EngineeringBhanu · Class 4-5
Baandh ka design: moti neev, majboot deewar aur paani ka darwaza
Chalo ek kahani sunte hain. Aman ke gaon ke paas ek naya chhota baandh ban raha tha. Engineer didi ne bataya: 'Hum pehle zameen jaanchte hain, phir deewar ki shape banate hain, aur aakhir mein paani nikalne ka raasta.' Aman soch mein pad gaya — teen kaam kyun?
Socho pehle… phir dekho jawab
Kyunki baandh ko teen kaam karne hain: paani ka dhakka jhelna (moti deewar), zameen par tike rehna (majboot neev), aur zyada paani ko surakshit nikalna (spillway). Ek bhi kaam chhoot jaaye toh baandh khatre mein.
Deewar: paani gehrai ke saath zyada dabata hai, isliye deewar neeche moti. Kai baandh apne bhaari wazan se khade rehte hain — unhe 'gravity dam' kehte hain.
Neev: deewar majboot chattan ya theek se dabaayi mitti par tikti hai. Neeche se paani risne (seepage) na paaye, iska bhi dhyaan rakha jaata hai.
Spillway — paani ka surakshit darwaza: baarish mein jheel bahut bhar jaaye toh paani deewar ke upar se nahi, ek bane-banaye raaste aur gate se nikalta hai. Isse deewar surakshit rehti hai.
Kadi: baarish hui, phir jheel bhari, phir engineer ne gate khol kar dheere paani chhoda, isliye baandh bhi bacha aur neeche ke gaon mein achanak baadh bhi nahi aayi. Gate kholne se pehle neeche ke gaon ko suchna di jaati hai.
Humne kya kiya :- Baandh ke teen hisse samjhe — moti deewar, majboot neev aur spillway.
Isse kya hua :- Pata chala ki engineer har khatre ke liye pehle se raasta banate hain: zor ke liye deewar, zameen ke liye neev, zyada paani ke liye darwaza.
Ghar pe try karo
Bade ke saath thaali mein gili mitti ka tikona baandh banao aur uske ek kone mein pencil se ek chhoti naali kaato (spillway). Peeche dheere-dheere paani bharo. Paani kahan se nikla — deewar ke upar se ya naali se? Copy mein chitra banao. Mitti baad mein gamle mein.
Wow!
Kallanai baandh 2,000 saal se bhi purana hai — Chola raja Karikalan ke samay ka — aur aaj bhi Kaveri ka paani baantne mein kaam aata hai!
Mummy-Papa ke liye
Aaj bachche ke saath mitti ka baandh aur uski chhoti naali (spillway) banaiye, aur poochhiye: 'Jheel bahut bhar jaaye toh engineer kya karte hain?'
3 sawaal
- Baandh ka spillway kis kaam aata hai?
Jawab dekho
Zyada paani ko surakshit nikaalne ke liye. Spillway zyada paani ko deewar ke upar se nahi, bane raaste se surakshit nikaalta hai.
- Jo baandh apne bhaari wazan se khada rehta hai, use kya kehte hain?
Jawab dekho
Gravity dam. Gravity dam apne wazan se paani ka dhakka jhelta hai.
- Baandh ki deewar neeche moti kyun hoti hai?
Jawab dekho
Neeche paani sabse zyada dabata hai. Paani ka dabaav gehrai ke saath badhta hai, isliye neeche moti deewar.
NCERT se jodo: NCERT Class 4-5 EVS — paani ke srot aur use jama karna; Class 10 Geography ka 'jal sansaadhan' wala vichar (idea in words)