Signing of MoU!

On October 4th a Memorandum of Understanding was signed between Mr Motsoka William Moeng in his capacity as Acting Head of Department at LDA and Professor Lotta Andersson, SMHI and Linköping University. The agreement will cover the period until June 30, 2015.


Visits to University of Limpopo and University of Venda

During the first week of October, Prof. Lotta Andersson, Ass. Profs. Phil Graham and Julie Wilk visited the Universities of Limpopo (Polokwane) and Venda (Thoyoyandou) to hold discussions with faculty members and invited guests on crop and livestock requirements for temperature and water and possible recommendations to farmers related to excessively wet and dry conditions.

At the University of Venda an extra presentation on Climate Change and the IPCC was held for faculty and students.


Installing the last sensor in Mokwakwaila

During November 2013 we also installed a third sensor station in Mokwakwaila. The station has two soil moisture sensors on two different depths.

We got the opportunity to install the sensor at the school. The principal kindly accepted us, even though it was exam period when the learners should have piece finalizing their tests.

The sensor is comparatively close to the first sensor we installed at the site. The first sensor, however, was installed in the (maize) field, whereas this is on the school's ground.

Examples on measured data

Just to give an update on what the sensors report. In Mokwakwaila I downloaded the temperature information and the data from the rain gauge, as well as the soil moisture sensors. The data of these sensors are sampled once each day.

In the figure below we see the measured rain fall (yellow) and the shallow and deep soil moisture sensor (blue and red, respectively). The rain gauge gives us the instantaneous value (well, integrated over one day), and the soil moisture sensors show how much is stored in the ground. We see that the shallow sensor reacts within the same day, whereas the deeper one (also larger volume) reacts later. This illustrates how slowly the moisture penetrates the ground and how quickly it evaporates from the upper layer. On the last of October, Mokwakwaila received 43 mm of rain. We can also see from the data how the soil moisture increases slightly before arrival of the large rain quantities. This is partly due to the small amounts of rain that occurs the weeks before the last of October.

Below we show the measured soil temperature out in one of the fields. The first measurements started in June and indicated some 20 degrees. Since then, the average temperature has increased some 6 degrees. We see that the variations are quite big within a few days.

Installing more sensors in Lambani

Earlier this week, we installed more sensors at on of the sites. We were kindly invited by one of the high schools to have one of the stations installed there. The station contains a logger, and three soil moisture sensors.

We got help digging from some of the learners and staff at the school. Ashley, far on the left, is from the LDA office in Polokwane.

The trip continued up-hill for the installation of the third sensor station. This time in the field. It was a warm day...


Community workshops

Visit at two of the project sites

On June 5-6, 2013, the project team visited the Lambani and Mokwakwaila communities in the Lambani and Letaba River Basins of north-eastern Limpopo. In order to understand the use of the drought-prediction model and how information could be disseminated to the stakeholders, we met local farmers to learn of their challenges and what is most needed in terms of early warning systems.

At the workshop, the farmers were mainly crop farmers growing maize, beans, peanuts, pumpkins and had some livestock.The stakeholders mainly requested information about the rainy season (when to plant). They receive this type of information from local weather forecasts, mainly from the radio and tv. They also use information from natural signs such as the behaviour of plants, animals and stars e.g. birds, insects and locusts. If one knows it should be good rainfall year, one would plant more maize. One can also plant different crops e.g. millet or crop varieties. If they know when there will be more water in the rivers, they can plan when to do laundry. Livestock holders can harvest and store grass for fodder. If a dry year is forecasted livestock feed can be bought earlier and people might reduce their livestock numbers. Livestock can also be gathered and drinking facilities built.

During the visit to Mokwakwaila two wireless sensors and a rain gauge were installed in the community to measure rainfall and soil moisture. This data will be collected and combined with information on natural signs and seasonal forecasts in order to create more locally relevant information about rainfall, soil moisture and river flow.

Two workshops in Polokwane

Drought resilience and Sensors for measuring soil moisture

Two workshops were held in Polokwane at the LDA on June 3-4. They introduced the project on local-scale early warning systems of drought.

