Uncertainty in Hydrology

I have been working and developing hydrological models in many cases. From the simplest model (Lumped Catchment model) to the integrated and complicated model (MIKE SHE). I realised that every model has its own assumption and limitation. This is something that every hydrologist must understand well. I recommend to all new hydrologist to have a look the manual and standard procedure of any kinds of model do you use. For example, rational method is the simplest and commonly model used to calculate flood discharge. This method is not suitable in a bigger and undeveloped areas. Similarly, physical based model will give you a number of parameters that you need to put. The more detailed the model, the more uncertainty it is. We are dealing with nature which partially cannot be predicted. So know the limitation of the model is important.

The are two ways in hydrological model: stochastic or deterministic. Some scientist may prefer to use deterministic model. This means every steps in hydrological processes are determined. Contrary, stochastic model doesn't really care about the processes. The main concern is inputs and outputs. As long as the input can predict the outputs accurately, then the processes are neglected. We have to understand the limitation of each model. Deterministic models for example, it requires parameters which cannot have an exact values. There are people try to come up with the parameters but all are based on study which may not applicable in other areas. Stochastic model is a future model. Stochastic model relies on samples data. The more we have data the better model prediction. The samples data is also problematic. To predict accurately, the data must be good in quantity and quality. In term of quantity, the numbers of data must really represent the geographical condition spatially. For example, rainfalls depend on latitude, longitude and altitude. These major parameters in determining the rainfall depth. So the numbers of rainfall stations must really represent the latitude, longitude and altitude. In the area where the surface areas are undulating, more stations are required.

Rainfall Stations

In term quality, I found many data are not well screened. It was simply collected without any proper screening processes. Field data measurement can be error in many ways. The rainfall data for example, the location and position of the rain gauge is determined the accuracy of the measurement. In monsoon times, the rain was not fell vertically. It was influenced by strong wind which may cause the collected rain are less than the actual rain. If we understand the uncertainty of the data, we can go to next step to develop stochastic model.

I believe, stochastic model is a future model. Many water agencies have invested a lot in data collection. It means in the future, we will have more data accurately. the stochastic model will be much robust then before and it can be used in more wider regions.

Stochastic Model of Peak Floods

Psycology in Water Related Project

Pyschology is a science which study the behaviour and thinking of individual or groups. This science seems unrelated with water projects but today I learned that this science is important.

Currently, I am handling a flood mitigation projet with total cost of  USD 2.4 million. We have a technical meeting to disscuss about which available options that can be implemented in this project.

Regional Flood Frequency Analysis

Regional Flood Frequency Analysis (RFFA) is one of methods which commonly used to determine design floods in rural areas. The example of utilising this method is for designing water-related structures such bridges, regulators, and dams.

Probability Distribution of Annual Maximum Streamflow

Two major steps in creating RFFA are: (1) determine the homogeneity regions (2) produce a frequency curve. Both of these steps need statistical analysis specifically probability distributions.

Among many method of RFFA, Index Flood Method initiated by Darlymple (1960) is the famous one. He proposed that homogeneity region is based on recurrence interval of 10 years and probability distribution using EV 1 with method of moment (MOM). United States of Geological Survey (USGS) is also adopting this method in their standard procedures.

To do this analysis, the first step is collecting the data. The importance data needed are as follows:

1. Annual Peak Flow
Annual peak flow or Maximum Annual Flood (AMAX) usually can be collected from water authority. This is a peak daily discharge within a year. The data was derived from rating curves of water levels and flow measurement. It is important therefore to check the raw data and plot them together so we can get the sense of the quality of the data.

The data must be random and independent. If the peak discharges are getting higher and higher over the years. This is an indication that we cannot use this data. Probably due to rapid development or control structures have been built in the catchment area.

2. Annual Rainfall
Annual rainfall is a cumulative of rainfall within a year. Similar to flow data, the rainfall data should have not a trend over the years. If the data higher from time to time or vice verse then it cannot be used as it was not independent anymore.

3. Catchment Area
Catchment area is the most significant parameter in determining the peak flow. Other factors such as slope, altitute, may also contribute to rising flow significantly. However, adding more parameters which make formula much complicated and the results are significantly improved, it is better to take the simple one but still represent the reality.

Penyaring Sampah

Baru-baru ini ada kawan saya menanyakan apakah bisa bikin desain untuk penyaring sampah. Saya jawab bahwa perusahan tempat saya bekerja sudah pernah membuat sistem hidrolik penyaring sampah. Kemudian saya tanya berapa kapasitas sampah untuk disaring? Jawabannya Kali Ciliwung kira-kira berapa ya....

