Spatio-temporal trend mapping of precipitation and its extremes across Afghanistan (1951–2010)

Theoretical and Applied Climatology - The civil war, harsh climate, tough topography, and lack of accurate meteorological stations have limited observed data across Afghanistan. To fulfill the gap,...     

Spatial and temporal variation in the trends of hydrological response of forested watersheds in Thailand

Thailand has undergone significant forest cover changes in recent decades, and this is likely to have altered the hydrological functioning of many watersheds; however, such potential impacts are not fully understood. To contribute towards a better understanding of the potential hydrological impacts of forest cover changes, this study examines the temporal trends of several hydrological indices in eight watersheds of Thailand over the period from 1982 to 2013. A number of hydrological indices (runoff coefficient, baseflow index, flow duration indices, streamflow elasticity, dryness index) were analysed using a combined Thiel–Sen/Mann–Kendall trend-testing approach, to assess the magnitude and significance of patterns in the observed data. These trend tests indicated that the change in the hydrological response of watersheds varied with the change in structure and composition of forest species. A significant increase in runoff (viz. average flow) was observed in those watersheds covered with natural forests, whereas a significant reduction in runoff (viz. baseflow and low runoff) was observed in those watersheds where the land cover was changed to Para rubber plantations and reforested areas. It is also noteworthy that the watersheds covered by natural forest showed more streamflow elasticity than plantations or reforested areas. These results highlight the importance of considering both forest types/dynamics and watershed characteristics when assessing hydrological impacts.     

Was the July 1981 rainstorm over Rajasthan unprecedented?

The rainstorm of 17 to 21 July 1981 which caused exceptionally heavy rains and floods in arid Rajasthan, was analysed. It was observed that 7 stations in the rainstorm area broke their previous 80-year record of one-day rainfall, and two of these stations equalled their respective estimates of probable maximum precipitation (PMP). A comparison of areal raindepths of this rainstorm with the similar raindepths of past severe-most rainstorms of this region showed that this rainstorm gave unprecedented raindepths up to about 38 850 sq. km (i.e. 15 000 sq. miles) for a 3-day duration.     

Design storm studies for the Upper Krishna river catchment upstream of the Almatti dam site

Summary The Almatti dam is the major engineering feature in the development of water resources in the Upper Krishna river forming a storage reservoir of 6425 million m³ at spillway crest level. In this paper, the design storm rainfalls for different return periods and also the Probable Maximum Precipitation (PMP) for the catchment above Almatti dam have been estimated to review the adequacy of the flood spillway design for the dam. The design storm rainfalls of various return periods have been computed from a statistical analysis of point and areal time series of annual maximum rainfall. In evaluating the PMP, the maximum observed rainfall obtained by Depth Duration method were maximized as the orography of the Western Ghats plays profound influence over the catchment. It was found that (area 35925 km²) the highest areal rainfalls over the catchment were 14.0 cm, 21.5 cm and 24.6 cm in 1, 2 and 3-day durations, respectively. These are scaled up by a factor of 1.23 to obtain the PMP rainfalls. The areal PMP estimates for the upper Krishna River (UKR) catchment above Almatti dam have been found to be 18.0 cm, 27.0 cm and 31.0 cm, respectively.With 6 Figures     

Site selection for managed aquifer recharge in the city of Kabul,Afghanistan, using a multi-criteria decision analysis and geographic information system

Hydrogeology Journal - While the success and sustainability of managed aquifer recharge (MAR) strongly depends on many characteristics of the site, it is necessary to integrate the site...     

A hydrometeorological analysis of the severe rainstorm of 20–22 September 1900 over the Gangetic West Bengal

A hydrometeorological study is made of the September, 1900 severe rainstorm which led up to the record rain-falls over Gangetic West Bengal with subsequent disastrous flooding in the Damodar and the Hooghly rivers. The spatial extent of the rainstorm for different durations has been examined by constructing the isohyetal patterns based on rainfall records of stations affected by the storm. Areal rainfalls for 1,2 and 3-day periods are calculated and the values have been compared with similar values from other major rainstorms of the region. The comparison revealed that the September, 1900 rainstorm was the heaviest for 1,2 and 3-day durations for all the areas. The storm contrib-uted rainfalls of 33.0 cm, 52.0 cm and 62.0 cm over an area of 10,000 km2 in 1,2 and 3 days respectively. This rainstorm could, therefore, be considered as an important input in flood and design storm studies in the Gangetic West Bengal region. A relationship between point to areal rainfall has also been developed with a view to evaluate areal PMP estimates.