Urban flooding and waterlogging in the northern part of Kabul City

Urban flooding and waterlogging are the big challenges in urban areas of Afghanistan especially in the northern part of Kabul city. Such flooding during monsoon become common in recent years. Urban flooding occurs due to unsustainable urban expansion, change in catchment topography, and increase impervious surface, poor link between catchment drainage structures. Obstruction of the drainage structures leads to waterlogging so that stormwater overspills and blocks the roads against traffic and businesses. Over a decade, drainage systems had been undesirably upgraded in proportion to population growth, caused an increase in frequency of urban flooding and waterlogging. However, very few studies have been conducted to address this issue. Therefore, the objective of the study was to evaluate pre and post-development land-use changes and delineate flooding prone area, identify the factors causing urban flooding and waterlogging and finally, to identify catchment discharge from the rainfall using HEC-HMS. For this purpose, land-use changes over 45 years of pre and post-war periods (1964-2009) were evaluated using CORONA 1964 imagery with new update 2009 imagery 10x10cm resolution of Kabul city. Climate Hazard Group InfraRed Precipitation with Station (CHIRPS) and the ministry of energy and water (MEW) rainfall data set were used to estimate discharge from rainfall. The land-use changes scenarios were analysed by using geographical information system (GIS) under the causes of the increase of urban flooding. The results revealed that unsustainable development activities in the natural water flow path are the major cause of increasing flood in the study area. There are other factors as a poor link between Wazerabad canal and existing drainage structures, catchment characteristic, undesirable combined drainage structures law enforcement and less attention to maintenance which contribute to urban flooding and waterlogging. The study suggest that the sub-drainage structure should be linked to Wazerabad canal by considering sufficient slop, segregation of sewer system where applicable, public awareness, structural and non-structural approaches for urban flood mitigation , law enforcements, sediment and solid waste trap at each drainage inlet as well as system cleaning and maintenance after each rainfall are recommended

Spatio-temporal pattern in the changes in availability and sustainability of water resources in Afghanistan

Water is gradually becoming scarce in Afghanistan like in many other regions of the globe. The objective of this study was to evaluate the spatial changes in the availability and sustainability of water resources in Afghanistan. The TerrestrialWater Storage (TWS) data of the Gravity Recovery and Climate Experiment (GRACE) satellite obtained from three different institutes, having 1° × 1° spatial resolution for the period 2002-2016 was used for this purpose. Sen's slope method was used to assess the rate of change, and the Modified Mann-Kendall test was used for the evaluation of the significance of trends in TWS. After, the concept of reliability-resiliency-vulnerability (RRV) was used for assessing the spatial distribution of sustainability in water resources. The results revealed a significant decrease in water availability in the country over the last 15 years. The decrease was found to be highest in the central region where most of the population of the country resides. The reliability in water resources was found high in the northeast Himalayan region and low in the southwest desert; resilience was found low in the central region, while vulnerability was found high in the south and the southeast. Overall, the water resources of the country were found most sustainable in the northeast and southwest and least in the south and the central parts. The maps of water resource sustainability and the changes in water availability produced in the present study can be used for long-term planning of water resources for adaptation to global changes. Besides, those can be used for the management of water resources in a sustainable and judicious manner