What is the main concern when placing a water bladder on uneven ground?

The primary concern when placing a water bladder on uneven ground is weight distribution. An uneven surface can lead to an unstable positioning of the bladder, which can cause several issues, such as stress concentrations on certain parts of the bladder that may lead to damage or rupture. Proper weight distribution is crucial to ensure that the bladder remains stable and functions effectively. If the weight is unevenly distributed, it can also cause the bladder to deform, reducing its capacity to hold water securely and potentially leading to leaks or collapses.

Other factors, such as drainage capacity, might be relevant in various contexts, but they do not directly address the immediate concern related to the stability and integrity of the water bladder on uneven terrain. Similarly, sand depth and water temperature are more situational and less directly impactful on the operational safety and effectiveness of placing the bladder. Therefore, weight distribution stands out as the critical factor in ensuring the bladder's proper function and longevity when placed on uneven ground.