The Drought Resilience workshop more specifically dealt with identifying existing seasonal forecasts and natural signs, their uses as well as shortcomings in terms of format, dissemination, local relevance and reliability. Identified local signs included changes in plant condition e.g. abundance of certain indigenous plants and nuts and time of flowering; animal behaviour of donkeys, birds, cattle, insects; and the behaviour and appearance of wind, stars and moon. Signs as well as weather forecasts are used to determined which crops and crop varieties to plant, when to plant, how much to plant, irrigation scheduling, if and when to gather fodder and reduce livestock numbers, land preparation and disease management. Shortcomings in existing systems include the lack of local reliability and relevance of seasonal forecasts because they give vague and unclear classifications and are disseminated in scientific language and coarse format. Locally relevant recommendations also need to accompany the seasonal forecasts. Discussions were also initiated on which drought indicators are most useful which include precipitation, temperature, onset and amount of rainfall and soil moisture.

The Sensor workshop specifically introduced the sensor system to be used within the project and went over their description, cost, installation, measurement and transfer of data and maintenance. Discussions were held on current soil moisture sensors, how data could best be transferred, location criteria and possibilities, responsibility for uploading information and maintenance of equipment. Information was also shared about lessons learnt and expertise from existing field trials taking place in South Africa, Malawi and Kenya.


Project visit at the Lambani Site

On June 5, 2013, the project team had the pleasure to get invited to the Lambani village in the northeastern parts of Limpopo. In order to understand the use of the drought-prediction model and how information could be disseminated to the stakeholders, we met the local representatives and discussed with them, Five women and five men received us in their village.
We had a discussion seminar around some different topics and this is some of the compiled material from the interviews.

At the workshop, the farmers were mainly crop farmers. In general, people in the region might own between 3 to 35 cows. The stakeholders mostly need information about the rainy season (when to plant). This information is received from the weather forecast. The main crops in the region are maize, beans, peanuts pumpkins, and various types of nut. If one knows it is a good year, one would plant more maize. Among the people at the workshop, no one used any irrigation scheme.

Morning discussions

Where do you get water?

We get the municipality water (piped) and from the river. Water is not received every day.

Which months are most important?

October through January

How do you decide when to plant? What is the normal planting date?

Essentially, one waits for the rains, sometimes it comes in November. If not, one waits to December, etc. through January. If it rains for five days and seems to be good enough, then one could plant.

How much does it vary?

It's very different each year. When the rain comes from the South, one shouldn't plant because it has a lot of damage. When it comes from the North it is good.

Afternoon discussions

What are the signs in nature that you recognize?

If there is a shadow around the moon, then it will be rain in the coming days. When the swallows arrive it will be rain. If it becomes very hot, it will rain tomorrow. If there are stars and astaratars (?) it is going to rain within a few months if they are close to each other. When the birds are crying, it will be a rain. If there are many (?) worms, it will be a dry year. Before planting, if locusts (grasshoppers) arrive it will be a rainy year.

If you see the signs, who do you tell?

We tell lots of people and some listen. You talk to the neighbors.

How many people recognized these signs?

A few are seeing them – mostly the old people. Some follow, some do not. They instead listen to the television. Not many are using the signs. They rely mostly on weather forecasts on the radio station.

How can early warning information be useful?

If we hear that it is going to rain, we may plant, but if we hear it will be dry, there is not much one can do. Some cannot do anything. What about those with animals? If there is a dry year – they will buy and feed early – There is not more they can do. They will not sell their animals. Some will reduce their livestock. Some wait to witness (if it is really getting dry) because sometimes what was said, does not happen. If they wait too long until it is dry, they cannot sell.
They get long-term forecasts but they are not so reliable.

What if the radio signs say different things?

They rely more on natural signs than the radio. Sometimes they are told that it will be rain, but it does not come. So they stick to the natural signs. The radio forecasts are quite local. E.g., in Lambani it is going to rain.

If they knew there would be more or less water in the river ahead of time, is it useful?

For planning when to do laundry. The cattle can go and drink the water. The flow should be medium flow, not too high.
When the soil is wetter, they would try to plant. When the soil is wet, there seeds will germinate. But they will not do any different responses.


1st Workshop On The Internet Of Things (IOT 2013)

Dr. Antoine Bagula, with the University of Cape Town, is organizing the 1st Workshop On The Internet Of Things (IOT 2013) in October this year. The workshop is held in conjunction SAICSIT 2013 in East London, South Africa. More information is found here:
All papers will be published in an abstract booklet that will be distributed at the workshop venue. Extended versions of selected papers will be published, after a rigorous reviewing process, as chapters in a book with ISBN published by UNESCO (pending approval) or papers in an international journal (pending approval).
Dr. Bagula and Dr. Muthoni Masinde worked on a project for combining indigenous knowledge and distributed wireless sensors for weather and drought prediction. Within this work Dr. Masinde created here ITIKI framework, a bridge between IT and indigenous knowledge (IK). See more at the researchers home pages.


