Spatiotemporal impacts of land use land cover changes on hydrology from the mechanism perspective using SWAT model with time-varying parameters

Abstract

It is critically important to quantify the impact of land use land cover (LULC) changes on hydrology, and to understand the mechanism by which LULC changes affect the hydrological process in a river basin. To accurately simulate the hydrological process for a watershed like the Wei River Basin, where the surface characteristics are highly modified by human activities, we present an alternative approach of time-varying parameters in a hydrological model to reflect the changes in underlying land surfaces. The spatiotemporal impacts of LULC changes on watershed streamflow are quantified, and the mechanism that connects the changes in runoff generation and streamflow with LULC is explored. Results indicate the following: (1) time-varying parameters’ calibration is effective to ensure model validity when dealing with significant changes in underlying land surfaces; (2) LULC changes have significant impacts on the watershed streamflow, especially on the streamflow during the dry season; (3) the expansion of cropland is the major contributor to the reduction of surface water, causing decline in annual and dry seasonal streamflow. However, the shrinkage of woodland is the main driving force that decreases the soil water, thus contributing to a small increase in streamflow during the dry season.

Impacts of climate change and LULC change on runoff in the Jinsha River Basin

“…SWAT model has got the ability to simulate and predict the long-term changes of various hydrological elements under different land use types, soil types and management practices on the large scale complex basin (Abbaspour et al, 2007;da Silva et al, 2018;Gassman et al, 2007;Li et al, 2018;Liang et al, 2017). In SWAT model, runoff is firstly calculated for each Hydrological Response Unit (HRU) and then routed to obtain total runoff for the watershed.…”

“…Being important parts of environmental changes, the Land Use/Land Cover (LULC) change and climate change have significant impacts on the hydrological cycle through changing processes such as precipitation, evapotranspiration and infiltration, thus affecting the rainfall-runoff processes (Liu et al, 2008;Yin et al, 2017) and the amount of available water resources Luo et al, 2011). Therefore, the study of runoff response to LULC change and climate change is of great importance in water resources planning and management (Chen et al, 2018;Li et al, 2009Li et al, , 2018Liu et al, 2014;Pan et al, 2017;Yang et al, 2018;Yin et al, 2017;Zhang et al, 2012).…”

Hydrological Modeling of the Paligad Watershed (India) Using HSFP Model

“…1. The total drainage area of the watershed is 59 km 2 . Geographically, the area consists of lower Himalayas, sub-Himalayas, structural hills, terraces, flood plains, etc.…”

“…In the last two decades, many efforts were made to better understand the impacts of land use change on hydrological processes. The spatially distributed hydrological models were widely employed to predict the hydrological responses to land use change [1,2]. Conventionally, this is done by setting up a hydrological model for a baseline land use scenario (LUS).…”

Application of Meteorological and Hydrological Drought Indices to Establish Drought Classification Maps of the Ba River Basin in Vietnam

“…Hydrological models, including physical-distribution-based models, such as the European Hydrological System Model (MIKE-SHE), Topography Based Hydrological Model (TOPMODEL) [30], the Hydrologic Modelling System (HEC-HMS) [31,32], the Variable Infiltration Capacity (VIC) [33], the Soil and Water Assessment Tool (SWAT) [34], the Soil and Water Integrated Model (SWIM) [35], and the Water-Global Assessment and Prognosis (WaterGAP) [36], are capable of simulating temporal-spatial variations in hydrological processes and assisting us to understand the mechanisms of influence behind land use impacts [37][38][39][40][41][42]. Many studies have demonstrated the ability of SWAT to detect the impacts of land use and climate change on hydrological components in different areas [43][44][45][46][47].…”