Bibliography: Land Degradation in South Africa project

and some farmers are indeed doing this. The following recommendations are made:

any programme of managing communal woodland should be part of a wider programme

of social forestry. Social forestry, in turn, would have to be integrated into

regional rural developmental strategies; innovative initiatives for sustainable

and equitable use of wood resources in protected areas should be supported,

rather than trying to impose uniformity of policy among the various conservation

agencies; and the support of the agricultural extension services in the

commercial sector, and the Agricultural Unions, should be sought in developing a

strategy for the exploitation of wood on commercial farms.

Ref ID : 446

972. Garland, G. Rates of soil loss from mountain footpaths: an experimental

study in the Drakensberg Mountains, South Africa. Applied Geography 7:41-54,

1987.

Reprint : Not in File,

Keywords : SOIL EROSION; KWAZULU NATAL

Ref ID : 447

973. Garland, G. Experimental footpath soil losses and path erosion risk

assessment in the Natal Drakensberg.University of Natal, Pietermaritzburg. ,

1988. Doctoral Dissertation.

Reprint : Not in File,

Keywords : SOIL EROSION; KWAZULU NATAL

Ref ID : 449

974. Garland, G. and Broderick, D. Changes in the extent of erosion in the

Tugela catchment, 1944-81. South African Geographical Journal 74(2):45-48, 1992.

Reprint : In File,

Keywords : SOIL EROSION; KWAZULU NATAL; COMMUNAL AREA; SUSTAINABLE AGRICULTURE;

ENVIRONMENTAL HISTORY; EROSION; KWAZULU; LAND USE; CONSERVATION

Abstract : Stereoscopic air photos from 1944/5 and 1976-81 were used to conduct

a temporal comparison of area affected by erosion in the Tugela catchment area.

The results show that the amount of eroded terrain had decreased with time.

There was no significant difference in eroded area between KwaZulu and Natal in

either time period, and both administrative regions showed a decline in eroded

area from 1944/5 to 1976-81. This and other relevant studies indicate a decline

in erosional activity in the area. This may be due to land use changes or

improved conservation techniques, but could also result from medium or long term

changes in variables intrinsic to the erosion system.

Ref ID : 450

975. Garland, G. and Humphrey, B. Field measurements of discharge and sediment

yield from a soil pipe in the Natal Drakensberg, South Africa. Zeitschrift fur

Geomorphologie N.F. 36(1):15-23, 1992.

Reprint : In File,

Keywords : SOIL EROSION; SEDIMENTATION; KWAZULU NATAL; MONITORING; RAINFALL;

FLOODS

Notes : Continuous monitoring of discharge and sediment yield from a seasonal

soil pipe in the Drankensberg Mountains showed that some 9% of rainfall was

converted to discharge. Lag times varied from 1hr 7 mins to 7hrs 30 mins and

the highest recorded discharge rate was 3,47 l sec-1. Peak flood discharge was

correlated with total storm rainfall but unrelated to rainfall intensity.

Sediment was yielded at a mean monthly rate of 56g m-1 of pipe, and most was

collected during the first few flow events following dry periods. The study

concludes that conditions necessary for pipe evolution and hydrological function

in the Drakensberg include strongly seasonal rainfall, duplex soils, concave

hillslopes, high soil moisture storage capacity, and a point of egress in a soil

cliff or gully side.

Ref ID : 295

976. Garland, G.G. Rural non agricultural land use and rates of erosion in the

Natal Drakensberg. Envir.Cons. 6(4):273-276, 1979.

