The rising intensity and frequency of extreme temperature events are caused due to climate change and are likely to affect the entire world. In this context, the Himalayas are reported to be very sensitive to changes in temperature extremes. In this study, we investigate the variability of temperature extremes over the Northwest Himalayas in the early 21st century (2000–2018). Here, we used 14 temperature indices recommended by ETCCDI (Expert Team on Climate Change Detection and Indices). The present study reveals the trends of extreme temperature indices on the spatial scale for the western part of the Northwest Himalayas. The 14 temperature indices were used to assess the behavior of extreme temperature trends with their significance. This study reports that the northwestern region of the study area has a cooling effect due to an increase in the trends of cold spells, cold days/nights, and frost days, while the southwestern region significantly shows the warming effects due to the increasing trends in warm spells, warm days/nights, and summer days. On the other hand, the eastern region of the study area shows mixed behavior, i.e., some places show warm effects while some reveal cold effects in the early 21st century. Overall, this study implies the northwestern parts have cooling trends while the southwestern and southeastern parts have warming trends during the early 21st century.

Hydrological regimes influence an aquatic ecosystem’s biotic composition, structure, and functioning. But construction of dams or anthropogenic activities substantially alter the hydrologic regimes. In this study, we used a method named as the “Indicators of Hydrologic Alteration” to examine the degree of hydrologic alteration at seven flow gauge stations in the Mangla watershed. The assessment of alteration is carried out according to the Range of Variability (RVA). This method relies on analyzing hydrologic data obtained from existing measurement points (e.g., stream gauges) within an ecosystem or model-generated data. We used 33 parameters categorized into 5 groups based on magnitude, duration, frequency, timing, and rate of change to characterize hydrologic variation within a year statistically. We then examine the hydrologic perturbations by comparing the measure of central tendency and dispersion for each parameter between the “pre-impact (1967–1994)” and “post-impact (1995–2014)” periods. The results show that within the Mangla watershed, the high alteration was noted in the magnitude of monthly flows and extreme flows at Azad Pattan, Gari Habibullah, Palote and at Muzafarabad stations. The flow at Domel and Kohala stations are found in low hydrological alteration among all groups of indicators. The study indicates that Neelum Basin at Muzaffarabad has significantly high alteration with maximum negative values. On the other hand, a high frequency of alteration observed in the monthly flows and extreme water conditions. Overall, a moderate alteration is observed in the whole watershed, which may produce adverse effects on the aquatic ecosystem of the Mangla watershed.

The sustainability index identifies a strategy that defend or improve the desired water management features of the basin in the future. The Upper Indus river basin is a high mountain region and consider third freshwater tower. The flow of the river consists of melting glaciers, snow, rainfall. Beyond the polar regions, the Upper Indus Basin has the largest area of glaciers in the world (22,000 km2).  About 220 million people depend on Indus Basin water for agriculture and drinking purpose. Under the changing climate, sustainability is becoming a challenge for the freshwater resources. The integration of climate variables with RRV indicators is a new approach to meet this challenge. In this study the sustainability of the upper Indus is quantified. The probabilistic concept of resilience, reliability and vulnerability is applied to rainfall variability and drought patterns. The monthly Standardized Precipitation-Evapotranspiration Index (SPEI) grided data (0.5o 0.5o) generated by climate research unit (CRU)version 4 has been used for study during the period 1901–2018. Based on the SPEI pattern, the SPEI of -0.5 was selected as the threshold (demand) to evaluate the sustainability. The results indicate the frequency of drought events in the western part of the basin is much higher than the eastern part. However, the frequency of drought events in the basin is high but the capability of the basin to resilient the droughts varies from 0.57 to 0.83. The value of reliability indicator varies from 0.8 to 0.86 and vulnerability of drought in the basin is in the range of 0.2 to 0.45. The average water sustainability index of the basin is 0.4 which lies in the category of a satisfactory state.The results of the conceptual framework of RRV can provide a more comprehensive basis for designing watershed health variables and drought management plans. Keywords: Upper Indus Basin, Water sustainability, RRV concept, SPEI, Drought.

Drought, a recurring natural phenomenon, poses significant challenges to water resource management and agricultural sustainability worldwide. This study examines meteorological drought characteristics in Punjab province, Pakistan, during 1991–2022 using the standardized precipitation index (SPI) and reconnaissance drought index (RDI). Drought severity was classified based on SPI and RDI thresholds (mild, moderate, severe, and extreme), enabling a systematic assessment across temporal scales. Statistical measures, including correlation (R) and Root Mean Square Error (RMSE), were employed to evaluate the consistency and accuracy of the indices. Various drought periods were identified across 3, 6, 9 and 12-month timeframes, confirming the presence of both short-term and long-term drought conditions. Extreme drought years in 1997 and 2002, severe drought in 1991, 2000, 2001, and 2005, and milder drought periods in 1993, 1999, and 2004 were identified. Strong correlations (R = 0.84–1) and low RMSE (0.03–0.085) values between SPI and RDI indices indicate their effectiveness in assessing long-term drought conditions. District-level analysis highlighted regional variability, where southern and central districts—such as Bahawal Nagar, Bahawal Pur, Multan, Muzaffargarh, Rajanpur, RYK, and Vehari—are more prone to drought due to consistently high maximum temperatures, limited rainfall, and elevated evaporation rates. Historical temperature and rainfall data from NASA Power were utilized, although limitations in spatial resolution and coverage were acknowledged. The novelty of this study lies in its combined application of SPI and RDI at multiple temporal scales with district-level resolution, providing region-specific insights for drought monitoring. The findings offer practical implications for developing localized drought management strategies and support broader climate change adaptation efforts in semi-arid regions. Future research should explore integrating additional datasets or satellite imagery for enhanced analysis, as well as incorporating socio-economic factors to better capture community vulnerability and resilience.