GEOMORPHIC PARAMETERS PREDICT HYDROGRAPH CHARACTERISTICS IN THE SOUTHWEST1

ABSTRACT: Critical design characteristics of ephermal runoff such as hydrograph rise time, duration, mean peak discharge, volume, peak-volume ratio, and maximum flood were related to physical basin parameters such as area, shape, slope, drainage density, basin relief, stream length, and combinations of these in intermontane watersheds representative of the Mexican Highland section of the Basin and Range Province. Parameters used were restricted to those easily obtainable from maps or aerial photographs. A parameter expressing basin shape and size was developed which proved to be as accurate a predictor as others used in existing prediction equations tested and was simpler and faster to derive. Simple prediction equations derived for hydrograph characteristics were all significant except for volume at the 5% level; three were significant at the 1% level. Relationships determined are applicable in semi-arid basins of the Southwest up to 60 square miles (155 km²) in area.     

Climate dynamics and extreme precipitation and flood events in Central Europe

Past changes and possible future variations in the nature of extreme precipitation and flood events in Central Europe and the Alpine region are examined from a physical standpoint. An overview is given of the following key contributory physical processes: (1) the variability of the large-scale atmospheric flow and the associated changes of the North-Atlantic storm track; (2) the feedback process between climate warming and the water cycle, and in particular the potential for more frequent heavy precipitation events; and (3) the catchment-scale hydrological processes associated with variations in major river flooding events and that are related to land-use changes, river training measures, and shifts in the proportion of rain to snowfall. In this context an account is provided of the possible future forecasting and warning methodologies based upon high-resolution weather prediction and runoff models. Also consideration is given to the detectability of past (future) changes in observed (modeled) extreme events. It is shown that their rarity and natural fluctuation largely impedes a detection of systematic variations. These effects restrict trend analysis of such events to return periods of below a few months. An illustration using daily precipitation from the Swiss Alps does yield evidence for pronounced trends of intense precipitation events (return period 30 days), while trends of stronger event classes are not detectable (but nevertheless can not be excluded). The small detection probability for extreme events limits possible mitigation of future damage costs through an abatement of climate change alone, and points to the desirability of developing improved early forecasting/warning systems as an additional no-regret strategy. This revised version was published online in July 2006 with corrections to the Cover Date.     

防灾减灾：西海固地区可持续发展的基础

根据调查和有关资料，本文研究了西海固地区自然灾害的基本特征，分析了自然灾害对可持续发展的影响和制约作用，探讨了防治自然灾害，实现可持续发展的基本对策。     

烟台地区在业人口就业结构分析

根据人口普查资料，本文从行业和职业方面对烟台地区在业人口的就业结构现状及变动特点进行了系统分析，并在此基础上对农业剩余劳动力的转移问题作了深入探讨。     

Changing effluent chemistry affect survival,growth and physiological function of <Emphasis Type="Italic">Acacia nilotica</Emphasis> seedlings in northwestern region of India

Recycling and conservation efforts for water are the need of the day because of the lack of new water sources and the ever-increasing demand for drinking water. Seedlings of Acacia nilotica L. were irrigated with: canal water (T₁, control); municipal effluent (T₂); textile effluent (T₃); steel effluent (T₄); textile + municipal effluent in 1:1 ratio (T₅); steel + municipal effluent in 1:2 ratio (T₆); steel + textile in 1:2 ratio (T₈) and steel + municipal + textile in 1:2:2 ratio (T₇) with views to observe effluents effect on the seedlings and its adaptability and to recommend safe disposal of these effluents. Seedlings in T₆, T₇ and T₈ showed 50% lesser height and collar diameter than those in control. Seedlings in T₂ attained greatest height, collar diameter, numbers of branches and produced 140 g dry biomass seedling⁻¹. Highest concentration of manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) and lowest concentration of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in the seedlings of T₄, T₆, T₇ and T₈ resulted in nutritional imbalance, mineral toxicity and reduction in photosynthetic (Pn) and transpiration (E) rates and caused seedling mortality. Seedlings of T₃ had highest sodium concentration and low concentration of Ca, Mg and micronutrients resulting in nutritional imbalance, augmented chlorosis and reduced gas exchange and biomass by half as compared to control. Increased growth, Pn and E and biomass in seedlings of T₅ over T₃ and survival period in T₆, T₇ and T₈ seedlings suggested a beneficial effect of effluents mixing. Unscientific disposal should be avoided and toxic concentration of metal ions␣may be reduced for long-term application and harmless disposal of effluents in afforestation and urban development.     

