## 2 Materials and Methods
### Materials
#### 2.1.2 Data  
Data used in this study were a Digital Elevation Model (DEM), land use map, soil data (soil physicochemical and biological properties, soil map), hydro-climate, and agronomic data. The Figure 2 shows essential input data for the SWAT model.  
Figure 1: Location of Lobo basin in Côte d’Ivoire [29].  
The Digital Elevation Model (DEM) of 30 m \(\times\) 30 m resolution, in the Northern Hemisphere projection UTM Zone 30, downloaded from the website [[https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)]([https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)), accessed on 1 February 2018, has been used to extract the hydrographic network and delineate the watershed.  
The land use map has been obtained throughout four (4) 22 February 2018 sentinel-2 satellite images treatment using ENVI 4.7. These images include four (4) bands that are 2, 3, 4, and 8, and were obtained from the website [[https://sciub.copernicus.eu/dhus/#/home](https://sciub.copernicus.eu/dhus/#/home)]([https://sciub.copernicus.eu/dhus/#/home](https://sciub.copernicus.eu/dhus/#/home)), accessed on 1 February 2018. For this study, we considered Five classes of land use: forest evergreen (11%), degraded forest (9%), agriculture and fallow (77%), urban (0.5%), and water (2.5%).  
To run the SWAT model, soil physicochemical and biological properties (texture, available water content, hydraulic conductivity, bulk density, and organic carbon content of different soil layers) and soil map are required. These data are available in the FAO  
Figure 2: Essential input data for the SWAT model.  
database [30] and have been completed using physicochemical properties cited above obtained after field sampling and in-laboratory analyses. The dominant soil of the basin is the sandy-clay-loam, about 38%, followed by the sandy-loam soil (32%) of the basin.  
Hydro-Climate Data  
The climate data at a daily time step were obtained from the SWAT model website [[http://globalweather.tamu.edu/](http://globalweather.tamu.edu/)]([http://globalweather.tamu.edu/](http://globalweather.tamu.edu/)), accessed on 1 February 2018. These data include minimum and maximum temperatures, precipitation, relative humidity, solar radiation, and wind speed. The use of these data is justified by the fact that in the watershed, there are few data available that can allow adequate hydrological modeling of the watershed. Some authors, such as [PERSON] and [PERSON] [31], believe that global gridded climatological datasets (GGCDs) could be combined with hydrological modeling to understand hydrological processes in data-scarce environments. Therefore, for this study, eleven (11) climatic stations were used over the period 1979--2014. The monthly streamflow data were collected from the National Drinking Water Office (ONEP in French) for the period from 1981 to 1994 at the Nibehibe hydrometric station.  
The types of fertilizers, the doses applied to each type of crop, the types of crop, agricultural practices, and agricultural calendars on the watershed were used in this study. Agronomic data come from the processing of the National Center for Agronomic Research technical sheets. They are available online at [[https://cnra.ci/nos-fiches-techniques/](https://cnra.ci/nos-fiches-techniques/)]([https://cnra.ci/nos-fiches-techniques/](https://cnra.ci/nos-fiches-techniques/)), accessed on 1 January 2020.