Question map
Which of the following is/are the most likely cause/causes of sheet-flood found in western part of Rajasthan? 1. Scanty rainfall 2. Sudden high intensity rain 3. Loose sandy soil with scanty vegetation Select the correct answer using the code given below.
Explanation
Sheet-floods in western Rajasthan are primarily driven by sudden, high-intensity rainfall events rather than the overall scanty annual rainfall [4]. In arid regions, sheet-floods occur when unconfined flood water moves down a slope as a continuous sheet. This phenomenon is exacerbated by the physical characteristics of the Thar Desert, where loose sandy soil and scanty vegetation provide minimal resistance to surface runoff [3]. While sandy soils generally have high infiltration rates, the presence of subsurface Kankar layers (calcium carbonate) can restrict water infiltration, forcing water to flow overland. Additionally, the lack of vegetation interception allows high-intensity rain to rapidly saturate the surface or exceed infiltration capacity, leading to flash floods and sheet wash [1]. Therefore, sudden high-intensity rain and the combination of loose soil with sparse vegetation are the direct geomorphic causes of sheet-flooding.
Sources
- [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > WINDS > p. 59
- [4] INDIA PEOPLE AND ECONOMY, TEXTBOOK IN GEOGRAPHY FOR CLASS XII (NCERT 2025 ed.) > Chapter 3: Land Resources and Agriculture > Dependence on Erratic Monsoon > p. 37
- [3] NCERT. (2022). Contemporary India II: Textbook in Geography for Class X (Revised ed.). NCERT. > Chapter 1: The Rise of Nationalism in Europe > Arid Soils > p. 11