Identifikasi Perubahan Penggunaan Lahan dan Karakteristik Hidrologi DAS Citarum Hulu

Abstract

The Citarum watershed is one of the priority watersheds due to problems of critical land, flooding, erosion, and sedimentation which continue to increase every year. As the main catchment area that contributes to maintaining the availability of water resources, the upstream Citarum watershed continues to experience a reduction in forest and an increase in built-up land. A research aimed to analyze land use changes to the hydrological characteristics was carried out at the Watershed. The methods used include interpretation of SPOT image data, analysis of land use changes, and determining the values of KRA and KAT. The results of the analysis of land use change conditions in 2009-2018 saw a reduction in forest area (-5.5%), rice fields (-17.4%), and shrubs (-60.8%). Land use increased in built up land (39.7%), dry land agriculture (13%), plantations (6.4%), and open land (95.5%). The highest discharge occurred in 2010 at 606,3 m3/second and the lowest discharge in 2012 was 4,3 m3/second. The KRA and KAT values of the Upper Citarum watershed were moderate and very high. The multiple linear regression model of the relationship between land use changes that affect river flow fluctuations is Y = 2380.5 + 0.9 rainfall -206.5 forest + 6.1 build-up area -31.8 dryland agriculture + e. Other factors that influence the increase in river discharge are the slope of land slopes, rainfall patterns, and inadequate land use methods.
 Keywords: hydrological characteristics, landuse change, Upper Citarum watershed

Health assessment of The Upper Citarum Watershed, West Java, Indonesia

“…The Very unhealthy level (on average) shows that there is no continuity of water flow and the ability of the land to infiltrate the water. This is due to the reduction of permanent vegetation land over several years based on [22]. According to [22], the upper Citarum watershed has decreased permanent vegetation by 11.5% within ten years (2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018).…”

“…For this reason, the annual flow coefficient value that has been obtained using the calculation above is classified into five categories, such as (table 3): The calculation results are classified into five classes, i.e., 0-20% is very unhealthy, 20-40% is unhealthy, 40-60% is moderately unhealthy, 60-80% is healthy, and 80-100% is very healthy [18] [21]. Land use data in this study uses data from research by [22], who analyzed SPOT 6 and 7 high-resolution image data for conditions in 2009 and 2018 in the upper Citarum watershed [22]. Land change in the upper citarum watershed between 2009 and 2018 there was a decrease in rice fields (-17.4%), forests (-5,5%), shrubs (-60,8%), and land use increases in dryland farming (13%), built-up areas (39,7%), plantation (6,4%), and bare land (95,5%) [22].…”

“…Land use data in this study uses data from research by [22], who analyzed SPOT 6 and 7 high-resolution image data for conditions in 2009 and 2018 in the upper Citarum watershed [22]. Land change in the upper citarum watershed between 2009 and 2018 there was a decrease in rice fields (-17.4%), forests (-5,5%), shrubs (-60,8%), and land use increases in dryland farming (13%), built-up areas (39,7%), plantation (6,4%), and bare land (95,5%) [22]. The area of land use can be seen in the table 4.…”

Spatial and temporal distribution of estimated surface runoff caused by land use/land cover changes in the upstream Citarum watershed, West Java, Indonesia

“…Previous studies found that LULC change (vegetated cover to built-up land) contributes significantly to the frequent flood occurrences in the upstream Citarum Watershed (e.g. FRosyidie, 2013;Fernandos et al, 2020;Tanika et al, 2020;Yulianto et al, 2020;Atharinafi and Wijaya, 2021;Fadhil et al, 2021;Husodo et al, 2021).…”

“…Several studies reported that the built-up land in the upstream Citarum Watershed has decreased significantly. Fadhil et al (2021) found that during 2009-2018 the built-up land in the upstream Citarum Watershed increased 11,305 ha or 39.7% while the forest cover reduced by around 1,611 ha (5.5%). Husodo et al (2021) reported that the vegetated cover land in the upstream Citarum Watershed decreased around 35% within 1989-2019.…”