Surendra Singh
Articles
Prediction of runoff in the Um-U-Lah catchment of extremely humid area of Cherrapunji, India
Geographia Polonica (2011) vol. 84, Special Issue Part 2, pp. 127-139 | 
Full text
doi: https://doi.org/GPol.2011.S2.10
Abstract
In the studies of runoff prediction, the Variable Source Area (VSA) methods are becomingincreasingly more pronounced especially for the humid areas, such as the North-Easternareas of India. Such methods of physically-distributed modelling system are greatly dependenton land surface characteristics (slope gradient, hydrological soil types and land use/ land coverpatterns) that are stable spatially, and on the temporarily fluctuating pattern of precipitationintensity. Considering grid cells of 10 m*10 m size in a micro-areal watershed of 103 ha calledUm-U-Lah that is situated in the extremely humid area of Cherrapunji, having an average slopevarying from 4 to 30 percent, and with sandy-loam porous soils with grass land dominating vegetalcover, the mapping of the saturated area adopting the Topographic Wetness Index (TWI)was made to measure the location and extent of saturated areas, which contract and expand inproportion to the changes in intensity of effective rainfall. After calibrating the Curve-Numberbased VSA model at effective available soil storage of 5.88 mm (AMC-III Soil conditions) and atInitial Abstraction of 1.746 mm, the rainfall simulation were conducted. It is found that increasingdepth of effective rainfall quickly expands the saturated areas over the flat lands of hill-topsand slopes in the watershed. At 8.25 mm of effective rainfall depth, about 85.03 percent areas ofwatershed becomes saturated directly contributing to runoff.
Keywords: runoff process, extremely humid area, variable source area and topographic wetness index
, epartment of Geography, North-Eastern Hill University, Shillong-793014, India
, Department of Geography, North-Eastern Hill University, Shillong 793 022, India
Preface
An appreciation to professor Leszek M. Starkel
Geographia Polonica (2011) vol. 84, Special Issue Part 1, pp. 7 | Full text
doi: https://doi.org/GPol.2011.S1.1
, department of Geography, North-Eastern Hill University, Shillong-793014, India
, epartment of Geography, North-Eastern Hill University, Shillong-793014, India
Articles
Rainfall, runoff and soil erosion in the extremely humid area around Cherrapunji, India
Geographia Polonica (2002) vol. 75, iss. 1, pp. 43-65 | Full text
Abstract
The present paper includes a characterization of the environment in the extremely humid Cherrapunji region (with annual rainfalls from 8 000 to 24 000 mm), as well as a description of a new project and preliminary observations on runoff and soil erosion. Due to deforestation, soils are degraded. The investigation is based on existing meteorological records, measurements of rainfall intensity by way of pluviometers, and observations of selected geomorphological and hydrological processes conducted in an experimental catchment. Heavy rains mainly occur during late evening and continue till morning. The runoff follows the heavy rains immediately, even if the soil profiles may absorb 100 mm of rainfall over 3-4 hours. Deeper layers of the soil profile are still satura-ted during the first half of the dry season. During the rainy season, saturated sheet flow also prevails in the valley bottoms. The present-day rate of soil erosion is very low due to heavy overland How continuing for centuries, and the formation of a stony pavement on slope surfaces as well as of river channels cut in resistant rocks with iron crusts. This has been documented by measurement of ,rCs contents in soil profiles.
Keywords: rainstorm, overland flow, soil erosion, Cherrapunji plateau, '7Cs
[starkel@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
, epartment of Geography, North-Eastern Hill University, Shillong-793014, India
[soja@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
, Homerka Laboratory of Fluvial Processes, Institute of Geography, Polish Academy of Sciences, Frycowa, Poland
, department of Geography, North-Eastern Hill University, Shillong-793014, India
[pawel@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland