International Journal of Civil Engineering and Technology (IJCIET) Volume 10, Issue 02, February 2019, pp. 330–340, Article ID: IJCIET_10_02_036 Available online at http://iaeme.com/Home/issue/IJCIET?Volume=10&Issue=2 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 ©IAEME Publication Scopus Indexed HYDROLOGICAL CHARACTERISTICS ANALYSIS DUE TO CHANGES IN LAND USE WITH THE SWAT MODEL IN THE KOTO PANJANG HYDROPOWER CATCHMENT AREA Nurdin Doctoral Student in Environmental Science of Riau university, Pekanbaru, Indonesia Syaiful Bahri University of Riau, Pekanbaru, Indonesia Zulkarnain University of Riau, Pekanbaru, Indonesia Sukendi University of Riau, Pekanbaru, Indonesia ABSTRACT This study aims to analyze the hydrological characteristics as a result of changes in land use with the help of the SWAT hydrological model and can provide recommendations on the best land use in the Koto Panjang Electric Power catchment area. Based on the results of the analysis using the SWAT hydrological model, it was seen that there were effects of land use changes in 2011 and 2014 on hydrological characteristics; yield of water (WATER YLD) of 2,413.38 mm, and 1.008, 65 mm, runoff coefficient (C) of 0.19 and 0.063 respectively, and river regime coefficient (KRS) of 11.449 and 12.212, respectively. The best land use to be developed in agricultural cultivation areas as a recommendation to maintain water stability in the Koto Panjang hydropower catchment area is a simple and complex agroforestry pattern in scenario III, which is run together with hydrological characteristics in the form; water yield (WATER YLD) of 1.038, 41, surface runoff coefficient (C) of 0.023, and river regime coefficient (KRS) of 11.13. The hydrological characteristics in scenario III are far better than 2014 land use characteristics (existing). Key words: Land use, SWAT model, Hydrological characteristics, the catchment area Koto Panjang Hydroelectric Power. Cite this Article: Nurdin, Syaiful Bahri, Zulkarnain, Sukendi, Hydrological Characteristics Analysis Due to Changes in Land Use with the Swat Model in the Koto Panjang Hydropower Catchment Area, International Journal of Civil Engineering and Technology (IJCIET) 10(2), 2019, pp. 330–340. http://iaeme.com/Home/issue/IJCIET?Volume=10&Issue=2 http://iaeme.com/Home/journal/IJCIET 330 [email protected] Nurdin, Syaiful Bahri, Zulkarnain, Sukendi 1. INTRODUCTION Good planning for land use is very important in improving the performance of a catchment area in maintaining water stability used for various interests, especially for the benefit of the wider community. Increased population growth affects land conversion, especially from forest areas to non-forest areas or cultivation areas. The Koto Panjang hydropower catchment area is in three districts, namely, Kampar, Pasaman, and Lima Puluh Kota. Quoting from the Central Statistics Bureau of Pasaman Regency (2016), Pasaman Regency was dominated by Mapat Tunggul Selatan District with a population growth of 1.56%. Based on the Central Statistics Bureau of Lima Puluh Kota Regency (2016), Lima Puluh Kota Regency was dominated by Kapur IX Subdistrict with a population growth of 1.02%, Bukik Barisan District with a population growth of 0.85%, and Pangkalan Koto Baru District with a growth of 0. 82%. From the data sources of the Central Statistics Agency of Kampar Regency (2016) it was noted that in Kampar District there were two subdistricts in the catchment area, namely XIII Koto Kampar District with a population growth of 1.48%, and Koto Kampar Hulu Subdistrict with a population growth of 3.81%. Population growth which tends to increase causes the ongoing development process is also very fast, causing changes in land use patterns, where the built space increasingly dominates and urges natural space to change functions (Suasti et al, 2012) [1]. Changes in land use due to an increase in population affect the hydrology characteristics of watershed (Mobarok, 2015) [2]. The results of the interpretation of Landsat images in 2002 land cover of forest in the catchment area 1,167.08 km (Mulyadi, 2003) [3]. According to Mustiono (2010) [4] over a period of eight year forest cover experienced a major change to 904,327 km, mainly changed to cultivated crops and open land. The extent of open land or deforestation can accelerate the flow of water to the reservoir and also affect fluctuations that affect the level of the reservoir water level. The hydrological model of the Soil and Water Assessment Tool (SWAT) can help simulate the effects of land use changes on hydrological characteristics in producing water. According to Junaidi, and Tarigan (2012) [5] SWAT which is connected to GIS and integrates with Decision Support System (DSS). Firdaus et al. (2014) [6] said, the SWAT model can analyze the best hydrological response based on the determination of conservation techniques. Likewise, Singh et al. (2013) [7] said, the method used for calibration and validation using SUFI-2 and GLUE from SWAT CUP. The purpose of this study is to analyze the hydrological characteristics due to changes in land use, and can provide recommendations on the best land use in the catchment area of Koto Panjang Hydroelectric power. 2. LITERATURE REVIEW Changes in land use due to an increase in population affect the hydrology characteristics of watershed (Mobarok, 2015) [2]. The results of the interpretation of Landsat images in 2002 land cover of forest in the catchment area 1,167.08 km (Mulyadi, 2003) [3]. According to Mustiono (2010) [4] over a period of eight year forest cover experienced a major change to 904,327 km, mainly changed to cultivated crops and open land. The extent of open land or deforestation can accelerate the flow of water to the reservoir and also affect fluctuations that affect the level of the reservoir water level. The hydrological model of the Soil and Water Assessment Tool (SWAT) can help simulate the effects of land use changes on hydrological characteristics in producing water. According to Junaidi, and Tarigan (2012) [5] SWAT which is connected to GIS and integrates with Decision Support System (DSS). Firdaus et al. (2014) [6] said, the SWAT model can analyze the best hydrological response based on the determination of conservation techniques. http://iaeme.com/Home/journal/IJCIET 331 [email protected] Hydrological Characteristics Analysis Due to Changes in Land Use with the Swat Model in the Koto Panjang Hydropower Catchment Area Likewise, Singh et al. (2013) [7] said, the method used for calibration and validation using SUFI-2 and GLUE from SWAT CUP. The purpose of this study is to analyze the hydrological characteristics due to changes in land use, and can provide recommendations on the best land use in the catchment area of Koto Panjang Hydroelectric power. 3. MATERIALS AND RESEARCH METHOD This research was conducted in the water catchment area of Koto Panjang Hydroelectric Power Plant, in West Sumatra Province consisting of Pasaman District in Mapat Tunggul Selatan District, Lima Puluh Kota District in Kapur IX Subdistrict, Bukit Barisan and Pangkalan Koto Baru, in Riau Province within Kampar Regency consisting of Koto Kampar Hulu Subdistrict and XIII Koto Kampar subdistrict. Equipment needed are: soil sample testing equipment, GPS devices, computer devices, GIS software, SWAT consisting of ArcSWAT and SWAT CUP SUFI 2. The source of the research data consisted of Land use maps 2014, Image of Shuttle Radar Topography Mission ( STRM) (30 x 30) m for Digital Elevation Model (DEM) data input with scene numbers are ASTGTM2_N00E100 and ASTGTM2 _S01E100, Administrative maps of Kampar, Pasaman, and Lima Puluh Kota year 2008, land use maps year 2014, maps of the river, map soil type, slope class map, climate data (consisting of temperature, relative humidity, wind, and solar radiation, rainfall data) year 2009 - 2014, discharge data and water level of in the Koto Panjang Hydroelectric power catchment area year 2009 - 2014. Several management scenarios in land use were simulated to determine the best land use management in the catchment area of Koto Panjang Hydroelectric power. Stages of activities consisting of collecting maps data, processing data input, and running SWAT models, calibration and validation, outputs and land use management simulations. Collection of Maps and Data consisting of; soil type map, land use map in 2011 and 2014 results of image interpretation, slope class of land map, Digital Elevation Model (DEM), physical properties data of soil from laboratory analysis based on soil samples in the catchment area, climate data, and river maps. Input data processing consisting of; Watersheed Deliniator delineated based on input data in the form of DEM data, Hydrology Respont Unit (HRU) analysis based on land use maps input data, slope class maps, soil type maps and physical properties data of soil tests. Climate data base (Weather Data Generator) by creating climate generator data results from calculation of rainfall data, temperature, solar radiation, humidity, and wind speed. The Method of Running the SWAT Model is to describe the catchment area (Watersheed Deliniator) with a stage consisting of: entering DEM data, determining the river network, determining the catch outlet points, and calculating catch parameters. Conduct HRU (Hydrology Respect Unit) analysis in the form of defining data input with an overlay between year 2011 and 2014 land use maps with land maps, and slope classes. Providing climate data other than rain to calculate evapranspiration using sampling methods in the form