Reprint : In File,

Keywords : SOIL EROSION; KWAZULU NATAL; LAND USE; EROSION; CONSERVATION; RUNOFF

Notes : Land erosion in wilderness, conservation, and recreational, areas may be

accelerated by certain non-agricultural land management practices. Examples

from the Natal Drakensberg are used to demonstrate how certain types of land

modification such as burning, the construction of unpaved access roads, and the

creation of paths and tracks - may result in rapid acceleration of erosion

rates. Such management practices may promote land erosion by removing

protective vegetal cover, compacting soil, and concentrating runoff -with the

result that resistance to erosion can decrease significantly through time. The

exponential rate of increase in erosion rates is emphasized. It is suggested

that this is a consequence of gradual increase in land erodibility interacting

with meteorological events, such that after a critical level of erodibility is

passed, rainstorms with far shorter return-periods than those occurring

previously will be capable of transporting large quantities of soil.

Ref ID : 660

977. Garland, G.G. Mapping erosion with airphotos: panchromatic or black and

white infrared. ITC Journal :309-312, 1982.

Reprint : In File,

Keywords : SOIL EROSION; REMOTE SENSING

Abstract : Relative frequency of panchromatic and black and white infrared

photography in identifying linear erosional features in a dryland farming area

in Transvaal, South Africa, was investigated. Results showed that while

panchromatic prints produced the best overall results and a combination of

panchromatic and black and white infrared photography the worst, values obtained

from some of the test sites were anomalous. The study concluded that for the

particular purpose of this investigation, no advantage is to gained from black

and white infrared cover.

Ref ID : 296

978. Garland, G.G. An appraisal of South African research into runoff erosion.

South African Geographical Journal 64(2):138-143, 1982.

Reprint : In File,

Keywords : SOIL EROSION; LAND USE; SEDIMENTATION; KWAZULU NATAL; RUNOFF;

EROSION; RAINFALL; RAINFALL EROSIVITY; POLICY

Abstract : Recent reviews and textbooks show that SA has contributed very little

to the field of soil erosion research. Strongest areas of research are the

study and estimation of sediment yield, and the evaluation of rainfall

erosivity, whilst major weaknesses include the lack of knowledge of the nature

and extent of erosion, and a poor understanding of the machanics of erosional

processes. General co-ordination of research policy is required if research is

to make a significant contribution to the solution of problems caused by soil

erosion.

Ref ID : 297

979. Garland, G.G. Changes in the nature and extent of agriculturally eroded

areas in Natal, and the relationship of such changes with land use and sediment

yield. 1986.

Reprint : Not in File,

Keywords : SOIL EROSION; LAND USE; SEDIMENTATION; KWAZULU NATAL

Notes : Report to the Department of Agriculture and Fisheries.

Ref ID : 846

980. Garland, G.G. The soil spoilers. In: Rotating the cube - environmental

strategies for the 1990's, edited by Preston Whyte, R.A. and Howe,

G.Durban:University of Natal, 1990,p. 69-72.

Reprint : In File,

Keywords : SOIL EROSION; SEDIMENTATION; EROSION; CONSERVATION; SUBSIDIES

Notes : This article deals with the questions: what does soil erosion cost?;

who is responsible?; and what can be done about it? The author suggests that

much can still be done to prevent soil erosion from destroying the fabric of the

country. He advises that the community must be alerted about the perils of soil

erosion, they must be taught to recognise the symptoms and given the opportunity

to become involved early on in the conservation planning stage. A system of

subsidies may be considered. Well qualified, empowered and trained extension

officers, preferably from the community are needed. Only completed, extension-

officer-approved conservation work should be paid.

Ref ID : 448

981. Garland, G.G. Technique for assessing erosion risk from mountain footpaths.

Environmental Management 14(6):793-798, 1990.

Reprint : In File,

Keywords : SOIL EROSION; EROSION; RAINFALL; AID

Abstract : One of the most pressing problems facing wilderness managers in the

ecologically fragile Drakensberg Mountains, SA, is that of path erosion, since

it detracts from the wilderness experience and is very costly to remediate. As

increasing demand for wilderness and outdoor recreation places greater pressure

on paths and trails, it will be necessary to increase path network size and

capacity, and it is important that new paths are routed such that maintenance

requirements are minimal. This study describes the development of a technique

based on the site and environmental variables of rainfall, topographic slope,

and lithology, which enables assessment of path erosion risk before paths are

planned and constructed. The technique was tested on a path at the Drakensberg

resort of Loteni, and showed good correlation with actual path degradation.

