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Project Overview

In recent years there has been a trend in parts of Tasmania for land use change away from traditional grazing enterprises to more intensive cropping, and often irrigated cropping, activities. In the past land use intensification has occurred by transferring technology and experience from one area to another. However, as the soils and climate are often different this has, on occasion, resulted in considerable damage to the soil and economic losses to the farmer. This project was initiated to identify some of the risks and hazards in three selected study areas around the State, Waterhouse, Tunbridge and the Coal River Valley. The full findings of the study are presented in a compendium of reports available from the Department in CD format or directly from the pdf documents below.

The project involved a range of activities at each study site. These included:

• A resource inventory and hazard identification, incorporating soil and unique area mapping (UMA), soil physical characterisation and salinity surveys (using an EM31 instrument) and assessment of the contribution of rainfall to the salt budget.
• A review of salinity and water balance models available that might assist with predicting impacts of land use change on the water balance; and
• Investigations of groundwater flow systems to determine their relevance to salinity processes in each study area.

Salinity Hazard Assessment

A number of activities were undertaken in each area to determine the risk of expanding salinity as a result of land use intensification. Estimates of below ground salt storage were made using an EM31 instrument. This tool simply sends an electromagnetic signal into the ground and captures the strength of the return signal which, at least in part, is related to the amount of salt storage to a depth of about 5 metres. The data collected was used to generate maps of sub surface salt storage for each study area. Table 1 provides details of the extent of each salinity class identified.

	Non Saline	Slightly Saline 2-4 dS/m	Moderately Saline 4-8 dS​​/m	Very Saline 8-16 dS/m	Extremely Saline > 16 dS/m	Total
Coal River Valley	513	3197	898	8	0	4616
Tunbridge	212	2190	2080	150	1	4633
Waterhouse	1	1019	4735	614	31	6400

Table 1. Areas of land (ha) within the various salinity classes (ECese) in each study area

Project Reports and Documents

Overarching Report (468 KB)

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Coal River

Land Degradation Salinity Risk Project - Coal River Valley Report (1.06 MB)




Coal River Valley Map 1a - Dominant Soils of the Coal River Valley (10.87 MB)




Coal River Map 1b - Salinity Classes of the Coal River Valley (10.58 MB)




Coal River Map 1c - Areas of Sodicity Risk (10.42 MB)

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Tunbridge

Land Degradation Salinity Risk Project - Tunbridge District Report (1.76 MB)




Tunbridge District Map 2a - Dominant Soils (5.01 MB)




Tunbridge District Map 2b - Salinity Classes (4.82 MB)




Tunbridge District Map 2c - Areas of Sodicity Risk (4.74 MB)




Tunbridge District Map 2d - Areas of Waterlogging risk (4.53 MB)




Tunbridge District Map 2e - Wind Erosion Risk (4.64 MB)

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Waterhouse

Land Degradation Salinity Risk Project - Waterhouse District Report (2.91 MB)




Waterhouse District Map 3a - Dominant Soils (8.17 MB)




Waterhouse District map 3b - Wind Erosion Risk (8.54 MB)




Waterhouse District Map 3c - Waterlogging Risk (7.84 MB)




Waterhouse District Map 3d - Salinity Classes (8.20 MB)

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Additional reports and studies

Land Degradation Salinity Risk Project - Modelling Report (829 KB)




Land Degradation Salinity Risk Project - Hydrological Studies (387 KB)




Land Degradation Salinity Risk Project - Communications Strategy (653 KB)