Quantifying the Individual Contributions of Climate Change, Dam Construction, and Land Use/Land Cover Change to Hydrological Drought in a Marshy River

Peng Qi,Y. Jun Xu,Guodong Wang

doi:10.3390/su12093777

Abstract

Hydrological drought for marshy rivers is poorly characterized and understood. Our inability to quantify hydrological drought in marshy river environments stems from the lack of understanding how wetland loss in a river basin could potentially change watershed structure, attenuation, storage, and flow characteristics. In this study, hydrological drought in a marshy river in far Northeast China at a higher latitude was assessed with a streamflow drought index (SDI). A deterministic, lumped, and conceptual Rainfall–Runoff model, the NAM (Nedbor Afstromnings Model), was used to quantify the individual contributions of climate change, land use/land cover (LULC) change, and river engineering to hydrological drought. We found that in the last five decades, the frequency of hydrological droughts has been 55% without considering LULC change and reservoir construction in this wetland-abundant area. The frequency of hydrological drought increased by 8% due to land use change and by 19% when considering both the impacts of LULC change and a reservoir construction (the Longtouqiao Reservoir). In addition to the more frequent occurrence of hydrological droughts, human activities have also increased drought intensity. These findings suggest that LULC and precipitation changes play a key role in hydrological drought, and that the effect can be significantly modified by a river dam construction.

Highlights

Hydrological drought is one of the four major types of drought occurrences, alongside meteorological drought, agricultural drought, and socio-economic drought [1,2]
Several recent studies [9,10,11,12] have found that hydrological droughts have sharply increased in both frequency and intensity in many parts of the world due to climate change and/or due to increased water demand caused by population growth and rapid expansion of the agricultural, energy, and industrial sectors
This study is the first to assess the individual contributions of precipitation change, potential evapotranspiration change, land use/land cover change, and a river dam construction to hydrological droughts in a marshy river in far Northeast China at higher latitudes

Summary

Introduction

Hydrological drought is one of the four major types of drought occurrences, alongside meteorological drought, agricultural drought, and socio-economic drought [1,2]. In China, many regions have been found to show a clear increasing trend in the frequency of hydrological drought, for instance, in the Xijiang River Basin [15], the upper Yangtze River basin [9], the Hexi Corridor [16], and the Aksu-Tarim River Basin [17]. These studies have provided new insights into site-specific variations in hydrological drought, our knowledge is still limited regarding hydrological droughts of marshy rivers that drain a large area of marsh wetlands into a river basin. According to Acreman and Holden [18], river basins with a large percentage of wetlands could be affected by wetland loss in terms of basin water attenuation, storage, and discharge, likely changing the frequency and intensity of hydrological drought

Objectives

Methods

Findings

Conclusion