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Based on the statistical data, the CO2 emission of urban passenger traffic (UPT) was studied for the period from 2000 to 2014 in Taiyuan using the so-called "down-up" method of IPCC2006. Furthermore, the "coal-electricity-vehicle" development strategy was evaluated. The most significant changes of the UPT were the exponential growth of private vehicles and the very slow development of public transport service. The average annual growth rate of the CO2 emission from UPT was 11% with a total of 4.

Microbial transport in porous media is a hot issue in fields of hydrology and water environment. Researches on the issue are helpful to restrain water-borne diseases and to improve the efficiency of polluted groundwater recovery. Over the past 15 years, the understanding about microbial transport in a saturated porous media has been improved substantially. However, the DLVO theory and the colloid filtration theory cannot support a sufficient explanation in microbial transport. Straining, heterogeneity, pore scale force/ torque balance, microbial features, growth and death significantly affect the microbial transport of which mechanisms and modeling need to be enhanced in future studies. In addition, results from laboratorial studies are mostly different with field results, which highlights the necessity to do more field researches. In field experiments, there are many uncontrollable factors and complex situations compared with laboratorial experiments. More field experiments will offer valuable chances to get a thorough comprehension of microbial transport promoting development of transport mechanisms and models. New models tend to become more complicated when trying to integrate more mechanisms. Therefore, how to find the main mechanisms simplifying models and improving efficiency is also a key question.

Karst covers more than 20% of lithosphere area. Karst groundwater resource is a vital water resource. However, a karst water-bearing system is a kind of dual media with distinct hydraulic properties, of which heterogeneity is significant and two mechanisms of surface water infiltration are of the same importance. The connection across precipitation, surface water and karst groundwater is very close. And the conversion among them is nonlinear with considerable complexity. Hydrologic processes, flow rates and the discharging area are readily impacted by the changing environment in a karst groundwater flow system. Discharges of karst springs are of scale effect and multi-fractal characteristics. And the composition of discharge is complicated and changeable. Furthermore, hydrogeochemical characteristics of karst groundwater are sensitive to the changing environment determined by variable hydrologic processes of karst and biogeochemical reactions. Therefore, traditional geohydrologic methods can't be applied directly in a karst basin and the common difficulties in hydrologic researches tend to be amplified. At present, researches in karst hydrology are relatively laggard. The karst in China is type diversity and representative all over the world. Studies in regard to karst hydrologic processes and the karst CO2-H2O-CaCO3 system have made progress in China. In future, responses and feedbacks to the global change, water resource and environment, and hydrologic processes modeling of a karst groundwater flow system are the potential researching hotspots.