Biostratigraphic correlation of the ten most important Permian-Triassic boundary sections throughout Tethys enables establishment of four conodont and ammonoid subdivisions within a stratigraphic interval, one to a few metres thick, representing less than I Ma. In ascending order, they are conodonts(Clarkina chargxingensis-C. deflecta Zone; Hindeodus typicalis Interval; Isarcicella parva Zone and I. isarcica Zone) and ammonoids(Pseudotirolites-Pleuronodoceras Zone, lower Otoceras Zonel, upper Otoceras Zone and Ophiceras Zone). Most of them can be traced to Notrh America and the Arctic region. Carbon isotope investigations of 24 sections along Tethys and in Greenland and Spitzbergen confirm the consistency of 813 C negative excursions at the Permian-Triassic boundary, together with an ineonsistent Ir anomaly. Eight sections show that in most cases there is a succession of: Ir anomaly (denoting the end-Permian catastrophic envirorment); 813C excursion (biomass loss, extinction); P/T boundary (origination of newcomers; potentially capable of intercontinental correlation within that short time interval). There is an intercontinental sequence boundary at the top of the Permian, and a transgressive surface at the P/T boundary followed shortly by a maximum flooding surface. An intercontinental anoxia event accompanied the transgression. Three delineations of the mass extinction phases and three population explosions have been recognized and can be more or less correlated in South China and the Southern Alps. Radiometric dating of the volcanogenic boundary clays of Meishan, Shangsi and the main-stage Siberian Tunguss Traps give an almost identical age of 250 Ma, thus implying a synchronous interregional volcanic event. There are a few palaeomagnetic transforms within the PTB strata. Thus, multidisciplinary research of the P/T boundary strata allows subdivision of this short interval into more than ten intercontinentally correlatable pars. Each subdivision averages less than 100ka in duration. This may be the highest resolution obtained so far in pre-Cretaceous rocks. High-frequency. Milankovitch-type cyclic deposits within the P/T boundary beds enable correlation of even higher resolution in the Lower Yangtze area. This high resolution is made possible because the P/T transition is a time of saltation and catastrophy in geological history. Causality of the aggregation of events merits further investigation.

In the middle reaches of the Yangtze River, the floods have become more and more frequent, and the water level rises higher than before. The damages are becoming ever more serious. This is primarily a consequence of human activity in the river basin. Three aspeets deserve particular attention. First, destruction of vegetation has led to soil erosion in the upper reaches. In the past 30 years, the forest cover has been reduced to half, while the area exposed to severe erosion doubled in size. In the long run, this can be expected to increase flooding. Second, land reclamation and siltation has reduced lake sizes. This has resulted in decrease of the flood storage capacity. Third, the construction of levees has caused flood levels to rise due to restricted flood discharge capacity. Establishment of the Great Jinjiang levee caused silting up of the riverbed and valley in the mid-reaches of Yandtze. Consequently, the discharge capacity decreased to 60,000-68,000m3/s, which is sufficient only for ordinary floods. This article concludes that the deteriorating flood situation is the result of inappropriate human intervention in the natural environment. It is suggested that the appropriate strategy should change from “keeping the flood away” to “giving the flood way”. Related tacties and strategies under consideration are briefly summarized.