Read the given passage and answer the questions that follow.
Floods are not new to India and this sub-continent, but in recent years the problem has received much greater attention perhaps largely because it has led to much greater damage than in the past. Even though information on the impending occurrence of floods is now more accurate and certainly timelier, often there is very little time or support infrastructure in place by which damage can be minimised. This is particularly true in the case of flash floods resulting from sudden and excessively heavy rain.
In the case of India, flooding is very much a function of the seasonal nature of our rainfall. The monsoons are spread over a short period during the year and often bring a concentrated volume of rain, which cannot be absorbed by the earth and finds outlet only in the form of streams that join up with our major river systems. But, flooding is not confined only to the main rivers of the country, often smaller tributaries and streams can cause heavy damage as well. Once these streams spill over their banks they could cause excessive harm, mainly because those living near the banks of these streams particularly in mountain areas do not have easy recourse to moving away quickly.
One major factor that could lead to a higher severity of flooding in the future is the danger of climate change. While the evidence of the nature of impacts resulting from climate change on precipitation and flooding at the regional level is not entirely clear, it could happen that the Indian subcontinent witnesses and suffers the effects of a significantly changed pattern of monsoons. One set of scientists has estimated that the monsoons could be shorter in duration, but far more intensive. In other words, much greater precipitation would take place in a much shorter period of time, thereby increasing the danger of floods. Climate change is the result of human actions through the increased concentration of greenhouse gases in the atmosphere, of which carbon dioxide is the most prominent.
At the local level also human actions have heightened the danger of flood through the cutting of trees in the mountains as well as in the plains. In the case of India, the ecological damage through deforestation of the Himalayas has led to large-scale erosion of the mountain slopes and high levels of siltation. This leads to deposition of silt on the riverbeds in the plains and hence spill-over of water whenever the volume in the river reaches a certain level. With siltation on the river beds, flooding occurs even at very shallow water levels. However, even in cases where forecasts have been timely and generally accurate, people have often been reluctant to move away, because in most cases they lack the means and physical options for moving away from a danger zone to one that is relatively safe. In the case of flash floods, forecasts are difficult to make, and often the time available for relief is very short.
Which of the following human actions increases the danger of flooding?