varsha
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is lekh mein sandarbh ya sootr naheen diye gaye hain. krupaya vishvasaneeya sootron ke sandarbh jodkar is lekh mein sudhaar karein. bina sootron ki saamagri ko hataaya ja sakta hai. (December 2015) |
varsha (Rainfall) ek prakaar ka sanghanan hai. pruthvi ke satah se paani vaashpit hokar oopar uthata hai aur thanda hokar paani ki boondon ke roop mein pun: dharati par girta hai. ise varsha kehte hain.
anukram
parichay
vaayu mein mila jalavaashp sheetal padaarthon ke sampark mein aane se sanghanan (condensation) ke kaaran osaank tak pahunchata hai. jab vaayu ka taap osaank se neeche gir jaata hai, tab jalavaashp paani ki booaindon athva olon ke roop mein dharaatal par girne lagta hai. isi ko varsha kehte hain. kisi bhi sthaan par kisi nishchit samay mein barase hue jalakanon tatha himkanon se praapt jal ki maatra ko vahaaain ki varsha ka maap kehte hain.
garami ke kaaran utpann jalavaashp oopar aakaash mein jaakar failata hai evam thanda hota hai. at: jaise jaise vaayu oopar uthati hai, usamein jalavaashp dhaaran karne ki kshamata kam hoti jaati hai. yahaaain tak ki adhik oopar uthane se vaayu ka taap us ank tak pahunch jaata hai, jahaaain vaayu jalavaashp dhaaran kar sakti hai. isse bhi kam taap ho jaane par, jalavaashp jalakanon mein parivrtit ho jaata hai. isi se baadalon ka nirmaan hota hai. fir baadal jal ke kaaran dharaatal par baras padte hain. jalakan banane ke uparaant bhi yadi vaayu ka taap kam hote hote himaank se bhi kam ho jaata hai, to jalakan himkanon ka roop dhaaran kar lete hain jisse himvarsha hoti hai. varsha ke liye do baatein aavashyak hain :
- (1) hava mein paryaapt maatra mein jalavaashp ka hona, tatha
- (2) vaashp se bhari havaaon ka sheetal padaarthon ke sampark mein aane se thanda hona aur osaank tak pahuainchana.
varsha ke prakaar
varsha teen prakaar ki hoti hai :
sanvahaneeya varsha (Convectional rain)
is prakaar ki varsha adhiktar bhoomadhyarekheeya pradeshon mein praaya: prati din hoti hai. bhoomadhyarekha par adhik garami padne se samudron se prachur maatra mein jalavaashp bankar vaayu mein mila karta hai; garami aur vaashp ke kaaran aardr vaayu halki hokar oopar uthati hai aur iska sthaan grahan karne ke liye anya havaaeain aati rahati hain. oopar uthi vaayu oopar jaakar thandi hoti hai tatha failati hai. vaashp ki maatra adhik hone se osaank tak pahunchane ke liye taap ko kam girna padta hai. at: vaashp sheegra jal ka roop le leta hai aur prati din praaya: do baje ke baad ghanaghor varsha hoti hai. is varsha ko sanvahaneeya varsha kehte hain.
parvatakrut varsha (Orographical rain)
vaashp se bhari havaaon ke maarg mein parvaton ka avarodh aane par in havaaon ko oopar uthana padta hai jisse parvaton ke oopar jame him ke prabhaav se tatha hava ke failakar thanda hone ke kaaran hava ka vaashp booaindon ke roop mein aakar dharaatal par baras padta hai. ye havaaeain parvat ke doosari or maidaan mein utarate hi garam ho jaati hain aur aaspaas ke vaataavaran ko bhi garam kar deti hai. vishv ke adhiktar bhaagon mein isi prakaar ki varsha hoti hai. maanasooni pradeshon (Bhaarat) mein bhi isi prakaar ki varsha hoti hai. is varsha ko parvatakrut varsha kehte hain.
chakravaat varsha (Cyclonic rain)
is prakaar ki varsha garam aur sheetal vaayuraashiyon ke aapas mein milne se hoti hai, kyonki halki garam vaayu oopar uthati hai tatha bhaari sheetal vaayu neeche baithati hai. at: oopar uthanevaali vaayu thandi hokar varsha karne lagti hai. is prakaar varsha praaya: sheetoshn katibandh mein hua karti hai.
varshaamaapan
kis sthaan par kitni varsha hui hai, ise maapane ke liye ek yantr kaam mein laaya jaata hai, jise varshaamaapi (Rain gauge) kehte hain. ise ek nishchit samay mein tatha nishchit sthaan par varsha mein rakhakar paani ke barasane ki maatra ko maap liya jaata hai.
varshaamaapi kai tarah ka hota hai. varsha adhiktar inch ya seinteemeetar mein maapi jaati hai. varshaamaapi ek khokhala belan hota hai jiske andar ek botal rakhi rahati hai aur uske oopar ek keep laga rahata hai. varsha ka paani keep dvaara botal mein bhar jaata hai tatha baad mein paani ko maapak dvaara maap liya jaata hai. is yantr ko khule sthaan mein rakhate hain, taaki varsha ke paani ke keep mein girne me kisi prakaar ki rukaavat na ho.