1) When Price is above EMA10, EMA21 & MA50
2) Momentum (Length of candles) & closing of candles
Strong Trend - If price is rising & doesn't touch or close below EMA10
Moderate trend - If price is rising & often penetrating EMA10 & 21 & taking support at MA50
Length of candles also defines the strength of trend. Longer the candle, higher the momentum thus strong trend. Shorter the candle, lesser the momentum thus trend not so powerful & may fade soon. Its like after consuming Creatine, you can have more reps in Gym.