When used as a tool in path network planning, it can aid in the selection of

low-maintenance routes and also help in planning maintenance budgets.

Ref ID : 532

982. Garland, G.G. Non-agricultural soil erosion. Paper presented at the Durban

Environmental Week Seminar: Soil is life, Durban. 1991.

Reprint : In File,

Keywords : SOIL EROSION; EROSION

Notes : That soil erosion occurs in a variety of environmental settings other

than those dominated by agricultural activity is a well established fact. Soil

losses at construction sites, and in some urban situations for example often

rank amongst the most severe of all forms of erosion. Such soil losses are a

matter of concern not so much because they represent the depletion of non

renewable resource, but rather because the eroded material gathers in gutters,

on roads, in storm water disposal systems and so on, becoming dangerous and

difficult to clear. Other non agricultural erosion takes place in Nature and

Game Reserves, Wilderness areas and so on, and since this form of soil

disturbance has a rather higher public profile and is usually considered to be

an environmental hazard, it forms the focus of the talk in this paper.

Ref ID : 620

983. Garland, G.G. South African soil conservation policy. Paper presented to

the Conference of the IGU Study Group on Mediterranean Erosion at the University

of Cape Town, 14-17 January 1994.Anonymous Anonymous Durban:Geographical &

Environmental Sciences, University of Natal. :1-11, 1994. Soil conservation

cannot hope for sustained national success unless conducted within the structure

of a clear, long-term national policy. This paper offers a brief review of the

historical evolution of South African soil conservation policy, indicating the

principle factors which have influenced development to its present form over the

last 200 years. The main characteristics of present policy - its dualistic

nature, the fact that it sees soil loss primarily as an agricultural rather than

an environmental problem, and its non-coercive approach to conservation; are

considered within the context of an overall evaluation of success and failure.

Weak points of current policy include failure to establish overall

responsibility for soil conservation, enequitable division of conservation

resources, and inadequate base-line data on soil erosion rates, processes and

distribution. Its strengths are acceptance of the need of soil conservation,

recognition of the interdependence of soil and water conservation, and a working

conservation infrastructure. Political changes envisaged for 1994 could herald

a significant redistribution of agricultural land, with the resulting need to

modify present soil conservation policy substantially. The paper concludes by

outlining some of the important issues to be considered in any policy overhaul.

Reprint : In File,

Keywords : SOIL CONSERVATION; POLICY; LEGISLATION; CONSERVATION; SOIL EROSION;

EROSION; WATER CONSERVATION

Ref ID : 690

984. Garland, G.G. Soil erosion in South Africa: a technical review.Anonymous

Pretoria:National Department of Agriculture. :1-52, 1995.

Reprint : In File,

Keywords : SOIL EROSION; EROSION

Notes : Of all aspects of technical South African soil erosion research,

modelling is the weakest, and with few exceptions our efforts have contributed

little in the way of understanding the universal truths of the soil erosion

process. Given an infatuation with measurement of soil losses which has

persisted since the 1950's and before this is surprising, since a data base of

measured values forms the basis for empirical modelling procedures, and is

essential for validating results from other modelling approaches. There could be

a number of reasons for poor performance in this field, but most stem from

introspective research approach geared mainly towards solving specific national

or local problems. This has led to immense variation in data collection

techniques, with consequent inconsistencies in form and quality. Spatial

location of data collection sites has been driven by the same objectives, with

the result that available information is unsuitable as a data base for empirical

soil loss modelling. If empirical modelling is not well-served then physically-

based modelling has received even less attention. The excuse of data

restrictions although relevant, are less pertinent here since physically-based

modelling depends more upon scientific understanding of process. It seems that,

with some exceptions, South African researchers have not considered theoretical

contributions to universal knowledge as a priority, and have been content to

concentrate on immediate solutions to local problems.

