Land use parameter
The major classification are provided in Table below.
- grassland
- coniferous forest
- decidious forest
- mixed forest
- agriculture land
- shurbland
- bareland/per.snow
- waterbodies
- rockyMountains
- glaciers
- urban, densely
- settlement, loosely
- meadows and pastures
- bogs and wetlands
The land-use classes with similar features can be merged together which behaves similarly to hydrological dynamics. In case of few classes are available in the data (such as only Forest class), the user can exclude other sub-classes such as (deciduous or coniferous).
The J2000 hydrological model requires information of land-use and land-cover types as provided in Table below. Some information might differ in ecological zones such as LAI. However, some information are primarily similar in every parts of the world (such as root depth). The parameter values which are different in different ecological zones (such as LAI in Table xx) has to be adjusted by users based on the climatic and ecological conditions of the study area. For example, the LAI value is different in tropical (India) and temperate (Germany) region. In Germany the value of LAI is low during winter season as most of the leaves fall due to low temperature. However, in the tropical reason, few leaves are left in trees during winter season. However, certain information such as root depth remains same for each vegetation type for different zones. Users are free to change these values based on direct field measurement or literature. The detailed information about the land-use parameters and the application in different modules are provided in Table below.
- landuse.par
| parameter | description |
|---|---|
| LID | land use ID |
| albedo | albedo in % |
| RSC0_1 | minimum surface resistance for water-saturated soil in January |
| ... | |
| RSC0_12 | minimum surface resistance for water-saturated soil in December |
| LAI_d1 | leaf area index (LAI) at the beginning of the vegetation period |
| ... | |
| LAI_d4 | leaf area index (LAI) at the end of the vegetation period |
| effHeight_d1 | effective vegetation height at the beginning of the vegetation period |
| ... | |
| effHeight_d4 | effective vegetation height at the end of the vegetation period |
| rootDepth | root depth |
| sealedGrade | sealed grade |
The relevancies of these variables in calculation of differnt water cycle components are provided in the following documents.
Krause 2001, Krause 2010, Nepal 2012
The land-use parameter file of two regions are provided herewith, as an example land-use parameter file (Thuringia region, Germany) land-use parameter file (Dudh Kosi, Nepal, Himalaya)
Users have to prepare the land-use file in raster format with certain resolution. The resolution depends upon a catchment to be modelled. If the catchment is small (600 km2), the resolution between 30-90 is suitable depending upon the resolution of the available dataset. Similarly, for meso-scale catchment (4000 km2), resolution between 250-500 m is suitable. The resolution of the dataset is important for deriving the number of HRUs.
