罗布泊野骆驼自然保护区野双峰驼的分布与生态环境的关系

罗布泊野骆驼自然保护区位于我国西部极旱荒漠带 ,以世界级濒危物种———野双峰驼为主要保护对象 ,也保护当地特有的地貌、盐泉、丝绸之路遗迹及其他珍稀动植物物种 ,面积 7 86× 10 4km2 ,实际控制面积 15× 10 4km2 。该保护区分布有野双峰驼约4 0 0～ 4 80头 ,分布于戈壁、低山残蚀丘陵、谷地和沙漠地带 ,在不同生态环境中野骆驼的种群数量及生态习性各异。     

IMPROVED RAINFALL/RUNOFF ESTIMATES USING REMOTELY SENSED SOIL MOISTURE1

ABSTRACT: Remotely sensed soil moisture data measured during the Southern Great Plains 1997 (SGP97) experiment in Oklahoma were used to characterize antecedent soil moisture conditions for the Soil Conservation Service (SCS) curve number method. The precipitation‐adjusted curve number and the soil moisture were strongly related (r²= 0.70). Remotely sensed soil moisture fields were used to adjust the curve numbers and the runoff estimates for five watersheds, in the Little Washita watershed; the results ranged from 2.8 km² to 601.6 km². The soil moisture data were applied at two spatial scales, a finer one (800 m) measuring spatial resolution and a coarser one (28 km). The root mean square error (RMSE) and the mean absolute error (MAE) of the runoff estimated by the standard SCS method was reduced by nearly 50 percent when the 800 m soil moisture data were used to adjust the curve number. The coarser scale soil moisture data also significantly reduced the error in the runoff predictions with 41 percent and 28 percent reductions in MAE and RMSE, respectively. The results suggest that remote sensing of soil moisture, when combined with the SCS method, can improve rainfall runoff predictions at a range of spatial scales.     

COMPOSITE VS. DISTRIBUTED CURVE NUMBERS: EFFECTS ON ESTIMATES OF STORM RUNOFF DEPTHS1

ABSTRACT: The U.S. Department of Agriculture Curve Number (CN) method is one of the most common and widely used techniques for estimating surface runoff and has been incorporated into a number of popular hydrologic models. The CN method has traditionally been applied using compositing techniques in which the area weighted average of all curve numbers is calculated for a watershed or a small number of sub-watersheds. CN compositing was originally developed as a time saving procedure, reducing the number of runoff calculations required. However, with the proliferation of high speed computers and geographic information systems, it is now feasible to use distributed CNs when applying the CN method. To determine the effect of using composited versus distributed CNs on runoff estimates, two simulations of idealized watersheds were developed to compare runoff depths using composite and distributed CNs. The results of these simulations were compared to the results of similar analyses performed on an urbanizing watershed located in central Indiana and show that runoff depth estimates using distributed CNs are as much as 100 percent higher than when composited CNs are used. Underestimation of runoff due to CN compositing is a result of the curvilinear relationship between CN and runoff depth and is most severe for wide CN ranges, low CN values, and low precipitation depths. For larger design storms, however, the difference in runoff computed using composite and distributed CNs is minimal.     

Assessment of traffic related air pollution in urban areas of Macao

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｙｅａｒｓ,ｍｏｒｅａｎｄｍｏｒｅｃｉｔｉｅｓｈａｖｅｓｕｆｆｅｒｅｄｆｒｏｍａｉｒｐｏｌｌｕｔｉｏｎｃａｕｓｅｄｂｙｖｅｈｉｃｌｅｄｉｓｃｈａｒｇｅ.Ｍａｎｙｏｆｔｈｅｐｏｌｌｕｔａｎｔｓｆｒｏｍｖｅｈｉｃ?..     

AR-2型的室内双参数环境监测保护设备

对AR 2型室内双参数环境监测保护设备的工作特点进行了介绍,并对其工作原理进行了详细地分析。这种设备在天然气或—氧化碳含量超限时具有监测报警功能,同时能启动控制通风设备,改善室内环境,是人民身心健康和生命安全的保护设备。     

Suspended particulate and colloidal matter in natural waters

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒｅｉｓｃｏｎｓｉｄｅｒａｂｌｅｅｖｉｄｅｎｃｅｔｈａｔｐａｒｔｉｔｉｏｎｂｅｔｗｅｅｎｓｏｌｉｄａｎｄａｑｕｅｏｕｓｐｈａｓｅｈａｓａｍａｊｏｒｅｆｆｅｃｔｏｎｔｈｅｏｃｃｕｒｒｅｎｃｅ,ｔｒａｎｓｐｏｒｔ,ｆａｔｅａｎ...     

Fractal characteristics of filamentous bacteria in activated sludge and its significance

ＩｎｔｒｏｄｕｃｔｉｏｎＲｅｓｅａｒｃｈｅｒｓｉｎｍａｎｙｃｏｕｎｔｒｉｅｓｈａｖｅａｎａｌｙｚｅｄｍａｓｓｉｖｅｌｙｆｏｒｔｈｅｐｒｏｂｌｅｍｏｆｂｕｌｋｉｎｇｏｆａｃｔｉｖａｔｅｄｓｌｕｄｇｅｉｎｗａｓｔｅｗａｔｅｒｔｒｅａｔｍｅｎｔ,ｐａｒｔｉ?..     

A new shock tube configuration for studying dust-lifting during the initiation of a coal dust explosion

The traditional defence against propagating coal dust explosions is the application of dry stone dust. This proven and effective safety measure is strictly regulated based on extensive international experience. While new products, such as foamed stone dust, offer significant practical benefits, no benchmark tests currently exist to certify their dust lifting performance in comparison to dry stone dust. This paper reviews the coal dust explosion mechanism, and argues that benchmark testing should focus on dust lifting during the initial development of the explosion, prior to arrival of the flame. In a practical context, this requires the generation of shock waves with Mach numbers ranging from 1.05 to 1.4, and test times of the order of 10's to 100's of milliseconds. These proposed test times are significantly longer than previous laboratory studies, however, for certification purposes, it is argued that the dust lifting behaviour should be examined over the full timescales of an actual explosion scenario. These conditions can be accurately targeted using a shock tube at length scales of approximately 50 m. It is further proposed that useful test time can be maximised if an appropriately sized orifice plate is fitted to the tube exit, an arrangement which also offers practical advantages for testing. The paper demonstrates this operating capability with proof-of-concept experiments using The University of Queensland's X3 impulse facility.