A Study of Precipitation Changes from 1990 to 2020 in the Leh District of Ladakh Using Innovative Trend Analysis

Abstract

Precipitation plays a crucial role in the hydrological cycle and water resource management in climate-sensitive regions. Identifying the long-term changes in precipitation is essential for understanding the regional climate dynamics. The innovative trend analysis (ITA) method was used to study the seasonal and annual trends in precipitation over the Leh district from 1990 to 2020. The ITA results showed a statistically significant negative monotonic trend in annual precipitation at-2.45 mm. On a seasonal scale, the ITA results showed a significant monotonic decreasing trend in precipitation in spring (March-May) (-3.50 mm), winter (December-February) (-2.29 mm), and summer season (June-August) (-2.03 mm); however, the autumn season (September-November) showed a non-monotonic insignificant decreasing trend (-0.05 mm). The winter and spring seasons contributed largely to the overall decline of precipitation. The High coefficients of variation in seasonal data indicate strong interannual variability, and the percentage bias values suggest deviations in seasonal precipitation behaviour. The results highlight a shift toward decline and erratic seasonal rainfall, which can have negative implications for water management in the region. Since the communities in the region depend on winter precipitation (snowfall) for water availability, artificial glaciers are the primary adaptive measures to mitigate water stress. Results from the present study can guide future initiatives aimed at mitigating the implications of changing precipitation on rural livelihoods and other sensitive ecosystems in the Himalayan region.