Seperti kita ketahui bersama Kali Ciliwung adalah salah satu sungai yang punya tingkat polusi tertinggi di dunia. Sampah apapun baik sampah domestik, industri, barang bekas ada di sana. Perkiraan sampah yang ada bisa sampai 60 ton ketika musim hujan. Hal yang tidak mugkin dilakukan penyaringan sampah secara otomatis. Jalan satu-satunya yaitu dengan mengangkut sampah secara manual yaitu menggunakan krane diatas pontoon dan truk pengangkut sampah.

Melihat kompleknya permasalah kali ciliwung, saya sarankan dengan menggunakan penekanan sosial di kawasan tadah hujan. Faktor utama sampah di Kali Ciliwunga adalah kesadaran masyarakat dalam menjaga kebersihan lingkunhan khususnya sungai. Itu dulu dilaksanakn secara intens dan berkesinambungan. Setelah itu bisa dilakakukan managemen pengelolaan kawasan tadah hujan. Tentu saja apapun solusi yang diterapkan harus melibatkan masyarakat secara aktif.

Jobs in water sector

After I graduated from UNESCO-IHE in April 2015, I am back to my home town in Kediri, Indonesia to meet my family. While I was enjoying togetherness with my family I tried to apply jobs which related to my background study. Surprisingly, it is not so hard to get a job in a water sector. After 3 months of trying, I got 3 job offers. The fist offer is come from a local NGO which has water quality monitoring project in Ciliwung River. This offer is based-project job which means they only need me on the specific project. After project has done, I need to find another job again. This is dilemma for me as I have a family to feed. The next offer is a PhD position in one of reputable university in Malaysia. I was thingking this is a good option for me but then I need a real experience not just study. Finally, I chose the last offer i.e. working with a water consultancy firm in Malaysia.

One thing that could be important during finding a job in a water sector is connectivity. IHE is the most reputable inatitute to create water profeaaionals around the world. Wherever I go, I alwaysJ find alumni that can support me i  many aspects. So, thanks to IHE for doing a great job and wish can withstand forever.

Feasibility Study of Hydropower

Back to Part 1

Feasibility study is a process of finding a feasible project for further development. This term should keep in mind of all engineers. As I know many works done by consultant always have a conclusion that the site is feasible for further development. In this case is a feasibility study of Mini-hydropower. This conclusion shall refer to real finding and thorough study and not just to get a job. If the findings show that the site is not feasible then the conclusion should say NOT feasible and need to find another location to be studied. Do not ever compromise with quality. In the same time, we may offer another location to be studied that maybe accepted by client.

In the field of hydropower especially Mini-hydropower (1-10 MW), I found that this business is booming in Indonesia. After government  has decided to increase the feed-in tariff to USD 0.12 / kWh, many investors interested to invest in this field. Furthermore, this chance has attracted the local proponents to bridging between investors and local government. So, a simple and rough pre-feasibility were conducted by them and sent it to investors. For example, they mentioned that in the specific river has potential of Mini-hydropower with capacity of 9MW. With knowing the feed-in tariff, for sure the investors would interest with that proposal. After checking the potential location it was found that actually the potential power is not 9MW. Furthermore to generate 5MW it is much difficult to be realised.

Technical aspect is important but there are some other factors that much influencing the successful of project i.e. local government. Local government plays an important role to the successful of mini-hydropower development. When an investor interested to develop hydropower, they will come to the local government to assess their area whether has a potential for developing hydropower. If the local government is good, then they will proceed the permits accordingly otherwise they will ask something in such a way they gonna get money (i.e. corruption).

   

The Atlantean Conspiracy: 200 Proofs Earth is Not a Spinning Ball

I have no idea about the earth anymore. It seems the description of earth is totally different with what I learned during study in colleges. Link below shows the proofs that thett earth is not what I was thinking and maybe you also think. Take a look this:
The Atlantean Conspiracy: 200 Proofs Earth is Not a Spinning Ball

So, what do you think?

