Committed to the same Aristotelian and Ptolemaic principles as their European counterparts, Arab astronomers produced highly accurate records of celestial motions and sought solutions to the same discrepancies between observation and theory. But none of these involved questioning geocentrism; astronomy was often pursued as an aid to religious observance, giving accurate times for holidays and rituals. Copernicus drew on Islamic writings as on many others, but claims that his heliocentrism in some way depended on them are unacceptable, given their unquestioning geocentrism. In his great work on Chinese science, Joseph Needham showed that it was often superior to Western natural philosophy both empirically and in its understanding of basic natural processes. He attributed its failure to produce a Copernican-Newtonian revolution to various external factors. But the notion that it had such potential rests on the false assumption that its strengths were the ground out of which a science capable of overturning the bases of its own practices might emerge. Such a capacity depends instead on the presence of conditions favorable to rendering the sphere of science autonomous. Only in the nineteenth century, spurred by modern chemistry, biology and physics brought by Western medical missionaries, would Chinese science take this turn.

Chapter 4 delves into the “great leap” of small hydropower during the Maoist period. It analyzes the distinctive feature of the expansion of the hydropower nation as it was influenced by Maoist ideology: Mass participation. Despite the common assumption that Communist China blindly pursued mega dams, Mao believed in “walking on two legs”: Large Soviet-style dams on the one hand, and small indigenous hydro projects that could be built and operated by the masses on the other. With the goal of boosting agricultural productivity and rural electrification, the PRC state mobilized communes nationwide to harness local rivers for the generation of electricity. This chapter examines local experiences of small hydro campaigns, focusing on Yongchun in Fujian Province. Across the country, tens of thousands of small hydroelectric power stations were constructed within a few years. The lack of prior hydrological investigations and professional knowledge, however, meant that many of these stations were not able to deliver stable electrical output, while they also resulted in the fragmentation of local rivers.

Covers erosion process, types of erosion, estimation of erosion using universal and modified universal soil loss equations, sediemnt yield and its determination, temporal distribution of sedienmnt yiled, sediemnt loads in channels, sediemnt transport, sediemnt properties, fall velocity, sediemnt transport functions, sediment routing, reservoir sedimentation, and erosion and sedimentation modeling in HEC-HMS.