Chapter 7 Mersey I - Introduction

Within a Geographical Information System (GIS) framework, readily available spatial datasets, such as land use and geology, have been used to explore the controls on river water quality. Understanding the relationships between catchment characteristics (or metrics) and river water quality provides a base for determining how future changes in both land use and climate will impact river water quality. Therefore, it is important to determine the processes that regulate river water quality in landscapes under increasing pressure from human population, whether from urbanisation or more intensive food production.

The Mersey Basin is one of the UK’s most environmentally varied regions, with rich rural landscapes and urban-industrial centres. Industrial prosperity in the region over the last few hundred years resulted in severe pollution of the many rivers in the basin. Although there has been significant improvements in water quality in recent years (see The Mersey Basin Campaign), the rivers in the Mersey Basin are still subjected to a number of sewage and industrial inputs, and agricultural runoff.

You can explore the basin below:

7.1 Overview

In this practical you will explore the controls on river water quality in the Mersey Basin and develop empirical models of river water quality across the region.

7.1.1 Topics covered in this practical

  • Terrain analysis, including catchment delineation and derivation of catchment characteristics;
  • Writing and execution of scripts;
  • Multiple linear regression to create models of catchment hydrochemistry;
  • Methods for model evaluation.

7.1.2 Intended Learning Outcomes

  • Gain practical experience of modelling environmental phenomena using a Geographical Information Systems (GIS) framework;
  • Gain practical experience of hydrological modelling using GIS;
  • Gain practical experience of manipulating and analysing raster datasets;
  • Gain practical experience of using Map Algebra functions and writing scripts;
  • Gain practical experience of using multivariate analysis;
  • Understand some of the key controls on river water quality;
  • Be able to critically evaluate model outputs.

7.1.3 Assessment

This practical forms the basis for Assessment 2, full details of which are provided on Canvas here.