Trend Analysis of Rainfall, Land Cover, and Flow Discharge in the Citarum Hulu–Majalaya Basin
Akbar Rizaldi, Muhammad Syahril Badri Kusuma, Arno Adi Kuntoro, Hadi Kardhana
Abstract
Floods and drought have been essential aspects of the water issue for over the past 50 years. Several studies have found that they are caused by massive land cover and climate changes. Many climate change studies have been conducted to establish their characteristics using historical data. However, land cover change is a human need that inevitably has to be undertaken to improve the standard of living. Changes in land cover affect the response of land to rainfall, which inevitably affect the amount of run-off generated into rivers. Discharge, land cover, and rainfall are variables that are related to each other. By understanding one variable, we can understand the condition of others, which can describe the situation of the catchment area. This study aims to determine the rain, land cover, and discharge trends in the Citarum Hulu - Majalaya Basin. The historical data obtained by the ground station were used to analyze the rainfall and discharge. A hydrology model was used to establish the change in the land cover parameters, specifically a semi-distributed SWAT model. The non-parametric Mann-Kendall test was employed for the trend analysis and was applied to the annual maximum rainfall and discharge data and the curve number (CN) values. The results show the three are positive trends in maximum rainfall and CN value which affect the discharge value.