基于资源禀赋特征的怒江流域高山峡谷区经济发展策略思考

怒江流域高山峡谷区域具有集边疆、山区、民族、贫困为一体的特征,是我国典型的欠发达地区.尽管目前怒江流域已经进入工业化初期的经济发展阶段,但是长期闭塞、贫困和工业基础薄弱使流域经济发展动力不足.怒江流域的发展要把握云南建设面向东南亚、南亚开放的重要桥头堡这一战略机遇,立足自身的资源优势,引进外界资本与技术,打造水能资源经济,培育生态服务产业,同时通过交通基础设施建设和人力资本的培育改善发展环境.     

科尔沁沙地生态环境质量综合评价

基于研究区2000年土地利用图形数据、土地沙漠化监测数据、环境状况公报数据以及统计年鉴数据，采用中华人民共和国环境保护行业标准《生态环境状况评价技术规范（试行）》HJ／T192—2006）规定的生态环境状况评价的指标体系和计算方法。从旗、县尺度上对科尔沁沙地的生态环境状况进行综合评价。结果表明：2000年科尔沁沙地各旗县的生物丰度指数为22．01-37．96。植被覆盖指数为25．20～45．86，水网密度指数为22．51—30．97。土地退化指数为1．47—21．06。环境质量指数为57．98～59．84，综合生态环境质量指数为25．28～33．25。根据国家生态环境状况分级标准判断．该区域生态环境状况属于较差级别．意昧着该区域植被疆盖度较差。严重干旱少雨．物种较少。存在着明显限制人类生存的因素。     

科尔沁沙地生态系统服务价值变化研究

研究土地利用变化引起的区域生态系统服务价值的改变。可定量评价土地利用活动对区域生态环境的影响。基于1995年和2000年的土地利用数据．应用谢高地等人制定的中国陆地生态系统单位面积服务价值表．估算了科尔沁沙地土地利用变化引起的生态系统服务价值的改变。结果表明。从1995—2000年5年间。科尔沁沙地的耕地增加4．87％。林地减少2．25％。草地减少0．03％．水域减少1．32％．湿地增加0．54％，城乡工矿居民用地减少3．21％。未利用地减少8．83％；研究区内土地利用变化的区域差异性很大．表现为大部分旗县仍维持着毁林毁草开荒的不合理土地利用活动。科尔沁沙地生态系统服务价值从1995年的1463．67亿元增加到2000年的1467．36亿元。净增加值为3．69亿元，增幅为0．25％；其增加值并非因耕地面积增大所产生．而是个别旗县的大面积沙荒地得到有效治理所致。     

西南岩溶石山地区岩溶水资源合理开发利用模式

针对湘西洛塔岩溶区特殊的地质环境所造成的干旱缺水、水土流失、生态环境恶化等问题的特点，在调查、分析洛塔自然条件与水土资源、生态环境基本条件的基础上，实施了13处岩溶水资源开发利用示范工程。通过系统总结洛塔地区岩溶水资源合理开发利用技术与方法及岩溶水资源开发利用成功经验，提出了以岩溶水小流域为单元对岩溶水资源进行综合开发利用的5种模式：①地下河堵洞引水开发利用模式；②地下河出口及岩溶大泉引水开发利用模式；③凿引水隧洞拦截地下河开发利用模式；④地表地下联合水库开发利用模式；⑤表层岩溶泉开发利用模式。通过对失败工程的案例分析，认为在岩溶水资源开发利用过程中，应查清工程的岩溶发育规律及工程地质条件，分析经济技术支持的可行性，然后采取相适应的开采方式与方法。岩溶水资源进行综合开发利用的5种模式的提出，为在湘西实施“水源〖DK1〗·土地〖DK1〗·生态”持续发展战略，发展生态经济，实现脱贫致富，促进社会经济、生态环境良性循环，提供了切实可行的实用技术与方法借鉴。