全国环境质量状况总的来看有所改善，但生态环境保护形势依然严峻

环境保护部副部长李干杰今日表示,全国环境质量状况总的来看有所改善,但生态王不境保护形势依然严峻,还面临不少困难和挑战。主要体现在以下方面。一是全国水环境质量不容乐观。长江、黄河、珠江、松花江、淮河、海河、辽河、浙闽片河流、西南诸河和西北诸河等十大水系的国控断面中,～类、～类和劣类水质的断面比例分别为71．7％、19．3％和9．0％。     

Modeling tropical river runoff: A time dependent approach

Forecasting of rainfall and subsequent river runoff is important for many operational problems and applications related to hydrology. Modeling river runoff often requires rigorous mathematical analysis of vast historical data to arrive at reasonable conclusions. In this paper we have applied the stochastic method to characterize and predict river runoffofthe perennial Kulfo River in southem Ethiopia. The time series analysis based auto regressive integrated moving average （ARIMA） approach is applied to mean monthly runoff data with 10 and 20 years spans. The varying length of the input runoff data is shown to influence the forecasting efficiency of the stochastic process. Preprocessing of the runoff time series data indicated that the data do not follow a seasonal pattern. Our forecasts were made using parsimonious non seasonal ARIMA models and the results were compared to actual 10-year and 20-year mean monthly runoff data of the Kulfo River. Our results indicate that river runoff forecasts based upon the 10-year data are more accurate and efficient than the model based on the 20-year time series.     

Climate transformation to warm-humid and its effect on river runoff in the source region of the Yellow River

The change characteristics and trends of the regional climate in the source region of the Yellow River, and the response of runoff to climate change, are analyzed based on observational data of air temperature, precipitation, and runoff at 10 main hydrological and weather stations in the region. Our results show that a strong signal of climate shift from warm-dry to warm-humid in the western parts of northwestern China （Xinjiang） and the western Hexi Corridor of Gansu Province occurred in the late 1980s, and a same signal of climate change occurred in the mid-2000s in the source region of the Yellow River located in the eastern part of northwestern China. This climate changeover has led to a rapid increase in rainfall and stream runoff in the latter region. In most of the years since 2004 the average annual precipitation in the source region of the Yellow River has been greater than the long-term average annual value, and after 2007 the runoff measured at all of the hydrologic sections on the main channel of the Yellow River in the source region has also consistently exceeded the long-term average annual because of rainfall increase. It is difficult to determine the prospects of future climate change until additional observations and research are conducted on the rate and temporal and spatial extents of climate change in the region. Nevertheless, we predict that the climate shift from warm-dry to warm-humid in the source region of the Yellow River is very likely to be in the decadal time scale, which means a warming and rainy climate in the source region of the Yellow River will continue in the coming decades.     

渤海海域新近系河流相砂岩储层描述技术

针对海上河流相砂岩油田单砂体厚度薄,井间储层横向变化快,纵向上油气水间互,平面上连通性差等特点,渤海通过十多年的不断探索和实践,发展完善了定量描述砂体展布的储层描述技术.该技术很大程度上解决了在海上探井井距大,井控程度低,取心资料较少等情况下的储层横向展布问题,并基于已钻井资料,总结出如何在探井之间寻找潜力砂体的经验.随着渤海越来越多的河流相油田投入开发,储层描述技术的可靠性也得到证实.大量实例证明,该技术是渤海油田新近系河流相砂岩储层预测与描述的有效技术手段,其思路和方法也可借鉴到类似地质背景下的河流相岩性油气藏评价.     

