Impact of changes in land use and climate on the Runoff in the coastal areas of South China—A case study of the Nanliujiang catchment

Mingzhi Yang,Fan Lu,Yong Zhao,Ya Huang,Baoqi Li,Baodeng Hou,Weihua Xiao,Dachuan Jiang

doi:10.1051/matecconf/201824602001

Abstract

The intense climate changes and human activities have a great impact on the variation of the runoff of the coastal area of South China. In this work, the Soil and Water Assessment Tool (SWAT) is used to quantify the impact of land use and climate change of the Nanliujiang catchment on the runoff by setting 4 scenarios of land-use and climate change. The results show the runoff of the simulated and measured values had a similar trend. The value of relevant coefficient is above 0.8, and the value of Nash-Sutcliffe efficiency coefficient is about 0.8, which indicate that the SWAT model is fit for the study area. The annual average runoff depth during the period from 1995 to 2013 has increased by 53.5mm, of which the land use change resulted in 13.0mm increase on the annual average runoff depth while the climate change resulted in 40.9mm increase on the annual average runoff depth, therefore, the climate change has greater effect then the land use change. This work will delineate some helpful information for the water resources management as well as ecological protection in the coastal area of South China.

Highlights

The IPCC Fifth Assessment Report (AR5) on climate change points out that, in the last half a century, almost all parts of the world have gone through the global warming process [1], and region with the fastest growing temperature is the mid - northern latitudes [2]
The land use classification system of the Soil and Water Assessment Tool (SWAT) model is based on the United States Geological Survey (USGS), based on the relevant research data, code conversion of land use is done within the river basin; c) Soil data for study area was provided by the China Soil Science Database.The cubic spline interpolation method is used to convert soil particle into USGS standards
The paper aims to analyze the impact of land use and climate change on runoff in the Nanliujiang basin based on the SWAT model with four scenarios

Summary

Introduction

The IPCC Fifth Assessment Report (AR5) on climate change points out that, in the last half a century, almost all parts of the world have gone through the global warming process [1], and region with the fastest growing temperature is the mid - northern latitudes [2]. The intense human activity has a large impact on hydrology and water resources, of which the change of land use and land cover is one of the most important factors affecting water resources. It has been conducted much study on that subject in home and abroad [3,4,5,6]. The Nanliujiang catchment is located in the south of Guangxi province (Figure 1), lies between longitudes 109°00'03' to110°23'12′′E and latitudes 21°35' 54'to 22°52' 32′′N, borders the Darong Mountain on the North, the North Bay on the South The rain season lasts from May to September and accounts for 60% to 80% of the total annual amount, the maximum runoff usually occurs in July and August, the maximum and minimum monthly runoff rate 5~50

Methods

Results

Conclusion