Using white space for communication

Today I came across an interesting article how the white space can be used for internet access in rural South Africa. There are trials in Cape Town (Western Cape) by Google.

Now, Microsoft will team up with University of Limpopo and also look into this ( Read the article on ZDNet).

With "white spaces" one implies frequency space that is allocated to some kind of service (TV, Radio, etc.) but not used allocated. Since the space is not used, it can then obviously be "hi-jacked" for other purposes. Such as for example internet communication and relaying of communication.

In our project we have been looking for ways to have a cheap way of communicating from our sensor stations to the central office (and back). We would like to avoid GSM because of them being rather power hungry and expensive. Could this be an option? As indicated in the article, ranges up to 5.4 km can be covered (metric version of 3 miles, one would presume). For example, in Mokwakwaila, we are not far away from a school and it would possibly be an option to install a communication bridge through their channel. It could also be interesting from an educational perspective to have the students use and understand the information on drought, soil moisture and weather prediction. There could be active labs to support this in the schools.

More information on the Cape Town trials are found here.


Values from Mokwakwaila

The first month's, or so, data from our two sensor stations in Mokwakwaila has now been entered into our spread sheets and published on the soil moisture pages. Notice that the data on the pages need some more trimming. There will also be some comments with respect to what the two different sensors display, etc. Many thanks to Ms Nemauluma who collects the data currently.


Rain at reference site

Yesterday we had a good amount of rain pouring down over Linköping, Sweden. So today is a good day to scan the values in the data logger to further test the equipment and check the levels that were recorded. The graph and data set is given on the soil moisture page.

It started to rain in the morning, at some 09.00 and stopped in the afternoon at some 16.00. During this time, the logger recorded 29 tips, i.e., 29 mm of rain.

In Linköping, an extreme value of 35.2 mm was recorded at one of the SMHI's stations (probably at the airforce base in town, some 5 kilometers away from our site). This means that the values are in parity, but further checking should be done, perhaps with a manual rain gauge too.


Installing a reference sensor

To further develop the readout circuitry and options for the data logger and the sensors, we installed one reference site in Linköping such that we can do local trials. The whole was dug in a lawn, some 50m away from the closest fields. These fields are currently mainly used to grow silage.
We did not dig the hole too deep in this case, we just want to study how the sensors can be calibrated and mainly to interact with the logger through our mobile phones. We will also have reference values available to align with the sensors in South Africa. We dig down three different sensors, EC-5, 10HS, and 5TE from Decagon. The reference values with open-air humidity and fully submerged in water are given in the table. The different sensors give slightly different results but they are also designed for different volumes. Saturated values are fairly identical.

Sensor typeDepthOpen-air [cub-m/cub-m]Submerged [cub-m/cub-m] Temp [C]
EC-5 10cm-0.1400.574N/A
10HS 40cm-0.2790.505N/A
5TE-h 60cm-0.0230.51828.7

Some 30 minutes after installation, we could measure these values from the sensors.

Sensor typeDepthDug down [cub-m/cub-m]Temp [C]
EC-5 10cm0.217N/A
10HS 40cm0.210N/A
5TE-h 60cm0.02019.3

Luckily, we got help from a field application engineer to install the sensor and mainly dig. It was also useful to have help when sorting out which cable goes to which sensor. Sort of.
Below we find the final view of the installed sensor station (bar the straps being shortened). There is an ECRN-50 rain gauge from Decagon on the top. It was slightly damaged in a car incident and we have to check if it works properly, otherwise we need to ship it for service.

We need to also verify the ECRN-50 rain gauge.


Indigenous knowledge

In our project we also want to ask how signs in nature can be used predict a dry season - a drought? Traditionally, there is quite a large set of indicators that humans have used to predict an upcoming drought. The knowledge of how to interpret these signs has been passed on through the generations. This indigenous knowledge (IK), how can it be recorded and combined with measured data to predict drought? Can we use the language of indigenous knowledge to also disseminate information local community: the instruments and models predict a drought, and it corresponds well with the signs of nature.

In our workshops we had discussions - farmers, representatives of the department of agriculture, ourselves: how could these signs be used?

Some of the results coming up from the discussions were documented on posters as the ones below. The discussions will be compiled and presented.
More information on this topic can for example be read at

The first hole!

The first post and the first hole dug!

On June 5, we installed the first two sensor stations in the Mokwakwaila community, Greater Letaba Municipality.

Even though it is Winter in South Africa at this point, the weather is still warm for us Northerners. However, this particular day there were some drizzle and cloudy. Perfect day for digging.