Free Data and Software for Hydrology and Hydraulic

Introduction

In many water-related projects, hydrology and hydraulic analysis is enviable process that need to be properly conducted. In the hydrology analysis, the availability of data is the most concerning issue especially in developing and emerging countries. Basically, data used in the hydrological analysis are as follows:

ü  Rainfall data

ü  Landuse map

ü  Contour/ land surface slope

ü  Soil properties

ü  DEM

Those data are important in the process of setting up the hydrological model. In the hydraulic analysis, data are retrieved from the hydrological model (i.e. hydrographs). Besides that, some data are needed in constructing hydraulic model. Generally data below are required in the hydraulic modelling:
ü  River/ channel cross sections
ü  Detail hydraulic structures (e.g. weir, pump, bridge,      sluice, etc)
ü  Floodplain
ü  Water level and discharge

Sources of Data

As data is essential in hydrology and hydraulic analysis, the availability of its data is important. However, some data are treated as confidential and some of them are subject to commercialization. Fortunately, some organizations and authorities open their source of data. The following are source of data that we can download for free:

1.  USGS EarthExplorer

United States Geological Survey (USGS) provides certain data which is important in hydrology analysis e.g. Aerial Imagery, Digital Elevation, Digital Maps, Land Cover, Radar, etc. Here is the link: http://earthexplorer.usgs.gov/

In order to download the data, it is required to register and then specify the interested location and type of data. If the data is available, the download files will pop out and ready to be downloaded.

2. NASA

Through their project called Tropical Rainfall Measuring Mission (TRMM), NASA has provided daily rainfall data with the grid size of 0.5 x 0.5 degree. Find out the data in the link below:

http://mirador.gsfc.nasa.gov/cgi-bin/mirador/presentNavigation.pl?tree=project&dataset=3A12%20(Version%20007):%20Monthly%200.5%20x%200.5%20degree%20mean%202A12,%20profile,%20and%20surface%20rainfall&project=TRMM&dataGroup=Gridded&version=007&CGISESSID=2a5b73a32d1c0730451c405e08138767

The other free available rainfall data is provided by NOAA

http://www7.ncdc.noaa.gov/CDO/dataproduct

Software

                 1.    GIS

         Pre and post-processing data is key aspects in measuring the quality of water-related projects. GIS is the only way how to deal with it.  The most powerful and used for GIS processing is ArcGIS. As this software is not free, there are several freeware can be used as alternative.

v        QGIS
QGIS is a powerful tool for GIS processing data. Most of essential tools for hydrological analysis are available in QGIS plugin.

v        GRASS GIS 
If you want to process your LiDAR or remote sensing data, this free software is the most recommended.

v        SAGA GIS
If you want to know the quality of Germany product in GIS tool then this software is the answer.

v        HydroDesktop
If you need to visualize and analyze hydrologic and climate data, this software is suit for it.

2.     Hydrological software

v        HEC-HMS
One of Product of US Army Corp of Engineers is very famous in hydrological modelling. It’s free and provides several hydrological methods which almost applicable in many places.

v        Other hydrology models
If you are interest trying different hydrological model that most of people not familiar with than you can access this link: https://csdms.colorado.edu/wiki/Hydrological_Models

3.          Hydraulic software

v         HEC-RAS
No one deny that this hydraulic software is awesome. The newest version is 5.0 which you can use to simulate 2D flood modelling. If there is free out there why still need to buy??? Ask why..

v         SWMM
SWMM is a 1D stormwater network modelling. It suits for modelling sewer or stormwater network underground.

After all, no matter what software that you are going to use, the most important things how you understand the physical meaning behind it. Thus, interpreting model result is also the important part. The other thing is garbage in garbage out. If you don’t have a good data in terms of quantity and quality, do not try to build the model otherwise it will be just a garbage. Last but not least, do not stop sharing your knowledge even it is just a tiny sand. You never know how it benefits others.

Add in comments if you know more about the available data and free software out there. Thanks!!

Preparation for becoming a Hydroinformatics student

To be a Hydroinformatics student at UNESCO-IHE will be NOT so easy. There are couple of things that need you to be prepared. As its name, Hydroinformatics composes of two words i.e. Hydro and Informatics. It combines two different knowledge from different specialities. Hydro discusses about hydrology and hydraulic. At least you need to know about the basic knowledge of hydrology and river hydraulic. I am myself has a background of Ocean Engineering which no any relation with hydrology. Honestly, I found difficulties in the beginning year as hydroinformatics student. Be prepared for hydrology lessons is important. There some hydrology books are available on internet you can download and study it. The key words in hydrology are: precipitation, evapotranspiration, runoff, infiltration. At least you understand those words and little bit practices on its calculation, I think it is good enough.

