Spatial and Temporal Variations in Water Quality and Land Use in a Semi-Arid Catchment in Bolivia

Ingmar Messing,Benjamin Gossweiler,Abraham Joel,Ana Maria Romero,Ingrid Wesström

doi:10.3390/w11112227

Ingmar Messing, Benjamin Gossweiler + Show 3 more

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https://doi.org/10.3390/w11112227

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Abstract

Increasing pressures caused by human activities pose a major threat to water availability and quality worldwide. Water resources have been declining in many catchments during recent decades. This study investigated patterns of river water quality status in a peri-urban/rural catchment in Bolivia in relation to land use during a 26 year period. Satellite images were used to determine changes in land use. To assess water quality, data in the dry season from former studies (1991–2014), complemented with newly collected data (2017), were analysed using the National Sanitation Foundation-Water Quality Index method and the Implicit Pollution Index method. The highest rates of relative increase in land use area were observed for forest, urban, and peri-urban areas, whereas relative decreases were observed for water infiltration zones, bare soil, shrubland, and grassland areas. The water quality indices revealed clear water quality deterioration over time, and from catchment headwaters to outlet. Statistical analyses revealed a significant relationship between decreasing water quality and urban expansion. These results demonstrate the need for an effective control programme, preferably based on water quality index approaches as in the present study and including continuous monitoring of runoff water, mitigation of pollution, and water quality restoration, in order to achieve proper water management and quality.

Highlights

Human activities and climate change are imposing increasing pressures on water availability and quality worldwide
According to Giri and Qiu [4], water quality [5] in watersheds [6,7] is affected by changes in land use and cover, which result from the interaction between anthropogenic and natural drivers
On reviewing secondary sources of data and information, we found that most of the values reported in former studies in the catchment were obtained by sampling or measuring water quality and flow parameters, rather than analyses including modelling and/or multivariate statistics to determine the relationship between land use and water quality

Summary

Introduction

Human activities and climate change are imposing increasing pressures on water availability and quality worldwide. Land use changes have a significant impact on hydrological system components such as surface runoff, infiltration, and interflow [1]. The loss of pervious surfaces such as shrubland, water infiltration zones, grassland, and forest reduces water infiltration and increases the variation in water flow by causing high streamflow [2]. Assessing the impacts of land use and land cover changes on hydrology is the basis for watershed management and ecological restoration [3]. According to Giri and Qiu [4], water quality [5] in watersheds [6,7] is affected by changes in land use and cover, which result from the interaction between anthropogenic and natural drivers. Haidary et al [9] made similar findings for some wetlands in Japan, whereas in the state of Ohio, USA, Tong and Chen [10] found a significant relationship

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