Ref ID : 1129

985. Garland, G.G. Land and soil degradation.Anonymous 1998,

Reprint : In File,

Keywords : LAND DEGRADATION; SOIL EROSION; ECONOMIC ASPECTS

Notes : Until recently, solutions and management strategies dealing with land

and soil degradation tended to be based on neat and tidy combinations of

artfully designed engineering structures, often backed by complete changes in

agricultural practice. Now, it is becoming clear that the issue is far more

complicated than originally thought, eg. some degradation may well be natural,

cyclic and reversible; ecosystems may be far more resilient than previously

thought; some land is probably naturally unstable; and economic responses may

not be as devastating as is often claimed etc. These uncertainties are

compounded by lack of faith in land remediation and degradation control

strategies and research approaches which led to their development. Presently,

world thinking points to conclusions that much land degradation is natural, the

causes of human induced degradation are at best unclear, social and economic

effects are less severe than we thought and engineering solutions alone will

provide neither a sustainable deceleration of degradation rates nor remediate

ravaged land successfully. Against this background, the author looks at the

South African situation.

Ref ID : 798

986. Garland, G.G. and Olivier, M.J. Predicting landslides from rainfall in a

humid, sub-tropical region. Geomorphology 8:165-173, 1993.

Reprint : In File,

Keywords : SOIL EROSION; RAINFALL EROSIVITY; CLIMATE; RAINFALL

Abstract : Topography, geology and a humid sub-tropical climate make the Durban

region on the east coast of SA particularly prone to sliding mass movements.

Records of individual landslides and landslide events between 1970 and 1990 were

compared with 22 rainfall variables calculated for the same period. Correlation

coefficients demonstrated statistically significant relations between annual and

wet season landslide frequencies and maximum 3-day and maximum monthly wet

season rainfall, whereas precipitation for shorter and longer periods was

unrelated. Envelopes of critical values for cycle and total coefficients based

on the percent of mean annual rainfall were identified for both the timing and

magnitude of landslide events. They suggest a two-stage equilibrium condition

for the rainfall-mass movement relationship, controlled by average wet season

rainfall. Moreover, once the pattern of rainfall for any particular wet season

is established, the envelopes allow the prediction of rainfall conditions

necessary for landslides to occur. The likelihood of an inaccurate prediction

is approximately 10%.

Ref ID : 844

987. Garland, G.G., Robinson, J., and Pile, K. Policy, perception and soil

conservation - a case study from Cornfields, Natal.Anonymous Pretoria:HSRC. :1-

41, 1994.

Reprint : In File,

Keywords : COMMUNAL AREA; POLICY; SOIL CONSERVATION; SOIL EROSION; KWAZULU

NATAL; EROSION; CONSERVATION

Notes : The principle goals of this research were to address the inadequacy of

information on: (1) soil erosion policy in small-scale and subsistence

agriculture in SA; (2) perceptions of soil erosion amongst small-scale and

subsistence land users in rural areas; and (3) the extent and character of soil

erosion in such areas. These aims were accomplished by a broad review of South

African soil conservation policy in general, followed by a small pilot study in

the African freehold area of Cornfields, Natal, with a view to planning a more

comprehensive analysis over a far broader geographic area at a later stage,

should results warrant it. More precise objectives of the work were to attempt

to assess to what extent the needs of black farmers have influenced soil

conservation policy and practice, to evaluate the Cornfields community's

perceptions of erosion against physical evidence gathered by scientists, and to

consider the role of conservation policy in shaping the perceptions and

practices of Cornfields land users. The project effectively embraced two

distinct research avenues: a review and a critique of South African soil

conservation policy historically and in the current period; and an assessment of

erosion perceptions and conservation practices of the Cornfields Community.

Each is dealt with in a sperarate section of the report (Parts II and III) after

which the conclusion (Part IV) details the implications of the research findings

and includes some possible directions for future research and policy

formulation.

