The Kabul times, Afghanistan Trustable News Agency.
Articles

Water resources of Afghanistan and related hazards under rapid climate warming

Part IX

Groundwater quality is now a major issue in the most populated cities of Afghanistan, as population increases in the country’s main cities have increased not only consumption but also groundwater vulnerability to pollution. In general, nine contaminants have been found, which represents a concern for human health and agriculture. The contaminants that were above World Health Organization (WHO) standards were: boron (79.5% of the samples ranged from sensitive to very sensitive for agriculture crops Arsenic exceeding WHO limits (10 µg/L) was found mostly in the central provinces of Farah, Panjshir, Laghman, Faryab, Logar and Kabul (19% out of 72 samples), and in the Ghazni (58% out of 348 samples) province. A higher concentration was later found in Ghazni and Maidan Wardak provinces in 61% of the water samples (out of 764 samples) (Saffi and Eqrar). Arsenic contamination in groundwater is a matter of great concern, yet no complete dataset exists that covers the entire country. The major factors that threaten groundwater resources in Afghanistan are identified as domestic and industrial wastes, septic tanks that are rapidly increasing in cities, and agricultural activities (Saffi and Kohistani, Hayat and Baba. Zaryab suggests that ~81% of the nitrate contamination in Kabul city originates from sewage, 10.5% from natural soil losses, and only 8.5% from chemical fertilizer (8.5%). n the wet season, contamination from sewage increases to ~87.5% due to a poor sewage system. In Kabul city only 20% of households are connected to wastewater treatment system or used toilets with storage tanks; others used cesspits and dry toilets. From hydrogeochemical aspects, groundwater quality in the Kabul basin has been labelled as very hard due to high calcium and magnesium concentration Jawadi, and in lower Kabul basin the major factors controlling groundwater chemistry in the aquifer were found to be dissolution of carbonate, gypsum anhydrite minerals, weathering of silicates, ion exchange and mixing (Zaryab). The lack of groundwater policies and regulations in place poses a serious risk to groundwater quality over the next 10–20 years due to likely population growth, significant mining activities (which are only just beginning), increased industrial activities, and expansion of agriculture (Hayat and Baba). This requires urgent attention from policymakers. Afghanistan has always been exposed to floods due to intense rainfall, rapid snowmelt, or a combination of the two (Shokory). Floods are the most frequent natural hazard in the country, causing on average $54 million of damage per year (World Bank). In May 2014, floods in 14 northern provinces caused more than $100 million in damage (World Bank). Climate projections and dependence of the water cycle in Afghanistan on the cryosphere suggests that there may be new and increased flood hazards for Afghanistan (Savage). Iqbal analysed flood frequency and intensity in the Kabul basin for the period 1981–2015 and also projected changes for 2031–2050 and 2081– 2100 using the RCP 4.5 and 8.5 scenarios. The flood magnitude that currently has a return period of 50 years is predicted to shift to a return period of 9 to 10 years by 2031–2050 and even to 2 or 3 years by 2081–2100. There are three broad sets of processes responsible for these changes: An increase in the frequency of extreme precipitation events; (2) increases in temperature are likely to lead to reduced storage of snow in all basins in winter with a shift towards higher winter peak flows; as most precipitation in Afghanistan falls in winter, more liquid precipitation may lead to less snow storage and more runoff; and (3), despite declining spring precipitation (NEPA and UNEP), more precipitation may be falling as rain to a higher elevation when basins are still snow covered. The latter might thus increase the probability of “rain-on-snow” events, which often cause high flows. From: Hydrological Sciences Journal

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The Kabul times, Afghanistan Trustable News Agency.