HKDSE Geography/E2/Impacts of Droughts
Impacts on Physical Environment
Impacts on Hydrosphere
Droughts will reduce the discharge of the Huang He or even lead to cut-off and drying of lakes along it. This will worsen the problem of silting in rivers and reservoirs as deposition increases with decreasing velocity, lowering the storage capacity of the Huang He. It will even lead to increased sea water intrusion at the river mouth; Lijin has experienced increased days of cut-off.
Impacts on Biosphere
The negative effects of droughts on the hydrosphere will destroy aquatic ecosystems. Vegetation cover may wither and die because of the drought as they lack water supply. Animals will die from dehydration as well. This will reduce the biodiversity of the area.
Moreover, sea water intrusion and cut-off at the river mouth are unfavorable for the development of mudflats, mangrove swamps and wetlands. The habitats of migratory birds and other animals are destroyed.
Impacts on Human Activity
Impacts on Primary Industry
Cut-off of rivers will reduce the water supply for irrigation. Decrease in rainfall and increase in evaporation rate also decrease soil moisture and possibly lead to salinisation. The growing seasons of crops shorten and farming area/pastureland shrink. Crop failure may occur, decreasing yields and farmers' income.
The cut-off of rivers and increased silting destroy aquatic ecosystems and reduce fish catches, decreasing the income of fishermen. Fish ponds may dry up and this leads to a decline in the aquaculture sector as well.
The decrease in food supply leads to inflated food prices.
Impacts on Secondary Industry
Cut-off of rivers is detrimental to secondary industries which rely on water, like dyeing and breweries.
The secondary industry is also negatively affected by a decrease in power generated through hydro-electric power.
Impacts on Tertiary Industry
Tourism industry is adversely affected since natural fluvial landscapes are damaged during droughts and are thus less attractive to tourists.
The transport industry is affected as the decrease in river discharge increases the difficulty of navigation and reduces accessibility.
Impacts on Households
Less water is available for daily-life activities like cooking and bathing. Water quantity also decreases, threatening public health.