In hydraulic part, probably we are little bit understand if your bachelor background is engineering. However, it will be much focused on river hydraulic. Laboratory exercises on river hydraulic will be conducted. Key words in hydraulic are: Manning, Chezy, Saint Venant, Steady/unsteady flow. Be familiar with those words is important as well. After all, the most important part is informatics. It will be simultaniously talking about modelling, modelling and modelling. Not only that, you also need to be good in IT especially programming. Any programming languages that you have understand will be benefit to your study. Matlab will be used almost all the time. Some language programming such as C, Java, Python will also be discussed. Last but not least is a Thesis part. In Hydroinformatics you cannot just have a topic of hydrology, hydraulic, or flood modelling separately. You need to combine the knowledge in Hydro and Informatics. For example: Optimization of flood mitigation measures. The mitigation measures is a processed result of hydrology and hydraulic analysis then you combine with informatics i.e. optimization. This is what I have done in my thesis. The other thing is the MSc program in IHE takes 18 months. So, be prepared not having much time for vacation L

Lessons Learned from Flooding in West Sumatera

In January 2016, West Sumatera suffered a devastating flood that caused loss of life and massive damage to local properties. There are 10 Regencies that was badly affected by this flooding. The worst damaged areas were in Pasaman, Lima Puluh Kota and Solok Selatan Regencies. National Agency for Disaster Management (BNPB) has been identifying the flood damages. It was estimated that 1,003 homes hit by floods and 3,863 people are forcefully evacuated. Flash flood in Pasaman has destroyed 340 hectare of farmlands. In Sijunjung, 276 houses were submerged under the flood water and landslide has cut the only access way to Pekan Baru, Riau. Six person were reported died and one person is still missing after flood water swept him away. 400 houses were also badly damaged in Lima Puluh Kota. BNPB also pointed out that the flooding is not receded yet and even it gets wider spread in February 2016. Clean water, sanitation and food supply are the concerns of BNPB after the disaster.

Flooding in Lima Puluh Kota (Photo is courtesy of Sutopo, BNPB)

The Meteorological Department of Indonesia (BMKG) reported that rainfall in West Sumatera for January 2016 generally was categorized as normal rainfall (i.e. 101mm – 300mm). Only in Solok, Sijunjung, and Tanah Datar Regencies which reported has high rainfall (i.e. 401mm – 500mm). Normal rainfall was derived according to the rainfall data which have ranges of 85% to 115% from the average monthly rainfall over 30 years of recorded data. Director General of Water Resources said that the flash flooding happened in Padang is not due to high rainfall but it was caused by severe blocking of the river at the upstream areas. As proof, fallen trees, natural overgrowth, and rubbish were found in the river after flooding. Unfortunately, there is such a comprehensive study showing the main factors of the flooding. Local people in Solok Selatan informed that the flooding is the worst over 20 years. Batang Suliti and Batang Bangko Rivers in Lima Puluh Kota which were never overflowed over 40 years, it caused flooding in January 2016. From the information above, it can be summarized that the flood is not only caused by the high rainfall. There are other factors that probably as the main trigger of the floods happened. WALHI, an environmental organization in Indonesia said that flooding in West Sumatera is not due to climate factor only, it was also caused by environment damages.  Exploitation of natural resources have been tremendously occurred in West Sumatera. According to the data from Ministry of Energy and Mineral resources (ESDM), 262 mining and mineral exploration have been approved in 2015 for various commodities such as gold, bauxite, coper, calcite and coal. In Solok Selatan for example, it has area of 15,786 hectare for mining exploration purposes which certainly influences the infiltration rates. Subsequently, it leads to higher generated runoff. There are also illegal mining explorations along the river of Batanghari which now using heavy equipment in their operation. Besides that, palm oil plantation has become a major commodity in west Sumatera especially in Pasaman Barat.  This also contributed in changing the hydrological processes (runoff, soil moisture, and evapotranspiration). In the future, there will be more natural resources exploration as the government of west Sumatera currently has preparing 74 new contracts for mining exploration.

There are flood action plans that probably can be taken by the authorities to reduce floods in the future.

1. Flood Risk Assessment is necessary to do.This will give information on which specific areas have higher risks of flooding and how much the damage cost is. Subsequently, it will help the authorities to determine priorities in action.
2. Evaluation on permits for exploitation of natural resources. This includes the evaluation on the existing mining exploration and checking their operational procedures whether according to the environmental criteria or not. 
3. Forestation. This is the way to restore the existing catchment as the deforestation activities massively occur.
4. Improvement in river capacity and drainage system including the flood plain areas.
5. Controlled flooding in specific areas where damage can be limited e.g. contructing dikes, detention ponds, weir dredging, etc.
6. Flood forecasting. This is a good way to warn people about flooding and quick actions can be done by the authorities to minimize the impacts of flooding.

Finally, the most important factor in whatever actions that going to be taken is the awareness of government to put this issue as their first priority even pessimistically it would not happen.