility for it. None of them on their own are enough, and most can cause harmful unintended consequences for biodiversity. The experience of western states in developing consensus principles for reauthorization of the Endangered Species Act provides an example of common-sense ways to improve management of biodiversity, notwithstanding the complexity and large stakes involved. The WGA's proposed changes call for increasing the role of states, streamlining the act, and increasing certainty for landowners and water users. To achieve sustainable conservation for biodiversity, the better question is not “Who is/should be in charge?”, it is “How do we get this done?” To answer this, we need goals, guidance, and bottom lines from federal laws, and management and oversight at the state level, but they all need to support local on-the-ground partnerships. Sustainable conservation requires the active participation of those who live there. WGA's experience in coordinating the Great Plains Partnership as well as its work with watershed efforts shed light on what to expect. Multilevel partnerships are not easy and require a different way of doing business. The ad hoc, sitespecific processes that result do not lend themselves to being legislated, fit into organizational boxes, or scored on a budget sheet. They do require common sense and a longterm perspective.     

Pressures,trends, and impacts in coastal zones: Interactions between socioeconomic and natural systems

This paper assesses the status of coastal zones in the context of expected climate change and its related impacts, as well as current and future socioeconomic pressures and impacts. It is argued that external stresses and shocks relating to sea-level rise and other changes will tend to exacerbate existing environmental pressures and damage in coastal zones. Coastal zones are under increasing stress because of an interrelated set of planning failures including information, economic market, and policy intervention failures. Moves towards integrated coastal zone management are urgently required to guide the coevolution of natural and human systems. Overtly technocentric claims that assessments of vulnerability undertaken to date are overestimates of likely future damages from global warming are premature. While it is the case that forecasts of sea-level rise have been scaled down, much uncertainty remains over, for example, combined storm, sea surge, and other events. In any case, within the socioeconomic analyses of the problem, resource valuations have been at best only partial and have failed to incorporate sensitivity analysis in terms of the discount rates utilized. This would indicate an underestimation of potential damage costs. Overall, a precautionary approach is justified based on the need to act ahead of adequate information acquisition, economically efficient resource pricing and proactive coastal planning.     

气候变化与自然灾害

气候变化与自然灾害是当今科学研究的两大热点，两者之间在一定程度上具有相关性，但目前要确切地定量计算气候变化对自然灾害的强度和出现频率的影响还很困难。本文在分析气候变化与自然灾害关系的基础上，研究了气候变化对我国自然灾害的影响。研究结果显示：１．在千年尺度上，长江流域的大旱和气候变冷成正相关，而长江流域的大涝以及黄河流域的大旱和大涝与气候冷暖过渡期成正相关；２．在百年尽度上，近１０４２年来，共出现２８１次全国性大旱和大涝，平均每百年出现２７次，在地域分布上以南涝北旱为主；３．就百年至千年尺度的气候变化对自然灾害的影响而言，气候冷冷组合期（１３０１～１９００）易发生全国性大涝，而冷暖组合期（９５０～１３００年，１９０１～１９９１年）易发生全国性大旱。总的来说，冷冷组合期的大旱大涝发生频率明显大于暖期，但不同地区有差异；４．在其它影响方面，台风、地震与海啸灾害在冷暖组合期（２０世纪）均有比冷冷组合期（１４和１９世纪）多的趋势。因此，气候变暖将使防灾任务更加艰巨。     

我国石油工业环境保护相关法律问题

目前,我国对石油工业领域环境保护立法,采取的是特殊行业规制与一般规制相结合的模式。总体上看,我国石油工业环境保护领域已建立起初步的法制框架,但仍须进一步完善立法、执法、制订应急预案和建立信息公开机制等。     

渭河径流特性研究

由于工农业的快速发展,渭河径流逐年减少,污染加重,河道淤积不断发展,洪涝灾害时有发生,对中下游人民生产生活造成严重影响.为了减少洪害,减轻污染,必须保证渭河常年径流稳定.     

生活事件分析法在煤矿企业中的应用

我国煤矿一再的发生事故,绝大部分原因是人为失误.根据人为失误的发生机理,本文提出了生活事件分析方法,并研制了其配套应用程序,对某煤矿企业的人因事故危险性进行了实际评价.该方法可方便地应用于煤矿企业人为事故的预防工作中.