Pradeep K. Rawat

Spatial variability assessment of river‐line floods and flash floods in Himalaya

Purpose – The main objective of the study is to identify the vulnerable areas for river‐line and flash flood hazard and its mitigation through GIS Database Management System (DBMS) of geo‐hydrometeorological parameters. The Dabka watershed constitutes a part of the Kosi Basin in the Lesser Himalaya, India in district Nainital has been selected for the case illustration.Design/methodology/approach – The Dabka DBMS is constituted of three GIS (Geographic Information System) modules, i.e. geo‐informatics (consists of geomorphology, soils, geology and land use pattern, slope analysis, drainage density and drainage frequency), weather informatics (consists of daily, monthly and annual weather data about temperature, rainfall, humidity and evaporation) and hydro‐informatics (consist of runoff, sediment delivery, and denudation). The geo‐informatics and weather informatics modules carried out by comprehensive field work and GIS mapping than both modules used to carry out hydro‐informatics module. Through the int...

Impacts of Climate Change and Hydrological Hazards on Monsoon Crop Patterns in the Lesser Himalaya: A Watershed Based Study

The Lesser Himalaya region is a densely populated, nonglacial tract of the Himalaya. About 95 percent of the regional population depends on agriculture and forest resources but both have been declining rapidly in recent decades due to climate change and hydrological hazards. The main objective of this study was to assess the integrated impacts of climate change and hydrological hazards on monsoon crop patterns in the Lesser Himalaya through a geographic information system (GIS) database management system (DMS). The DMS comprises four GIS modules: climate informatics, land use informatics, hydro-informatics, and agro-informatics. The Dabka watershed in India’s Uttarakhand State is part of the Kosi Basin in the Lesser Himalaya in District Nainital and was chosen as a case study. The climate of the study area, depending on elevation, falls into three climatic zones: subtropical, temperate, and moist temperate, which are favorable for mixed forest, pine forest, and oak forest respectively. The results of the climate-informatics analysis suggest that in recent decades all these climatic zones have shifted towards higher altitudes and the areas of oak and pine forests have decreased. Forest degradation has accelerated hydrological hazards (high runoff, flash floods, river-line floods, soil erosion, and landslides) in monsoon periods, which affected about 22 percent of the cultivated land annually in 2005–2010. Monsoon crop yields decreased by an annual average of 1.40 percent between 1985 and 2010 while the population of the study area increased by an average of 2 percent each year in the same period. The negative correlation between annual crop yields and population growth has led to increased food security risks.

Declining Changes in Spring Hydrology of Non-glacial River Basins in Himalaya: A Case Study of Dabka Catchment

Natural springs are the key source of water for the stream flows within non-glacial river basins and constitute the main source of drinking water and irrigation. Therefore, assessment and inventory on spring hydrology are essential for formulation of successful sustainable development plans in the region. Consequently the main objective of the study was to assess the geohydrological processes of the springs using GIS technology. The Dabka catchment constitutes a part of the Kosi Basin in the Lesser Himalaya , India in district Nainital has been selected for the case illustration. The results suggested that most of the perennial springs exist along the thrust/fault planes and fluvial deposit areas and the most of the non-perennial springs exist along the fracture/joints and shear zones. The water yield of these springs varies greatly but maximum rate was monitored for thrust and fault controlled springs. The changing pattern of the spring hydrology suggested drying up of some springs and the reduced discharge of others due to accelerated land use changes by anthropogenic and climate change factors during last 2 decades (1991–2011). Consequently, there is a decline in the flow of the main Dabka River and its streams by 35 %.

GIS development to monitor climate change and its geohydrological consequences on non-monsoon crop pattern in Himalaya

