HIMALAYAN LANDSLIDE MANAGEMENT AND PLANNING

In many steep or mountainous terrains, landslides are among the most deadly and common natural dangers. They frequently happen without warning and result in the loss of life and property. Landslides mostly occur as a result of geological and geomorphologic processes that control the local terrain. However, external forces including severe rain, earthquakes, flooding, snow melting, stream erosion, changes in ground water levels, volcanic eruption, or any combination of these natural phenomena can cause landslides to occur on unstable slopes. According to earlier studies, human activities such as the expansion of the built-up and agricultural areas, clear-cutting, shifting cultivation, and shoddy road construction have a cumulatively negative impact on many mountainous regions, increasing the frequency and magnitude of landslides. As a result, both internal and external causes are predicted to contribute to a rise in the frequency, size, and volume of landslides.

Furthermore, due to climate extremes in vulnerable hilly or mountainous locations, the frequency and size of landslides are further increasing. Despite this, numerous nations experience widespread landslide-related human tragedies, material losses, and economic losses. The negative effects of landslides on the natural landscape must also be acknowledged, including their spatial distribution, frequency, amplitude, and volume. In addition to increasing slope instability or slope failure, the landslides may result in tree losses, forest fragmentation, and changes in land use and land cover. By moving copious amounts of debris, especially in landslide-prone locations, the landslide can also have an impact on the water quality of river systems and reservoirs. However, the role and impacts of landslides on the natural environment are frequently disregarded, and their impact and disruption on the natural landscape have received less attention. Therefore, an interdisciplinary approach is required to reduce the probability of landslide occurrences in unstable slopes and analyze the short- and long-term negative consequences of landslides on the natural landscape.

The Himalayas are one of the world's most brittle and unstable mountain ranges. Over 13% of India's land area is subject to landslide risk, with the Himalayan region and hilly areas particularly vulnerable. This includes the northeast and northwest Himalaya, the western Ghats and Konkan hills (in Tamil Nadu, Kerala, Karnataka, Goa, and Maharashtra), as well as the eastern Ghats of the Aruku area in Andhra Pradesh.

Landslides regularly happen in the Indian Himalayan Region (IHR) as a result of internal elements such lithologies setting, greater altitude, steep slope, delicate soil, high relief, and groundwater.

Landslides in India's rainy seasons pose serious problems for the Himalayan region and mountainous locations, and the research area, the Rudraprayag district, is no exception. However, in these landslide-prone areas, the database and research are still insufficient. This study's primary objectives are to:

 

(1) Create a multi-temporal landslide inventory map using geospatial platforms in a data-scarce environment;

(2) Assess a landslide susceptibility map using the weights of evidence (WoE) method in a Geographic Information System (GIS) environment at the district level;

(3) Provide a thorough understanding of recent advancements, gaps, and future directions related to landslide inventory, susceptibility mapping.

A typical process goes like this: First, from 2011 to 2013, 293 landslides polygons were manually digitized using Google Earth and BHUVAN (Indian earth observation visualization). On the basis of the previous study, a total of 14 landslide causative factors were chosen, including geology, geomorphology, soil type, soil depth, slope angle, slope aspect, relative relief, distance to faults, distance to lineaments, distance to streams, and distance to roads, land use/cover, and altitude zones. Further we can use various analysis methods for monitoring and management of the factors and ultimately the landslides.

CONCLUSION

                                                                                                                               

Additionally, the Indian Himalayas' delicate nature and ongoing human disruption of the natural environment can worsen slope instability and create a number of risks, which may be further affected by climate change or extremes. However, the earlier research on different natural disaster risks was taken into account independently, which would have tainted the conclusions of risk assessment. It is now obvious how one risk can affect others. As a result, in mountainous or hilly regions of India, numerous risks may impact the same natural landscape, posing major environmental issues. Therefore, a comprehensive strategy is required to address numerous hazards and reduce disaster risk in the Indian Himalaya Region (IHR).