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The natural flow regime is confirmed to be the main driving factor in maintaining diverse species and abundant production of river floodplains. However, disturbance of human activities have affected natural hydro-geomorphical process, reduced habitat heterogeneity, and weakened ecological service functions. Thus, it is necessary to assess ecological water requirements and furthermore provide a quantitative operational basis for restoring natural flow regime. Macroinvertebrates are considered as good indicators of hydrological regime changes due to their confinement to the bottom, limited abilities of movement, and low tolerance. This paper deals with systematic ecological investigations in the Wuhan branch of the Yangtze River during 2007–2008. Altogether, 32 taxa of macroinvertebrates belonging to 13 families and 27 genera were identified. The density and biomass of total macroinvertebrates were 181 ind m −2 and 0.29 g dry mass m −2 , respectively. Canonical Correspondence Analysis (CCA) revealed that the important environmental factors influencing macroinvertebrate abundance were flow velocity (U), water depth (Z), and total nitrogen (TN). The relation between habitat weighted usable area and water discharge was analyzed on basis of creating suitability curves. Weighted usable area of habitat showed unimodal changes with increasing water discharge, i.e., first increased and then decreased, and weighted usable area of habitat reached the maximum when flow discharge was 21,000 m 3 s −1 . [ABSTRACT FROM AUTHOR]

This paper defines transport superiority from three aspects: quality, quantity and advantage, which are respectively measured by highway network density, proximity to the transport arteries and location advantage degrees. The historical transmutation, spatiotemporal differentiation of the transport geographical pattern in Wuhan Urban Agglomeration, as well as the correlation between transport superiority and economic development level are analyzed quantitatively by applying GIS technology and mathematical model. A number of valuable implications have been drawn. First of all, the changes of historical prosperity and wane in Wuhan urban agglomeration region were closely related to the transport geographical pattern. The unique modern traffic geographical advantages bred the prosperity of Wuhan area, while the development of contemporary transportation technology resulted in the homogenized pattern of traffic superiority in China and thus the wane of Wuhan as the 'center' or 'terminal' of trade and transportation. Secondly, the regional comprehensive transport superiority of a layer structure, with that of the central city, Wuhan, being highest and those of the dies along the Yangtze River and the Wuhan--Jiujiang industrial belt decreasing gradually. Thirdly, the absolute and relative differences of the transport superiority in Wuhan Urban Agglomeration had enlarged from 1980 to 2010, showing a continuously strengthened trend of polarization. Fourthly, there is a significant coupling relationship between transport superiority and economic development level in Wuhan Urban Agglomeration, with a large percentage of population and industry of this area concentrating in the small number of counties with prominent transport superiority. [ABSTRACT FROM AUTHOR]

The HJ- 1 satellite is a naive optical satellite, specializing in the environment and disaster monitoring, which has a high time and space resolution, and could be downloaded freely. So it's able to monitor the sediment concentration timely, continuously and accurately, and has a good application prospect for monitoring the second type inland water by remote sensing. This paper has taken the middle reaches of Yangtze River in Wuhan as the study area. A precise sediment concentration calculation model is developed, by making use of the first and third bands of CCD data in HJ-1 satellite. After this, it retrieves the sediment concentration in Wuhan reach, and gets its space distribution map on November 14th, 2008. The result has showed that the root mean square error (RMSE) of this model is 8. 84 mg/L, and the mean absolute percentage error (MAPE) is 13. 6%. The sediment concentration in Yangtze river is higher than Han river near Wuhan city, and the concentration is higher near the central bar than other areas. [ABSTRACT FROM AUTHOR]

Abstract: This paper examines the characteristics of historical floods and associated monsoon precipitation in the Yangtze Catchment, with specific attention given to the middle and lower Yangtze basin. Based on in situ field observations and historical discharge, flood duration, and land-use information, etc, we propose a number of flood characteristics of the basin: 1) floods have occurred more frequently after 1950s, however, changes in discharge can only partially explain the occurrence of the floods; 2) spectral analysis on the annual mean water discharge during 1860–1985 in Hankou hydrological gauging station of the middle Yangtze River reveals 16.4-year and 2.5-year flood recurrences, which become shortened from what has been recorded in the Chinese historical literature on millennial time scale; 3) floods after 1950s tend to have higher water levels (both mean and peak) and longer duration than before, but with remarkably limited inundation area; and 4) a series of flood waves generated by monsoon precipitation in 1998, initiated from the middle Yangtze, highlights the basin-wide climate hazards with a recurrence of around 60 years. Intensifying anthropogenic activity in the last century, including deforestation, dyking, and lake–coast reclamation etc. that results directly in riverbeds aggradation and shrinkage of lake water area in the middle Yangtze basin, are the key causes for recently human-induced floods in the basin. Threatened land property in the basin reminds us to harmonize with the river and provide more space for flooding. [Copyright &y& Elsevier]

In order to periodically investigate the population and distribution of the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) in its main distribution range in the Yangtze River, a passive acoustic system deployed on a cargo ship as a moving platform, rather than a dedicated research ship, was developed. A stereo acoustic event data-logger (A-tag) was installed on the cargo ship to passively detect phonating animals. In three surveys carried out in the Yangtze River from Wuhan to Shanghai, an average of 6059 clicks in each survey and 284 porpoises in total were acoustically detected along an 1100-km stretch. The animals were detected frequently in most of the survey range except two 'gap sections' with 40 and 60 km lengths, respectively, where no animals were detected in all three surveys. Detected group sizes of the animals in each 120-s time window were not significantly different among the surveys, but the distribution pattern was different and suggested seasonal migration. The cargo ship based passive acoustic survey was effective in detecting phonating animals and can potentially monitor the distribution and population trend over time. Compared to surveys that used dedicated research ships, the present method is more cost effective. [ABSTRACT FROM AUTHOR]