What is the best way to manage sudden influx of water into our rivers in monsoon? How can it best utilized by Pakistan ? thanks
Dear Anwar javed,
Thanks for sending me this question. Your question is related to Environment and water management and I am not an expert of these fields but I will try to answer your question.
Unexpected massive rains and heavy snowfalls may cause uncontrollable flood and havoc to the human settlements and civil infrastructure resulting of loss of human lives and multi billion dollar destruction. Rain clouds are being constantly monitored on global and regional scale through radar and satellite which provides the basis for the local weather forecast. Annual rainfall data is available in nearly all countries meteorological offices that help to take preventive measures to protect from flood if rainfall expected to be more than usual.
There are several methods to control floods; rivers usually flow in a narrow channel most of the year in dry season but each river has its own flood plain on the both sides of the river which stretch almost ten to twenty times in size to the river original channel bed where excess water starts to flow when channels start to over flow due to excessive rainfall and additional water influx coming from catchment area. These river channels should be clean as much as possible from silt (desilting) which comes with water by dredging through machines such as Dredgers and Excavators.
River will always bring silt,most of the rivers overflow when their original path has low capacity due to silting. Process of desilting and dredging of river beds are regular processes to maintain rivers, canals and sea ways. Rivers capacity and accommodation for water should not be reduced rather in areas where floods are expected capacity should be be increased. One has to be alert for overcoming flood events and smart to plan flood management well in advance. Maintaining the river path from excessive silting is a challenging and most expensive work and I figure the work was not regular.
River channels embankments and levees and flood plain embankments should be constantly monitored, inspected and repaired and strengthened throughout the year whenever a leakage occurs. Sand bags around the embankments should be ready to utilize as second line of defense from flooding. Modern water measuring gauges help to monitor water fluctuation and any increase of pressure once noticed additional resources should be activated for strengthening embankments.
Dams and Barrages are useful methods to control rivers and to reservoir water for irrigation, drinking water supply and for power generation. Large open areas or lakes may also be prepared to divert and collect flood water near the rivers and flood plains to control excessive flood water.
Floods are useful for us, as it has been good for agriculture, water brings a new layer of fresher and fertile soil which lay out in the agriculture field whereas sediments flow out in the sea not only stop sea incursion to the land but also provide natural enriched organic material to the sea life.
Forestation and natural or artificial vegetation are probably very effective method to control the flood specially in mountainous and hilly areas within the catchment area