The Relationship between Precipitation and Elevation of the Watershed in the Khirthar National Range

Abstract

Precipitation plays a pivotal role in the evolution of the ecosystems. Many watersheds in Pakistan and particularly in parts of Sindh are ungagged, which urge to estimate the precipitation and other parameters using feasible models for effective planning and management of water resources. Regression analysis is usually employed to understand the hydro-climatic relationships of a watershed. The present study is aimed to investigate the relationship between precipitation and elevation through developing linear regression models for various levels of precipitation data and map their spatial variability in the KNR (Khirthar National Range), Sindh, Pakistan. The precipitation data of 7 meteorological stations covering the study area were used with DEM (Digital Elevation Model) data of 90 m resolution for altitudinal trend analysis. The results of the linear regression model showed a close relationship between the precipitation of various time-scales and elevation, i.e. coefficient of determination R2 values ranging within 0.82060.9604. The correlation was significant at P<0.05 for mean annual, mean monthly, and mean seasonal (Rabi) precipitation. The spatial variation in precipitation was between 127.78-697.98 mm at annual and from 10.84-58.09 mm at mean monthly level. The lapse rate of increase in precipitation with elevation was 27.03 mm per 100 m for annual and 2.24 mm per 100 m for monthly level. At seasonal level, precipitation varied from 24.17-137.87 mm during Rabi (winter) and between 105.78-525.36 mm during Kharif (summer) season. Similarly, the monsoon precipitation (July-September) ranged between 92.24359.93 mm in the study area. The higher precipitation estimated over elevated areas of the region at seasonal and annual levels needs to be harvested through adopting adequate water management techniques for improving agriculture productivity in the downstream areas.

Does Catchment Nestedness Enhance Hydrological Similarity?

“…This originates a more pronounced decrease of in nested catchments – with a stronger decrease of streamflow correlation, as per Equation . Similarly, catchment area and relief affect the mean rainfall intensity and peak runoff within the contributing catchment (Sanchez‐Moreno et al., 2014; Sasaki & Kurihara, 2008; Soomro et al., 2018). Consequently, because of the enhanced variability in size and elevation, nested catchment are likely to display more heterogeneous streamflow dynamics and lower streamflow correlations at larger distances.…”

Spatial and Temporal Variation in Vegetation Cover and Its Response to Topography in the Selinco Region of the Qinghai-Tibet Plateau

“…High-altitude regions experience reduced precipitation, prolonged exposure of surfaces to sunlight, and increased evaporation rates, leading to a gradual decline in soil moisture. Consequently, normal vegetation growth and development are hindered [58]. Furthermore, lower temperatures at higher altitudes reach the minimum threshold for vegetation growth, resulting in reduced vegetation cover [51,59].…”

The relation of the economic value of rice field agricultural land with the location characteristics in Cugenang District, Cianjur Regency

“…On the highlands, the conditions of the slopes are steep and narrow. Paddy farmland on the highlands will require a bench terrace manufacturing model [25], so it will require more cost capital and labor. In addition to land management, topographical conditions also affect rivers in the highlands.…”