nalysis of climate extremes using Max-Stable processes in the Haihe River Basin

In or der t o understand the r esponse of H aihe Riv er Basin ( H RB) to ex tr eme climate events in the context of global warming, climate va riables ( t emperatur e and precipit ation) fr om 1961 to 2016 wer e used. The RClimDex model, M2K tr end test and Max2St able model, and the climate ext remes of H RB w as modeled and analyzed. The spatial and tempor al distribut ion and variatio n char acteristics of temper ature and pr ecipitation extr emes in HRB wer e studied. T he results showed that TXx displayed a decreasing t rend fr om north t o south with a r ang e of 30240 e , of w hich 36240 e account ed for most areas in the H RB. T Xx ex hibited a decreasing trend in the south and increasing t rend in the north. T he pr ecipitatio n extr eme value RX1day show ed a decreasing t rend fr om southeast to northw est with a r ange of 502100 mm of w hich 60290 mm occupied most ar eas. The o verall RX1day show ed a downw ard tr end amo ng which the Circum2Bohai Sea Reg io n had the lar gest downwar d tr end. The GEV model fitting results showed that the t em perat ur e ex tr emes w ere mainly affected by latitude and elevat ion, and decr eased w ith the in2 cr ease of latit ude and elevat ion and the variatio n fluctuation was st rong er in the no rth compa red south in the H RB. The ex tr eme value of pr ecipit ation RX1da y w as gr eat ly affected by the altit ude and lo ng itude, w hich w as mainly represented by the spatial distribut ion that decr eased w ith the increase o f altitude, followed by the spat ial distributio n that incr eased fr om w est to east with the chang e of long itude. Based o n the Q2Q per centile g raph, no n2parametric ex tr eme value co efficient H, GEV and Max2Stable par ameters, and the determinat ion co ef ficient R2 of the intensity scatt er plot for the r ecurrence perio d, it w as determined that the Max2Stable mo del co uld well simulate the climate extr emes in t he H RB and GEV had the same effect. Climate ex tremes T Xx and RX1day wer e mainly affected by latitude, lo ng itude, and altitude, but the additio n of distance from the co ast could only o pt i2 mized the establishment of the TXx model. The spatial distribution of temper ature ex tremes TXx once in 2 years, 10 y ears, 50 years, and 100 y ea rs showed an incr easing dist ributio n pattern fr om nort heast to southw est, and the high2v alue areas w ere dis2 tributed in most o f the so uthw est, w ith the hig hest temper atur e r eaching 40244 e . The spatial distributio n of extr eme ra infall values TX1day once in 2 y ears, 10 y ears, 50 years, and 100 years w as mainly affected by latitude, fo llow ed by lo ng itude and alt i2 tude. All of them showed a decr ease from the southwest to the no rth, and the high value areas w ere distribut ed in the south2 w est. Cent rally, the maximum precipitat ion w as 802200 mm.

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