RAW dependencies:

- $I_1 \leftarrow I_2$
- $I_1 \leftarrow I_3$
- $I_1 \leftarrow I_4$
- $I_2 \leftarrow I_4$

WAR dependencies:

- $I_2 \leftarrow I_1$
- $I_4 \leftarrow I_1$
- $I_4 \leftarrow I_2$

Consider a normal pipeline execution:

$$\begin{array}{|c|c|c|c|c|c|c|c|c|}\hline

&\bf{t_1}&\bf{t_2}&\bf{t_3}&\bf{t_4}&\bf{t_5}&\bf{t_6}&\bf{t_7}&\bf{t_8}\\\hline

\bf{I_1}& \text{IF}&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\bf{I_2}&&\text{IF}&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\bf{I_3}&&&\text{IF}&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\bf{I_4}&&&&\text{IF}&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\end{array}$$

So, there are RAW hazards for $I_2$ and $I_3$ with $I_1$ and for $I_4$ with $I_2.$ (Not all dependencies cause a hazard. Only if a dependency causes a stall in the given pipeline structure, we get a hazard) These hazards causes the following stalls in the pipeline:

$$\begin{array}{|c|c|c|c|c|c|c|c|c|}\hline

&\bf{t_1}&\bf{t_2}&\bf{t_3}&\bf{t_4}&\bf{t_5}&\bf{t_6}&\bf{t_7}&\bf{t_8}&\bf{t_9}&\bf{t_{10}}&\bf{t_{11}}\\\hline

\bf{I_1}& \text{IF}&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\bf{I_2}&&\text{IF}&-&-&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\bf{I_3}&&&-&-&\text{IF}&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\bf{I_4}&&&&-&-&\text{IF}&-&\text{ID}&\text{EX}&\text{MEM}&\text{WB} \\ \hline

\end{array}$$

Now, with operand forwarding from $\text{EX} - \text{EX}$ stage we can do as follows:

$$\begin{array}{|c|c|c|c|c|c|c|c|c|}\hline

&\bf{t_1}&\bf{t_2}&\bf{t_3}&\bf{t_4}&\bf{t_5}&\bf{t_6}&\bf{t_7}&\bf{t_8}\\\hline

\bf{I_1}& \text{IF}&\text{ID}&\underset{1}{\boxed{\text{EX}}}&\text{MEM}&\text{WB} \\ \hline

\bf{I_2}&&\text{IF}&\text{ID}&\underset{1}{\boxed{\text{EX}}}&\text{MEM}&\text{WB} \\ \hline

\bf{I_3}&&&\text{IF}&\text{ID}&\underset{3}{\boxed{\underset{1}{\boxed{\text{EX}}}}}&\text{MEM}&\text{WB} \\ \hline

\bf{I_4}&&&&\text{IF}&\text{ID}&\underset{3}{\boxed{\text{EX}}}&\text{MEM}&\text{WB} \\ \hline

\end{array}$$

Thus all hazards are eliminated.

Ref: http://cseweb.ucsd.edu/classes/wi05/cse240a/pipe2.pdf