The main objective of the study was to assess climate change and its geohydrological impacts on non-monsoon crop pattern at watershed level through GIS development on climate informatics, land use informatics, hydro-informatics and agro-informatics. The Dabka watershed constitutes a part of the Kosi Basin in densely populated Lesser Himalaya, India in district Nainital has been selected for the case illustration. This reconnaissance study analyzed the climatic database for last three decades (1982-2012) and estimates that the average temperature and evaporation loss have been rising with the rate of 0.07?C/yr and 4.03mm/yr respectively whereas the average rainfall has been decreasing with the rate of 0.60mm/yr. These rates of climate change increasing with mounting elevations. Consequently the existing microclimatic zones (sub-tropical, temperate and moist temperate) shifting towards higher altitudes and affecting the favorable conditions of the land use pattern and decreased the eco-friendly forest and vegetation cover. The land use degradation and high rate of deforestation (0.22km2 or 1.5%/yr) leads to accelerate several hydrological problems during non-monsoon period (i.e. decreasing infiltration capacity of land surface, declining underground water level, drying up natural perennial springs and streams, decreasing irrigation water availability etc.). In order to that the non-monsoon crops yield has been decreasing with the rate of 0.60% each year as the results suggest that the average crop yield is just about 58q/ha whereas twenty five to thirty year back it was recorded about 66q/ha which is about 12% higher (8q/ha) than existing yield. On the other hand the population increasing with the growth rate of 2% each year. Therefore, decreasing crop yield and increasing population raised food deficiency problem and the people adopting other occupations which ultimately affecting rural livelihood of the Himalaya. Average temperature has been increasing with the rate of 0.07?C/yrAverage evaporation loss has been increasing with the rate of 4.03mm/yr.Average rainfall has been decreasing with the rate of 0.60mm/yr.Climate change accelerates drought hydrological problems during non-monsoon period.In order to that the non-monsoon crops yield has been decreasing 0.60% by each year.

Geo-diversity and its hydrological response in relation to landslide susceptibility in the Himalaya: a GIS-based case study

Assessment and inventory of landslide susceptibility are essential for the formulation of successful disaster mitigation plans. The objective of this study was to assess landslide susceptibility in relation to geo-diversity and its hydrological response in the Lesser Himalaya with a case study using Geographic Information System (GIS) technology. The Dabka watershed, which constitutes a part of the Kosi Basin in the Lesser Himalaya, India, in the district of Nainital, has been selected for the case illustration. The study constitutes three GIS modules: geo-diversity informatics, hydro informatics and landslide informatics. Through the integration and superimposing of spatial data and attribute data of all three GIS modules, Landslide Susceptibility Index (LSI) has been prepared to identify the level of susceptibility for landslide hazards. This resonance study, carried out over a period of five years (2007–2011), found that areas of most stressed geo-diversity (comprising very steep slopes above 30°, geology of Lower Krol and Lariakanta formation, geomorphology of moist areas and debris sites, land use of barren land with a very high drainage frequency and spring density) have a high landslide susceptibility because of high rate of average runoff (33 l/s/km2), flood magnitude (307.28 l/s/km2), erosion (398 tons/km2) and landslide density (5–10 landslides/km2). The areas of least stressed geo-diversity (comprising gentle slopes below 10°, geology of Kailakhan and Siwalik formation, geomorphology of depositional terraces, land use of dense forest with low drainage frequency and spring density) have the lowest landslide susceptibility because of the low rate of average runoff (6.27 l/s/km2), flood magnitude (20.49 l/s/km2), erosion (65.80 tons/km2) and landslide density (1–2 landslides/km2).

Geospatial analysis of climate change and emerging flood disaster risk in fast urbanizing Himalayan foothill landscape

ABSTRACT Himalaya foothill geo-environment is highly vulnerable for flood disaster due to climate change and dynamic upstream hydrological process which reshaped its downstream foothill geomorphology. Rapid urbanization has caused high rate of land-use change and natural resource degradation, enhancing the vulnerability of flood disaster in the region. The Ramnagar Himalayan Foothill area in Nainital district, Uttarakhand, India, has been selected for the case illustration. The key objective of the study was to investigate spatial dynamics of flood disaster risk due to climate change and rapid urbanization in the region. Development and integration of multiple GIS modules advocate that the extreme flood events have been increasing with the rate of four events/year due to climate change (i.e. increasing temperature and excessive rainfall events by 0.03 °C/year and two events/year, respectively). The fast urbanization and development of new colonies have caused to increase in built-up area (with 1.25% annually) and population density (with 87 persons/km2 annually) under different flood hazard zones. Consequently, 29% area of very low flood disaster risk zone has been converted into moderate (6%), high (8%), and very high flood disaster risk zones (15%) at the annual rate of 0.31%, 0.40%, and 0.77%, respectively.

Mitigating Climatic and Human Induced Disaster Risks Through Ecosystem Resilience: Harmonizing Built and Natural Environments in the HKH Region

The Hindu Kush Himalayan (HKH) region is environmentally stressed, economically under-developed and highly prone to climate change impacts and natural hazards. The region is affected by increasing frequency and intensity of flash flood and river-line flood which are among the most devastating types of hazard as they occur rapidly with little lead time for warning, and transport tremendous amounts of water and debris at high velocity.