Correlations between zooplankton assemblages and environmental factors in the downtown rivers of Shanghai,China

Most urban rivers play an important role in urban flood control and drainage in China, but pollution is fast becoming an issue of greater importance in water management. In this study, 63 zooplankton species were recorded in four downtown rivers in Shanghai between November 2007 and October 2008. Of these, 44 species belonged to the Rotifera, 13 to Cladocera, and six to Copepoda. The three most frequently occurring zooplankton （Brachionus calyciflorus, Microcyclops Ieuckarti, and Asplanchna priodonta） accounted for 80.00%, 76.84%, and 53.68%, respectively. Rotifera were found to be dominant, comprising 86.26% of total zooplankton, while cladoceran and copepod abundance amounted to 5.08% and 8.67%, respectively. Water temperature, salinity, electrical conductivity, and total nitrogen were of the greatest significance in the occurrence of zooplankton. Two species （Schmackeria forbesi and Lepadella ovalis） were notably more sensitive to environmental factors such as salinity and electrical conductivity than other species. The population size and community were inversely correlated with the increasing nutrient levels of the four rivers, suggesting that the water quality of the four rivers had been gradually recovering from a severe eutrophic state and that water conditions of the rivers had been gradually improved.     

利用伪归一化差异水体指数提取城镇周边

通过对归一化差异水体指数NDWI中的绿波段修正,提出了不依赖于中红外波段的伪归一化差异水体指数FNDWI（False NDWI）。使用NDWI和FNDWI分别在背景地物为城市、城郊、乡镇、村落和山区的遥感影像上进行河流水体提取,实验表明,FNDWI影像中城镇建筑用地与河流水体的可分离性较NDWI有所提升,提升率为116％～335％不等;相关性分析表明,河流宽度与可分离性提升率具有明显的负相关关系,相关系数为-0．82;分类结果显示,在城市和城郊区域,NDWI提取的水体中混杂有较多城镇建筑用地信息,而FNDWI提取的水体中基本未见混杂。总体上,FNDWI提高了2种地物的可分离性,剔除了NDWI影像混入的城镇建筑用地信息,较好地解决了NDWI城镇建筑用地与河流水体的混淆问题,尤其适用于城镇周边的细小河流。     

测碧海蓝天 绘雄伟河山

正中国,有一个美丽的神话:顶天立地的盘古大神,用身躯血脉造山川河流。从此,炎黄子孙在这片博大富饶的土地——中华民族最宝贵的财富上繁衍、生生不息。中国,有一段辉煌的历史:从夏禹巡山岳,定高山大川、根治水患开始,到康熙大帝为抵御侵略,开展全国性测绘工作,绘制《皇舆全览图》,这片土地的历史与测绘密不可分。新中国成立后,测绘更是为两弹一星绘发射点位、为钢都重建绘震区地图、为九八抗洪护航、为南水北     

神秘中亚 共同气象

广义的中亚包括中亚五国、中国新疆和俄罗斯西伯利亚中亚部以及蒙古国相关地区。狭义的中亚一般指以阿姆河和锡尔河两河流域为中心。苏联解体后形成一个比较共同的政治文化区域,     

Variation of freshwater components in the Canada Basin during 1967–2010

As a conservative tracer, oxygen isotopes in seawater are widely used for water mass analysis, along with temperature and salinity. In this study, seawater oxygen-18 datasets in the Canada Basin during 1967–2010 were obtained from the four cruises of the Chinese National Arctic Research Expedition(1999, 2003, 2008, and 2010) and the NASA database. Fractions of sea ice meltwater and river runoff were determined from the salinity-18O system. Our results showed that the river runoff decreased from the south to the north in the Canada Basin. The enhanced amount of river runoff observed in the southern Canada Basin may originate from the Mackenzie River, transported by the Beaufort Gyre. The river runoff component showed maximum fractions during 1967–1969, 1978–1979, 1984–1985, 1993–1994, and 2008–2010, indicating the refresh time of the river runoff was 5.0–16.0 a in the Canada Basin. The temporal variation of the river runoff was related to the change of the Arctic Oscillation(AO) index, suggesting the freshwater stored in the Canada Basin was affected by surface sea ice drift and water mass movement driven by atmospheric circulation.     

宁阳县农村居民点整理潜力测算与分级探析

通过对农村居民点整理潜力内涵和宁阳县农村居民点利用现状的调查研究,得到宁阳县农村居民点整理潜力的来源。运用户均建设用地标准法对宁阳县各乡镇农村居民点整理潜力进行了测算,得出宁阳县农村居民点整理潜力为6 738.33 hm2,各乡镇整理潜力系数在59.69%~71.64%之间,并将整理潜力划分为三级。对潜力预测结果进行了分析和思考。