Assessment of River Habitat Quality in the Hai River Basin, Northern China.

Yuekui Ding,Yu Zhao,Baoqing Shan

doi:10.3390/ijerph120911699

Abstract

We applied a river habitat quality (RHQ) assessment method to the Hai River Basin (HRB); an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 104 km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 104 km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m); lower coverage of riparian vegetation (≤40%); artificial land use patterns (public and industrial land); frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m3); single flow channels; and rare aquatic plants (≤1 category). At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p < 0.01) and urban land (r = 0.998; p < 0.05); and was significantly and positively correlated with grassland and woodland (r = 1.000; p < 0.01). Intensive artificial land use; created through urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08–16.56); caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated.

Highlights

River habitat has been defined as the local physical, chemical and biological features that provide environments for instream biota [1]
Most surveyed sites were in the moderate river habitat quality (RHQ) category, which ranged from 0.48–0.62
Further analysis showed that human pressures on river ecosystems had a significant impact on RHQ, based on the principle that population density, city distribution, industrial production, and land use type were significantly different between mountain areas and plain areas (Figure 5, Table 4)

Summary

Introduction

River habitat has been defined as the local physical, chemical and biological features that provide environments for instream biota [1]. It is important to assess the physical river habitat when evaluating river health [2]. Due to increasing awareness of the importance of river health and the increased application of habitat evaluations, many studies documenting a range of habitat assessment methods have been published. A brief review of this literature shows that methods for evaluating river habitat can generally be classified into two groups. The first group involves partial to macro-scale evaluation and mapping, often by means of remote sensing techniques [4,5,6]. This approach is based on geographic information system (GIS) spatial analysis and remote sensing image data.

Methods

Results

Discussion

Conclusion