A plant takes up water to replace the water it loses by transpiration. So anything that increases the rate of transpiration also increases the rate of water uptake. Water vapour is lost from the leaves, and this pulls more water up the xylem from the roots. Three environmental factors matter at GCSE: light intensity, air movement and temperature. The uptake can be measured with a potometer.
Light intensity. In bright light the stomata open for photosynthesis, so more water vapour can diffuse out. A higher light intensity increases the rate of water uptake. In the dark the stomata close and the rate is low.
Air movement. In still air, water vapour builds up around the leaf and the concentration gradient is small. Moving air blows the water vapour away, which keeps the concentration gradient steep, so the rate increases.
Temperature. When it is warm, water evaporates faster from the mesophyll cells and the water vapour diffuses faster, so the rate increases. In cool conditions the rate is lower.