Impacts of Land-use and Land-cover Changes on River Runoff in Yellow River Basin for Period of 1956–2012

River runoff is affected by many factors, including long-term effects such as climate change that alter rainfall-runoff relationships, and short-term effects related to human intervention(e.g., dam construction, land-use and land-cover change(LUCC)). Discharge from the Yellow River system has been modified in numerous ways over the past century, not only as a result of increased demands for water from agriculture and industry, but also due to hydrological disturbance from LUCC, climate change and the construction of dams. The combined effect of these disturbances may have led to water shortages. Considering that there has been little change in long-term precipitation, dramatic decreases in water discharge may be attributed mainly to human activities, such as water usage, water transportation and dam construction. LUCC may also affect water availability, but the relative contribution of LUCC to changing discharge is unclear. In this study, the impact of LUCC on natural discharge(not including anthropogenic usage) is quantified using an attribution approach based on satellite land cover and discharge data. A retention parameter is used to relate LUCC to changes in discharge. We find that LUCC is the primary factor, and more dominant than climate change, in driving the reduction in discharge during 1956–2012, especially from the mid-1980 s to the end-1990 s. The ratio of each land class to total basin area changed significantly over the study period. Forestland and cropland increased by about 0.58% and 1.41%, respectively, and unused land decreased by 1.16%. Together, these variations resulted in changes in the retention parameter, and runoff generation showed a significant decrease after the mid-1980 s. Our findings highlight the importance of LUCC to runoff generation at the basin scale, and improve our understanding of the influence of LUCC on basin-scale hydrology.

Modularized Production of Value-Added Products and Fuels from Distributed Waste Carbon-Rich Feedstocks

We have adapted and characterized electrolysis reactors to complement the conversion of regional- and community-scale quantities of waste into fuel or chemicals, The overall process must he able to contend with a wide range of feedstocks, must he inherently safe, and should not rely on external facilities for co-reactants or heat rejection and supply, Our current approach is based on the upgrading of hio-oil produced by the hydrothermal liquefaction （HTL） of carbon-containing waste feedstocks, HTL can convert a variety of feedstocks into a bio-oil that requires much less upgrading than the products of other ways of deconstructing hiomass, We are now investigating the use of electrochemical processes for the further conversions needed to transform the hio-oil from HTL into fuel or higher value chemicals, We, and others, have shown that electrochemical reduction can offer adequate reaction rates and at least some of the nec- essary generality, In addition, an electrochemical reactor necessarily both oxidizes （removes electrons） on one side of the reactor and reduces （adds electrons） on the other side, Therefore, the two types of reac- tions could, in principle, he coupled to upgrade the hio-oil and simultaneously polish the water that is employed as a reactant and a carrier in the upstream HTL, Here, we overview a notional process, the possible conversion chemistry, and the economics of an HTL-electrochemical process,