Module 12

Question 1

lumped models

Answer 1

describe the catchment as a single entity,
assuming that rainfall falls evenly
throughout the catchment, the
hydrological parameters are uniform
everywhere, and the rainfall runoff
processes are linear
▪ they lump the inherent spatial variability
of environmental variables into catchment
average characteristics

Question 2

distributed models

Answer 2

distributed models – incorporate a variety of
spatially varying data from a
proliferating set of spatial databases
on land use, land cover and soil
characteristics, and high-resolution
precipitation, temperature, and other
environmental variables
▪ they facilitate simulations and
predictions with higher resolution
than lumped models, but also
improve hydrological predictions by
using spatially distributed
parameters of physical relevance

Question 3

catchment properties are determined by (5)

Answer 3

size, shape, topography, soils, and vegetation

Question 4

SWAT

Answer 4

SWAT (Soil and Water Assessment Tool) to simulate the quality and quantity of surface and groundwater, and predict the impact of land management practices and climate change on water, sediment, and agricultural
chemical yields in complex catchments with varying soils, land use, and management over long periods

Question 5

▪ GIS can play 3 roles: IN LANDS USE

There are also 3 basic types of analyses

Answer 5

1. maintaining and managing general purpose data
2. generating specific-purpose information from such data
3. using such information in land use decision-making contexts

1▪ site selection: identifying the best or optimal
site or sites for a particular land use activity
among a set of feasible sites
2▪ land evaluation: assess the fitness of suitability
of a given tract of land for a defined use
3▪ land allocation: a comprehensive assessment of
potentials and feasibility of land resources,
seeking to provide a compromise solution that
attempts to maximize suitability of lands for
multiple objectives

Question 6

4 important critera of land use analysis

Answer 6

▪ planning criteria: planning regulation, visual intrusion, noise and safety
▪ physical criteria: construction accessibility and foundation strength
▪ ecological criteria: wildlife habitat, hydrology and impacts on birds
▪ economic criteria: wind resources, road access and land clearing costs, and grid
connection costs

Question 7

spatial unit map

Answer 7

▪ the spatial unit map excludes the restricted areas by applying the land use constraints;
each spatial unit represents an alternative area for sugarcane production and contains the
score values for all the allocation criteria

Question 8

‘residual kriging’

Answer 8

, a process by which regression residuals are
incorporated into the procedure to improve overall accuracy – not a typical GIS
feature but can be applied by:
1. represent the point observations in a feature class
2. represent independent variables in individual raster layers
3. conduct a multiple regression analysis by combining the point observations with the
independent variable rasters
4. calculate the residuals at each observation point by subtracting the observed value from
the estimated value by regression at the point
5. implement ordinary kriging to interpolate the residuals and creating the residual raster
6. implement the regression model created in 3 by combining all the independent
variable rasters via map algebra to produce the regression raster
7. add the residual raster and the regression raster to produce the final map representing
the final estimates of the dependent variable

Question 9

moving-window

approach

Answer 9

, using focal functions
available in many GIS versions to
estimate annual mean NO2
concentration by computing a
measure of the emissions intensity at
the focal cell as the distanceweighted
sum of emissions in
surrounding cells in the specified
neighbourhood