Ref ID : 845

988. Garland, G.G. and Stocking, M. Soil conservation re-visited: some policy

considerations for post-apartheid South Africa. Unpublished paper presented to

an International Seminar on Environment Sustainable Development and Human

Health, Banaras Hindu University, Varanasi, India, February, 11-15, 1995. 1995.

Reprint : Not in File,

Keywords : SOIL CONSERVATION; POLICY

Ref ID : 2015

989. Geldenhuys, C.J., Le Roux, P.J., and Cooper, K.H. Alien invasions in

indigenous evergreen forest. In: The ecology and management of biological

invasions in southern Africa, edited by Macdonald, I.A.W., Kruger, F.J., and

Ferrar, A.A.Cape Town:Oxford University Press, 1986,p. 119-131.

Reprint : Not in File,

Keywords : FOREST; SOUTHERN AFRICA

Ref ID : 451

990. Gerber, F. and Grobler, D. 'n Identifikasiemetode vir die identifisering

van dispersieve gronde.Anonymous South Africa:Department of Water Affairs,

Forestry and Environment. 104, 1980.

Reprint : Not in File,

Keywords : SOIL EROSION

Ref ID : 587

991. Gerber, J.J. The effect of water stress and clipping on the growth and

carbohydrate reserves of Pentzia incana.University of Natal, Pietermaritzburg. ,

1993. Master of Science.

Reprint : Not in File,

Keywords : VELD MANAGEMENT; GRAZING EFFECTS

Ref ID : 2488

992. Gerber, L. Range monitoring in the semi-arid zone: a preliminary model to

predict biomass production using remote sensing (a ground truthing

method).Anonymous Upington:ARC-Range and Forage Institute. , 1999.

Reprint : In File,

Keywords : MONITORING; MODELS; REMOTE SENSING; NDVI; RAINFALL; BIODIVERSITY;

KAROO DESERTIFICATION; STATISTICS; VEGETATION DYNAMICS; VELD CONDITION

Notes : The author notes that the relationships vound between NDVI, LAI and

green biomass is depicted in the paper. For both sites, LAI was correlated very

well with green biomass production. These two linear relationships are very

similar, with the exception that LAI was mostly less than 1 in the sparsely

vegetated Kalahari sites, while it was distributed more evenly in the Karoo -

values of 3.5 was obtained for LAI. These results confirm the fact that an

indirect technique, rendering instantaneous results, such as LAI, can be

implemented successfully for the determination of rangeland biomass production.

NDVI was found to be non-linearly related to LAI for both sites. This

relationship was best described by the function, y=a+b(rx). There were no

significant differences between the curves established for the Karoo and

Kalahari, although much variation could be detected at the Kalahari site. This

fact can be largely attributed to vegetation canopy cover and structure. The

area has lower canopy cover as well as low grass:shrub ratios. The woodiness

could contribute to inaccurate estimations of NDVI and LAI in addition to the

interference from high reflectance values from the red soils (Major 1990, Price

1992). NDVI and LAI were very well correlated for the Karoo sites (R2=81%).

The implication from these regressions, is that NDVI values can be used for

estimation of green biomass production. Seasonal variation in LAI and NDVI was

measured at the Kalahari sites. LAI decreased from a range of 0.5-0.6 (measured

in April 98 and March 99) to values ranging from 0.2 to 0.34 measured during

August to January. This trend corresponded well with precipitation patterns.

The peak in LAI observed during April 98 followed a period of precipitation

during Feb/Mar 1998. The same trend could be observed when LAI was high during

March 99 - this growth period was preceded by rainfall events from November to

January 199. NDVI measurements reflected the same trend, the only difference

being the high NDVI values obtained for August 99 (when low LAI values were

observed). It is also evident that the majority of NDVI values observed for

this site was relatively high. LAI and NDVI values obtained for all camps at

the Karoo sites are also illustrated. LAI and NDVI values in Afrikaner trials